Class Book. o u — Copyright^ /f G^fVT/T Fig. 8. — longitudinal Section Through a Grain of Wheat. neath the bran coats is found a single layer of large cells full of granular material of a protein nature. This coating completely encloses the endosperm and germ and is usually spoken of as the layer of aleurone cells or the cerealine layer. The endosperm is the largest and most important part of the kernel; it is the food part of the grain, the portion utilized in the making of ordinary flour. It contains cellulose in the cell walls, a small amount of mineral matter, sugar and practically all of the starch and protein available as food. Nature designed 56 FOOD INDUSTRIES it to serve as food for the young plant during the early stages of growth. The germ is the part from which the plant is to be repro- duced. It is more complex in its composition, containing cellu- lose and soluble carbohydrates, a large proportion of nitrogenous matter and -is rich in oils and mineral matter. Fig. 9.— Section Through Part of a Grain of Wheat. a — Cellular Structure, b— Starch Granules, c — Protein. Value of Wheat. — Its wide adaptation to different climates and soils, the ease of cultivation, a quick and abundant harvest, great number of varieties and the intrinsic food value, of the kernel would be sufficient to make wheat the leading food grain. There is still another reason, however, which gives it the rank of king among cereals. This lies in the fact that it can be so readily utilized in the making of bread. This quality wheat shares only with rye and both owe their bread producing power to the nitrogenous constituents of the endosperm. Osborne and Voorhees in their investigation of the protein FOOD INDUSTRIES 57 content of wheat discovered five distinct proteins, the most im- portant of which were gliadin and glutenin, both occurring in the endosperm in about the same amount, 4.25 per cent, of the entire grain. In the presence of water these proteins unite to form gluten. To the peculiar properties of this gluten, wheat bread owes its lightness and digestibility, thus giving it first place among the civilized nations of the world. The other cereals con- tain similar proteins, but not in the right proportion to form gluten. With rye flour, gluten can be formed, but it does not make as light or as acceptable a loaf. Varieties. — Migrating as it has for many centuries, meeting different conditions of climate, soil and methods of cultivation, wheat is now grown in a vast number of varieties. The United States Department of Agriculture after long experimentation reduced the number to 245 leading varieties. For the sake of convenience wheat can be divided into two large classes, winter wheat and spring wheat. Winter Wheat. — For the varieties of winter wheat, seeds are planted in the fall. Enduring the cold and dampness of the winter, a maximum of starch and a minimum of protein are developed in the endosperm. Flour made from this wheat is soft and does not give enough gluten to make as desirable a loaf of bread as spring varieties; yet it was the flour used among the so-called civilized nations of Europe until the time of Liebig. He was the first to suggest that the right kind of flour was not being used for bread-making. Either the process of milling must be changed or a new wheat must be grown. His experimenta- tion was along the lines of agriculture, to grow a variety higher in gluten- forming proteins and lower in starch content. Spring Wheat. — Amid much ridicule and after many failures, Liebig finally convinced agriculturalists that wheat for bread- making should be grown quickly. The temperature was most important; dry, hot weather was necessary. Seed if planted in the spring would ripen in the late summer or fall and be ready for harvesting in August or September. This opened a new era in the cultivation of wheat. Soon a hard spring wheat was being grown that in time was utilized largely for the making of 58 FOOD INDUSTRIES ' bread. An extended study of its production brought about many reforms along agricultural lines which were also felt by the growers of winter wheat. These new ideas have enabled farmers to grow many varieties of winter wheat higher in their protein constituents than the first spring wheat grown. With the devel- opment of hard spring varieties, new milling processes were found necessary, the development of which was to place the miller among the world's manufacturers. OLD MILLING PROCESSES. The history of wheat would be far from complete without a study of milling processes, for the story of wheat must ever be intimately connected with the history of the production of flour. Here again we find wonderful progress from the rude processes of ancient civilizations to the modern roller mills, where can be seen the greatest mechanical perfection and whose capacity is so great, that they can produce in a single day enough flour to feed a small city for an entire year. It has been suggested that wheat was first eaten raw, for when driven by the pangs of hunger primitive man plucked the wheat grain from the stalk, using his teeth as mill-stones, and that it was this grinding motion which first gave him the idea of invent- ing some rude instrument which would break up the hard berry for him. Whether this idea be true or not, we find that various forms of apparatus were early invented to make the grinding process easier and more effective. All primitive nations reduced grain to a meal by means of a hand-stone. Hand-Stones. — The form of these stones was varied, but they all consisted of two stones, one of which held the grain while the other was used for pounding. Fig. 10. The first real grinding came into use when the lower stone was given a concave surface and the grain being placed within the hollow was rubbed back and forth by means of a stone-crusher. These primitive mills were always operated by women and were the only mills used for some four thousand years. They must have been used by the aboriginals of all countries, for large numbers of them have been found showing their use among the prehistoric Swiss lake FOOD INDUSTRIES 59 dwellers, the Babylonians, the natives of Ninevah, Assyria and Egypt and again in many parts of the New World. So far as their structure, detail and finish are concerned, tablets indicate that saddle-stones made this side of the Atlantic were superior to those of Europe and Africa. Milling was not a separate indus- try, but part of the work of each household in which the meal was first made then baked into cakes or bread. In some parts of the world this operation is still carried on. In sections of the northern part of Africa women are the millers, doing their work in saddle-stones in much the same way as it was done in the earliest historic times. Fig. 10. — Hand-stone. The Mortar and Pestle. — In time the stone-crusher became elongated into the pestle, and the saddle-stone was fashioned into the mortar (Fig. n). This marked the step from barbarism into civilization. In the mortar period the Geeks substituted men as flour-makers. These men were called pounders and in the decline of Grecian supremacy, a band of them were led captives into Rome. As prisoners of war, these craftsmen were set to work at their occupation, grinding and baking. From this fol- lowed the custom of using slaves as the millers during the days of the Roman Empire. Quern. — To the Romans, the ancient world was indebted for inventing the first milling machine in which the parts were mechanically combined. It was a simple grinding machine giving a circular motion and was known as the quern. It consisted of 6o FOOD INDUSTRIES two stones, the upper one conforming to the shape of the lower upon which it revolved. This upper stone was hollowed out in the center, making a hole sufficiently large to receive the grain to be ground and had on the side a handle to facilitate the turn- ing of the stone. This was the mill in use at the dawn of the Christian Era and it still can be found in China, Japan, among the Arabs and in some isolated sections of Europe. It was the original British flour mill and was destined in that country to be the cause of a long political strife. In the early days of the use of the quern, women did the grinding, but gradually this work was given to slaves and criminals. The first marked improve- ment was the grooving of the grinding faces of the stones and in time the enlargement of the mill. Fig. ii.— The Mortar and Pestle. As the quern increased in size another motor power was found necessary. This for a long period in many countries was sup- plied by cattle, although in parts of northern and western Europe the water mill early came into use. With the enlargement of the mill and the introduction of different motor power, milling passed from the household to the hands of the professional FOOD INDUSTRIES 6l miller, who at first did the village grinding, then passed to a larger district. In some countries wind was used instead of water and we find crude wind-mills appearing as early as 600 A. D. The earliest mills of the United States were operated by horse-power, wind and water being later introduced. Grist Mills. — While the motor power was being changed, devel- opments appeared in the mill-stones and the grist mill came into existence. At the end of the eighteenth century this mill, driven by either wind or water, was doing a thriving business and it is only a comparatively short time since it had to give away to the modern roller mill. The structure at first was of few parts and the operation was simple. The entire wheat went into the flour ; there was no bolting and no separation into grades. The grain was at first crudely cleaned by screening, blasts of air being passed over the wheat to blow away chaff and lighter particles. The wheat was then passed to the mill-stones to be ground. Two large stones known as burr-stones were used, the upper one of which revolved. They were very heavy, sometimes weighing 1,500 pounds, and as a rule were imported from France. The stones were made up of pieces bound together with bands of iron. The inner surface was cut much like a grater and, as it wore smooth, the miller would again cut its surface with a steel pointed hammer called a mill-pick (Fig. 12). When the two stones touched in revolving, it was spoken of as "low milling." The grain was fed from above and the grinding motion con- tinued until the kernel was ground to a powder. The outer husks were torn into shreds and the germ, being plastic, rolled over and over until it assumed a cylindrical form. The main object of low milling was to make the largest possible amount of flour from the grain at the first grinding. The only separation made was that of the fibrous part which being lighter could be removed by a process of winnowing. As some of the bran was pulverized it was impossible to separate it from the flour. This gave the flour a dark color and impaired its keeping qualities. The germ also being rich in fat in time became rancid. During the nineteenth century marked improvements took place 62 FOOD INDUSTRIES in milling owing to the invention of many mechanical devices. Screens and bolters came into use which led to a practice of sift- ing and regrinding. The elevator, the conveyor, and the hopper- bag were invented and finally the middling purifier. Fig. 12. — Roughening Burr-Stones. (Courtesy of the Washburn-Crosby Co.) With the invention of the middling purifier, "high milling" or the gradual reduction process came into use. Here the stones were placed farther apart and the wheat was granulated rather than ground, sifted and reground. This gradual reduction being FOOD INDUSTRIES 63 found advantageous, more stages were introduced until a flour vastly superior in quality was being placed upon the market. When hard spring wheat, however, appeared other improve- ments were necessary. When our people visited Hungary, they were surprised to find what progress had been made along mechanical lines. There the grain was being crushed by means of rollers made of porcelain. Americans were very quick to see the advantage of this process and a roller-mill outfit was brought from Hungary to Minneapolis. Many changes in machinery were necessary to meet new conditions, but from 1881 the roller- mill rapidly increased and before the dawn of the twentieth cen- tury the long honored grist mill had practically disappeared. The substitution of rolls for mill-stones was the most radical advance ever made in the history of milling. It made possible the opera- tion of large flour mills which rank among our great commercial industries. Disadvanages of Old Processes. — T. They were very slow. In the' grist mill the stones were very heavy and could not be driven rapidly. II. The flour could not be ground as fine. If the stones were placed too close together, there was danger of the stone itself wearing away and becoming mixed with the flour. III. Friction caused heat which would affect enzyme action. Starch would be changed to a more soluble form and thus mak£ the flour more liable to be attacked by molds and bacteria. IV. The keeping quality was very poor. Farmers in olden times were in the habit of carrying grain to the mill in sacks and carrying home flour. It was said that the farmer was poor or that he could not conveniently carry more, but these were not the true reasons. He had learned by bitter experience that the flour would not keep. It was long before the cause for this was known. Old-fashioned flour contained the germ within which' is most of the oil of the wheat kernel. Oil becoming rancid soon spoiled and ruined the flour. In modern milling processes the germ is removed. 6 4 FOOD INDUSTRIES tn W u o (A P* O M ►4 o to to O s , u Tl V > j4 -5-i j _c K CI >. OJ T) re < u Si t^. >o US- bp .S •c— S — 5 ■ifi '•° to -c" rs— s^ "=■ X! 11 C to 1- 3 k o to iS u to 2 - s-sH olg to In. f T3" i :; :.■'!.■ . . • r ■w .'« i ■ mam - «i 3°7-7 grams of bread from 227 grams of Graham flour; b, 302.5 grams of bread from 227 grams of entire wheat flour; c, 301.5 grams of bread from 227 grams of standard patent flour. a, Feces from Graham bread; b, feces from entire wheat bread; c, feces from standard patent bread. Fig. 18. — Bread Made from Entire-wheat, Patent, and Giaham Flours, and Character of Feces from Same. (Courtesy of the U. S. Dept. of Agriculture.) FOOD INDUSTRIES JJ lievecl by many scientists to be all the protein that is available as food (Fig. 18). Undoubtedly the claims made by manufac- turers as to the value of the whole wheat flour have been greatly over-estimated, although its use occasionally gives a pleasant change in the diet. Gluten Flour. — Gluten flour is a substitute for patent flour, much used by people having diabetes or such diseases that the 'use of starch is undesirable in the diet. It is prepared from an ordinary good grade flour. Flour is mixed with water and allowed to stand. In time the starch washes out and if allowed to settle, a separation can be made. By repeated washings the starch content is reduced to 50 per cent. The product is then dried and ground to a powder. This process requires time and is troublesome and the manufacturer should be paid for his labor. The sale price for such flour should be approximately 22 cents per pound. A cheaper product is sometimes found on the market selling for 7 cents per pound. Manufacturers could not afford to put flour through this process and sell it at so low a figure; cheap gluten flour is simply a low grade flour containing bran. Cereal Department. — Many of the large mills have a cereal department where the so-called breakfast foods are manufactured by processes quite similar to those of the milling of flour. For further information see Chapter VI, Breakfast Foods. Semolina. — The preparation from wheat of a coarse meal known as "Semolina" is now largely carried by the miller. Sem- olina is used in the preparation of macaroni. See page no. RYE. Rye is a species of grain resembling wheat. During the Middle Ages it furnished much of the bread material for the great body of people in Europe, and is still 'extensively used in Russia and Germany by the peasantry, although it is gradually being superceded by wheat. Its cultivation is evidently not nearly as old as the other cereals, for there is no mention of it in ancient languages. It was known, however, to the Romans in Pliny's time. Rye is a very hardy plant and will grow in a soil too poor fo'r yS FOOD INDUSTRIES the majority of other food grains and too cold for the produc- tion of wheat. It thrives best and gives the largest yield under conditions favorable to wheat. The varieties grown are not nearly as great as the other cereals ; the principal types are known as winter and spring rye. Composition. — The starch content is much like that of wheat, a difference being detected only in the microscopic appearance of the granules. The nitrogenous constituents also resemble wheat as far as gliadin is concerned. There is no protein, exactly corresponding to glutenin; therefore, the gluten formed is not altogether similar to that prepared from wheat flour. It more closely resembles wheat gluten, however, than any other cereal and can be successfully used with or without a leavening agent for the making of bread. Uses. — Rye ranks second as a world's bread material. Rye bread is highly nutritious, but is less pleasing to the eye than wheat bread. It is dark in color, moist and compact in texture and has a peculiar sour taste. An extreme example is the black bread or pumpernickle of North Germany. A partial rye bread is often made by mixing the flour with wheat flour. This gives a greater yield of gluten and makes a larger and more palatable loaf of bread. Rye flour is used largely in the United States, but chiefly by the foreign born population. Rye is excellent for the production of malt used in the dis- tillation of spirits, and is much used in Europe for the making of gin and in this country for the manufacture of whiskey. The bran can be used as a cattle food and the straw for hats and in the manufacture of paper. Adulteration. — The adulteration of rye flour has been very frequent, flour of other cereals being added. Such admixture may be detected with the use of the microscope. The rye granule as a rule is larger than wheat and frequently has characteristic markings as a cross, slit or star. CHAPTER VI. BREAKFAST FOODS AND COFFEE SUBSTITUTES. A canvass of our markets would reveal to-day an endless variety of cereals listed under the name of breakfast foods. In the early days of America, the only cereals utilized to any extent were wheat as wheat flour and corn as samp, hominy, cornmeal and hulled corn. In New England the custom prevailed of using popcorn as a breakfast food. Bread crumbs were also fre- quently toasted and used for that purpose. Oatmeal was later introduced by the Irish and Scotch immigration and finally bar- ley, rye and rice, but their use has always been more or less lim- ited to the foreign born population. It was not until the latter part of the 19th century that a new interest was awakened in this class of foods. Much experi- menting was done on the cereals, new methods of manufacture were developed and many new products were placed on the mar- ket listed under the name of "The Cereal Breakfast Foods." Probably no class of foods has ever been so extensively and in- geniously advertised. In a comparatively short time a bewild- ering variety could be purchased in the local markets ; many ap- peared to remain indefinitely, but a far larger number soon could be found only in forgotten places. This constant and ever in- creasing variety of breakfast foods is giving to the cereals an important place in the dietary which was not known in the past history of our country. Classification. — Although the list of these foods is so long and varied, they fall very readily into four classes. /Whole grain. Uncooked <^ ^Part of grain. Partly cooked. Cooked. Malted. The grains commonly used in this country are oats, wheat, corn and to some extent barley and rice. In the majority of 8o FOOD INDUSTRIES breakfast foods, only one variety of grain appears, at other times two or more are mixed. Breakfast foods are prepared directly from these cereals, either by mechanical manipulation, culinary processes or malting. Many times such changes are brought .about in order to make the product ready either for immediate consumption or for serving after a moderate amount of cook- ing. These changes in composition usually consist in the more or less complete rupturing of the starch granule and sometimes bringing about its conversion into more soluble forms. Other substances of the nature of condiments are often added as maple sugar, cane sugar and salt. Particular methods of preparation are usually trade secrets. Uncooked. — The whole grain variety is best represented by oatmeal. This is practically the old-fashioned cereal with mod- ern methods of preparation. Ingenious devices have been in- vented for the removal of foreign seeds, dirt and other sub- stances of an undesirable nature. The roller process is now used instead of the old idea of crushing but the rolls are supposed only to take off the outer husks. These are removed now quite thor- oughly so the amount of cellulose left is much smaller than for- merly. Sometimes there is a gradual reduction of the kernel so oatmeal may be in the granulated form. This is more common in Canada than in the United States. Varieties consisting of parts of grain may be found in farina and cream of wheat. They are prepared from the hard, granu- lated particles of wheat usually taken from the first or second breaks in the manufacture of flour. It is the part of wheat from which patent flour is made. This class of breakfast foods is usually made from hard spring wheat as soft winter wheat is apt to break down too finely. The uncooked cereals are sold at a lower price as there has been less manipulation by the manufacturer. They require, how- ever, a longer cooking in the home. Partly Cooked. — By far the largest number of the break- fast foods of to-day belong to this class ; 90 per cent, of the oat- meal consumed in the United States is in this form, on account FOOD INDUSTRIES ' 8l of its easy preparation in the home. The first of these cereals to be introduced was the rolled oats. The preliminary treat- ment of cleaning, kiln-drying and hulling is practically the same as with the uncooked varieties. The "groats" then pass through a process of steaming and while still moist go to heated rolls which flatten them into flakes. Additional cleaning processes are sometimes used to loosen and remove the fine particles of floury matter before the flakes are put into packages. Almost all of the grains are now being flaked, while peas and beans are also found in the Canadian market. Originally this process of steaming was thought to cook the grain so thoroughly that only a few minutes were necessary in the home. It is now known that the heat has not been applied long enough and such cereals need to be thoroughly cooked before serving. Less water is needed as much has been absorbed in the steaming process. On account of the flattened condition of the grain exposing more surface it is not necessary to give as long a time as in uncooked cereals. More time, however, should be allowed than is stated on the package. Cooked. — The ready to serve varieties are numerous and are prepared in various ways. The most common forms are : i. The flaked cereals closely resembling the rolled variety, but heat has been continued for a longer time. They sometimes con- sist of one cereal as flaked rice or they may be combinations of grain as wheat and barley. Other substances, such as syrup and salt, are frequently added and some flaked varieties have passed through an additional process of parching or toasting, thus giv- ing them a darker color and producing a flavor which is relished by most people. Several of these flaked varieties as Cranose Flakes and Force were patented at Battle Creek, Michigan, the center for the development of breakfast foods, and were among the earliest of the ready-to-eat foods. 2. The puffed variety, such as Puffed Corn, is made by placing the grain in sealed cylinders which are kept revolving at a tem- perature of approximately 550 F. for an hour. The moisture within the grain turns to steam, which on being released suddenly 82 FOOD INDUSTRIES from the cylinders causes an explosion of the starch granule and a puffing up of the cereal. This idea was undoubtedly taken from the old-fashioned custom of popping corn. A special variety of corn is cultivated with a hull strong enough to resist internal steam pressure. During the period of heating the starch is thoroughly cooked ; eventually the hull bursts and releases the cooked starch. 3. There is but one example of the shredded variety, but so popular is it among Americans that it stands in a class by itself. "Shredded Wheat Biscuit" as it is called, was the first breakfast food to appear on the market made from wheat. Its manufac- ture dates from 1895. The whole wheat kernel appears in the product and special machinery is needed for its preparation. After a thorough cleaning the cereal passes through some twenty to twenty-five different processes, the most important of which are the following: 1st, the whole wheat is steam-cooked for about thirty-five minutes without being flavored then dried to remove excessive moisture; 2nd, by special machinery the grains are drawn into shreds which are piled in layers, cut into miniature loaves and baked. 4. Variety resembling crumbs, as Grape-Nuts. This break- fast food is prepared from wheat and barley ground together, made into a flour, kneaded into bread dough and baked. The bread is then sliced, toasted and crushed. Grape-Nuts has had a very large sale in the United States, Canada and England for a number of years and is now gradually being introduced in the commercial centers of foreign lands. Malted Preparations. — The cereal grains are all rich in starch and on account of the hard impervious nature of the walls of the starch granules such food is not easy of digestion in the raw state. A long slow cooking is necessary not only to rupture the granule, but to make the starch more soluble. The digestive fluids under ordinary conditions can then readily take care of the product. To further aid digestion it was suggested sev- eral years ago that the cereal starch be subjected to the action of malt. Malt contains an enzyme called diastase which has the FOOD INDUSTRIES 83 power of rapidly liquifying starch after the cell walls have been ruptured and then converting it into dextrin and maltose. Mal- tose is soluble and several steps nearer the completion of the di- gestive process. The amount of starch which has been changed to dextrin and maltose depends upon the thoroughness with which the malting process has been conducted. Manufacturers of these products claim that the process has been thorough and these cereals are highly recommended for people with weak di- gestion. It is a question whether this claim is always true or whether malt has simply been added to give flavor after the cereal has been cooked with dry heat. Heat would readily change starch to dextrin without the aid of diastase and is a much quicker process than that of malting. For information as to the malting process see Chapter XI, Alcoholic Beverages. Such a cereal has a pleasant taste relished by many people and adds va- riety to the diet, but it is not completely predigested. Experiments along this line have been carried out at the Iowa Experiment Station on a number of malted breakfast foods. It is difficult, however, to decide whether the malting process has actually been carried out or whether malt has been added, but there are strong evidences to make scientific men feel that in many cases the cereal has been cooked by dry heat. The term malted is often used when malt has simply been added, as malted milk. Milk cannot be malted in the sense of adding diastase to it ; it can only be reduced to the powdered form then mixed with ground barley malt. Much has been said of the advantage of using predigested foods in order to relieve the digestive tract of part of its normal work. It is a question, however, as to the wisdom of taking habitually artifically digested foods. The human body under normal conditions is well fitted to perform this work for itself and the digestive organs need a certain amount of exercise to keep them in proper condition. It has often been quoted "A well man has no more need of predigested food than a sound man has of crutches." These cereals, therefore, should be taken more for their pleasant taste and to give variety than for their so called predigested value. .84 ' FOOD INDUSTRIES Adulteration. — While in advertising much has been said greatly over-estimating the virtues of the breakfast foods, the experi- ment stations and pure food examiners have discovered very- little adulteration. Manufacturers as a rule use good whole- some material, processes are modern and conditions at the fac- tories most sanitary. Goods are protected while in the dealers' hands and are so packed that they can easily be taken care of by the householder. Comparisons of Old and New Cereals. — The old-fashioned cereals were much more economical. Manufacturers did not charge for extra manipulation. They were bought when dry, so consumer was not paying for water which had been added during manu- facturing processes, and as they appeared on the market in bulk the box was not included in the weight. Uncooked cereals which have been thoroughly cooked in the home digest just as easily as predigested kinds and are equally nutritious. In these respects they are superior to some varie- ties of partly cooked. There is no reason to believe that a pre- pared food is more favorable to health than cereal itself prop- erly cooked. On the other hand, much can be said in favor of the use of prepared breakfast foods for they are usually palatable, whole- some and nutritious. They save much time, labor and fuel in the home and are well suited for the use of the housekeeper, who must depend upon the use of the kerosene, gas or electric stove. From a sanitary standpoint there has been a great improvement; being sold in cardboard boxes well lined with air-tight paper, they are protected from air, moisture, dust and micro-organism. Unless carefully packed a cereal will not keep well. Moist cli- mates make it liable to be attacked by mold growth and it is apt to become infested with insects. The chief point against the modern cereal is the excess cost. The cost of cereal per pound is 2 to 3 cents; cost of prepared cereals 10 to 15 cents. The cereals, nevertheless, pound for pound, are the cheapest com- plete food that can be found on the market and they form a legit- imate and valuable food. FOOD INDUSTRIES 85 COFFEE SUBSTITUTES. For several years past another cereal product has been found on the market known under the name of coffee substitutes. They are in many cases put up by the same manufacturers as the breakfast foods and like them seem to be gradually increas- ing in number. They are as a rule made of parched grains of wheat and barley sometimes mixed with wheat middlings, pea- hulls and molasses. Some of the first products also contained a low grade coffee added to give flavor. Experiments made at the 'Connecticut Experiment Station, however, show that the present day coffee substitutes are as a rule made from the cereal grain as claimed by the manufacturers and that there is now very little adulteration of any kind. It is claimed that they are harmless, unstimulating, have a flavor resembling coffee and yield much greater nourishment at lower cost. The color and flavor resembling coffee are largely due to the fact that the carbohydrates present are caramelized; this also occurs in the roasting of coffee. See Chapter XXI, Tea, Coffee and Cocoa. Few coffee lovers will agree that the flavor strongly resembles coffee as the coffee bean also contains certain volatile bodies which give that beverage the much desired aroma and taste. Substitute coffee where coffee has not been added is perfectly harmless, unstimulating, and furnishes a beverage for those who cannot take coffee. There is little truth, however, in the extravagant claims made in advertising matter as to the nutritive value of the beverage. This value is hardly worth con- sidering, since experiments have shown that skim milk is from three to twenty times as nutritious. CHAPTER VII. UTILIZATION OF FLOUR. BREADMAKING. By far the oldest and most important product made from flour is bread. The art of breadmaking dates back to the remotest ages of mankind and so important is this world's food-stuff that it is known almost universally as "The staff of life." With the possible exception of milk and eggs, there is no article of the diet that is more generally used by human beings and that is so well able to sustain life. It is to its constant use that we owe the wonderful development along the lines of the cultivation of wheat and the equally marked progress found in its milling oper- ations. In a broad sense bread includes all forms of baked flour, whether leavened or unleavened, but our common use of the word refers only to those forms in which leavening agents are used, other products being spoken of as pilot bread, crackers, passover bread and biscuit. Originally all bread was eaten with- out leaven for the savage after crushing or grinding his meal, baked it in the ashes of his camp fire. The result was a bread of hard, tough material not easy for the digestive fluids to act upon. This evidently was only the custom among the most primitive people, for the use of leaven is very ancient. The Israelites while in Egypt used leavened bread, the Greeks were known to have cultivated the yeast plant and in the ruins of Pompeii an oven was found containing 81 loaves of bread not unlike our own. With the use of leaven, a type of bread was produced, more easily masticated, better in flavor and more easily digested. Primitive Breadmaking. — Crude methods of breadmaking can be studied not only in the earliest historic records but among some of the more primitive nations of to-day. Evidently bread was used in the stone age for burnt specimens have been re- covered among the Swiss Lake Dwellers ; the pyramids of Egypt bear testimony to its early use and again we find evidences of bread in the mound tombs of North Africa and Asia. The method FOOD INDUSTRIES 87 of preparation was undoubtedly very simple, probably much like that used by some of the wild tribes that inhabit parts of Africa at the present time. It is their custom to grind grain between two stones, make it into a paste with water, then bake in the ashes of a camp fire. In different parts of the world similar products can be found. Natives of -some of the West Indies prepare a thin round cake of meal which is obtained from the cassava root; the product is known as cassava bread and furnishes the principal food among the common people. In Mexico and Central America, a bread known as "tortillas" is prepared by the natives from Indian corn by first parboiling the grain to soften it, then crushing by means of a stone rolling pin. The paste is baked on a plate of iron. The "tortillas" is sold at many of the market places by native women and as it is more highly relished when served hot, it is usually baked on a small portable charcoal stove at the market. Among the well-to-do classes of India, a round, flat cake of unleavened bread called "chapatties" is prepared from wheat flour and baked on a griddle or on coals. A similar product is made by the poorer classes from cornmeal, millet, barley or a coarse, hard grain known as ragi. In Palestine and Syria women are still the millers and bakers, grinding the meal in small stone hand-mills after the same custom that was used long before the beginning of the Christian era. The coarse meal obtained is made into flat cakes and baked on a hearth, which consists of two stones raised on end over which an iron plate is laid to hold the bread. Bread made in other parts of the Orient as in Egypt and Turkey has quite a different appearance. Here the material is rolled or pounded into a flat dough similar to our pie crust; two layers are then put together united at the edges and baked in a very hot oven. The expansion of the air between these layers puffs up the dough and gives the appearance of a large loaf. A flat bread of coarse barley meal is also made in the northern part of Europe, particularly among the Norwegian peasants. The progress from these primitive breads to the modern white loaf used by the civilized world has needed as much study and 88 FOOD INDUSTRIES experimentation as the development of all other industries. Probably the most marked change was the use of leaven and it is generally supposed that the world owes this important step to the Egyptians. They seemed to have carried the art of breadmaking to a high state of perfection, as did also the early Greeks, who are known to have had at least 62 varieties of bread. From the days of these ancient civilizations mechan- ically there seemed to be little progress for centuries, and it has been left to the modern scientist to develop the art of bread- making. Leavened Bread. — So far as the ingredients are concerned, the present day bread might be considered a very simple food, for there are only four materials needed in this operation — flour, water, yeast and salt. Other materials, such as butter, lard, sugar, milk, fruit or spices might be added to give flavor and variety, but they are not essential to breadmaking. Although the in- gredients are so simple, scientists tell us that the chemical changes taking place in the preparation of the loaf are very profound. In order to understand at least a small part of these changes it is necessary to consider the raw material to be used. Flour. — At the present time our first-class bakers are using a standard flour for breadmaking. It is high in the gluten form- ing proteins so will absorb more water and gives a larger, lighter and better flavored loaf. For milling processes see Chapter V. Water. — It should be free from dirt or contamination of any kind. See Chapter II, Water. Until recently it was supposed that hardness or softness did not materially affect water to be used for breadmaking. According to the research work of Dr. Kohman (see page 92) it is now believed that salts of lime stimu- late the growth of yeast. In the household many prefer to use milk in part or altogether as the liquid. It makes an equally light loaf, contains a larger amount of protein and fat, is equally digestible, but the dough is slightly longer in rising. Salt. — Salt is used in breadmaking for the flavor it imparts, for without it the dough would be insipid and as a soluble mineral food for the yeast. The amount varies according to the type bread and in different localities even with the same variety. It should FOOD INDUSTRIES 89 never be used, however, in such quantities as to be readily tasted or the delicate aroma and flavor of the bread will be destroyed. It is believed that salt added in small quantity stimulates the capacity of the palate for recognizing flavors of other substances. This accounts for the importance of salt as a flavoring agent. Another reason has been given for the use of salt, but it is not now believed to be important. It has the power of control- ling some of the chemical changes which take place during fer- mentation, so was considered a preservative. In relatively large amounts it checks alcoholic and ropy fermentation, but it does not inhibit the lactic acid and many other bacteria so its influence as a preserving agent is very limited and can hardly be important enough to be considered. . Yeast. — Yeast was the first leavening agent in the world's his- tory and is still by far the most important. How it first came to be used is not told us, but the knowledge that wild yeast is always present in the atmosphere leaves but little to the imagina- tion. Its use might easily have been discovered by accidentally exposing dough to the atmosphere and afterwards finding out that it made a lighter loaf. From this simple custom of exposing dough to the air we might readily trace the practice of saving a small amount of raised dough from day to day to act as a leaven- ing agent for the next baking. Gradually the art of cultivating yeast became the practice among the civilized nations. Although yeast has been used as a leavening agent for many centuries very little was really known about it until the time of Pasteur. . It is now believed that yeast, molds and bacteria be- long to a class of substances known as ferments. Until quite recently these ferments were divided into two classes: ist, en- zymes, such as diastase and ptyalin called unorganized ferments ; 2nd, yeast, molds and bacteria, known as organized ferments. Recent research has revealed that micro-organisms cannot do their work as ferments, without the presence of enzymes within their cell-walls so that classification no longer can be used. Yeast, molds and bacteria are now known to be living organisms. They are microscopic forms of plant life, which in their desire for food can act upon substances, bringing about many profound 90 FOOD INDUSTRIES changes. Although the nature of these changes may not be known to the average house-wife, with the effects of many she is quite familiar. Milk after standing for a time, particularly in a warm place changes in its nature; it develops acid qualities and is spoken of as being sour. Butter under certain conditions becomes rancid. Cider when fresh has a decidedly sweet taste which in time gradually disappears and is replaced by an unmis- takable flavor of alcohol. It is quite common to speak of this product as hard cider and every house-keeper knows that should hard cider be kept long enough it will turn to vinegar. These changes and many others modern scientists have traced to the fermentative actions of micro-organisms. In the fermentation brought about by the yeast plant two very important products are found, alcohol and carbon dioxide, which are used throughout the world whether the races are civilized or still in a semi-barbarous condition. Alcohol is particularly de- sired by all industries preparing stimulating beverages and car- bon dioxide is needed for the lightening of bread. It is to the manufacturer of alcoholic beverages that we owe the scientific study that has been given to the yeast plant. When viewed through a microscope yeast is found to consist of a single round or oval cell. It is perfectly colorless — belonging to a class of plants without chlorophyll — the fungi. Each cell is an individual plant consisting of an. outer wall of cellulose filled with protoplasm. In this condition yeast is usually spoken of as in the resting state. Being a living organism yeast is capable of reproducing itself should conditions be favorable. The normal reproduction is through a process of budding. If a little of this resting yeast is put under conditions favorable for growth, a daughter cell or bud is formed within the cell. The bud pushing its way through the wall rapidly develops, separates from the parent cell, and in its turn is able to become a parent cell. When growth is very rapid the cells sometimes fail to separate, and adhering, form a chain of cells which can easily be seen under the microscope. Pasteur states that on one occasion he watched two cells for two hours; during that time they multiplied into eight. FOOD INDUSTRIES 9 1 Under favorable conditions some yeasts are reproduced by the formation of spores. These spores can resist many adverse circumstances, such as a lack of moisture, insufficient food and marked changes in temperature. It is to their hardy nature that we owe the constant presence of yeast in the atmosphere. In this state it has been discovered yeast can live on the earth for some little time, until wind carrying them into the air, gives an opportunity for settling amid favorable surroundings and again growth and reproduction take place. The favorite home for the yeast plant is on the skin of grapes and other fruit, a fact well appreciated by those engaged in the wine industry. The rapidity of the growth is much influenced by surrounding the yeast with favorable conditions of temperature, suitable food, oxygen and moisture. The temperature found to be most favorable is JJ° -95 ° F. Below yj° F. the growth is slower and a little above 32 F. it is practically arrested. The vitality of the cell is not destroyed *by a low temperature for even after exposure to 32 ° F. yeast "will grow if the conditions are once more favorable. Above 95 ° F. yeast will become gradually weakened by heat until it is finally killed at a temperature of 140 F. if the yeast is moist.- Dry yeast can stand a much higher temperature, 200 F., without destroying life. Although yeast grows most rapidly between 77°-95° F. it is sometimes advisable to keep the temperature lower to pre- vent the action of undesirable micro-organisms. Brewers in the United States and on the continent are now using a lower tem- perature although bakers seldom, if ever, take advantage of this fact. Food for yeast growth must contain carbohydrate, nitrogenous compounds and appropriate inorganic matter. The last two food principles are necessary for the healthy development of yeast for they constitute as in human life, the building material of the cells. Pasteur discovered that unless these substances are given to yeast they act like cannibals, the stronger cells existing on the weaker. From our standpoint the carbohydrate is the most im- 92 FOOD INDUSTRIES portant food for the yeast as it is to these compounds that we look for the production of alcohol and carbon-dioxide. All forms of carbohydrate cannot be utilized by yeast but should the compound not be available as food, yeast carries its own enzyme, much as we do, which can convert it into a form which can be utilized. There are two important enzymes in yeast — invertase and zymase. The function of invertase is to convert maltose into glucose or sucrose into glucose and fructose by the process of hydrolysis : CuH^Ou + H 2 — 2C 6 H 12 6 . Glucose being an available food for yeast it 'is attacked by zymase which breaks down the sugar into alcohol, carbon dioxide and a number of other substances in small quantities, such as fusel oils, succinic acid and glycerin. C 6 H 12 6 — 2C 2 H 5 OH + 2C0 2 . According to the research work of Dr. Kohman* carried on at tli2 University of Pittsburgh, the effect of adding soluble salts of lime and ammonia to the dough results in the increased growth and stimulation of the yeast organism to a remarkable degree. The Arkady yeast food containing these salts has recently come into use. It is claimed that the use of this food has the follow- ing advantages: ist, it stimulates the gas production of the yeast so that half the quantity of the yeast regularly used will suffice for leavening the dough; 2nd, it helps to conserve the gluten of the flour thereby giving the dough greater stability; 3rd, less carbohydrate is consumed by the yeast because of the smaller quantity of yeast used ; 4th, the flavor is improved due to the con- servation of the natural substances, such as gluten and sugar in the flour, and to the fact that because of the lesser quantities of yeast used fewer objectionable by-products are produced; 5th, the bread made by the process has less acidity. The opinion that the addition of lime is harmful or in any sense an adulteration is not in accordance with the results of the research work of Emmerich and Loew.f These authorities defi- * The effects of the mineral salts contained in natural water upon the fermentation of bread, By Henry A. Kohman, Ph. D. t Calcium Bread and Its Virtues, By Emmerich and I,oew. FOOD INDUSTRIES 93 nitely state that this is the most feasible method of maintaining the lime balance in the diet. It is now the custom of the best German bakers to combine with the dough previous to baking definite quantities of soluble lime salts in the form of chlorides. Micro-organisms also need oxygen, some taking it in the form of atmospheric oxygen 2 and others from their food. Yeast needs atmospheric oxygen. Pasteur discovered that an abund- ance of air caused the plant to develop rapidly, but the evolu- tion of alcohol and carbon dioxide was very slow, while in a limited amount of oxygen fermentation proceeded rapidly and the cell growth was arrested. This idea has been of great bene- fit to brewers and to scientific bread bakers who now know when to regulate the supply of oxygen. In fact one of the largest and best known breadmaking concerns in the United States make their bread under a process patent, based on the idea of mixing dough in such a manner as to inject into the dough an unusual amount of atmospheric oxygen. Leavening Effect of Yeast. — With these facts in mind the leavening effect of yeast can easily be seen. A mixture of flour and water readily supplies the moisture and food, flour con- taining all the necessary compounds — carbohydrate, protein and mineral matter. If this material be kept exposed to the atmos- phere and at a suitable temperature, yeast will multiply very rap- idly and will spread throughout the dough. As a result of its action much carbon dioxide is developed, which in forcing its way through the dough becomes entangled in the gluten. The latter being elastic stretches, thus giving porosity and lightness to the mass. Yeast Preparations — Breadmaking. — The oldest method of pre- paring yeast was very probably that used by the ancient Egypt- ians, who succeeded in obtaining wild yeast and growing it in dough. A portion of this dough or "leaven" was always saved for the next baking and as it contained yeast cells, again yeast could be grown when needed. This simpje custom has been used more or less from those early days to modern times and in some parts of the world it is still practiced. The home brew used by 94 FOOD INDUSTRIES our ancestors and which can still be found in isolated districts is a preparation of this kind. The leaven saved from the last baking is mixed with suitable material for the rapid growth of yeast. A decoction of hops, potatoes and water was used and when the yeast had developed part of this material was added to the dough. A similar practice can be found in Scotland at the present time. The "barm" as it is called is prepared by allow- ing yeast to grow in malt extract and flour before adding it to the bread dough. In some parts of the continent particularly in France and Switzerland, this ancient method is still used by bakers and poor country people. The bread has a sour taste, which is relished by many, due to the development of lactic and butyric acid bacteria. Some authorities consider bread made in this way more healthful as the acids developed are supposed to assist in digestion. The taste, however, is disagreeable to the majority of people and the best authorities of our country con- sider that a high grade commercial yeast is more reliable and much more convenient. Brewer's Yeast. — One of the earliest commercial yeasts was obtained from brewers. During the fermentation of beer, es- pecially where a high temperature is used, much of the yeast is carried to the top of the vats by the escaping carbon dioxide. It is called by the brewer top yeast. This yeast was skimmed from the top of beer and was sold in the liquid form. Little care was given to sanitary conditions and the product was thor- oughly unreliable. It was dark in color and carried with it the flavor and aroma of the hops. Bread made from it was some- what smaller in volume, due to slow fermentation, dark in color and had a faintly bitter flavor. It has now almost entirely been superseded by distiller's yeast, which at the present time is sold in the form of the compressed yeast cake. Compressed Yeast Cake. — Distiller's yeast is lighter in color and possesses a rather pleasant taste. At the time that fer- mentation is most energetic the yeast is skimmed off the surface and is conveyed by wooden drains to sieves. All foreign matter is removed and the strained liquid passes on to the settling cis- terns. Here the yeast settles and the liquid is drawn off. The FOOD INDUSTRIES 95 yeast is generally mixed with starch and put into presses which squeeze out much of the moisture, leaving a dough-like paste. Starch is said to be added because it permits more water be- ing removed, which greatly aids the keeping quality. In recent years, however, the foremost yeast manufacturers of our country have discovered that by strict laboratory control and the develop- ment of pure culture, compressed yeast of great strength and uni- form quality and flavor can be successfully and commercially made without the addition of starch. The latter, in fact, is now looked upon as an adulterant. Yeast is then partly dried, made into cakes, and carefully wrapped in metal or waxed paper to protect it from bacteria. This is the best all-around yeast that is used at the present time. It is more expensive, but will work evenly and quickly, and will give a finished loaf of bread with a good volume and texture and having an agreeable taste, odor and color. A good quality should be slightly moist, possess a creamy white color and break with a fine fracture. Dried Yeast. — There is one great disadvantage to compressed yeast; even under favorable conditions it will only keep fresh for a comparatively short time. The yeast begins to die and other forms of micro-organisms soon develop, giving rise to unde- sirable flavors in bread. For people who live in isolated dis- tricts, another type of compressed yeast called dried yeast is put on the market. More starch has been added and more water removed. Although a low temperature is used to dry the yeast some of the cells are undoubtedly killed, so it is not as satisfac- tory a form to use as fresh yeast. On account of the dryness, however, decomposition cannot set in and some of the yeast and spores will remain alive for a considerable length of time, and when mixed with water and a soluble carbohydrate will slowly begin to grow. Salt Rising. — This old and crude method of leavening, for- merly imputed to wild yeasts, has been definitely determined to be due to the growth and development of certain gas forming types of lactic acid bacteria. Unlike the yeast these forms de- velop a mixture of hydrogen and carbon dioxide, at the same time producing lactic acid which accounts for the difference in flavor 96 FOOD INDUSTRIES so highly regarded by some people. This form of leaven in the clry state has now become a commercial product and can be bought similarly to yeast preparations. Object in Breadmaking. — Given the necessary ingredients, it is the baker's object to produce a result which will be pleasing to the sight, agreeable to the taste, easy of digestion and nutritious. Steps in Breadmaking. — Fermentation. — The methods of fermenting dough are somewhat varied but there are only three in common use: 1st, straight or off-hand dough; 2nd, ferment and dough; 3rd, sponge and dough. No matter which method is chosen the best material possible to procure should be used, the ingredients should be thoroughly mixed and in proper pro- portions, and the greatest cleanliness should be observed through- out the entire operation. Straight or Off-hand Dough. — With this method all of the ingredients while luke-warm are thoroughly mixed. Care should be taken that the proper proportions are used ; too little yeast will give a badly raised dough and too much will cause excessive gas which stretches the gluten beyond its limit, causes it to break open and the gas to escape, thus making a heavy, soggy loaf of bread. The dough is then set aside to rise in a moderately warm tem- perature (77°-95° F.). It should be kept as free from drafts as possible and should be left exposed to the atmosphere or • lightly covered, as the presence of oxygen aids the growth of yeast. As fermentation proceeds the dough increases in bulk and becomes light and porous. When sufficiently aerated with gas it is thoroughly kneaded by hand or machinery. This operation causes the escape of waste gases, incorporates fresh air, revives the activity of the yeast, has a toughening effect on the gluten and assists its elasticity. The dough is shaped into loaves, al- lowed to ferment again and then baked. Bread made in this way takes from 3 to 10 hours according to the amount of yeast and the temperature used. There are several distinct advantages to this method — all labor of sponging and extra manipulation is saved and bread is produced in less time. It is far more con- venient when bread is made at home. Ferment and Dough. — Among many bakers the first step FOOD INDUSTRIES 97 is the preparation of the ferment ; that is, the cultivation of the yeast by giving it appropriate food. Potato mash is still largely employed for food, also raw and scalded flour, malt extract and commercial yeast foods. The ferment takes about 5 hours, but is still used by bakers for two reasons : first, it enables an origin- ally small amount of yeast to do much work; second, the young yeast cells are very vigorous. This yeast is then incorporated with water, flour and salt and a dough is made similar to the straight-dough method. The Sponge and Dough Method. — In this process the dough is made in two stages by allowing the yeast to work for a period in a portion of the flour and water. Several different sponges are used — the quarter, the third, the half and the three- quarter, according to the amount of flour added. Fermentation proceeds from 2 to 12 hours and the remaining material is incor- porated. Care should be given to mix the second portion of flour thoroughly with the sponge or the bread will contain lumps on which the yeast has had no opportunity to work. The dough as it is now called is allowed to rise again, is kneaded into loaves and baked. Although it takes longer and requires more manipu- lation the sponge method has many advantages : first, on account of its slackness, it requires much less yeast (this is a considerable saving where bread is made in large quantities) ; second, hard wheat flour on account of its absorbing power does not produce a desirable loaf of bread when made by the off-hand method — a sponge gives a lighter and more elastic loaf ; third, bread made with a sponge is usually finer in texture and has a better flavor; fourth, it keeps better; fifth, some believe that less work is in- volved in mixing as the sponge softens on standing. Baking. — The dough should be evenly baked in an oven ranging from 450 to 550 F. according to the variety of bread. The heat should not be too great at first or the bread will harden too quickly. The gas in the interior will not have a chance to expand the gluten and the result will be a heavy bread. In some bakeries the temperature is gradually raised during baking. The effect of this heat is to rapidly expand the gas which in its turn expands the gluten and swells the loaf. As gluten is protein in 7 98 FOOD INDUSTRIES nature it very shortly coagulates and thus holds the loaf in shape after the escape of the gases. The surplus moisture, the alcohol and acids volatilize. In time the starch granules are ruptured and become suitable for human food. On the outer portion or crust on account of the intense heat, most of the starch is dex- trinized and a small portion is converted into glucose. The inner part or crumb is not subjected to such a high temperature, since dough is a poor conductor of heat. The interior is not heated above the boiling point of water so the changes in the carbohy- drate grow less as it approaches the center of the loaf. The yeast, bacteria and enzymes present in the dough are destroyed during the baking. This sterilizes the bread. Cooling. — As soon as completely baked, the loaves of bread should be placed on sieves or bread-racks so that the air can cir- culate around them until they are thoroughly cool. This gives the gas and steam within the loaves an opportunity to escape and pre- vents the bread from becoming damp. A Modern Bread Factory. — In strong contrast to the old- fashioned cellar bakery with its dingy and many times unsanitary surroundings, the modern bread factory has arisen. Here can be found bread being manufactured on a large scale in a well ventilated, sun-lighted building equipped with facilities as nearly perfect as modern science can suggest. An electric plant for lighting the building and running the machinery, a cold storage plant and hot water system for regulating temperatures, elevators, conveyors and slides for carrying material from one part of the building to another, can be seen. Many curious devices in machinery have been invented, so that the human hand needs scarcely touch the product from the time that the raw materials enter the building until the finished loaf is ready to be carried out for delivery. Conditions insuring thorough cleanliness are carefully sought and the bread is made amid thoroughly sanitary surroundings. Only a high grade flour, good yeast, distilled water and the best available material for shortening are used. Before being utilized the flour is passed through a sieve con- taining rotary brushes and a surprising amount of wood, lint, dust and other foreign material is removed. When needed, FOOD INDUSTRIES 99 the sifted flour passes automatically to electric bread mixers, as does also the required amount of water, dissolved yeast, salt, etc. As the bread mixer revolves, filtered air is fed to the dough in order to hasten the action of the yeast and give whiteness to the product. The mixing operation requires some 25 minutes. The mixer is then turned over and the dough drops into the raising Fig. 19. — Flour Sifter and Blender. (Courtesy of Ward Baking Co.) trough, where it is allowed to rise in a sunny, white-tiled room for 3 hours. As soon as the dough is in proper condition, the bottom of the tub is removed and the dough proceeds by gravity through an opening in the floor to an apartment below, where it is automatically carried to a machine which weighs and cuts it into uniform pieces. It passes on a moving platform in separate loaves to a number of kneading devices which roll and press it into shape. The loaf travels forward and backward on a con- IOO FOOD INDUSTRIES veyor, where it is allowed to rest before it drops into a pan ready for the second rising. The pans are removed to an apartment heated to no° F., and the bread is allowed to rise. It is then baked in a traveling oven at a temperature, of 450-550 F. After being removed from the oven, the bread falls on racks from which place it proceeds by an incline to the floor below where after cooling, it is wrapped and sealed in paraffin paper. Fig. 20. — Mixing Machine with Dough About to be lowered Into Raising Trough (Courtesy of Ward Baking Co.) Souring and Its Prevention. — The souring of bread is due to the development of lactic and butyric acid ferments. This may be caused by a poor grade of yeast which is apt to contain un- desirable bacteria, by a poor flour which on account of the presence of certain nitrogenous bodies gives a medium particu- larly suitable for bacterial growth, by dirty vessels, by allowing the sponge to proceed too far thus giving undesirable ferments an FOOD INDUSTRIES IOI opportunity to develop. It may be prevented by using a high grade flour, a good yeast and by thorough cleanliness. Too. high a temperature during fermentation and prolonged raising of the sponge and dough should be avoided. Sudden changes in tem- perature should be guarded against. Adulteration of Bread. — Alum has been largely used and evi- dently for a long period. English history speaks of Henry VIII Fig. 21.— Machine for Dividing Dough Into Equal Parts of Equal Weight (Courtesy of Ward Baking Co.) ordering his baker to be hanged for using alum in bread intended for the King's table. This subject has been much discussed of late years and its use has been finally prohibited by the Pure Food Law. As a rule alum was used with a poor grade flour or with a flour that had been kept for a long time under unfa- vorable conditions. When flour deteriorates the protein some- times changes, becoming more soluble and will not make a good 102 FOOD INDUSTRIES dough. Alum will cause it once more to become insoluble and a better gluten will be formed. The loaf is larger, less sodden, whiter and gives the appearance of a better grade flour. Losses in Fermentation. — In the preparation of bread by means of yeast, appreciable losses of dry material must necessarily take place. This is caused by the formation of volatile matter during fermentation, such as carbon dioxide, alcohol and acids. They Fig. 22. — Front View of Dough Divider. (Courtesy of Ward Baking. Co. are driven off, to a large extent, at the temperature of baking, so have no nutritive effect. Estimates of this loss have been made and as a rule it has been found to be approximately 2 per cent, although it may be much higher under unfavorable con- ditions. Tiebig calculated that the loss in Germany daily would supply 400,000 persons with bread and it has been estimated that 300,000 gallons of alcohol are annually wasted in the bakers' FOOD INDUSTRIES IO3 ovens in London. There has been much experimenting and large sums of money expended in trying to recover this alcohol but without success from the baker's standpoint ; the bread was found to be dry and unpalatable. This inevitable waste has led to attempts to convert dough into a porous form by other methods than that of fermentation. Many mechanical and chemical proc- esses of aerating dough with C0 2 have been invented, but in Fig. 23 -Machine for Wrapping Bread with Paraffin Paper. (Courtesy of Ward Baking Co.) England and the United States, only two have met a slight suc- cess. Chemical Process. — Use of baking powders. See Chapter VIII. Aerated Bread. — In this process cold water is saturated with C0 2 . This highly charged water is then mixed with flour under pressure in air"-tight chambers. When the pressure is lowered io4 FOOD INDUSTRIES the dough is forced out and blown up by the expanding gas. It is cut into loaves quickly and baked. This bread is very light, porous and involves no waste of material but unfortunately it has an insipid taste due to the absence of the by-products of yeast, so has never met with great success in the United States al- though it is still made in Great Britain. Fig. 24. — Bread After I,eaving Wrapping Machine. (Courtesy of Ward Baking Company.) THE CRACKER OR BISCUIT INDUSTRY. Those products formerly known in the United States as crack- ers and in England as biscuit originally included only varieties of unleavened bread, such as the commonly known pilot bread, ship's biscuits and water crackers, but the march of progress in the last half century has greatly enlarged the field of this in- dustry until it now includes many articles formerly considered cakes, pastry and confectionery. In both this country and in England the manufacture of bis- FOOD INDUSTRIES I05 cuit has been greatly improved and the output tremendously in- creased, one American firm alone manufacturing some four hun- dred or more varieties. Great manufacturing concerns have been attracted by this field of business and have by their efforts to produce a perfect product brought about improvements resulting in cleanliness and sanitation in the manufacture of these products. The dirty and unsanitary cracker bin and barrel of the A B C Fig. 25. — Baking Floor for Sponge Goods. (A) Steel Dough Cars. (B) Soda Cracker Machines. (C) Upper Parts of Reel Ovens. (Courtesy of National Biscuit Company.) grocery store, such as were formerly used when crackers and bis- cuit were sold only in bulk form, the chance for the small dealer to deceive, the many varieties of cheap scales, and such numerous handlings as were necessary to deliver the goods to the purchaser are all things of the past. The public now receives its biscuit in moisture and dust-proof packages, packed and sold under the best possible conditions and free from the touch of human hands on their journey from the factory to the table of the consumer. io6 FOOD INDUSTRIES Raw Material. — There is no food industry which uses such an enormous variety of foodstuffs and from so many parts of the -Flour Bolter, Blender and A. tomatic Weigher. (Courtesy of National Biscuit Company.) Fig. 27. Baking Floor for Sweet Goods showing Sweet Cracker Machine and Pans being placed in the Oven. (Courtesy of National Biscuit Company.) world as the biscuit industry. The basic ingredient is a flour; the ideal flour for most biscuit is one made from rich soft winter FOOD INDUSTRIES IO7 wheat although for special purposes Graham, whole whsat, corn, rye and arrowroot flour are used. Oatmeal and other cereal products enter into the manufacture of special kinds of biscuit. Eggs are used in many of the sweet varieties of crackers and cakes, and butter, lard, coconut and other vegetable oils form the principal shortening. About twenty different kinds of sugars may be used according to the purpose for which they are intended. These range in grain from the 4X sugar which is an impalpable powder up to the crystallized sugar, whose grains may be a quar- ter of an inch long. Some of the sugar comes from the refineries while other kinds are brown sugars straight from the plantations and impart to the biscuit a rich taste of molasses which is so delicious. High grade molasses itself and honey are also largely used, while whole milk or filtered water supply the moisture for the dough. The above are the basic ingredients used in the manufacture of biscuit. In addition there is almost an infinite variety of ac- cessories, such as fruits and nuts of all kinds, flavors, spices, cheese, chocolate, etc. These are worked into the biscuit in many different ways, for example : The fruits may be mixed with the dough or they may be used as a topping; the dough may be rolled into thin sheets with a layer of fruit between forming a sort of fruit sandwich; the fruit may be made into a jam and applied to the cake after it is baked. Similar variety of proc- esses may be used in the case of nuts, spices, chocolate and other accessories. Manufacturing. — The manufacture of biscuit may be divided into sponge, sweet and iced goods. The sponge goods are those commonly known as soda crackers, oyster crackers and the like. These are all raised with yeast. The greatest care must be taken throughout the process to keep all the conditions exactly uniform. In modern factories the temperature of the room in which the doughs rise is kept at about 8o° F. If the temperature falls be- low this a valve is automatically opened which introduces warm air to all parts of the room. In the summer time cold air is automatically supplied in the same way. Even the humidity of the room is mechanically controlled in some cases. This great I05 FOOD INDUSTRIES care is necessary in order to insure a uniformly high grade prod- uct. The first operation consists in taking the temperature of the flour. From this the temperature of the water can be calculated which will bring the sponge after mixing to a temperature of about J2° F. The yeast, flour and water are then mixed by machinery and the product which is called a sponge is allowed to lie in the proofing-room twelve hours or more. During this time the yeast acting on some of the carbohydrates of the flour produces carbon dioxide gas which raises the sponge to about three times its original size; at the same time the gluten is made more soft and elastic. The peculiarly appetizing taste of soda crackers which can be developed in this way and no other, is formed at this time in some unknown manner. After reaching its maximum height some of the gas escapes and the surface of the sponge drops several inches. It is then ready to be mixed into the dough. Soda, salt, shortening and more flour are added and the whole is remixed for about five minutes. It is then al- lowed to stand several hours more. During this time the soda neutralizes the acidity developed by the yeast and the whole dough rises again. When ready it is wheeled in its clean steel car to the dough brakes where by being rolled and folded between great rollers it is kneaded into the proper thinness, and is made ready for the machine which further shapes and stamps it into the form in which it is baked with the design and trade mark im- pressed upon the dough. It is now ready for the oven, where it is baked at a temperature of from 500 to 6oo° F. Fig. 25. After being baked and taken from the oven the biscuit are cooled and packed. The variety of sweet goods is almost infinite, depending not only on the ingredients used but upon the stiffness of the dough and the method of treating it. Some doughs are made with very little wetting. These doughs are rolled out, cut and baked on machines such as those described for sponge doughs and form the familiar hard sweets. Other kinds of doughs are much softer, ranging in stiffness down to that of heavy cream. These latter are the cake doughs. The dough is poured into the hopper of a FOOD INDUSTRIES IOO, so-called "wire cut-cake machine" and is forced thence through small holes. When the proper amount has come through it is cut off automatically by a moving wire and falls on a pan which is supported on a travelling apron below. This pan may be sent immediately to the oven or the pan with the unbaked dough upon it may be dipped in sugar, nuts, raisins, etc. The ovens used in the biscuit industry are. of a type developed especially for this industry and are of very interesting construc- tion. They are large hollow structures with a capacity of about that of an ordinary room, but are nearly two stories in height. The walls are of brick, several feet in thickness. The oven is heated by hard coal, fuel oil or natural gas from two fire boxes located in the bottom of the oven. The oven heats up slowly owing to the great thickness of the walls, but once heated through the bricks radiate a steady, "solid" heat on the crackers from every side. This is very necessary in order to secure a thorough even bake. Movable shelves are hung inside the oven on a struc- ture similar to a gigantic "Ferris Wheel" which can be started and stopped automatically, bringing the shelves one after the other to the oven's mouth which is situated in the upper part. As each shelf comes to the oven's mouth pans full of baked goods are withdrawn and their places are taken by other pans full of fresh dough. These pans are carried on the movable shelves around the circumference of the "Ferris Wheel" inside the oven and are then brought back again to the mouth of the oven thoroughly baked. In the icing room, marshmallow, jams, jellies, chocolate and other sweetmeats are applied to the already baked goods. The work is now being done more and more by machinery, thereby insuring perfect cleanliness and uniformity. These jellies, marsh- mallows, etc., may be deposited on the top of the cake or the whole cake may be dipped into them so that they form a complete covering. The cakes then go to the trolleys. These are large structures equipped with many hundreds of movable trays or wires, the cakes either resting on the trays or pinned on to the wires, are carried up and down and back and forth throughout the length of the trolley until they are thoroughly dried and IIO FOOD INDUSTRIES ready for packing. The trolleys, as a rule, are shut in to protect them from dust and dirt; temperature and moisture within are carefully controlled. Biscuits of all kinds, as soon as they are finished are packed in the modern moisture- and dust-proof packages. These may be cartons lined with waxed paper and carefully wrapped, or the familiar glass front can. They are then ready to start, often the same day that they are packed, on their journey to the ulti- mate consumer. MACARONI. In the world's food products made from wheat, macaroni has occupied an important place in the diet of several nations. The Japanese claim to be the original manufacturers but whether this be true or not, the Europeans first heard of it from the Chinese who had been using it for a long period. Although the Germans were the European discoverers of macaroni, it was the Italians who early learned to appreciate its virtues and to adopt it as a national food. By the 14th century, Italy was the only European nation that understood the preparation, and for nearly four hun- dred years she held the secret of the method of manufacture. The Italian macaroni industry had its birth in Naples from Whence it spread throughout Italy and finally to other parts of Europe, but it was not until the latter part of the 19th century that this product could be equalled in any other country. It was finally introduced into France where it has become an important industry. Although the United States is still a large importer of macaroni, there has been a great growth in the macaroni industry since the cultivation of durum wheat in our own northwestern states. In the preparation of macaroni a hard, very glutenous wheat is used, called macaroni wheat. The early Neapolitan manufac- turers won their fame on account of the excellent quality of the Italian wheat. Unfortunately the cultivation of native wheat is now sadly neglected in Italy. Russia for a long period has produced some of the finest varieties. They were grown exten- sively for macaroni-making long before Liebig started his experi- FOOD INDUSTRIES III mentation on hard wheat as a breadmaking material. Algerian durum wheat, the wild goose wheat of Canada and Argentina macaroni wheat are also largely exported for this industry. Manufacturing Processes. — In the macaroni manufacture the first step is the preparation of a coarse meal called "semolina" or "semola." Wheat is cleaned by steeping in water, dried by heat, ground and sifted. The husks and much of the starchy flour are separated leaving the light amber, glutenous part re- sembling a meal rather than flour. As a rule manufacturers of macaroni buy their semola from millers, rather than do their own grinding. The best macaroni is made by blending various grades of semola much as flour is blended for breadmaking. The semola is then put into an iron mixer, moistened with the smallest possible quantity of hot water and thoroughly mixed by machinery until the dough has a smooth and tough appear- ance. The mass is kneeded for a few minutes and is transferred to a cylinder. Pressure descends upon the dough, forcing it in strings slowly through the perforated plate which forms the bottom of the cylinder. The form of this plate fixes the char- acter of the macaroni. If the holes contain a steel pin or conical blade the dough takes the form of a pipe-stem and is known as tube macaroni. Holes without pins give solid macaroni known as spaghetti and vermicilli. A flat opening sometimes takes the place of a round hole and ribbon forms are made. When the strings of paste are the proper length they are cut either by hand or by automatic rotary knives. The macaroni is then thrown over reed poles to dry. When the weather is fine it is left exposed to the sunlight for about two hours. When partly dry, it is put into underground vaults and kept in this damp place for about 12 hours or until the dough has lost some of its brittleness and is once more pliable. The poles over which the macaroni hangs are then carried to storehouses where they re- main until the strings have a horn-like toughness. They are now ready to be inspected, sorted, weighed and packed for ship- ment. In case of bad weather the macaroni is dried under cover for a longer period. The yellow color is produced by the use of saffron or of a coal tar dye. 112 FOOD INDUSTRIES Domestic Macaroni. — There is a constantly increasing demand for macaroni made in the United States. The hardest variety of wheat is used especially the hard wheat of Kansas and that grown in the semi-arid lands. The drying, especially in the eastern states is done entirely indoors, the lengths being hung over wooden rods in heated apartments through which currents of air are driven. The product is very satisfactory and the sanitary conditions connected with the manufacture are largely in advance of those under which many imported brands are produced. Judging Quality. — A good quality of macaroni should have a soft yellowish color, should be rough in texture, elastic, hard, and should break with a smooth, glassy fracture. In boiling it should double its original size and should not become pasty or adhesive. As a Food. — Macaroni is a very palatable and nutritious food. It can be kept for a length of time without deterioration and is comparatively inexpensive. Being high in protein it readily re- places meat in the diet. CHAPTER VIII. LEAVENING AGENTS. Early in the history of the human family, it was found that in order to make bread easy to masticate and more readily digest- ible, it must be puffed up before it was baked. This could best be accomplished by a gas with heat to expand it. C0 2 was the first gas used, obtained through the agency of yeast, and nothing has ever been found that can equal its action as a leavening agent. Advantages. — (i) CO, is generated by the action of the yeast enzyme on the carbohydrate of the meal or flour, so no foreign substance is introduced into the dough; (2) The slow liberation of the gas causes it to have its full effect as a leavening agent ; (3) The by-products produced during fermentation give a pleasant taste; (4) Bread made by yeast is more easily digested. Disadvantages. — ( 1 ) The time required for leavening is long ; (2) Careful watching and studying of favorable conditions for the growth of yeast are necessary or the result will be sour or sodden bread ; (3) It involves a loss of carbohydrate in the form- ation of products which are volatile at the baking temperature ; (4) As yeast is a living organism, it is impossible to calculate the amount of gas produced. Chemical Agents. — The necessity of sometimes raising bread quickly has led to a study of chemical agents which will produce C0 2 . With this method the gas is liberated in the presence of water by the action of an acid or acid salt on a bicarbonate, usu- ally the sodium compound. The salt resulting from the chemical action of the acid and base remains in the dough. Advantages. — 1. The time is shortened. In a few minutes a light, spongy dough can be prepared which would require hours by the use of yeast fermentation; (2) No loss of the carbohy- drate is involved; (3) It is possible to calculate the amount of gas which may be produced if the composition of the chemical reagents is known. Disadvantages. — ( 1) The taste is not as good as that of bread raised by yeast; (2) The product is not as readily digestible; (3) 114 FOOD INDUSTRIES The residue resulting from the chemical action remains in the loaf. As these residues have no nutritive value, they can only be regarded as waste products, and may retard digestion. Early Use of Chemical Agents. — Long before the scientific inves- tigation along the line of these reagents was begun, the house- wife was making use of the same principle in the utilization of sour milk and saleratus to lighten dough. Although this method was very effective, it had two serious drawbacks: r. The acidity of the milk was apt to be over-estimated. Lactic acid is caused by the action of bacteria in milk on the lactose or milk sugar. CtfHjjOn.HjQ *-»• 4C 3 H 6 3 . When 0.9 per cent, is formed the action is stopped, the lactic acid acting as a preservative. In sour milk as used for cooking purposes, the acidity rarely exceeds 0.4-0.5 per cent. As a rule too large an amount of saleratus was used thus giving an excess of alkali. This affected the taste and interfered with protein digestion. 2. The saleratus of to-day is not KHCO s , but a cheaper and stronger compound NaHC0 3 , approximately four parts of which according to the molecular weight, will do the work of five parts of the potassium compound. Old recipes should therefore be reduced to j/5 of the amount suggested. In old cook books may be found the recipe for cream of tartar soda biscuit conforming very closely to proportions in use at the present time. Baking Powders. — The introduction of baking powders some fifty to sixty years ago was a great advantage although the early powders were very crude. The first one prepared had for its ingredients Na 2 C0 3 and H 2 S0 4 , but this proved too troublesome to be practical. Liebig suggested the use of the NaHC0 3 and HC1 which would give a residue of NaCl, a perfectly harmless product. The bicarbonate was found to be so satisfactory that its use has continued to the present time, but experimentation soon proved that the acid could not be used. Commercial HC1 almost invariably contains traces of arsenic, minute quantities of which could be found in the dough. Another acid ingredient was sought, one which would be effective, comparatively cheap, FOOD INDUSTRIES 115 with good keeping qualities and which would give a harmless residue. In the early sixties Professor Horsford patented a compound consisting of acid phosphate of lime and bicarbonate of soda with starch as a filler. Later, taking advantage of the old housewife's recipe of cream of tartar and soda, a similar product was put on the market. At a still later period powders containing alums and mixtures of alums and phosphate appeared but for many years the manufacture and sale of tartrate powders exceeded all others. Important forms of powders on the market are known as tartrate, calcium phosphate, sodium phosphate and alum phos- phosphate. Tartrate powders consist of mixtures of cream of tartar, bicarbonate of soda in proportion of two to "one by weight and dry starch about one-fifth by weight. In a few instances the cream of tartar is partially replaced by tartaric acid. Calcium phosphate powders consist of soluble acid calcium phosphate, bi- carbonate of soda and starch as filler. Sodium phosphate powders contain monosodium phosphate, bicarbonate of soda and starch. Alum phosphate powders consist of sodium aluminium sulphate, popularly known as S. A. S., acid calcium phosphate, bicarbonate of soda and starch filler. Until the passing of the law prohibiting their use, there were many straight alum powders on the market. They contained starch as filler, bicarbonate of soda and potassium, sodium or ammonium aluminium sulphate. They were very effective but were found to be so objectionable on account of the amount of alum present that their sale has been practically abolished. There has been much controversy as to the relative merits of these powders, the chief point of discussion being the residue, "What is it?" "What amount is present?" "Is it harmful?" Of the phosphate powders, the sodium compound is undoubtedly the least harmful and the most efficient. A glance at the following reactions and table will give some idea of the relative value. Il6 FOOD INDUSTRIES TARTRATE POWDER. 188 84 54 282 44 KHC 4 H 4 6 + NaHC0 3 + 3H 2 — NaKC 4 H 4 6 ,4H 2 + CO, 20 per cent, filler. 1 level T. of powder weighs 3.00 grams and contains 20 per cent, of starch. This yields approximately 0.4 gram C0 2 or 200 c.c. at o° C, which becomes 273 c.c. at ioo° C, the highest temperature of the oven. The residue of crystallized Rochelle Salts amounts to 2.5 grams. CALCIUM PHOSPHAf E POWDER. 234 168 180 CaH 4 (P0 4 ) 2 + 2 NaHC0 3 + ioH 2 -* 136 358 88 CaHP0 4 + Na 2 HP0 4 ,i2H 2 -f- 2C0 2 CaHP0 4 is insoluble in water ; it requires free acid for solution. 1 level T. of powder weighs 4.4 grams and contains 25 per cent, of starch. This yields approximately 0.72 gram C0 2 or 355 c.c. at o° C. which becomes 485 c.c. at ioo° C. the highest point of the oven. The residue of phosphates weighs 4.05 grams. SODIUM PHOSPHATE POWDER. 120 84 142 44 NaH 2 Po 4 + NaHCo 3 -+- uH,0 — ■ Na 2 HP0 4) i2H 2 + C0 2 2,2 per cent, filler. 1 level T. of powder weighs 3.75 grams and contains 32 per cent, of starch. This yields approximately 0.545 gram C0 2 or 274 c.c. at o° C. which becomes 374 c.c. at ioo° C. the highest point of the oven. The residue of soluble sodium phosphate weighs 4.41 grams. ALUM PHOSPHATE POWDER. 475 2 34 336 (NH 4 ) 2 A1 2 (S0 4 ) 4 + CaH 4 (P0 4 ) 2 + 4 NaHC0 3 + 144 245 192 8H 2 — A1 2 (P0 4 ) 2 + CaS0 4 ,2H 2 -f 132 644 176 (NH 4 ) 2 S0 4 + 2Na 2 S0 4 ,ioH 2 + ^C0 2 1 level T. of powder weighs 2.85 grams and contains ZZ J A P er FOOD INDUSTRIES 117 cent, of starch. ■ This yields approximately 0.32 gram C0 2 or 160 c.c. at o° C. which becomes 218 c.c. at ioo° C. the highest point of the oven. Residue weighs 2.17 grams. Weight of iT. of powder Weight of 1 T. of powder less the filler Weight of C0 2 Volume of CO., at o° C. Volume of COo at the oven tempera- ture Weight of the residue Remarks Tartrate 3 grams 2.4 grams 04 gram 200 c.c. 237 c.c. 2.5 grams All soluble in water. Residue con- tains water of crystal- lization. Calcium phosphate 4.4 grams 3.3 grams 0.72 gram 355 c.c. 485 c.c. 4.05 grams 27.5 % insol- ubl e in water. Residue con- tains water of crystal- lization. Sodium phosphate 3.75 grams 2.5 grams 0-545 gram 274 c.c. 374 c.c. 4.41 grams All soluble in water Residue con- tains water of crystal- lization. Alum phosphate 2.85 grams 1.9 grams 0.32 gram 160 c.c. 218 c.c. 2.17 grams 36.6 54 insol- uble in water. Residue con- tains water of crystal- lization. Relative Efficiency. — Tartrate powders are expensive, but they keep well so are effective when old. They yield a residue of Rochelle Salts which is soluble in water. Tartrate powders may be prepared at home by thoroughly mixing y 2 -pound of cream of tartar, %-pound of bicarbonate of soda and }4-pound of starch or lactose. Lactose has been found to be very effective as a filler. It has great lasting power but is more expensive. Calcium phosphate and alum phosphate powders are cheap but they do not keep well and leave a residue which is largely insoluble in water. They cannot be successfully made in the household. Until a conclusion was drawn by the Referee Board of the Department of Agriculture, alum in foods was considered deteri- mental to health. It is the belief now that aluminium compounds in such quantities as would be found in bread do not affect in- Il8 FOOD INDUSTRIES juriously the nutritive value or render them detrimental to health. Dr. Taylor calls attention to the fact, however, that the regular ingestion of sodium sulphate which acts as a cathartic, cannot be recommended. Since alum phosphate powders leave such a residue, biscuit prepared from them should not have a place in the daily diet*. Ammonia Powders. — Bakers have been using ammonium car- bonate very effectively as a leavening agent. It has the great ad- vantage of leaving no residue, but must be used in very small quantities or the product will taste of ammonia. (NH 4 ) 2 C0 3 — 2NH3 + CO, + H 2 0. Cream of Tartar. — Almost all of the cream of tartar and tar- taric acid used in this country are imported, the largest amounts coming from Germany and France. They are by-products of the wine industry being obtained from a certain kind of sour wine. Cream of tartar or potassium bitartrate is a normal con- stituent of grapes, occurring in comparatively large amounts. When the fruit is crushed and pressed in the preparation of wine, most of the tartrate salts being soluble pass out with the juice. There is no tendency for them to become insoluble and precipitate in crystalline form until the grape juice reaches 5-6 per cent, of alcoholic strength. This occurs during the fermen- tation process. It is customary to float branches of the grape vine in the fermenting vats. As the alcohol increases, gradually cream of tartar is deposited upon the sides of the vat and on the floating branches. The crystals carry down with them the color of the wine. They are known commercially as "argols." There is also a dark deposit at the bottom of a full barrel of new wine after it has stood long enough to settle, called the "lees." From argols, cream of tartar is made. "Lees" contains a larger amount of calcium tartrate and is used more extensively for the produc- tion of tartaric acid. Argols is not pure cream of tartar as it carries down in pre- cipitating, other constituents of the grape. These impurities must be removed. In the process of refining, the crystals of * See U. S. Bulletin 103. Alum in Foods. FOOD INDUSTRIES 119 argols are powdered, dissolved in boiling water and filtered to remove dirt and other foreign matter. The color can be removed with egg albumin or by filtering while hot through bone-black. The solution is then run into shallow receivers and as the clear liquid cools, cream of tartar separates and is deposited in thick masses of crystals. These crystals may be further purified by again dissolving in hot water and recrystallizing. When all the impurities are removed, the crystals are powdered in a mill and are then ready for the market. Tartaric Acid. — Tartaric acid may be prepared from the lees by the action of sulphuric acid. The calcium is removed in the form of a sulphate. CaC 4 H 4 6 + H 2 S0 4 — H 2 C 4 H 4 6 + CaS0 4 . Tartaric acid is used largely in pharmacy and in the textile in- dustry, either as the acid or as tartar emetic in certain dyeing processes and in calico printing. Acid Phosphate of Lime. — The soluble acid phosphate as used in the baking powder industry does not occur in nature, but must be manufactured. Calcium phosphate Ca 3 (P0 4 ) 2 , occurs in the mineral known as apatite or rock phosphate. It is a form that is insoluble in water, but can be readily made soluble by treatment with an acid. Ca 3 (P0 4 ) 2 + 2H 2 S0 4 «— CaH 4 (POA + 2CaS0 4 . The mixture of calcium phosphate and sulphate is separated by nitration, soluble phosphate being found in the liquid portion from which it can be crystallized. Bicarbonate of Soda. — The preparation of soda constitutes to-day one of our largest and most important industries. Alkali compounds have been used for cleaning purposes by the house- wife, for many centuries, but this represents only about one per cent, of the soda manufactured. It is also needed in many in- dustries such as soap-making, glass manufacture and in the bleaching of cotton and linen goods. The original alkali used was potassium carbonate obtained from potassium salts which are widely spread throughout plant 120 FOOD INDUSTRIES life. The housewife formerly obtained her supply from the ashes of her wood fire. Boiling water was poured over the dead embers of the fire, and the solution was boiled down giving a lye which was used for the preparation of soft soap. By further evapora- tion the lye yielded flat, pearly crystals of carbonate of potash commonly known as pearl ash. Being hygroscopic, on exposing to air pearl ash absorbs moisture and in this condition is very attractive to carbon dioxide, eventually resulting in bicarbonate of potassium or saleratus. This operation was usually conducted in the cooler portion of the chimney flue. For many years the manufacturer copied the housewife's process on a larger scale. Later when mineral deposits of potash compounds were discov- ered it became possible to prepare potassium salts from that source increasing the yield and lowering the cost of production. The largest deposits occur on the western coast of South America and in the region of North Germany which has Stassfurt as the center. It was not until the 18th century that another alkali was found to take its place. This was discovered by the Spaniards who prepared it by burning to ash a sea-weed found along their coast. It contained a sodium compound which yielded a carbonate on heating. The soda compound, being stronger and cheaper than potash, was readily received by the manufacturers and used by them, until the early days of the 19th century. Warfare at that time interfered with commerce and Spain being hostile, the French manufacturers were cut off from their source of supply. Napoleon was determined to get some means of replacing this alkali and as France was poor in mineral deposits, he offered a reward for the discovery of a practical process for making sod- ium carbonate. Everything used in the manufacture, however, must be obtained in France. Many chemists worked at this prob- lem and a process was finally discovered by Le Blanc which is used in many places at the present time. Le Blanc Method. — Le Blanc used in the preparation of soda, dry salt which he obtained from the sea, by the process of evap- oration. He then mixed together salt and concentrated sulphuric FOOD INDUSTRIES 121 acid, which were heated to a red heat causing the escape of hydro- 2NaCl + H 2 S0 4 — Na a S0 4 + 2HCI chloric acid and leaving a residue of impure sodium sulphate known as "the salt cake." The salt cake was broken up and mixed with powdered coal and limestone and was then treated in a reverberatory furnace, resulting in an impure product known as "Black Ash." Na 2 S0 4 + 2C — Na 2 S + 2C0 2 , Na 2 S + CaC0 3 — Na 2 C0 3 + CaS. Na^COs can be obtained from this residue by solution in water which eventually yields on evaporation the commercial form known as soda ash. Sal soda Na^COg, ioH 2 is obtained by crystallizing the solution of soda ash. Baking soda, bicarbonate of soda, is sometimes made by mix- ing the calculated quantities of soda ash and sal soda in a moist state forming the product into blocks and subjecting them to the action of carbon dioxide. 9Na 2 C0 3 + Na 2 C0 3 , ioH 2 + ioC0 2 — - 20 NaHC0 3 . Hydrochloric acid was practically unknown commercially until the invention of the Le Blanc process of soda manufacture. At first it was allowed to escape into the air and being washed down by rain it found its way into neighboring streams. This soon caused the destruction, of animal and plant life and was also a waste of a valuable by-product. Later it was discovered that HC1 could be run into water and sold. This opened up a new industry and did much toward making the Le Blanc method a commercial success. When more HC1 was produced than was needed, it was soon found that from it chloride of lime could be prepared, and a valuable disinfectant and bleaching agent was placed upon the market. Value of the he Blanc Process. — The raw materials salt, coal, limestone and sulphuric acid are common and inexpensive. The furnace and plant can be put up at a fairly low price. The by- products are important and have done much toward keeping this process in existence. Solvay Process. — The So.lvay method of preparing sodium 122 FOOD INDUSTRIES carbonate was invented in i860 by a Belgian named Solvay, and has practically superseded the Le Blanc process. Scattered throughout the world are large deposits of salt, sometimes in the dry state as in the salt mines of Germany and England, at other times in the form of brine. Brine wells occur more extensively and as the Le Blanc method required dry salt, it was found very troublesome to evaporate the water. The Solvay process can make use of the brine. This has been a great benefit to America for brine wells are abundant in Michigan, Louisiana and New York State. Syracuse is an important center in the American soda industry. Brine is also much easier to handle. It is pumped to the surface, saturated with ammonia, and then with carbon dioxide. NaCl + H 2 + NH 3 + C0 2 — NaHC0 3 + NH,C1. NaHC0 3 is separated by filtration. If sodium carbonate is wanted the bicarbonate is heated. 2 NaHC0 3 — Na 2 C0 3 + H 2 + C0 2 . The ammonium chloride obtained in this process can be de- composed by heating with quicklime, and the ammonia given off is again used for the treatment of another batch of brine. This process is cheaper and simpler than the Le Blanc and furnishes a purer product. Niagara Process. — By the use of electricity, a method of pre- paring soda has been discovered, which is a serious rival to both the Le Blanc and Solvay processes. Brine is run into partitioned tanks containing electrodes. When the current is turned on ion- ization of the salt occurs. NaCl + H 2 — NaOH + HC1. NaOH passes to the negative pole in one partition as it carries a positive change and HC1 goes to the positive pole in the other partition. Caustic soda can readily be utilized in the preparation of the carbonate and the bicarbonate. 2 NaOH + C0 2 «— Na 2 C0 3 + H 2 0, Na 2 C0 3 + H 2 Q + C0 2 — * 2 NaHCQ,. In this industry HC1 can again be used as a by-product for the preparation of chloride of lime or can be utilized in the acid form. CHAPTER IX. STARCH AND ALLIED INDUSTRIES. Starch is one of the most widely diffused substances in the vegetable kingdom. With the exception of the fungi, it has been found in varying amounts in every plant that scientists have so far examined. It occurs in relatively large amounts in different parts of the plant as in the seed (cereals), the root (cassava), the tuber (potato), the fruit (banana), the stem (celery, rhu- barb, sago), and in the leaves (spinach). Composition and Formation. — See Chapter I, Food Principles. Physical Characteristics. — -To the naked eye, starch has the appearance of a glistening white powder. It is neutral to litmus, has no odor or taste, does not crystallize and has a harsh feeling when rubbed between the fingers. When seen through a micro- scope, it consists of granules of various forms, round, oval, etc., differing greatly in size, according to the source. This has served as a valuable means of identifying starch. Although the size and shape may differ, all starch granules have a characteristic appearance. They are arranged in layers around a central nu- cleus. The outside consists of a substance closely resembling cellulose and within the granule or package is found the true starch. Physical and Chemical Properties. — Insoluble in cold water. With iodine, starch gives a characteristic blue color. Starch absorbs moisture from the atmosphere until it contains approximately 18 per cent. In very damp weather, it has been found to absorb a much larger quantity. When heated dry to 200 C. or more it is converted into dex- trin. When heated in the presence of water, the contents of the granules swell enormously owing to a large absorption of water, and cause the rupture of the outer wall. The starch freed from the package forms a viscous liquid known as starch paste. Uses. — While its place in the diet would alone make starch an important article of commerce, the manufacturer finds many 124 FOOD INDUSTRIES another market for his product. It is used: in laundries; for food, such as puddings, sauces and jellies; for candies, such as gum drops arid lozenges ; in baking powders ; in the textile in- dustry for stiffening and finishing fabrics ; in wall paper manu- facture as a filler, finisher and size ; for cosmetics, asbestos, soaps and adhesives; in brewing beer, ales and in the manufacture of alcohol; for the manufacture of dextrin and glucose. Source of Supply. — While starch is so widely distributed in the vegetable kingdom, there are comparatively few plants that can be utilized as a source of supply for the manufacture. In look- ing for his raw material, the starch producer must consider sev- eral important points: ist, the ease with which the plant can be grown in his locality; 2nd, the amount of starch yielded by the plant; 3rd, the ease of extraction; 4th, the presence of other constituents, such as protein and oil, which make the process difficult. With these points in mind, the European manufacturer chooses the potato, wheat and rice. The American uses corn and to a limited extent the potato and wheat. In the East and West Indies the cassava furnishes the chief source of starch. The arrowroot is utilized in the West Indies and parts of South America, and the sago in the East Indies. POTATO STARCH. The potato is a valuable source of starch on account of the great ease of extraction. The starch content is comparatively low as compared with corn and wheat, but protein, mineral mat- ter and oil are present in such small amounts that they do not interfere with the manufacturing processes. As a rule only about 20 per cent, of starch is found in the potato, although in certain parts of Germany the starch content has reached from 25-29 per cent. Potatoes can be grown very easily in temperate climates, nota- bly Germany, England, Scotland and Ireland. In the United States, Maine produces a high quality potato ; Wisconsin and Colorado also grow potatoes for the starch industry. The follow- FOOD INDUSTRIES 1 25 ing demonstration may be used to illustrate the simplicity of the method used : Extraction of Starch. — Clean and remove the skin from a small potato. Rub it on an ordinary grater, collect the gratings in a beaker of cold water, strain and allow the cloudy liquid to stand until the starch settles. Pour off the liquid. The starch can be purified by the addition of water, thoroughly mixing and allow- ing the starch to again settle. Remove the water by filtration and dry the starch with low heat. Although the manufacturer uses more or less complicated machinery to carry out these operations, the commercial pro- cesses are practically the same. Processes in Manufacture. — Cleaning. — The washing of po- tatoes must be thorough or the quality of the starch will surfer. The adhering dirt and sand are carefully removed by washing in revolving wooden drums, so constructed that the water carry- ing dirt and other impurities can escape through narrow open- ings. Inside the drums, devices, such as bristle or wire brushes, or revolving arms which rub the potatoes together, are some- times used to assist in the cleansing. Rasping.— The potatoes are reduced to a pulp in machines called raspers. These are usually revolving cylinders containing saw blades or knife edges to assist in the pulping process. Water is added at the time of rasping and the starch pulp is fed to a sifting machine. Sifting. — Shaking tables covered with gauze separate the starch from the potato pulp. The pulp can be pressed, dried, and sold as a low grade cattle food. The starch suspended in water passes through the sieves to settling tanks. When it has settled in a firm mass, it can be broken up and sent at once to a drying kiln or can be further refined. All root starches follow the same principle in the extraction of the starch. TAPIOCA. Tapioca is an important food product prepared from the starch of the cassava, a plant largely grown in Brazil and other 126 FOOD INDUSTRIES tropical countries. The extraction of the starch is carried out by the processes of grinding and washing with water, similar to those described under potato starch. The product is sometimes known as Brazilian arrowroot. In the manufacture of tapioca, the starch while still damp is placed in shallow pans and sub- jected to low heat. As the moisture is driven off, the tempera- ture is gradually raised until the starch granules burst and ad- here together, forming the mass into small irregularly shaped translucent kernels. A similar product may be obtained by mak- ing a starch paste, subjecting it to heat, and forcing it through Fig. 28. — Sheds and Board Used for Drying the Tapioca. (Courtesy of The Spiee Mill Publishing Co.) metal screens from which it is dropped and cooled. Tapioca is placed on the market in various forms according to the amount of heat used and differences in mechanical operations. Starch derived from other sources may be subjected to the same treatment and an equally nutritious product be obtained. As genuine tapioca, however, is always prepared from cassava starch, other imitative forms must be classed as substitution products. FOOD INDUSTRIES I27 Outline of the Corn Products Industry. — Cleaned. Kernel softened by steeping. Crushed. Separated by gravity. ( 1 ) Germ flows off from the top with the raw starch liquor, screened from the latter, dried, ground, pressed. (2) Hulls flow off from the bottom with the raw starch liquor, screened from the latter, then ground in burr mills and become part of gluten feed. (3) Endosperm (raw starch liquor) separated by grav- ( Starch ity on tables into -j (_ Gluten, which with corn sol- ubles obtained from steep- ing water, becomes part of the gluten feed. Starch is purified and sold as Starch — laundry lump, crystal, pearl powder, etc. 1. By process of roasting. Dextrin 2. By use of a dilute acid. f Boiled with dilute Glucose by process of hydrolysis < acid 0.06 % Neutralized. Filtered. Decolorized Concentrated. CORN PRODUCTS INDUSTRY. The abundance of the growth of corn in the United States and the many by-products obtained, make it an important source of starch, although the composition of the kernel involves elabo- rate methods for the extraction. The kernel of corn consists of an outer coating called the hull, the germ of which contains a comparatively large amount of oil, and the endosperm where are found starch and protein. 128 FOOD INDUSTRIES When received at the factory, the corn contains some impuri- ties and the kernel is in a dry, hard condition. Processes in Manufacture. — Cleaning. — Corn like other cereals contains a certain amount of foreign matter, such as bits of corn cob, pieces of wood, lint, dust and dirt. These are removed by screening, while magnets are used for drawing out bits of iron, nails and the like. Fig. 29. — Steeped Corn Running to Crushers. (Courtesy of Corn Products Refining Co.) Steeping.— In order to separate the kernel into its com- ponent parts, the hard, dry grain must first be softened. This is accomplished by steeping in water for approximately 40 hours at a temperature of no° F. Steam is injected to maintain the circulation and to keep the temperature at the desired degree. A very small amount of acid, 0.005 P er cent. H 2 SO s , is added to prevent fermentation. This is afterward removed by thorough washing. When the grain has absorbed sufficient moisture to cause a loosening and softening of the various parts, the water FOOD INDUSTRIES 129 is drawn off, leaving the kernel of corn in a moist, soft condition. The steepwater is evaporated and the solubles of the corn are incorporated with the gluten feed. The steeped corn is run to the crushers (Fig. 29). Crushing. — The softened grain is passed through a mill called the crusher (Fig. 30) which consists of two large disks set face to face having projecting teeth and rotating in opposite di- rections. The crusher is supposed to grind only to a coarse meal, thus leaving the germ and hull intact. Fig. 30. — Crushers. (Courtesy of Corn Products Refining Co.) Separation. — The resulting mass is fed to a long, narrow tank about 25 feet long, 4 feet wide and 8 feet deep, filled with starch liquor of about 8° Baume, where taking advantage of the difference in the specific gravity, a separation of the various parts is effected. The germ being the lightest rises to the top and floats over the weir at the end of the tank; the hulls sink to the bottom and flow off with the starch liquor (Fig. 31). The germs are passed over screens or shakers. They are then washed to i3° FOOD INDUSTRIES Fig. 31. — Separators. (Courtesy of Corn Products Refining Co.) Fig. 32. — Hydraulic Presses for Oil. (Courtesy of Corn Products Refining Co.) FOOD INDUSTRIES 131 free them from adhering starch, dried, ground fine, heated, wrapped in cloth and pressed (Fig. 32). The pressure causes the oil to flow out, leaving the oil cake which is sold for cattle food. The oil is cleared of foots by settling and passing through a filter process. It may be used for the manufacture of soap, soap powders, oil cloth, leather, paints and varnishes. By further refining with a treatment which removes the free fatty acids and other impurities, corn oil can be used for edible purposes as a salad oil, for frying and cooking and as a shortening for bread and cake. In this form, it is also utilized for pharmaceutical purposes. By a vulcanizing process, corn oil yields a substance called "paragol," which can be used as a rubber substitute in the preparation of such articles as shoes, rubber specialties and auto- mobile tires. The Hulls and the Endosperm. — The hulls flow off from the bottom of the separator together with the starch liquor (en- dosperm) just as did the germs from. the top of the separator. They then pass over screens, the starch liquor uniting with the starch liquor of the germs. The hulls being coarse are ground in burr mills, passed over screens, the starch liquor unites with the starch liquor of the germs and of the hulls, and the ground hull becomes part of the gluten feed, being mixed with the glu- ten and corn solubles. The starch liquor (endosperm) contains the starch and pro- tein matter, which is spoken of as gluten by the manufacturer. These must next be separated. This is effected by removing the starch liquor screened from the germs, hulls and ground hulls, directly upon tables from 60-120 feet long, 3 feet wide with an= incline of about 4 inches. As there is a difference in specific gravity, the starch settles while the liquid containing the protein flows over the end of the run and is caught in a tank below. The crude corn protein is mixed with the hulls, filter pressed, mixed with the corn solubles, dried, ground and constitutes gluten feed. The starch which settles to the bottom of the run is removed by being shoveled while in a solid, moist condition. The purifi- cation can be effected by the addition of water and again pass- ing over the runs on which the starch settles. This process can 132 FOOD INDUSTRIES be repeated until all foreign matter, such as traces of fat and protein are removed. Pearl starch, that to be used for baking powder and for certain classes of food starch, is prepared by breaking up the starch from the table and placing it on trays which are put up into iron wagons, run into kilns, and dried. The lump starch and crystal forms are prepared by mixing the starch from the tables with water, then running it into boxes with per- forated bottom lined with cloth (Fig. 33). The boxes are al- Fig. 33- — Dripping Boxes. (Courtesy of Corn Products Refining Co.) lowed to stand until the water runs off, then turned over and the thick slab of starch is broken up into cubes (Fig. 34). These are either wrapped in paper or put in trays and placed in drying ovens, where after ten or more days they are drawn out. Dextrins are produced in the same factory usually by the simple process of roasting. The different varieties depend upon the time and heat applied. Uses of Dextrins. — For the manufacture of gums, glues, muci- lage and other adhesives ; for cloth, carpets and twine ; for leather FOOD INDUSTRIES 133 dressings, paper and ink ; for food sauces ; in the textile industry, in sizes for strengthening the fiber and finishing the fabric. Also for thickening colors for calico and other printing. CORN SYRUP OR GLUCOSE. On account of its source commercial glucose is known in the United States as corn syrup. The term glucose is derived from the Greek word "Glykos" meaning sweet. It is a carbohydrate Fig. 34. — Emptying Starch from Drip Boxes. Breaking into Cubes. (Courtesy of Corn Products Refining Co.) of the monosaccharid group, C 6 H 12 6 , and is found in nature in the juice of many plants, such as grapes, cherries and sweet corn. Although it exists at times in relatively large amounts, the com- mercial source of glucose is always starch on account of the cheapness of that material, and the comparatively simple process of manufacture. In Europe glucose was first prepared from the potato starch during the early part of the 19th century, and has 134 FOOD INDUSTRIES long been looked upon as a nutritious food. It was not until after the Civil War, however, that American manufacturers started experimenting with corn starch as a source of supply for glucose. As grape sugar and corn syrup, it was soon placed upon the market. The products from corn compared very fav- orably with those made abroad from potato starch and so rapidly has the manufacture grown, that it is now one of our most im- portant industries. Glucose is sold in the liquid form, either white or colored, with or without flavoring, and as a solid in the powdered and crystalline form, all under various trade names. The commercial forms containing 50 per cent, or less of actual glucose are known as glucose. Corn sugar includes the solid forms of glucose con- taining more than 50 per cent. Uses for Liquid Glucose. — For confectionery, syrups, jams, jellies, pie filling, puddings, preserves and mince meat; in the brewing of beer; in chewing tobacco; in silvering glasses for mirrors ; in liquid soaps, hair tonics, blacking and shoe polishes ; in food sauces and in the canning of meats ; for pastes and sizes ; in the tanning of leather and in rice polishing. Uses for Corn Sugar. — In the manufacture of caramel (sugar coloring) ; in brewing of beers, porters, etc.; for vinegar; in the manufacture of lactic acid; in bread making. Processes of Manufacture. — Whether in Europe or America, whether from potato or corn starch, the manufacturer must use the process of hydrolysis to obtain glucose. This is accom- plished by heating starch in a closed digestor, with a minute quantity of muriatic acid. The amount of acid used represents proportionately about a fifth of the same acid contained in the gastric juice. The heating is continued until the starch reaction with iodine has disappeared. At the present time, a pressure of 35 pounds is maintained and the operation at that pressure is finished in about five to ten minutes. On the continent and in England H 2 S0 4 is the agent used for hydrolysis. This is afterwards neutralized with marble dust FOOD INDUSTRIES 135 which with the acid forms an insoluble precipitate. During the process of refining this precipitate is removed. H 2 S0 4 -f- CaCO s — CaSO, -f H 2 -| C0 2 . The American manufacturer prefers the use of HC1 although it is more expensive. With soda ash as a neutralizing agent, common salt is obtained as a residue, and being perfectly harm- less, the manufacturer is saved the trouble of removing it. American glucose therefore always contains sodium chloride. 2 HC1 + Na 2 CO s -~ 2 NaCl + H 2 + C0 2 . After hydrolysis, the glucose solution is filtered to remove small amounts of fat and protein occurring in the starch, and is then decolorized by passing through bone-black, a similar pro- cess to that used in the cane sugar industry. It is then evap- orated to various degrees of concentration. If hydrolysis has been continued until the dry substance in the liquid consists of at least 86 parts of glucose, the product after concentration instead of being a syrup, crystallizes and hardens into a sugar after it has been run into barrels or pans. CHAPTER X. THE SUGAR INDUSTRY. Source. — The disaccharid C 12 H 22 O ia , known as sucrose or sac- charose, is found in a large variety of plants. It is so apt, however, to be accompanied by the characteristic flavor of the plant, or other carbohydrates, such as starch, glucose or invert sugar, that unless it appears in relatively large proportions and can successfully be freed from the taste, it does not pay commercially to extract it. For the supply of raw sugar the world is largely dependent to-day on the sugar cane and the sugar beet. Sugar-producing plants of lesser importance in commerce are the maple tree, the date palm, the sorghum and the maize. History of the Sugar Cane.— Cane is the primitive source of sugar. Prior to its discovery, many centuries before the Christ- ian era, mankind was largely dependent upon honey as a sweet- ening agent, and the European nations knew little of its use until the 13th and 14th centuries. The original home of the cane was undoubtedly in the east, for mention of it is made in many of the sacred books of the Hindoos and Chinese. Its cultivation was gradually carried westward by the Persians and Arabs, and at the time of the crusades, sugar factories were found in opera- tion in Syria and Palestine. Carried still further westward by the Saracens and Moors the sugar cane was finally introduced into Sicily and Spain. The discovery of America shortly after this period led the Spaniards to carry the plant to the New World, where it was found that it could be successfully grown on the mainland and on adjacent islands. This opened a new field for the growth of the cane and laid the foundation of a great industry. History of the Sugar Beet. — The history of the sugar beet in- dustry dates only as far back as the early days of the 19th cen- tury. A half century before its introduction, the German chemist Margraff had called the attention of the Berlin Academy of Science to the fact, that sugar could be extracted from the beet. This discovery, however, lay dormant until an important histori- FOOD INDUSTRIES 137 cal event cut off the European nations from their supply of cane sugar. South-western Europe, at that time, was involved in warfare and a great continental blockade was established. The nations of Europe deprived of cane sugar searched for another supply to take its place. Sugar from the maple and glucose from the juice of grapes were used but could not supply the demand. A former pupil of Margraff, Achard, finally turned the attention of scientists to the beet, and a long series of investigations fol- lowed which had for its final outcome the birth of the beet sugar industry. It was first established in France by a decree issued by Napoleon, January 15th, 181 1, and was greatly fostered by him until the disastrous Russian campaign. Although the fall of that dynasty interrupted, it did not destroy the industry, and in the course of twenty years it had become of great commercial im- portance. Undoubtedly the great progress in this industry was largely due to the invention of the polariscope which greatly as- sisted in a rapid determination of the amount of sugar present in the beet. About this period German scientists became interested, and through their experimentation, marked progress was made in the cultivation of the beet and in the methods of manufacture, which in time placed Germany at the head of the sugar producing coun- tries of the world. While the beet sugar industry has reached its highest development in Germany it is rapidly becoming an important source of sugar in the United States. Comparison of Cane and Beet Sugar. — Since the time that beet sugar began to assume commercial importance, there has been much discussion in regard to the relative merits of these sugars for use in the household. Scientists claim that chemically they are the same, both having the formula C 12l H 22 11 , yet it has often been said that beet sugar is not as sweet as cane sugar, and that it cannot be used successfully for canning, jelly-making and pre- serving. Experiments along this line were carried on at the Cali- fornia Experiment Station by Prof. G. W. Shaw. The con- clusion drawn from his experimental data was that sugar derived from these two sources give equally satisfactory results both in the household and for commercial purposes. Any differences 138 FOOD INDUSTRIES occurring seemed due rather to processes of manufacture, such as degree of fineness in granulation, rather than to the composition of the sugars. Properties of Sugar. — From the manufacturer's standpoint, there are three important properties to be considered in preparing the raw material for the market; 1st, solubility in water; 2nd, crystallization ; 3rd, production of invert sugar. THE CANE SUGAR INDUSTRY. The manufacture of cane sugar as a rule is divided into two distinct industries: 1st, the plantation where the plant is grown, the juice extracted and made into raw sugar, the form in which it is exported ; 2nd, the refinery where the raw sugar is received, impurities removed and the sugar recrystallized, in which form it is placed upon the market. At the Plantation. — Growth. — The sugar cane belongs to the family of grasses. It can be grown in a variety of climates, but thrives best where it is moist and warm with intervals of hot, dry weather. Such conditions are found near the coast in tropical and sub-tropical countries. Cuba, Hawaii, Porto Rico, the Philip- pine Islands, raise the sugar cane extensively. In the United States this industry is confined to the Gulf States especially Texas and Louisiana. Outline of the Production of Raw Sugar. — Cane cut in the green stage. Cane crushed \ °, . : I crude juice. ~ , . . j ( woody fiber. Crude mice screened < • . J ■> I juice. Juice treated with milk of lime; residue removed. Juice concentrated, a. Boiled down in open kettles. Drained in hogsheads or casks \ ° I muscovado b. Boiled down in vacuum. Separated in centrifuge molasses, raw sugar. FOOD INDUSTRIES 139 Cutting. — When the crop is ready, the sugar cane is harvested by cutting the stalks as close to the ground as possible. Consid- erable care must be given that the plant is cut at the right time, for should it reach maturity, much sugar would be lost to the manufacturer. The sugar cane contains a substance known as pectose which in time changes to pectic acid. The presence of this acid rapidly converts the sugar into invert sugar which is not crystallizable. The sugar planter knowing well the damage this acid will do to his product cuts the cane while it is still green. Fig- 35- — Cane Mill, Philippines. (Courtesy of the School of Mines Quarterly, Columbia University.) At the "green stage," the plant contains the maximum amount of sugar and the minimum of undesirable substances. After stripping the leaves from the stalk and removing the green upper portion, the cane is taken to the mill for the extraction of the juice. Extraction of the Juice. — The most common method used with the cane is crushing by means of heavy mills. Cane-mills of to-day are of various types ranging from the crude ox-driven mill of primitive countries (Fig. 35) to a high power steam-driven roller mill where the most modern machinery can be found. As the cane is received at the mill it is delivered by I/J-O FOOD INDUSTRIES carriers to a high crusher (Fig. 36), which reduces the stalks to a pulpy fiber and extract much of the juice. This mass then passes to a mill composed of three rollers of the same size, set in such a way that the first and second are not so close together as the second and third. The rollers draw the cane within their grip, subjecting it on its passage to great pressure, and causing the rupture of the cells and the escape of more of the juice. A second and third mill are sometimes used, more and more of the juice being extracted by each roll. It is customary to spray the pulp Fig. 36. — Cane Crusher, Hawaii. (Courtesy of the School of Mines Quarterly, Columbia University.) as it passes between the rolls to secure a greater degree of ex- traction. From the roller-mill two products are obtained, the exhausted cane which is called begasse, and the extracted juice which must be purified before it can be converted into raw sugar. Even with modern machinery, the extraction of juice by this method is by no means perfect, — only from 75 to 80 per cent, of the weight in cane juice is obtained. As the sugar cane con- tains approximately 88 per cent, a considerable portion of the sugar is lost in the begasse. Much experimenting has been done to remove the juice from the cane by a method which will involve less loss. The diffusion method used so largely in the beet sugar FOOD INDUSTRIES 141 industry has been tried, but at present is being used in but few of the large plantations in the United States. Purification of the Raw Juice. — The second important step is the purification of the raw juice by straining, to remove bits of cane, and the addition of a clarifying agent. Milk of lime is the agent most commonly used and the mass is heated to boiling. This prevents fermentation, neutralizes the free organic acids of the juice and assists in the coagulation of the dissolved matter. A thick scum of impurities rises to the top of the kettle. This Fig- 37- — Open Pan Kvaporators, Philippines. (Courtesy of the School of Mines Quarterly, Columbia University.) consists of lime salts and albuminous matter and is known as "the blanket scum." The impurities are removed by skimming and by sedimentation and passage through a filter press. Evaporation. — The concentration of the juice may be carried out in two ways: 1st the old-fashioned method of boiling down in an open kettle; 2nd by the use of the vacuum pan. Large open pans or kettles usually made of copper and heated over direct fire are found now, only in primitive countries or on iso- lated plantations (Fig. 37). Their use has been found to involve a great loss of sugar, although the product obtained had an agreeable aromatic taste much preferable to the refined sugar of 142 FOOD INDUSTRIES to-day. It was customary to boil down the sugar juice until the mass began to crystallize. This necessitated a rise in temperature from 212° to 240°-25o° F. and resulted in the formation of caramel and invert sugar which must be looked upon as waste from the standpoint of the manufacturer. After crystallization had reached the desired point, the mass was freed from the syrup by simply being run while hot into hogsheads having fine perfor- ated bottoms, through which the molasses gradually drained out. The light brown sugar obtained as a result of this process was known as "muscovado" sugar. The molasses was very dark in Fig. 38. — Vacuum Pans, Hawaii. (Courtesy of the School of Mines Qucirterty, Columbia University.) color but of excellent quality and without further treatment could be used as a table syrup. In all modern sugar mills, evaporation is carried on in vacuum pans where concentration can be brought about with a lower temperature, i6o°-i8o° F., thus avoiding the losses always oc- curring in the open kettle method. The vacuum pan invented in England in 1813 is a large closed vessel usually made of cop- per containing steam-coils for heating, the vacuum being main- tained by a pump (Fig. 38). Suitable openings are made in the side for the entrance and exit of the juice, a window is inserted where the operation can be watched, and an opening from which FOOD INDUSTRIES 143 samples can be taken and tested. When the vacuum pan was first introduced into this industry only one was used. It has been found of great economic value, however, to use the vacuum evaporators in series of two, three or more, known as the mul- tiple effect vacuum (Fig. 39). When arranged in series, a low vacuum is maintained in the first vessel, a little higher in the second and still higher in the third and so on. The boiling point for each succeeding vessel is thus reduced. When the system is Fig- 39- — Multiple-effect Evaporating Apparatus in operation, the steam arising from the juice in the first vessel passes to the coils of the second vessel and serves as a heating agent. The steam from the juice of the second vessel in turn serves as a heating medium for the third vessel. After the clarified juice has been evaporated to a syrup, it is run into a single vacuum pan known as "the strike pan" when a high degree of vacuum is maintained (Fig. 40). There it is concentrated until the sugar begins to grain. Crystallization is allowed to continue until the pan is full of crystals the desired size. The mixture of crystals and syrup is known as "massecuite." The 144 FOOD INDUSTRIES vacuum is then broken, air is admitted and the bottom of the pan is opened so the contents can be transferred to a mixing ap- paratus where the massecuite is kept in gentle motion. While still warm the mixture is passed to a centrifugal machine which causes a separation of the crystallized sugar and the molasses. Fig. 40. — Vacuum Strike Pan. Centrifugal. — The centrifugal or centrifuge is a hollow iron drum containing a perforated basket (Fig. 41). It can be rapidly rotated during which the sugar mass is thrown against the sides of the basket and the molasses passes through the perforations. FOOD INDUSTRIES 145 The sugar is then bagged and shipped to the country where it is to be refined. This is known as "the first sugar" and the molasses drained from the sugar is called "the first molasses." This molasses may be sold for household use or as it contains much sugar it may be again worked over. This is accomplished by boiling it down in vacuum and again centrifuging. By this means a second Fig. 41. — Centrifugal Machines. (Courtesy of Sugar, Chicago, 111.) sugar and a second molasses are obtained. The second molasses may again be boiled down for a third sugar and molasses. While the third molasses still contains about 30 per cent, sugar, it con- tains so many impurities that the sugar will not crystallize. THE BEET SUGAR INDUSTRY. Growth. — Unlike the cane the sugar beet reaches its highest development in a north temperate climate, although where the soil has exceptionally good qualities, it has been grown success- 10 146 FOOD INDUSTRIES fully in sub-tropical regions, but is not apt to contain as much sugar. Moisture also plays an important part in the production Fig. 42. — The Wild Beet. (Courtesy of Sugar, Chicago, 111.) of a normal crop. The sandy soil, temperature, and moisture near our western rivers in Colorado, and neighboring States, furnish satisfactory farm land for this industry. Beets can also FOOD INDUSTRIES 147 be grown successfully in irrigated areas and large tracts of waste land it is hoped may be utilized in this way. Much experiment- Fig. 43.— The Sugar Beet of To-day. (Courtesy of Sugar, Chicago, 111,) ing is being done in regard to the cultivation of the beet, and great improvement has been made especially in increasing the sugar content (Figs. 42 and 43). The average percentage of 148 FOOD INDUSTRIES FOOD INDUSTRIES 149 sugar is 13-14 per cent., while on irrigated area it has been in- creased to 16-18 per cent. The yield per acre is still low, not exceeding eight tons, while in Europe twelve to thirteen tons are obtained (Fig. 44). Outune; of the; Production of Raw Bfft Sugar. — Beets are grown, harvested, topped. Washed. Sliced. Diffused j P ul P- ■ - ( crude juice. Crude juice is screened. Defecated. -p.. , f albuminous matter, etc. I juice. Concentratec Centrifuged Concentrated in vacuum, molasses, raw sugar. Topped. — After harvesting it is necessary to remove the tops with a small part of the neck of the beet. The object of remov- ing this portion is to prevent the large accumulation of mineral matter at the top from entering the factory, as it interferes with the crystallization of the sugar. This work in done in Europe as a rule by women and children. In the United States foreign labor is gradually replacing the custom of sending whole families into the field during the harvesting season. Washing. — On entering the factory the beets are first washed to remove adhering soil, sand and pebbles. This work is accom- plished in long troughs, each containing a revolving shaft which carries pins set in the form of a screw. These push the beets along the trough against a stream of water, and the rubbing against one another loosens the dirt which is carried away by the water. Extraction of the Juice. — In considering the method of extrac- tion of the juice from the beet the composition plays an impor- tant part. In the beginning of this industry the crushing process was used similar to that employed with the sugar cane, but was I50 FOOD INDUSTRIES found so unsatisfactory that it has been almost entirely replaced by the diffusion process. Water Fiber, etc Sucrose Invert sugar Mineral matter Nitrogenous matter. Germs acids, etc • . . Wax, fat, etc Composition of the Composition of the sugar cane sugar beet 67-75% 75-85 10-15 4-6 n-16 12-16 Q.5-I-5 0.0-0.3 0.5-1.0 0.8-1.5 0.4-0.6 I-5-2-5 0.2-0.5 0.4-0.8 0.4 0.2 A comparison of these two important sugar yielding materials will reveal marked differences in composition, which make neces- sary the employment of different processes for the extraction of the sugar. The cane which contains a relatively large proportion of fibrous material yields very readily to crushing by rollers, while the beet containing more water and less fiber is reduced to a pulpy mass very difficult to handle. It may also be noted that the beet contains more nitrogenous and mineral matter and less invert sugar than the cane. Slicing. — In order to obtain the best results with the diffusion method the beets are sliced into thin pieces by a machine con- taining revolving knives. These are known as chips in English, corsettes in French and schnitzel in German. The chips after being weighed are run into vessels in which a current of warm water displaces the juice in the beet by the process of osmosis. Foreign matter which is colloidal cannot pass through the cell walls of the beet; the sugar being crystal- line, however, passes out into the water. The Diffusion Battery. — The vessels in which the sugar is extracted are known as diffusion batteries (Fig. 45). They are usually arranged in a series of 10-12 upright iron cylinders called cells which are connected by pipes, the outlet from the top of one cell passing downward into the bottom of the next, and so on through the entire series. The cells can be placed in a row or in a circular position. FOOD INDUSTRIES 151 When ready for operation the chips are fed by means of a swinging trough into the cells through a manhole at the top, and warm water about 140 F. is passed through the system. The circulating liquid remains about twenty minutes in each cell, removes sugar from the beet chips and is passed to the next cell. Heaters or "juice warmers" are placed between the cells to again raise the liquid to the desired temperature. As the juice passes Fig. 45. — The Circular Diffusion Battery. (Courtesy of Sugar, Chicago, 111.) from battery to battery it grows stronger in sugar content. When it has become sufficiently concentrated it is sent to the defecating room and fresh water is passed through the batteries. The process is continued until practically all the sugar has been re- moved from the beet chips. There is rarely more than 0.5 per cent, loss of sugar with this method of extraction. During the sugar season the battery is constantly in use. Being arranged in series it is possible to circulate liquid through from 152 FOOD INDUSTRIES 8 to 10 cells while two are being emptied and refilled with fresh chips. Clarification of the Juice. — The sugar solution known as "the diffusion juice" is almost as black as ink as it comes from the batteries, and must therefore be clarified. This is usually accom- plished by adding an excess of lime, heating, and treating with C0 2 . The lime is converted into the carbonate form and in pre- cipitating carries down much of the impurities which are re- moved by a filter press. The process is usually repeated two or three times or until the liquid is clear. The first carbonation is stopped when the greater part of the lime has been precipitated, but while there is still about 0.1 per cent, of lime in solution. The impurities precipitated with the carbonate of lime are insol- uble in an alkaline solution, but redissolve in a neutral solution. After the first carbonation the juice is filter-pressed to remove the precipitated carbonate of lime and impurities, and then car- bonated a second time to precipitate most of the remaining lime, this time to an alkalinity of 0.02 0^0.03 per cent. The second filtration is usually through gravity filters where only a very gentle pressure is applied. The clear juice is then concentrated in vacuum and separated by the centrifuge into molasses and raw beet sugar, the processes being similar to those used for cane sugar. Raw beet sugar contains substances of decidedly unpleasant odor and taste, due to nitrogenous matter and mineral salts being taken up from the soil by the roots of the beet. It must there- fore always be refined even when modern machinery and up-to- date methods have been used. The molasses obtained can be worked over until most of the sucrose has been obtained. It is very impure, however, from mineral salts and nitrogenous com- pounds which give it so disagreeable an odor and taste that it is never fit for table use. REFINING OF RAW SUGAR. Raw sugars with the exception of maple are now refined be- fore being placed on the market. The refining of sugar was not practiced until about 500 A. D. It first appeared in Mesopotamia FOOD INDUSTRIES 153 and gradually traveled westward, refineries being erected in many of the European countries in the 15th and 16th centuries. As early as 1689 there was a refinery in New York City which is still the center of this industry in the Western World. This in- dustry has gradually grown until public taste now demands a pure white sugar. As before stated, so far as the beet sugar is con- cerned, refining is a necessity since the raw product has a disa- greeable odor and taste. Cane sugar, however, possesses in the raw state a more fragant odor and agreeable taste than in the refined product. Refining sugar is in theory a simpler process than the prepara- tion of the raw product, but it requires great care and attention to details. Experience has shown that it can only be done eco- nomically in very large establishments, which are usually located on a navigable river, where the cargoes can be readily received and unloaded. Refineries are built many stories high so as to take advantage of gravity in passing the solution from one pro- cess to another. An abundant water supply is also a necessity. The process consists essentially in dissolving the crude material, separating the impurities and recrystallizing the sugar. Outline; of the; Refining Process. — Raw sugar washed. Centrifuged j was |l s / ru P- & ( washed raw sugar. Washed raw sugar melted. Defecated. Filtered through bags | J^^ °" Iyiquor bone-blacked. Boiled down in vacuum. Centrifuged ] ( yellow sugar. Washing. — The raw sugar after being weighed is mixed with a low grade sugar solution. This process assists in removing soluble impurities. From the mixing tank the magma of raw sugar and syrup is fed into a centrifuge which is rapidly rotated. 154 FOOD INDUSTRIES The purified raw sugar remains on the sides of the basket and the syrup containing most of the coloring matter, dirt, glucose and gum passes through the perforations. The purified raw sugar is left 99-99^ per cent. pure. The Melter. — The washed raw sugar is dissolved in a melting tank which contains steam coils and a revolving arm for stirring. When the density of the liquid is about 30 Be., it is pumped into defecators or "blow-ups." Fig. 46. — Filter Bags. Defecators. — Here the solution is treated for the removal of such impurities as organic acid and fine suspended matter. Dif- ferent clarifying agents can be employed, such as alum or blood albumin. To a large extent now a treatment with calcium acid phosphate or phosphoric acid and milk of lime is used. The mixture is heated and agitated for about twenty minutes. Soon a flocculent precipitate separates, carrying with it suspended matter and some of the coloring. Filtration. — The impurities are removed by a mechanical filtra- tion through cotton-twill bags enclosed in coarse, strong netting sheaths. They are 6-7 feet long and 5-6 inches in diameter. The open end is tied tightly around a metallic nipple by which the bag is suspended (Fig. 46). The first run of liquor is often muddy and must be refiltered. When the filter bags have become exhausted they are rinsed in several waters. The mud washed FOOD INDUSTRIES 155 out contains about 20 per cent, of sugar part of which can be recovered. Bone-black Filters. — These filters are large cylindrical iron tanks filled with bone-black, a material obtained by the charring of bones and reducing them to a granular form by a crushing process. Bone-black has the power of decolorizing. About one pound is used to one pound of sugar. In passing through these filters the sugar solution loses most of its color, a small amount of ash and organic impurities. It is collected in storage tanks ac- cording to its color and purity. The char in time loses the power of removing color and must be revivified by being washed, drained, dried, put in a kiln and highly heated to expel organic impurities. Vacuum Pan. — The decolorized sugar solution passes to the vacuum pan and is then boiled to grain. Centrifugal. — After cooling, the separation of the sugar and syrup is accomplished by means of centrifugal force. At this stage blue water is sometimes used to give a white appearance to the sugar. The sugar is dried and passed through screens to separate it into grades. It is bagged or barreled to appear on the market as granulated sugar. Sugars are coarse grain or fine grain according to the length of time allowed in crystallizing. When the operation is slow, the crystals are large; rapid crystallization yields small crystals, Block sugar may be made in two ways. I. The boiled mass from the vacuum pan containing syrup ' and crystals of sugar may be drained into conical moulds and allowed to stand for about two weeks. It is occasionally washed by means of a pure sugar solution. The uncrystallized sugar slowly drains off through a small hole opened at the point of the cone. The dried sugar is then cut into cubes. A modified form of this process, which greatly shortens the time, is now being used in Europe and to a slight extent in America. By centrifugal force the cones can be freed in a few minutes from the syrup and the sugar after drying can be cut into blocks. 156 FOOD INDUSTRIES II. Granulated sugar while still moist can be pressed into blocks by an ingenious machine, and gently dried in an oven. Powdered Sugar. — Granulated sugar can be reduced to a pow- der. When very finely ground it is placed upon the market as confectioner's sugar. Yellow Sugar. — The syrup obtained as one of the final products in the refining process contains much sugar and can be worked over for a second sugar and second syrup. Sugar obtained by the treatment of syrups usually appears on the market as light brown sugar ; darker colors are largely low grade sugars. Utilization of the By-Products. — Wherever primitive methods for the extraction of cane sugar are used little thought is given to the by-products. This is not true, however, in progressive countries where modern machinery and methods are employed. Under such conditions the utilization of waste matter is being carefully considered. Such material is obtained as follows: 1st, refuse of the beet and cane ; 2nd, impurities removed in the clari- fying processes ; 3rd, molasses. The beet tops make an excellent food for cattle. They may be dried in the sun or with mechan- ical means or they may be converted into ensilage. The beet pulp remaining in the diffusion batteries, may also be utilized as cattle food in the form of wet pulp where it can be used im- mediately, in the dried state, or after conversion into ensilage. In the cane sugar industry the leafy portion of the cane top is fed to animals, while the bagasse has been utilized mainly, in the past, for fuel purposes. In recent years it has been discov- ered than an excellent quality of paper may be manufactured from bagasse. While very little is being done along that line at present the development of paper manufacture in connection with this industry, may prove of great importance. In both the cane and beet sugar industry the filter cakes ob- tained during the clarifying processes are rich in mineral matter and may be successfully used as fertilizer. Molasses constitutes the most valuable by-product. As it contains a large percentage of sugar which cannot be crystallized with ordinary methods, chemical means are being devised for FOOD INDUSTRIES 1 57 its extraction. Beet sugar molasses contains 50 per cent, of su- crose. By treatment with calcium, strontium or barium hydrox- ides., it is possible to precipitate the sucrose as insoluble saccharate which after filtration may be decomposed and recovered as su- crose. Beet sugar molasses being rich in nitrogenous and min- eral constituents may be utilized for fertilizing material with certain kinds of soil. It is also useful as a cattle food and for fuel purposes. Molasses from the cane industry may be used as a table syrup or for feeding cattle after being mixed with bagasse or such material as bran meal or similar products. In both the beet and cane sugar industries the molasses is used largely for the manu- facture of rum and alcohol. Lesser products obtained through fermentation of cane sugar molasses are acetic, butyric, capry- lic and other fatty acids. Many valuable by-products of a nit- rogenous nature may also be obtained from beet sugar molasses. Maple Sugar. — A sugar and syrup highly prized for confec- tionery and table use can be obtained from the maple tree. In the United States they are made almost entirely in Vermont, New York, Ohio and Indiana. The process is comparatively simple. In the spring when the sap begins to run the trees are bored and the sap escapes into receptacles. It is usually evap- orated in open kettles and allowed to crystallize. The sugar is sold in the raw state, as the delicate flavor so much desired is lost in refining processes. Date Palm Sugar. — In India the date palm yields a low grade crude sugar known as "jaggary." Much of this sugar is shipped to England for refining. Sorghum. — The sorghum cane belongs to a family of grasses resembling the sugar cane. It has been known and valued in China for many centuries. Many attempts have been made in this country in recent years to extract sugar from the sorghum but without great success. The juice contains dextrin bodies which prevent crystallization of part of the sugar. It is used largely, however, for the production of syrup. The stalks can be utilized for the manufacture of coarse wrapping paper and the seeds for fodder. 158 FOOD INDUSTRIES Cane Syrup. — Cane syrup is prepared largely in small mills in our own Southern States by the use of primitive methods. The juice of the sugar cane is extracted, clarified, partly inverted and evaporated until 25-30 per cent, of the water remains which is sufficient to prevent the crystallization of the sugar. Adulteration of Sugar. — With the exception of pulverized sugar very little adulteration has been found 'in the United States on account of the cheapness of the product. Sugar sold in the pow- dered form, however, has been adulterated from time to time with flour, glucose, chalk, silica and gypsum. CHAPTER XI. FRUITS, VEGETABLES AND NUTS. Among the most important commercial food products of the world are found fruits and vegetables. Whenever obtainable wild varieties of fruit seem to have been among the earliest foods used by primitive man and it cannot be told now with any degree of certainty when their cultivation was started. So long a time has elapsed, however, that with a few exceptions the cultivated products of to-day bear little resemblance to the very small, woody, inferior fruits of the wild parent. Whether savage or civilized every nation has also cultivated plants for use as vege- tables and those that are most highly prized are the result of long cultivation, the origin of most being lost in antiquity. Importance in the Diet. — In temperate climates fruits have been used largely on account of the pleasant flavor and the custom has long prevailed to look upon them more as an agreeable addi- tion to the diet rather than as staple food. It has been left to modern science to show the important part that fruit and vege- table acids and mineral salts, especially those containing lime, phosphorus and iron, play in maintaining the chemical equilib- rium of the body. Fruits and vegetables supply the organism with much of the necessary mineral matter in an acceptable form. For percentages of individual ash constituents in the edible por- tion of important fruits and vegetables see Sherman's "Food Products," pages 347-9. The peculiar type acids present produce by combustion bicarbonates which assist in maintaining the alka- linity of the blood, thus having the tendency to correct the ill effects of a diet high in protein. With certain exceptions fruits are mildly laxative due to cer- tain elements which they contain and to the cellulose which acts as a diluent and irritant to the intestinal tract. Many of the ordinary foods are too concentrated ; they lack bulk. This defi- ciency can readily be supplied by fibrous fruits and vegetables, such as primes, figs, apples, berries, lettuce, spinach, corn, beets, squash, tomatoes, cucumbers, etc. Most of these can be con- l6o FOOD INDUSTRIES sumed either in the raw or cooked condition. According to recent investigation some raw or uncooked foods, notably lettuce, tomatoes, celery, nuts and similar products appear to be essential in the diet since certain small components known as vitamins are destroyed during the cooking and canning processes. While not as yet well understood it is now believed that vitamins are essen- tial to health and their absence may be the cause of certain dis- eases, for example, scurvy and beri-beri. Fisher and Fisk* recommend that the diet in middle life should decrease in the consumption of meat and all flesh foods as age advances, and that fruits and vegetables, especially those of bulky character and low food value be increased. From an economic standpoint fruits and vegetables are reason- ably cheap sources of energy when compared with many other- foods. Their agreeable flavor, great variety, comparatively low cost, composition and importance in maintaing the chemical equilibrium of the body place them therefore, among our staple foods, rather than as pleasant accessories in the diet. Definition and Classification. — To define the terms fruits and .vegetables with any degree of accuracy seems almost an impos- sibility. An attempt has been made to differentiate between these two food products by the acid and sugar content, classify- ing those that contain both as fruits, all others as vegetables. On the whole that arrangement does not appear to be as satisfactory as the distinction current at the present day which depends largely on the usage. As a general custom vegetables are con- sumed together with meats, while those products which precede or follow the meal and form a separate course are known as fruits. It is apparent from these customs that fruits are largely considered as appetizers and stimulants of digestion. Fruits are generally divided into three classes: ist, stone, which include peaches, plums, cherries and apricots ; 2nd, seed, such as apples, pears, grapes, oranges, lemons and kindred fruit; 3rd, small, in which berries of all varieties are placed. The principal exceptions to these divisions are melons, cucumbers and tomatoes * How to l,ive, by Fisher and Fisk. FOOD INDUSTRIES l6l which are more nearly allied to what are popularly known as vegetables. Vegetables are usually classed as follows : tubers, represented by the potato ; roots, such as turnips, carrots and beets ; leaves, of which spinach and lettuce are the most important; flowers, which include such foods as cauliflower and Brussels sprouts; stalks, such as celery and rhubarb; shoots, of which asparagus is the most important. Composition. — The composition of a majority of ripe fresh fruit reveals a large proportion of water, a fair percentage of carbohydrates, a small amount of protein, organic acids, essential oils, ethereal salts and mineral matter. On account of the high water content in many varieties it has been suggested that fruits containing 80 per cent, or more be classed as "flavor fruits." This class would include many of the common fruits, such as apples, pears, peaches, plums, oranges and most berries. Fruits with less than 80 per cent, would be known as "food fruits" and would in- clude the banana, fresh figs and grapes. In most of the fruits and fruit products the carbohydrates are the food constituents most abundantly represented. Cellulose always appears giving stability to the structure. Pectose bodies are represented in a great number of fruits and vegetables, for example, green grapes, cranberries, currents and white turnips, the quantity growing smaller as the product reaches the period of ripeness. They give to fruit in the presence of acids the property of forming jelly. Other carbohydrates, such as cane sugar, invert sugar which in- cludes glucose and fructose, and starch occur in varying propor- tions. The flavor of fruit is due partly to organic acids which include malic, tartaric and citric. These acids are found in various proportions and frequently occur as acid salts of potas- sium, sodium o Fruit Products. — Various methods of preserving fruits and vegetables, for instance drying, preserving and canning are treated under the heading of Preservation of Foods and the by- products of fruits, such as the preparation of wines and cider under Fermentation Industries. Candied Fruit. — A wide variety of fruits are now being can- died or crystallized and should belong properly to the class of confectionery. The process used in Portugal, which is one of the most important producing countries, consists in repeatedly boil- ing the unripe fruit in strong syrup, draining after each operation and eventually drying the product on trays in the open air. An- other method frequently employed is boiling the unripe fruit 1 66 FOOD INDUSTRIES until tender, then suspending it in strong syrup, kept concen- trated by occasional evaporation, until the fruit has become al- most transparent. It is next placed in drying rooms until the syrup has crystallized. Jellies, Jams, Marmalades and Fruit Butters. — The preserva- tion of fruits, fruit juices and fruit pulp with sugar has grown to be an important industry in the United States. Jellies are sweetened products obtained by boiling fresh almost ripe fruit or berries in sugar syrup, straining while hot and allowing the clear liquid to cool and solidify. The solid fruit residue may be boiled for some time with additional sugar and water yielding an inferior type of jam. As a rule jam is prepared by reducing the entire fruit to a pulp and cooking in a sugar syrup. Fruit butters are less sweet than jams and usually have the addition of spice or cider. Marmalades are made by boiling the pulp or juice of thick-rind fruits, such as the orange, grapefruit or komquat and portions of their rind with sugar. Apple pulp is frequently added to give the peculiar transparent, jelly-like consistency. NUTSl Nuts as they appear in the market ready for use are in reality the pits of a variety of pulpy inedible fruits yielded by a large number of deciduous trees. It is the custom to dry and remove the pulpy envelope before storage and marketing. The impor- tation of nuts is still important commercially although many of these varieties which were formerly grown exclusively in foreign countries are now being successfully cultivated in many parts of the United States. California especially raises big crops of walnuts and almonds while Louisiana and Texas are noted for pecans. Except for a few varieties, which include almonds, Italian chestnuts and the English walnut, imported nuts are largely products of forest trees. On account of the tough and fibrous nature of the shell nuts survive rough handling in transportation in excellent condition, but it is a mistake to hold the opinion that they need not be protected from the attack of mold, insects and worms by suitable storage conditions. They can be safely car- ried through the winter if held in a cool, dry place, but cold FOOD INDUSTRIES 167 storage at a temperature just above freezing is desirable during the summer months. Composition. — The composition of the edible portion of nuts is evidently not understood by the average consumer. Until com- paratively recent years they have been considered in our coun- try merely as a luxury or something to be eaten at odd times, but fortunately a better appreciation of their food value appears to be gradually increasing. As a result of research work carried on at the California, Maine and Iowa Agricultural Experiment Stations a table has been published giving the average composi- tion of nuts and nut products.* The water content is usually low so nuts must be considered as concentrated food. With the ex- ception of chestnuts which contain notable proportions of starch all nuts consist largely of peculiar fats or oils usually of the drying class, protein and cellulose. Rich in oil are the pecans, Brazil nuts, butternuts, filberts, hickory and walnuts, all contain- ing from 60-70 per cent. fat. In general the nuts are also high in protein surpassing most ordinary animal and vegetable foods in this respect. Varieties which contain over 20 per cent, include peanuts, butternuts, almonds, beechnuts and pistachio. Starch as a rule occurs in small amounts with the exception of chest- nuts, which contain 73 per cent, and beechnuts, pinenuts and peanuts which have about 18 per cent. The agreeable flavor and odor of many nuts are due largely to harmless compounds of the glucoside class for example amygdalin of the almond. Digestibility. — On account of the high fat and protein content nuts are more desirable as the base of a meal rather than as the dessert. Excessive use of nuts at improper times has established for them a reputation of indigestibility which they do not deserve. When eaten in a reasonable manner they yield very satisfactory results but do not entirely replace animal protein. The roasting of chestnuts and other starch-containing forms tends to make them more digestible. The practice of salting almonds and vari- ous other nuts has no influence on their digestibility but modifies the taste making the large proportion of fat more acceptible to the palate. * Farmer's Bulletin No. 332. Nuts and their Use as Food. l68 FOOD INDUSTRIES Nut Products. — In foreign lands nut flours and meals are used in large quantities for preparing bread and cake but as yet they have found little favor in the United States. In general they are prepared from the ordinary edible nuts by blanching, thor- oughly drying and grinding. Nut oils, particularly that of the walnut, beechnut and peanut are highly prized as salad oils in some parts of Europe. South America uses Brazil nut oil for table purposes. Cocoanut oil is used largely in the tropics and in the United States not only for culinary purposes but on a large scale for technical applications. Recently nut pastes have come upon our market and on account of their agreeable taste and nutritive qualities are gaining rapidly in favor. Of these pea- nut butter is the best known. It is prepared by reducing the clean, roasted nuts to a paste by grinding. Salt and oil may or may not be added. On account of the high fat content they are apt to become rancid so are usually marketed in small jars. CHAPTER XII. ALCOHOLIC BEVERAGES. Alcoholic beverages may be classified as follows : f Beer. i Ale Malted fermented <{ -r, 1 j Porter. L Stout. Malted distilled be essential. Unfortunately cold storage poultry is generally thawed before it is offered for sale ; it is far safer for the house- wife to buy such products in the frozen condition. When poul- try is plucked it is very much easier to maintain constant tem- perature conditions, feathers are also apt to gather moisture and dirt. The reason why game is always offered for sale in the unplucked condition is due to the fact that the plumage is very attractive and adds considerably to the appearance of the carcass. In some communities local authorities require that poultry should be stored in the drawn condition but where this custom prevails special care must be taken that the cut surfaces are not contamin- ated. On the other hand undrawn poultry can be kept in storage for several months without danger of intestinal contamination. In fact the objection to undrawn poultry seems to be purely ethical but in any case the duration of the storage period should not be excessively extended. The nutritive value of poultry bears a close resemblance to other flesh foods, ducks and geese being rather more fatty than chickens and turkeys. The composition of the white and dark meat shows a difference in the coloring matter in the dark which also contains a trifle more fat and considerable more extractives. In plucked poultry the waste is less than in any other form of 220 FOOD INDUSTRIES flesh foods except cuts of lean meat. The waste is largely dimin- ished by the custom of utilizing the bony part and the adhering tissue for making extracts or soup. EGGS. Chief among the animal foods used throughout the world are eggs. In most countries hens' eggs are used to the largest extent although those of other domesticated birds, such as ducks, geese, turkeys and guinea-hens, are frequently found on the market. The use of eggs is much more common in Europe and the Orient than in the United States although the custom is gradually grow- ing in our country. As an industry egg production is on a very much firmer basis abroad, some countries furnishing enormous quantities of eggs for export to less favored localities. The custom here is to raise eggs on small farms near the section where they are to be consumed, although the industry has reached large proportions in Ohio, Indiana, Illinois, Iowa, Kentucky, Tennessee, Texas, Missouri and Minnesota. The uncertain quality and con- dition of eggs particularly the lack of uniformity is due to a deficiency in co-operation and a want of satisfactory standards. The market is such at the present time that only a distinction is made between fresh eggs and those which have been held in cold storage. If the eggs have been properly tested before being placed in storage and have not been kept in this condition for too long a period they are more reliable than the so-called fresh eggs of the open market. The practice of stamping the shell is not necessarily a protection since there is no penalty for falsifying dates. The active life of the hen is about a year during which time it is supposed to produce two hundred eggs. The chief difficulty is that the supply is largest during the warmer period of the year and may be entirely suspended or erratic during the cold season. Improper or insufficient feeding also influences egg production. Experiments have been carried on to ascertain the best conditions for increasing and averaging the yield. Hens lay best during March, April, May and June, a season when the ground has thawed and worms and insect life begin to appear. This gives FOOD INDUSTRIES 221 them naturally a supply of food. The great loss during trans- portation is largely due to poor packing and defective shells which have not sufficiently developed on account of lack of lime in the food. Physical Structure. — While the eggs of the wild birds vary greatly in color, tint, and plain or mottled appearance, those of the hen are either brown or white. Through a mistaken idea the difference in hens' eggs has greatly affected the market value, white eggs selling for a higher price in some localities, while other markets give the preference to the brown varieties. Examinations have been carried on at the New York State, Michigan and Cali- fornia Experiment Stations to determine their relative nutritive value. After much experimentation, the conclusion drawn was that there is no basis of fact for such popular belief. "Eggs of one breed whatever the color of the shells, are as nutritious as those of another, provided they are of the same size and the fowls are equally well fed." Composition of the Shell. — The shell or protective coating of the egg is very largely composed of mineral matter. According to Dr. Langworthy 93.7 per cent, is calcium carbonate while mag- nesium carbonate and calcium phosphate also appear in small amounts. Organic matter is present only to the extent of 4.2 per cent. When viewed through a magnifying glass the shell is shown to be very porous in its nature. This allows the evaporation of water and results in the gradual loss in weight of the egg. The decrease in specific gravity therefore furnishes a very satisfac- tory means of judging the freshness of an egg. Brine may be prepared by dissolving 2 ounces of salt in 1 pint of water. A perfectly fresh egg will sink to the bottom in this solution. Ac- cording to the experiments of Siebel, "An egg one day old will sink below the surface, but not to the bottom, when over three days old it will float on the surface, the amount of shell exposed increasing with the age." In marketing eggs, the freshness is usually told by a process called "candling." In a dark room, an egg is held between the eye and an artificial light; a fresh egg appears unclouded, homo- 222 FOOD INDUSTRIES geneous and translucent; a stale egg is cloudy and frequently contains dark spots ; a rotten egg appears dark colored. A sim- ple housewife's test may also be made by shaking an egg held near the ear. The contents of the egg should not move. If a slight movement can be detected it is somewhat stale ; if it rattles the egg is spoiled. Methods of Preservation. — The porous condition of the shell is to a great extent responsible for the^ rapid deterioration of eggs. Bacteria can readily enter and bring about such changes as to make the article unfit for human consumption in a comparatively short time. In early days eggs were always marketed near the source of supply but modern conditions frequently require the transporta- tion for long distances. On account of hens laying more plenti- fully in the spring it is also necessary, in order to secure an even distribution throughout the year, to store eggs for use during the fall and winter months. These facts have led to the study of the best methods of preservation. Cold storage has been found most effective a temperature near the freezing point being usually employed. In order to prevent bacteria from entering, eggs are sometimes coated with a non-porous substance. The most efficient of these has been found to be a 10 per cent, solution of sodium silicate (water-glass). The egg should be carefully wiped with a damp cloth, and either coated or placed in a jar containing the water- glass as quickly after it has been laid as possible. Eggs may also be preserved by the process of drying. Desic- cation may be accomplished by spreading the egg in a thin film on a dry surface, or by passing the product under pressure through drying chambers. Where fresh eggs have been used, and where the process of manufacture is such as to make the product palatable and care has been given to the storage, such a product is wholesome and may be held for a reasonable length of time. Dried eggs are used largely by bakers, in camps and on long expeditions where fresh eggs are not available. Composition of an Egg'. — As the contents of an egg are in- tended by nature to furnish the sole nutrition of the young chick FOOD INDUSTRIES 223 during the process of development, we may expect to find among its constituents, all the elements required for building pur-, poses. In this way it bears a strong resemblance to milk both being a perfect food for the animal for which it is intended. Water, protein, fat and mineral matter are well represented, while carbohydrate is present only in a small amount. The nutritive parts of the white are chiefly protein, largely in the form of al- bumins, and a small amount of mineral matter. Only traces of fat are present. The yolk is rich in fat, protein and mineral mat- ter. The fat occurs in the form of an emulsion, held in suspen- sion by vitellin, a phosphoprotein resembling the caseinogen of milk. Eggs are also rich in sulphur, phosphorus and such ele- ments as calcium, magnesium, potassium and iron in the form of salts. Another important food constituent present in the yolk is lecithin a compound which furnishes the body with phosphorus in a form which can be readily assimilated. The composition of the white and yolk given by Langworthy is as follows : Water Protein Fat Carbohydrate 49-5 15-7 33-3 CHAPTER XVI. THE PACKING HOUSE. Historical.- — The packing industry as it exists to-day was founded about thirty years ago, although packing in a very prim- itive way, has been practiced since the middle of the 18th cen- tury. Starting in the eastern United States, it spread westward and in time concentrated in centers near the source of supply of the raw material, thus saving the cost of freight on the live animal from the ranch to the market. So, naturally, the important commercial and railroad cities nearest the large grazing areas of the west and southwest Chicago, Kansas City, St. Louis, Omaha, St. Joseph, Indianapolis, Fort Worth and others have become the largest packing house centers. Their proximity to the corn belt and their water or rail shipping facilities have also been large factors in the development of the packing industry. The growth of this business has been very rapid. Although of comparatively recent origin it now ranks as one of the lead- ing industries of the United States. It is said to be the largest and most important industry which is strictly American in its conception and development. From the States it is rapidly spreading to most of the new countries of the world. Growth and Breadth of the Industry. — Important factors lead- ing to the rapid growth of the packing business have been arti- ficial refrigeration, concentration and the utilization of by-pro- ducts. In former times packing could only be carried on during the winter months, as meat cannot be kept in good condition for any length of time after slaughtering, unless the temperature is kept low. The introduction of artificial refrigeration has now made it possible to carry on the business throughout the year. Not only has refrigeration become essential in the packing house, but its use during transportation has regulated the supply of meat at all seasons. Where animals were driven or shipped to the place of consump- tion and slaughtered for local demand, the numbers were neces- FOOD INDUSTRIES 225 sarily very small and little thought was given to the by-products. The fresh beef, the hide, the horns and the tallow were the only products used; the remainder was thrown away. This involved a great waste of valuable material. When the packing business became concentrated the large amount of waste matter attracted attention. This resulted in the conversion of animal products that were not fitted for food or for manufacturing purposes into fertilizing material. The fertilizer department once established soon led to the study of the utilization of all by-products. As- sisted by Applied Chemistry, means were in time discovered by which every available part of the animal could be converted into a marketable product. The value of using waste matter which formerly had been an expense to remove is enormous. It has been greatly responsible for the rapid growth and development of the industry. The large modern packing houses consist of many departments, where frequently the by-products are elaborated to the finished articles, so that they go direct to the consumer from the packer; thus we find the high grades of fat being manufactured into butterine in one department, lower grades into soap in another department. The meat canning industry and the manufacture of products, such as beef-extracts, pepsin, sausages, gelatin, glue, lard, sheep skins, feathers and many articles too numerous to mention, are now frequently part of the packing industry. Processes in the Packing House. — Inspection and Slaughtering. On the arrival of cattle, sheep or swine at the stockyards, an inspection is made by a representative of the government and where pathogenic conditions are suspected, the animal is seg- regated and handled separately. A post-mortem inspection is also made on all animals and on all parts of animals, to be utilized as food (Fig. 54). As a rule animals found to be healthy are not slaughtered until the day after their arrival at the packing house, thus avoid- ing any abnormal conditions as over excitement and fatigue. After slaughtering they are bled and the hide, head, feet and internal organs are removed. They are then scrubbed and washed in each part, after which they are removed to the cooler, 15 226 FOOD INDUSTRIES where they hang until ready for shipment or until they are sent to the cutting room for curing, sausage making or canning. Beef are hung far enough apart to admit free circulation of air and the temperature is dropped as quickly as possible to 40°-45° F. where it is maintained for twelve hours, after which it is gradually dropped to 34° -35 F. The temperature is seldom allowed to fall to the freezing point. Fig. 54. — Beef Viscera Inspection. (Courtesy of Armour & Co., Chicago, 111.) Hides, Pelts and Bristles. — As the hide of beef constitutes the most valuable by-product, great care is given to the handling and curing, preparatory to delivery to the tanner. It is removed from the freshly killed animals by skilful workmen, freed from adhering flesh and fat and quickly cooled. A combination of fine salt and rock salt which has been crushed and screened, is FOOD INDUSTRIES 227 spread over each hide and they are piled one above the other. During the curing process which lasts for 25-30 days, more or less shrinkage takes place, after which the excess of salt is re- moved and they are prepared for shipment. The pelts of sheep are also removed after slaughter. When not disposed of while fresh, they are cured by salting and some- times treated so that the wool can be easily removed from the skin. After the slaughter and scalding of swine, the bristles are taken from the back and hams and are cured first by drying, either in the sun or with artificial heat and then by salting. They are used for the manufacture of cheap brushes. At the present time the best bristles are being obtained from Russia and China. Fat. — The second important by-product is fat, which is ex- tensively used for the manufacture of edible products and many useful articles. From the bullock three grades of fat are ob- tained. The first grade yields oleo stock from which by further treatment, oleo oil and stearin are obtained. The latter prod- uct is largely used in the preparation of compound lard. Oleo stock is frequently called butter-fat as oleo oil is one of the chief constituents of butterine. Oleo oil may be sent to a separate de- partment of the packing house to be made into artificial butter, or as raw material, it may be sold to the manufacturer of butter- ine. For this purpose, large quantities are shipped abroad, the greater part going to Holland from which place it is distributed to other European countries. A high grade of fat may also be rendered for edible tallow. This was the type fat used originally in the manufacture of oleo- margarine. For the manufacture of artificial butter see Chapter XIV. A second grade of fat is rendered for ordinary tallow which may be further separated into tallow oil and tallow stearin. Several grades of tallow are known. They may be used in soap making, candle manufacture and in the preparation of glycerin, oleic and stearic acids. Tallow may be utilized for lubricating purposes, being generally compounded with other material. From the sheep, tallow may also be obtained. It is hard and white in appearance and is known as mutton tallow. 228 FOOD INDUSTRIES One of the most important factors in the packing house is the rendering of the fat from hogs. Several grades prepared by different processes are placed upon the market, known as kettle rendered lard, prime steam lard, refined lard and compound lard. The last named product is a substitute for lard and consists largely of cotton-seed oil, oleo stearin and tallow. Kettle-ren- dered lard is the highest grade of household lard. It is generally Fig- 55- —Lard Boiling. (Courtesy of Armour & Co., Chicago. 111.) supposed to be made entirely from leaf lard, but only two-thirds leaf lard is used as a rule, the remaining amount being fat taken from the back. Neutral lard is made principally from leaf lard but by a more complex process (Fig. 55). The Feet. — From the feet of slaughtered animals a valuable oil known as neats-foot oil may be obtained. The bones are sawed, separated from the hoofs,- washed to free them from blood and subjected to live steam. During this process, the bones FOOD INDUSTRIES 229 fall apart and the oil separates. The bones may be ground into meal and the liquid containing dissolved protein may be utilized for the manufacture of glue. The oil which is drawn off is refined and used largely for leather dressing. Bone Products. — From the bones of the head and feet many useful products may be obtained. One of the most valuable is bone-black, which is largely used in the industries for decoloriz- ing, as in the bleaching of sugar, glucose and similar products. A black pigment may be secured also, and used as a pigment for paints and shoe blackings. Some bones are ground and used for fertilizing purposes while others are worked up into knife handles, buttons, combs, fans and many similar articles. Tankage. — Tankage is the name given to the residue which remains in the tanks where meat scraps have been rendered to extract the fat. In former years it was always considered waste material and was thrown away. The operation consists in boiling down the meat scraps, under pressure in a closed tank or "digester," for several hours. After all the parts are thor- oughly disintegrated from the effect of the high temperature, the fatty matter separates from the lean and can be withdrawn through outlet pipes and by the process of skimming. The ma- terial which remains in the vats is passed through filter cloth and pressed, until most of the water and any remaining fat are removed. It is then dried, screened, and used as fertilizer base. The commercial value depends on the amount of ammonia and bone-phosphate which it contains. As the tank water is very rich in material which contains ammonia, it is concentrated to a syrupy consistency in a vacuum pan, mixed with copperas and dried. It is known as "concentrated tankage" and is used for mixing with low grade tankage to increase the percentage of ammonia. Blood. — The blood which flows from the slaughtered animals is conducted through drains to large vats or receptacles, care being given to keep it free from refuse, manure, water and other foreign matter. It is then cooked by live steam until the albumin has coagulated after which it is pressed and dried. Dried albumin may be ground and screened if desired. Albumin is used extensively as a fertilizer. In the textilte industry un- 23O FOOD INDUSTRIES coagulated albumin is used in setting the color permanently in such material as gingham. The fresh drained blood is some- times used in beet sugar refining as a clarifying agent ; it is then known as "sugar house albumin." Mixing Fertilisers. — To make a complete fertilizer phosphoric acid, ammonia and potash must all be present. As only ammonia and phosphorus compounds are obtained from bones, tankage and blood, it is necessary to add a potassium salt, such as potas- sium chloride or sulphate. According to need they are mixed in different proportions and are thoroughly incorporated with a filler as earth or ashes which acts as a diluent, the fertilizer when used alone being too strong for plant life. Glue and Gelatin. — Glue and gelatin can be made from many by-products of the packing industry. The chief sources are the liquids in which have been boiled cattle and sheep's heads, feet, bones, sinews, hide trimmings, calves' heads and pigs'- feet. Many grades may be obtained from fine white gelatin to a low grade dark appearing glue, according to the part of the animal used, the condition of the raw material and the care in manufacture. In order to produce a high grade product, careful attention 'must be given to the raw material in order that decomposition does not set in. Only that which is in a sound, sweet condition should be utilized. It is also essential that a low temperature be used in concentrating the glue liquor, so that scorching and other undesirable changes may not take place. This is accomplished by evaporating the liquid, to the desired density in a vacuum pan from which it is clarified, chilled and run into molds. It is then cut into layers and dried in an oven. In order to dissolve the mineral matter, bones are frequently leached with an acid. By allowing them to remain in dilute hydrochloric (2 Be.) or phosphoric (6° Be.) for three or four weeks, the bones become soft and spongy. They are then freed from the acid by careful washing, after which they are converted into gelatin. Bleaching the bones before cooking the glue liquid is practiced by many manufacturers. Sulphur dioxide is most frequently used, although other bleaching agents may be employed, such as FOOD INDUSTRIES 23 1 zinc sulphate or chloride and peroxide of hydrogen. In addition to bleaching these agents act as preservatives thus preventing decomposition from setting in. Formaldehyde is also used in small quantities as a preservative. Canning of Meat, Beef Extracts, Sausages, etc. — As a rule the canning of meat is carried on as a separate industry. See Chapter XX. It is, however, one of the side issues that is fre- quently found in the packing house, being established with the view of saving a large proportion of meat that would otherwise be wasted, or would be sold at a very low price. In this way many of the cheaper cuts of meat, which are nourishing and healthy, can be utilized. The preservation of meat by hermet- ically sealing has led to still another department within the packing house. In the soaking and cooking of meat part of the water-soluble constituents are dissolved. By concentration in a vacuum pan, these waste liquors together with the bone liquid, may be converted into beef extracts. Fresh meat is rarely used for this purpose among packers, consequently the cost of pre- paring beef extracts by them is very small. For manufacturing processes, see Chapter XV. In the sausage department the packer finds another way of disposing of those portions of meat which are nutritious but not palatable in their original condition. Sausages, bologna, frank- furts, scrapple and similar products are prepared after various formulae placed upon the market. Besides meat from differ- ent parts of the beef and pork, such products may contain corn flour, cracker meal, boiled potatoes, starches and dextrins. These are frequently spoken of as "fillers" and serve to prevent shrink- age in bulk under the influence of heat. A great variety of flavoring agents are added, sugar, salt, white or red pepper, cinnamon, mace, allspice, cloves, coriander, carraway seeds, mar- joram and onions or garlic. Saltpetre and coloring matter, con- sisting of dyes of various kinds, assist in giving a better appear- ance. The use of borax and boracic acid for purposes of pres- ervation is still a common practice. The manufacture of animal casings from the round or small guts, middle or large intestines and bladders, of cattle, sheep 232 FOOD INDUSTRIES and hogs, furnish another example of the utilization of material entirely lost until the establishment of the modern packing house. In order to supply the demand artificial casings are prepared from cellulose to take the place of animal casings. To improve the appearance of casings, to insure against shrinkage and to prevent molding, varnish is sometimes used. It is prepared from shellac, boracic acid, ammonia and water. There is probably more chance for deception in the manufac- ture of these products than in any other form of animal food found on the market. When properly prepared they are highly prized as food products. The frequent use, however, of such material as borax, boracic acid, sulphite of soda, undesirable colorings and excessive quantities of filler, is making the inspec- tion of factories the only safeguard that the consumer has for protection against the adulteration of these products. Minor Packing House Products. — In connection with the pack- ing industry, many other branches may be found, such as the manufacture of chipped dried beef, the curing and smoking of tongues and hams, and the preparation of pharmaceutical prod- ucts from the various organs of slaughtered animals. From the mucous membrane of the stomach of hogs, pepsin is made and a similar ferment known as pancreatin may be obtained from the pancreas or sweetbreads of animals. In a like manner, from the bullock may be extracted cardine from the heart, medulline from the spinal cord, musculine from the muscular tissues and cerebrine from the brain. The thyroid glands of the sheep and the bullocks yield thyroidine. . It is claimed that these extracts from animals are beneficial in the treatment of diseases of human organs similar to those from which the extracts are prepared. CHAPTER XVII. MILK. Fig. 56.— Burnside Farm, N. Y. Source. — Milk is a white opaque fluid which is secreted by the lacteal glands of the female of all animals, which belong to the mammalian class. It is intended by nature to supply nourish- ment to the young, until such a time as it is able to take food similar to that utilized by the parents. In different parts of the world various animals are bred for the purpose of producing milk for the use of mankind. Prob- ably the goat was one of the first animals to supply milk to the human family, and in the rough, hilly districts of Europe, espe- cially in the Swiss Alps, it is still very common. The milk of the buffalo, the camel, the mare and the reindeer is frequently used, while in parts of Europe the ewe has produced much milk for the manufacture of cheese. History does not tell us how the cow came to be developed as a producer of milk, but in most civilized countries where the climatic conditions permit, cow's milk is the sole source of supply. It is not more desirable for human food than the milk of other animals, but in development the cow has shown herself to be able to give the best return for a given amount of care and feeding:. 234 FOOD INDUSTRIES Composition. — Chemically milk is composed of all the essentials necessary to sustain life for a long- period and is therefore fre- quently spoken of as a perfect food. It can only be regarded in this light, however, when utilized by the type of animal for which it is intended. The composition varies in different animals, even in animals of the same species, but the difference is rather in the relative proportion of the various constituents, than in the general prop- erties and composition of the ingredients themselves. The fol- lowing figures will give a general idea of the composition of cow's milk, although a great variation may occur according to the breed, age of cow, period of lactation, amount and character of the food, etc. Per cent. Water 87.2 Total solids 12.8 Fat 3.6 Carbohydrate 4.9 Protein 3.3 Mineral matter 0.7 Water is the largest constituent of the milk containing in solu- tion, semi-solution or in suspension, the remaining ingredients which are known as the total solids. Of these total solids fat is commercially the most important as it is the source of butter and to a great extent cheese. The amount differs more than any other constituent, being low in the Holstein and relatively high in the Jersey and Guernsey. The average should not fall below 3 per cent, and except in very rich milk, it will not exceed 5 per cent. Fat occurs in milk as an emulsion suspended in the milk serum in the form of globules. On account of their specific gravity these globules rise more or less readily to the top, when milk is allowed to remain at rest, and are then known as cream or top milk. Chemically the fat which is known as butter-fat exists in two forms, non-volatile and volatile. The non-volatile or insoluble fats make up about 90 per cent, of the total amount, and consist FOOD INDUSTRIES 235 of a number of fats of which palmitin, olein and stearin are the most important. The characteristic taste and odor of milk and butter are largely due to the existence of certain volatile fats, butyrin, caprin, caproin and caprilin which constitute the re- maining 10 per cent. Of these butyrin is the most important. It occurs in the largest proportion and is the fat which on de- composing yields butyric acid, readily detected in rancid butter. The carbohydrate in milk is known as lactose or milk sugar. It belongs to the disaccharid group as do sucrose and maltose, and is similar so far as its ultimate composition is concerned. The most marked difference is solubility; sucrose and maltose are very readily soluble in water while lactose dissolves with difficulty. Milk sugar therefore does not possess the sweeten- ing power of the other disaccharids and is not apt to pall upon the taste so rapidly. Lactose does not readily yield to yeast fermentation, but under the influence of certain bacteria found in all normal milk, it undergoes partial decomposition yielding lactic acid according to the following formulas : C w H M O n . H 2 — 4 CH 3 CHOH COOH. This change begins in the milk as a rule almost immediately after it is drawn from the cow and continues until 0.9 of 1 per cent, is formed, when further decomposition is checked by the lactic acid. The chief protein of milk is caseinogen which exists in an extremely fine colloidal state in intimate contact with calcium phosphate. Caseinogen will not coagulate on heating, but when subjected to an acid which combines readily with the calcium, it will precipitate in the form of a curd. It is very important com- mercially as it is one of the chief constituents of cheese. Albumin and globulin also occur in solution in milk but in relatively small amounts, approximately 0.5 of 1 per cent, of the total protein. They are essentially the same in chemical composition as the albumin and globulin found in blood and egg. Mineral matter is present in a relatively large amount, 0.7 of 1 per cent, in cow's milk and is utilized mainly for building pur- poses. Small amounts of a variety of salts occur — phosphate 236 FOOD INDUSTRIES of lime and potash, chlorides and sulphates of sodium and potas- sium, with very small amounts of iron and magnesium. Human milk contains much less inorganic matter, approximately 0.2 per cent, being present. It is frequently necessary therefore in infant feeding to modify milk so it will more closely resemble mother's milk. Milk contains several other constituents occurring in minute quantities. Lime occurs in combination with citric acid in the form of a salt known as citrate of lime. It is also rich in various enzymes which assist in the digestion of the protein, fat and milk sugar. For a short period after it has been drawn bactericidal bodies are present. The characteristic color of the fluid is largely due to lactochrome which occurs in varying amounts, and is generally supposed to be intimately associated with the palmitin IMPORTANCE OF THE MILK SUPPLY. Of all our standard articles of food none have received as much attention as the production and handling of milk. The reason for this may readily be seen for it has been found that milk is more apt to be dangerous to health than any common food product. It deteriorates very rapidly and as it is usually taken in the raw state, no protection is afforded the consumer through the process of cooking. The fact that it forms the sole diet of the human being at an immature age makes this problem a very serious one. Should there be any contamination, the child would be liable to take it when least able to cope with a disease. Besides the chemical compounds previously considered, milk contains a large number of bacteria which gain access to it after it is secreted. Unfortunately the warmth of the milk, the fluid condition and the composition make it a most favorable medium for the growth of these micro-organisms. They reproduce very rapidly and unless precautions are taken to inhibit their increase, the number becomes enormously large in a comparatively short time (Figs. 57-58). Through their action, changes begin to take place in the milk constituents and in time decomposition advances so far, that the milk is no longer fit for consumption. Bac t e ri alTe sts OF Creamery Milk i FARMER'S MILK DELIVERED TO CREAMERY SAME MILK AFTER PASTEURIZING lMIN. AT 155' f. SAME MILK. AFTER 5 MINUTES IN CREAMERY Mil K CANS WATER IN WHICH MILK CANS RECEIVE flNAL RINSING MILK FROM SAME CANS AFTER ARRIVAL IN NEW YORK CIT Y NEXT MORNING 5,000,000 BACTERIA PER CC 6700 BACTERIA PER CC 560.000 BACTERIA PER CC. 1.270.000 BACTERIA PER CC 90.000.000 BACTERIA PER CUBIC CENTIMETER Careless Handling NVMILK COMMIT TEE Bacteria Counts Tell the Story of Unsanitary Conditions Fig- 57- Bac t e hi alTe sts OF Creamery Milk i FARMER'S MILK DELIVERED TO CREAMERY same milk after pasteurizing 30 min. AT U5* F SAME MILK AFTER 3 MINUTES IN CREAMERY BOTTLES I WATER IN WHICH BOTTLES RECEIVE FINAL RINSING MILK FROM SAME BOTTLES AFTER ARRIVAL IN N.Y. CITY NEXT MORNING 28,000 BACTERIA PER C.C. 3,000 BACTERIA PER C.C. 3.000 BACTERIA PER C.C. NO BACTERIA 5,000 BACTERIA PER CUBIC CENTIMETER Careful Handling NYMILK COMMirrCC Bacteria Counts Tell the Story op Sanitary Conditions Fig. 58. FOOD INDUSTRIES 239 Diseases from Milk. — The greater number of the germs in milk are harmless excepting the germs of specific diseases, such as tuberculosis, typhoid, scarlet fever, diphtheria and septic sore throat. The most dreaded disease is that of tuberculosis. The bacilli may come directly from the cow affected with bovine tuberculosis, in which case there is a possibility of large numbers being present in the milk when it is drawn from the teats. Such milk when mixed with that drawn from other cows may con- taminate the supply from the entire herd. Expert examination has proved that the disease is as prevalent among cows as it is in the human family especially when the animal has been kept under bad hygienic conditions. Rosenau states* "The fact that bovine tuberculosis is frequently fatal, especially in children, may be divined from the fact that fifteen per cent, of the fatal cases of tuberculosis in children under five years of age that have been studied, were due to the bovine type of bacillus" and "from five to seven per cent, of all human tuberculosis is ascribed to infection with the bovine bacillus." This shows the importance of the care which should be given tO the milch cow and the necessity of making the tuberculin test from time to time. Milk may also be contaminated from persons having pulmonary- tuberculosis or through the contaminated clothing or unsanitary habits of the milker. It is believed that epidemics of diphtheria and scarlet fever have been caused by the milk supply, probably through secondary infection. The great importance of the health and cleanliness of the milker and his family is again shown in typhoid, since the cow does not have that disease. An impure water supply in which milking utensils are washed has frequently been the cause of the spread of typhoid. For this reason no water which is not above suspicion should be used about the dairy, for either drinking or washing purposes. In recent years pathogenic streptococci causing sore throat have been traced to infected milk. Cholera infantum is believed by some authorities to be due to the abnormal increase of bacteria of filth rather than to any one species of micro-organism. That it is due to milk bacteria has * Rosenau — The Milk Question, p. 100. 24O FOOD INDUSTRIES been proved by the fa'ct that the trouble occurs in greatest abun- dance at the season of the year when milk bacteria are most numerous, that it is chiefly confined to infants fed upon cow's milk and that the disease is greatly reduced when care is given to supply pure milk. Necessity for Cleanliness. — Milk easily becomes contaminated, since it is a favorite medium for the development of bacteria and must frequently be carried long distances. Hence cleanli- ness is an absolute necessity in the production and handling of our milk supply. Means should also be taken to prevent the growth of micro-organisms, for even when produced under sani- tary conditions, bacteria in small numbers are always present. Their development may be inhibited by dropping the tempera- ture immediately after milking to 50 F. and maintaining this temperature until the milk is delivered. The importance of per- fect cleanliness and low temperature cannot be over-estimated. Safeguarding the Milk Supply. — To safeguard the supply laws have been passed by the city and state governments, which while differing in detail, contain the same general rules. As regards composition milk must not contain more than 87-88 per cent, water and should contain 12-13 P er cent, total solids of which 3 per cent, should be fat. It must be guarded from producer to consumer, by surrounding it with sanitary conditions and a temperature sufficiently low to prevent rapid growth of micro- organisms. The addition of borax, boracic acid, salicylic acid, formaldehyde or other preservative is forbidden. Some cities also have a law in regard to the bacterial count but this has been found impracticable in large communities. Because of its wide usage as a food milk is more closely supervised than other articles in the diet. It is inspected at the farm, at creameries, during transportation, at receiving stations and in distributing centers. Regulations are now more or less enforced affecting surroundings where milk is produced. The water supply must be above suspicion. The utensils should be heavily tinned and seamless. They should be subjected each day to a thorough washing and if possible to live steam or exposure to sunlight. The stables should be light, well ventilated and fre- FOOD INDUSTRIES 24I quently whitewashed. No utensils, feed or other animals should be kept in the stables. Bedding and manure must be daily removed. The cow should be healthy and kept as clean as pos- sible. The milker and dairyman's family should be free from contagious disease. The milk should be drawn through a small mouthed sanitary milk pail and cooled immediately. During the journey to the consumer milk should be kept out of contact with air and should be iced. Sanitary conditions should also prevail where it is distributed. Although the state may control more or less the supply of milk from the producer to the consumer, once in the hands of the housekeeper, the law is powerless to control the handling of milk. Too frequently through ignorance or utter carelessness, milk which has been carefully handled by farmer and distributor is ruined by the housewife. It is as much her duty to see that milk is guarded carefully as it is of those who have handled it before her. The following hints to housekeepers have been con- tributed by some of the students of Teachers College : Buy only for daily use ; buy bottled milk whenever possible ; when milk must be bought from an open can, use a covered receptacle to put it in, such as a glass fruit jar; do not transfer bottled milk to another receptacle ; on receiving wash the top and outside of the bottle thoroughly and place at once near the ice in the ice box; do not mix old and new milk; since milk absorbs odors do not put it near strong smelling food ; keep well covered at all times ; when the bottle is empty rinse with cold water, wash thoroughly with hot water and set to drain away from dust; do not use milk bottles for any other purpose; if there is a contagious disease in the family until the danger is over, place a clean covered con- tainer where the milkman may pour the contents of the milk bottle which he is delivering into the container, or keep all bottles delivered during the period of illness before returning, at which time they should be thoroughly sterilized ; general rule — keep milk cold and free from dirt. Our Duty to the Producer. — As the study of the milk problem advances more and more has been required of the producer. The law now demands that cows must be in a healthy condition, 16 242 FOOD INDUSTRIES that old barns and surroundings must be cleaned or new barns built, stables must be whitewashed, the water supply must be examined, new utensils must be bought and more care must be given to cleanliness, which means more labor at an additional cost. These requirements have greatly added to the cost of the production of milk, and the farmer can no longer supply milk at a profit for the same price as when unsanitary conditions pre- vailed. The advance in price should therefore be cheerfully borne by the consumer who is receiving a far better product to-day than in years gone by. Testing of Milk. — Milk is usually tested by the lactometer which registers the specific gravity, and by the Babcock test which gives the percentage of fat and also assists in the detection of formaldehyde. The estimate of the amount of water and total solids is made together with the bacterial count. For further information in regard to these tests see a standard work on milk as Milk and Its Products by Wing, The Production and Handling of Clean Milk by Winslow, Harrington's Practical Hygiene, or Van Slyke's Methods of Testing Milk and Milk Products. Sterilization. — Even with ordinary care milk contains a large number of bacteria which multiply rapidly. As previously seen they may be a harmless type or those of specific diseases. These troubles have led to the treatment of milk by heat the oldest method being that of sterilization. As sterilization means the destruction of all micro-organisms, it is necessary either to hold milk at a temperature of 248 F. for 15 minutes or to raise it to the boiling temperature on three suc- cessive days. This insures not only the destruction of bacteria but spores of a highly resistant type and renders the milk practi- cally sterile. If air be excluded such milk can be held indefi- nitely. While undoubtedly this is the most effective method of protecting milk against bacterial decomposition, it unfortunately so alters the composition as to make it more difficult to digest. This has proved so serious an objection that sterilization has been practically abandoned in America, and either pasteuriza- tion or the use of clean raw milk has taken its place. FOOD INDUSTRIES 243 A B C Fig- 59.— Pasteurization of Milk. The milk passes from the receiving tank (A) through the clarifiers (B) to the pastuerizer (C) where it is heated to 145 F. It is then con- ducted to the holding tanks (Fig. 60). (Courtesy of the Sheffeld-Farms-Slawson- Decker Co.) "WHan*^ . S: ;:--•■- I hm 1 / ' : >:r*-'- ■'';:' : I ! !_ . ■ _ ■ • W~r ' •*'" ..." ^*^ '1 ' - ; '"_T r ~# [ J' Fig. 60.— Holding Tanks. Milk heated to 145 F. is conducted successively to four holding tanks where it is held for fifteen minutes in each tank. At a temperature of about 142 F. it passes back through the pasteurizers and is rapidly cooled. (Courtesy of the Sheffield-Farms-Slawson-Decker Co.) 244 FOOD INDUSTRIES Fig. 6 1. —Milk Coolers. (Courtesy, of the Sheffield-Farms-Slawson-Decker Co.) Fig. 62. -Milk Bottling Machine. (Courtesy of the Sheffield-Farms-Slawson-Decker Co.) FOOD INDUSTRIES 245 Pasteurization. — The term pasteurization means the heating- of milk below the boiling point, from 140 to 160 F., followed by rapid cooling (Figs. 59-62). This method was named from Pas- teur who suggested its use in 1864 for the preservation of beer and wine. It was not, however, until 1886 that the process was applied to milk. It differs from sterilization mainly in the degree of heat to which bacteria are subjected. All micro-organisms are not destroyed by this method so pasteurized milk will in time decompose. It has been found, nevertheless, that from 95 to 98 per cent, of bacterial life and practically all of disease bacteria have been rendered harmless, so milk thus treated can be kept from souring from twelve to twenty-four hours longer. If milk has been kept for a period before pasteurization, poisons may have been formed in it which heat will not destroy. It is there- fore absolutely essential that only clean, fresh milk should be pasteurized. The process can in no way take the place of clean- liness and should never be used to atone for unsanitary methods in the production and handling of the milk supply. If a low temperature has been used pasteurizing does not injure milk so far as its nutritive value is concerned and it af- fords a certain protection against such diseases as tuberculosis and typhoid which have been previously discussed. Certified Milk. — The term is intended to signify that the milk is certified as to its quality and wholesomeness by a medical milk commission. While pasteurization properly carried out has greatly assisted in safeguarding the milk supply of large cities, where enormous quantities must frequently be carried long dis- tances, it is by no means ideal. It frequently means a purified rather than a pure milk. This has proved satisfactory for or- dinary household purposes and for adults, but in infant feeding nothing can take the place of pure raw milk produced under ideal conditions. A standard of excellence has been fixed by medical commissions and milk which can satisfy these require- ments is sold under the name of certified or guaranteed milk. The bacterial count must be low, and it must possess the other characteristics of pure wholesome milk. This can only be se- cured by perfect cleanliness in regard to the dairy methods, 246 FOOD INDUSTRIES care of the cow, and health of the milker. To comply with sanitary regulations means an excess cost to the producer, so certified milk may be sold at a higher price. Such milk is fre- quently sold under the special name of the dairy, as Walker- Gordon milk. Modified Milk. — As the composition of cow's milk differs from that of human milk, being higher in protein and mineral matter and lower in milk sugar, it is frequently found necessary to change the composition of cow's milk to more nearly make it resemble that of the human being, or to give a milk of known composition especially adapted to the particular needs of the infant or invalid. Water, barley water, lime water or dextrin- ized gruel may be used as a diluent and cream and milk sugar may or may not be added. Such a product is called modified milk. All precautions stated above for the production and handling of clean milk as well as the requirements of the certifying Medical Society should be observed in producing modified milk. CHAPTER XVIII. MILK PRODUCTS. Condensed Milk. — The importance of milk in the diet and the rapid deterioration even under the most favorable conditions, have led to much experimentation along the line of its preserva- tion for a long period. In the early part of the 19th century an attempt was made to hold milk indefinitely by reducing the percentage of water. As a high temperature was used in the condensing process the result was a boiled milk, the composition of which greatly differed from the raw material. Lactose like any other sugar caramelized in time and gave to the finished product a dark color and a bitter taste. Lime salts, so necessary in the digestion of milk, were thrown out of solution and the protein matter was much altered in composition. The process proved a failure. It was not until 1856 that another attempt was made to pre- serve milk by condensing it. At that time Gail Borden was granted a patent "On a process for concentrating milk by evapo- ration in vacuo, having no sugar or other foreign matter mixed with it." The Borden process reduced the temperature to 160 F. and eventually resulted in placing a satisfactory product on the market. Although the early days of the condensed milk business were full of discouragement to the manufacturer, the industry has now grown to enormous proportions, rapid strides having been made during the past ten years. This shows great increase in the consumption of condensed milk not only in countries where the breeding of the cow is impossible, but also for use on ocean liners, in the navy, lumber and mining camps and in home markets. The successful condensing of milk requires that the raw material be produced under the best hygienic surroundings, and invariably the dairy conditions will be found to be in a high state of development, wherever milk is being treated by the con- densing process. There are two classes of condensed milk, sweetened and un- sweetened. 2 4 S FOOD INDUSTRIES FOOD INDUSTRIES 249 Process. — When milk is received at the factory it is tested, filtered to remove dirt, and quickly sterilized by raising the temperature of the milk to the boiling point. Sugar is added to the extent of about 16 pounds to ioo pounds of milk. The sweetened fluid is run into a vacuum pan and kept at a tempera- ture of approximately 130 F. until it is condensed about two and one-half times. When sufficiently concentrated it is run into 40 quart cans which are surrounded by ice. During this opera- tion which lasts one hour, the milk is constantly stirred with paddles after which it is immediately run into tin cans, capped, labeled and boxed. While not sterile this product will keep for a long period. The long continued heat should destroy most bacteria and the addition of sugar acts as a preservative. An unsweetened condensed milk meant for immediate use is put on the market by many condensing companies. The process of manufacture is essentially the same, with the exception that no cane sugar is added, and the concentration is a little over three times. It is usually sold in glass jars capped with paper caps, similar to fresh cream, and will remain sweet and fit for consumption as long as fresh cream. Evaporated Milk. — Evaporated milk is an unsweetened con- densed milk sold in hermetically sealed cans. As no cane sugar is added it depends entirely on sterilization for its keeping quality. The raw material is held in heating wells for ten to twenty minutes, then is run directly into the vacuum pan where it is concentrated two and a quarter times. After cooling the evaporated milk is immediately put into cans and sealed. The hermetically sealed cans are sterilized at a temperature of 235 ° F. for one-half hour. While cooling they are subjected to shakers to mix the jelly. This agitation breaks up any coagulum which may have formed during sterilization. The cans are finally placed in a curing room where they are kept for thirty days, after which they are examined before being placed on the market. As this product is sterile it will keep indefinitely. Concentrated Milk. — The Campbell process of concentrating milk has placed upon the market in recent years a small amount of milk, relatively free from bacteria, and which can be pur- 25O FOOD INDUSTRIES chased at the price of ordinary milk. The best fresh milk which can be obtained is used. After being tested the raw product is put through the centrifuge, in order to clarify it from stable dirt and to separate the cream and skim milk. The cream is pas- teurized, while the skim milk is heated for two or three hours at a temperature of 140 F. during which a continuous blast of filtered air is driven through it. Evaporation is continued until three parts of the original product is condensed to one part of the concentrated skim milk, after which the pasteurized cream is added. The product is placed upon the market in small bottles to which three parts of water must be added to give the original consistency. On account of the low temperature used, concen- trated milk has not materially changed in composition and after the addition of water, it appears to have the properties of ordi- nary fresh milk. According to Professor Conn the method of using combined heat and aeration destroys most of the bacteria, especially those of specific diseases, and gives a relatively safe milk even for infant feeding. On account of its concentration such milk when kept below 50 F. will last for a week or ten days. Milk Powders. — The process of reducing milk to the powdered form has become quite an industry in recent years. To obtain a successful product, the milk must be desiccated at a low tempera- ture in order to prevent chemical change from taking place. This is frequently accomplished by drying in a thin film on metal plates in vacuo. The resulting creamy white mass will unite readily with water to give the original consistency of the milk. On account of the fat, powders prepared from whole milk will not keep indefinitely unless placed in cold storage; those from skim milk have been found more satisfactory. They are used to a large extent for cooking where fresh milk cannot be obtained. Market Cream. — Cream is the fatty constituent of milk. It may be separated by the same methods as are used in butter-making, namely gravity and centrifugal force. When obtained by the use of the separator, which method is employed in practically all large dairy industries, less loss is involved, time and labor are saved and the product obtained is cleaner and richer. Sep- FOOD INDUSTRIES 25 1 arator cream will also keep longer since it does not contain so much of the entangled caseinogen. The composition which is based largely on the fat content is variable. The U. S. Standard cream must contain not less than 18 per cent, of milk fat but State standards vary from 15-20 per cent. Cream obtained by centrifugal force can be made to vary from "very light" as low as 8 per cent, to "very heavy" as high as 70 per cent. A good quality for commercial purposes contains from 18-25 P er cent, and very rich cream from 35-40 per cent. fat. The Commission on Milk Standards requires that no foreign matter be added, cream should contain only the ingredients of normal milk. In addition to preservatives, gelatin and calcium saccharate (visco- gen) have been used to increase the consistency of a low-grade product. Cream should be kept under the same conditions as have been recommended for sanitary milk. As it is generally ten or twelve hours older than the corresponding grade of milk the bacterial count is apt to be considerably higher, about five times the amount is allowed. Ice Cream. — The term ice cream as commonly used is applied to a variety of products prepared from frozen milk or cream. In the mountainous regions of the Far East sweetened fruit juices in a frozen condition known as sherbets were in common use in early ages. The custom of eating these frozen products was in- troduced into Europe by the Moors and the secret of their prep- aration became common property of the Spaniards and natives of adjacent countries. Ice cream as a frozen milk product was developed in the northern part of Italy, was carried from there to France and finally appeared in England during the reign of Charles II. In the latter part of the eighteenth century ice cream was publicly sold in New York City and one of the largest of the existing concerns began business in the same city in the early part of the last century. About sixty or seventy years ago frozen products made from cream with the addition of sugar and flavoring agents became known under the name of Phila- delphia Ice Cream. In contrast to that product mixtures of milk and sugar with eggs, boiled starch, gelatin, casein or similar substances were called Neapolitan Cream. Within the last ten 252 FOOD INDUSTRIES years a compound intermediate between the sherbet and ice cream known as Lacto or Sour Milk Ice Cream was introduced by Mortensen. The manufacture and consumption of these products have in- creased in enormous bounds due largely to the practice of com- bining ice cream with soda water especially during the heated season. In some localities creameries now find it more profitable to convert their product into ice cream rather than into butter. Standards at present call for 14 per cent, butter fat but if the product is to be mixed with nuts, eggs or other highly nutritious matter a lower per cent, of cream can be used. While it is advisable to maintain a high cream standard it is far more im- portant to be certain of a low bacterial count. To ensure safety some manufacturers pasteurize cream. This practice does not, however, eliminate the danger should ptomaines be present in the product due to unsanitary conditions. BY-PRODUCTS OF THE BUTTER INDUSTRY. The chief industry using milk is the butter industry which has been described in Chapter XIV. The most important by- products of this industry are mentioned below. Skim Milk. — For butter-making the fat is separated from whole milk very largely by the centrifuge. With this method only a trace of the other constituents is removed with the fat; this leaves the skim milk rich in protein and carbo- hydrate. As skim milk contains all the normal ingredients of ordinary milk except fat, it can very readily be used for cooking purposes, or as a beverage for people who find cream hard to digest. As the law, however, frequently forbids the selling of skim milk, it has been utilized to a great extent for cattle food or in many cases thrown away. This is a waste of valuable ma- terial for the protein and lactose can be recovered by the follow- ing comparatively simple methods. Dried Casein. — The skim milk is run into a vat and a small amount of sulphuric or acetic acid is added. This precipitates the caseinogen in the form of a curd which can readily be removed from the whey, washed, pressed, dried and sold as FOOD INDUSTRIES 253 dried casein. It is used in the paper, leather and textile indus- tries, as an ingredient of paints, glues, and cement, for the manufacture of imitation ivory articles and as several forms of concentrated food. Milk Sugar. — After the removal of the caseinogen the water may be evaporated (over hot water) from the whey until the lactose crystallizes. It is generally reduced to the powdered form and is much used in pharmacy and for infants' and invalids' food. Buttermilk. — Buttermilk is the fluid which is left after churn- ing in the process of butter-making. It is commonly used as a food for young calves and pigs, and as a beverage, esepecially during the summer months. The chief points in which it differs from milk are poverty in fat and increase in acidity, due to the formation of lactic acid which rarely exceeds 0.5 per cent. But- termilk is comparatively easy to digest on account of the absence of fat and the changed condition of the caseinogen which exists in a finely flocculent form. Artificially Soured Milk. — A milk which has been artificially soured by the addition of lactic acid ferments can now be found on the market, or can be prepared at home; it has been highly recommended by Metchnikoff. The product is prepared by pasteurizing pure fresh milk. The temperature is then lowered, cultures of lactic acid bacteria are added, the mass is held at ioo° F. for several hours, is then bottled and sold under a trade name. CHEESE. Historical. — Cheese has been known as a valuable food for at least one thousand years before the Christian era. It is believed to be one of the oldest products manufactured from milk and probably owes its origin to the accidental storing of milk curd. In the early historic days of the Roman Empire, cheese formed an important article of diet and is still used as a chief source of protein by the Italians as well as many other European nations. It is largely manufactured at the present time in France, Italy, Germany, England, Switzerland and Holland. The Americans produce large quantities of cheese especially in New York and 254 FOOD INDUSTRIES Wisconsin, but do not as a nation consume as much as the Europeans. The industry in America was started in a small way, prin- cipally by immigrants who sought to earn a livelihood in the New World by the same occupation that they had carried on in their native land. This is particularly true of the cheese indus- try in Wisconsin, which owes its origin to the settlement of twenty-seven Swiss families during 1845, m the rough hilly country of Greene County. For a long period the wives and daughters of the home were the cheese makers, but like many other industries, it was gradually transferred to the manufac- turer. The product is prepared from milk by processes which elim- inate water, and gather a large part of the solids together, in such a form that the nourishment is retained and capable of being preserved for varying periods of time. Many varieties are made at the present time. Cow's milk supplies most of the raw material, although the milk of the ewe and goat is used largely abroad for the manufacture of certain well known cheeses. As a rule milk is used in the natural condition and the product is then known as whole-milk or full cream cheese. Cream cheese is made from milk and cream, while skim-milk cheeses are manu- factured from milk from which part of the fat has been re- moved. Whatever the kind of milk used the general process of manu- facture is the same. The raw material must be treated in such a way as to precipitate the caseinogen in the form of a curd. This may be accomplished in two ways ; by the natural develop- ment of lactic acid and by the addition of rennet. The first variety known by some such name as pot cheese or cottage cheese is not a true cheese, as it has been prepared without the use of rennet, which is essential in cheese-making. This type cheese is prepared more frequently in the home, is soft in texture and has poor keeping quality. The second variety represents the many kinds of domestic and foreign cheese found in the mar- kets. FOOD INDUSTRIES 255 Composition of Cheese. — Generally speaking the composition of cheese is about from one-third to one-quarter each of water, fat and protein, with a small amount of mineral matter. The protein is largely predigested having been changed to casein by the action of rennet. Only a small amount of unchanged caseinogen can be found while in many well cured varieties, through the action of micro-organisms, part of the casein has been further changed to meta-protein, peptone and amino-acids. The mineral matter consists of the salts of milk with a small addition of common salt to improve the flavor. Cheese-making. — The large cheeses found in the American mar- ket are prepared by processes more or less copied from the Eng- lish Cheddar Process. Cheddar cheese was first made in the village of Cheddar, England, about 250 years ago. It has grad- ually grown in popularity until the manufacture has now spread over the civilized world. Process Used in Cheddar Cheese. Straining milk. Ripening— (82 ° -86° F.). | Mixing rennet. I Clotting. Cutting. j. Stirring. Cooking 98 F. Removing part of whey. Cheddaring or matting. Grinding. Salting. Pressing. Curing. The preliminary treatment of milk is of the greatest impor- tance. Successful cheese-making depends to a great extent on the purity of the raw material. Great losses are frequently caused by carelessness in the production and handling of the milk supply, for the quality of the milk in respect to cleanli- ness, determines largely the quality of the product that can be Under the influence of the lactic acid fermentation. J 256 FOOD INDUSTRIES manufactured from it. The same cleanliness should be observed as in the production of market milk, clean and healthy cows and milkers, sanitary conditions of stable, utensjls and other appara- tus. Special attention should be given that no odors can be absorbed from manure, pig pens or silos, and that the cow has not eaten strong smelling food, such as onions, garlic and the like. As quickly as possible after being drawn from the cow milk should be strained and cooled. To assist the escape of volatile matter, it is sometimes aerated by being poured through the air from one container to another. Stirring also helps the escape of animal odors as well as prevents the cream from rising to the top. As lactic acid is desired milk is allowed to ripen either naturally or by the addition of a starter, at a temperature of 82 - 86° F. Tests are made from time to time until the desired acidity has been developed. The milk is then run into shallow rectangu- lar tanks, so arranged that they can be readily tilted, and contain- ing pipes through which hot water can be circulated. A tem- perature of about 85 F. is maintained. While heating the milk is constantly stirred with paddles to prevent the cream from rising to the top. If any coloring matter is to be added it is put in at this time. When thoroughly mixed and of the desired temperature, the coagulative agent rennet is added, the mass is again stirred for a few minutes and is then allowed to rest. The active principle of rennet is found in the lining of the stomach of milk fed animals. As a rule it is obtained from calves although it has been taken from pigs and puppies. Through the action of rennet, the conjugated protein caseinogen is split into simple proteins, casein and pseudo nuclein, thus making cheese a predigested food. The activity of rennet is greatly assisted by keeping the mass at body temperature, and by the successful ripening of the milk in an earlier stage. The clot or curd as it is known to the manufacturer, forms in about ten to fifteen minutes, but is usually allowed to stand one-half hour before it is put through the process of cutting. The mass is then firm enough to break with a clean fracture, when gently pressed with the finger. Until recent years, the curd was simply broken into irregular FOOD INDUSTRIES 257 pieces with the hand or some instrument, in order to allow the escape of the whey. Experimentation has proved that there is less loss in the fat content if the curd is cut into uniform pieces. The process is now carried on by curd knives which cut the mass into small cubes. As the whey makes its escape, the cubes sink to the bottom of the vat and are kept from uniting by a gentle agitation of the entire mass. In order to facilitate the further separation of the whey, the temperature is raised to 98°-ioo° F. This shrinks the curd until it is about one-half of its former size and causes the development of more lactic acid. When sufficient acid has developed the whey is again removed and the curd is allowed to mat together (ched- daring), various changes taking place during the process. The curd is then ground, in order to reduce it to particles of con- venient size for receiving the salt and pressing into shape. The salt is added principally to give flavor. It has, however, another influence, for salt having a great attraction for water, the curd is hardened. The mass is next put into a press for twenty-four hours to give it shape. After being taken from the press the curd is put into the curing room, where it undergoes fermentation for four or six weeks or longer. During this time the cheeses are turned at frequent intervals and are rubbed on the outside with whey butter, a fatty liquid which rises to the top of the quietly standing whey. Curing. — As cheese is not eaten for its nutritive- value alone, but more frequently for the strong appetizing taste, this part of the process is most important. It consists in subjecting the cheese to the action of micro-organisms, which in their desire for food, decompose material giving rise to characteristic flavors During this series of fermentations which are not altogether understood, gases develop which cause holes to be formed in the cheese. The ripening process is carefully guarded as to temperature so it will not proceed too rapidly or too far, in which case putrefactive fermentation is apt to set in. As much of the success of cheese-making depends on the curing, bacteria and molds are now being carefully studied in connection with this industry. Methods once established by 17 258 FOOD INDUSTRIES which ripening can be controlled, will insure a uniform product, an extension of the manufacture of certain varieties of cheese, and a saving of much money to the industry. For information in regard to the manufacture of well known cheeses, such as Roquefort, Edam, Camembert and Brie, see a standard book on dairy products, Milk and Its Products by Wing or The Practice and Art of Cheese-making by Van Slyke and Publow. Uncured Cheeses. — Several varieties of soft uncured cheeses may be found on the market, of which Neufchatel and Philadel- phia cream cheese are the best known. They are prepared by coagulating ripened milk with rennet, allowing the 'curd to de- velop a mild acidity, after which the surplus moisture is re- moved by drainage and pressure. The curd is then ground, salted, molded into shape and wrapped in thin paper and tinfoil. Adulteration. — The only extensive form of adulteration prac- ticed is the substitution of lard for the usual amount of fat. Lard and skim milk can be mixed together with coloring matter, put through a process to emulsify the lard, after which reg- ular processes of cheese-making can be carried out (filled cheese). Although adulteration has not been practiced to any large extent, much misbranding of cheese has been discovered in the United States. Cheese manufactured in this country has been frequently found to bear a label conveying the impression that the article is of foreign make, also, that the cheese has been made of cream and milk, when only whole milk has been used. CHAPTER XIX. PRESERVATION OF FOODS. Methods used in preserving food material may be classified as follows : Physical Chemical Use of Preservatives ( Drying. -j Cooling. (_ Sterilization and exclusion of air. f Sugaring. | Salting. { Smoking. j Use of fats and oils. (^ " " spices. Borax and boracic acid. Sulphurous acid and sulphites. Benzoic " " benzoates. Salicylic " salicylates. Formaldehyde. Peroxide of hydrogen. The attempt to preserve food material has been practiced from the earliest ages, many centuries before the cause of decay was understood. This custom undoubtedly arose from the desire to hold provisions obtained in a successful chase or during an abun- dant harvest, for periods of famine, inclement weather, or for use at other seasons. Modern life is making this subject of vast importance, for the crowding of people into large cities neces- sarily means the carrying of food for long distances, and present habits of living demand the open market for twelve months in the year. To meet this problem, bacteriology has been called upon to make plain the habits of the micro-organisms, which live on food and are the cause of the decay. DRYING. Drying is the oldest and simplest method the principle being exclusively the withdrawal of water. Mold can live on a very small amount of moisture for it is frequently seen growing on damp floors, walls, cloths, food and the like. Bacteria demand considerable water and will not grow unless well supplied. They 260 FOOD INDUSTRIES need a medium that is practically liquid for they are only able to absorb food in a fluid condition. Many types of bacteria will cease to grow when the amount of water falls to 30 per cent, and all stop developing when it is below 25 per cent. Nature uses this method of preservation for when grain is ripening much of the moisture which was present in the green stage gradually disappears, leaving the mature grain shriveled and dry. If this were not so putrefaction would soon take place. Much of our food material classed as non-perishable — cereals, starch, sugar, flour and meal — is preserved in this way. That they are good food for micro-organisms can readily be seen by their rapid decomposition when water is added. Drying seems to be very much better adapted to fruit and vegetables than it does to protein matter. The class of sub- stances known as dried meat and fish are simply reduced to a more or less dry condition after which another method of pres- ervation is added. This may consist in the addition of salt, sugar or other harmless preservative, or the product may be smoked. These cases will be referred to in detail under their special heading. In early days sun-drying was used entirely and only surplus crops were preserved. The disadvantages of the old-fashioned method were loss of flavor and color, due to oxidation or en- zyme action; and contamination of the freshly exposed surfaces by the dust of the atmosphere and insect life. Certain fruits such as grapes which are commonly dried intact are still cured by this method owing to the protection of the tough skin and the pres- ence of organic acids. Modern methods in the production and drying of fruit have led to an enormous increase in the industry during the past ten years. Large orchards are now planted specifically for the pro- duction of fruit for drying and in many places the fruit is as carefully chosen and handled as that which is being placed on the market in the fresh state. In California and such sections as are free from rain and excessive moisture open-air drying is still extensively employed in conjunction, however, with modern sanitary methods. Carefully selected, mature fruit is thoroughly FOOD INDUSTRIES 26l cleaned by brushing and washing' if necessary. It is then sur- face dried, cut into desirable shapes by machinery, placed on trays, sometimes sulphured for bleaching and disinfecting pur- poses and dried in the sunlight. In countries with less depend- able weather conditions in-door drying is largely employed. Sev- eral methods are now in use: 1st, hot air drying in which the fruit is placed in a cabinet, kiln or tower shaped evaporator through which hot air pipes are conducted, provision being made to carry off the evaporated moisture; 2nd, the vacuum drier operated by alternate exhaustion and renewal of warm air thus rapidly removing the moisture; 3rd, filtered air at ordinary tem- perature may be employed thus protecting the fruit from a loss of flavor which occurs in both of the former methods. The increased output of the present day has resulted in not only a greater consumption of dried fruits at home but has placed such products in the European markets where they can fre- quently be bought for a lower price than fresh native fruit. COOLING. The principle with this method of preservation is surrounding food with temperature conditions unfavorable for bacterial de- velopment, this may mean low temperature or actually freezing according to the product. The thermal death point of micro- organisms ranges between wider limits than any other form of life. Boiling does not kill all types, neither does freezing. The best temperatures at which to hold food in cold storage, or to which it should be raised with sterilization, are now being care- fully studied. The physical properties of the food product must also be considered. With fruit which has a high water content and a fragile carbohydrate tissue the expanding force of the ice crystals is highly destructive; fruit should never be frozen. In the case of flesh foods less water and a tough highly elastic tissue, minimizes the effect of the force, hence these products can be frozen if desirable. Advantages of Cold Storage. — 1st, No nourishment is taken from food; 2nd, no foreign matter is added; 3rd, no new taste is imparted so the flavor is not greatly changed ; 4th, the digestibility 262 FOOD INDUSTRIES is not diminished ; 5th, a large quantity of perishable goods can now be kept that were formerly thrown away. Disadvantages of Cold Storage. — 1st, The keeping quality is impaired especially when too low a- temperature has been used. The physical condition is frequently altered so bacteria can more readily act upon it as with meat or fish. Such food should be consumed as quickly as possible when taken from refrigeration ; 2nd, fruit deteriorates rapidly after having been in cold storage. This is frequently caused by a large amount of moisture con- densing on the surface of cold fruit when taken into a warm place, thus making the conditions most favorable for mold growth ; 3rd, it has led unscrupulous dealers to hold back prod- ucts for high prices. In spite of these disadvantages cold storage has been one of the best methods so far used for preserving foods. Beginning in i860 its use has spread enormously and has made possible the uniform distribution of fresh foods, such as meat, poultry, eggs, milk, fruit, vegetables and the like throughout every part of the country. By an interchange of the surplus with foreign nations, it has vastly improved the world's food supply and has greatly remedied the enormous waste, in many sections of both hemispheres. Manufacturers' methods of coolings are either employment of ice or the expansion of compressed gas, as used in the ammonia process. The housewife must as a rule depend upon an ice . chest which is generally kept too warm. The temperature of an ordinary refrigerator registers from 50 to 6o° F., whereas it should be kept below 50 F. Precautions in Care of the Ice Chest. — 1st, Do not wrap ice in newspaper for it is only in melting that a low temperature is maintained ; 2nd, keep ice chest well filled with ice ; 3rd, keep the chest as dry as possible as cold damp air harbors many low forms of plant and animal life; 4th, charcoal should not be utilized for lining as it soon becomes clogged and makes a fine incubator for bacteria; 5th, wash frequently with warm water and a neutral soap. The preservation of food in refrigerators depends on three FOOD INDUSTRIES 263 conditions — low temperature, ventilation and dryness. Low tem- perature can only be secured by the melting of the ice. Ventila- tion in the past depended entirely on the opening and shutting of the door but in all well constructed refrigerators of the modern type provision is made for circulation of air. Dryness depends upon the rapid change of air in the ice-box and in a certain sense is connected with the question of ventilation. STERILIZATION AND EXCLUSION OF AIR. See Chapter XX — The Canning Industry. SUGARING. Preserving by means of sugar is not used to as large an extent to-day as it was in former years. The great improvements achieved by canning manufacturers have made their products so popular that they have largely taken the place of the old-fash- ioned preserves. The antiseptic action of sugar appears to be due to the ease with which bacteria give up to concentrated solutions a part of their constitutional elements thus weakening their reproductive power. The old-fashioned housekeeper's recipe usually read — "A pound of sugar to a pound of fruit," thus the product was as a rule protected against fermentation. It was quite possible, however, for mold to grow but the formation always occurred on the surface and could readily be removed. Melted paraffin poured over the top of the preserved product largely protects it against mold growth. The great disadvantage with this method is the altered taste. Sugar is added in such large quantities that the strength of its flavor conceals or destroys other flavors that are desired, such as the pleasant acidity of many fruits. A second inconvenience is the large quantity of sugar that is required in order to preserve a small quantity of fruit, hence the use of it is very expensive. Preserved fruit is used to-day only as a sweetmeat. It has been found possible to preserve meat and fish by the use of sugar alone. Although this method has never been used with protein material in America, it is still customary in Por- tugal to preserve fish, such as the salmon, by splitting, cleaning 264 FOOD INDUSTRIES and sprinkling the interior with sugar. The claim is made that fish prepared in this way can be kept for a long time with a per- fectly fresh flavor. SALTING. The keeping of food material with salt has been used from very early times. The discovery of its preservative action was probably accidental, due to the finding of animal carcasses em- bedded in the saline deserts of Asia. Ancient wine makers fre- quently used salt water with the object of keeping their product for a longer period, and Pliny speaks of flesh food being treated with salt and meat being preserved with brine. The custom of salting fish was also known to the Greeks and Romans, but it seemed to have been used more as an incentive to the consump- tion of wine than because of any wish to add to the keeping quality of the product. The efficiency of salt as a preservative is probably due to the fact that in saturated solution the greater part of the tissue pro- tein is insoluble. Further, salt being a highly crystalline com- pound readily penetrates the tissue and in a short time the liquid portion reaches the point of saturation desired. The process of removing the salt before using is the reverse of the above and is termed freshening; this operation is more or less completely carried out just previous to cooking. There are three methods of salting as follows: 1st. Dry-salting or powdering where the sodium chloride in the powder form is freely rubbed on the sur- face of the object, the operation being repeated until the mois- ture appears to be absorbed. In many cases the material has been partially dried previous to salting. This method is now confined to certain types of fish. 2nd. Wet-salting — a slight modi- fication of the above with less salt used. 3rd. Pickling — the com- monest method of salting consists of immersing the product in a saturated solution of salt (pickle) and adding more dry salt from time to time, in order to overcome any diluting tendency, due to the admixture of the pickle and tissue liquid. In case of red meats salt-petre is added to the pickle on the plea that it tends to retain the color. This method is extensively used for vegetables, meats and fish. FOOD INDUSTRIES 265 . While salt is harmless and is needed in the diet this method on the whole has not been found satisfactory. The flavor is greatly altered, the physical nature of the product is so changed by the toughening of the fiber that it is more difficult to digest and the loss of nourishment due to osmosis is considerable. Other methods of preservation have to a great extent taken the place of salting. SMOKING. The art of smoking meat and fish to assist in its preservation has been practiced from remote ages. The custom probably originated from the habit of suspending food material within the tent or primitive dwelling. Being close to an open wood fire, smoke arose saturating the hanging material and not only gave it an agreeable taste, but greatly assisted in the keeping quality. This simple practice is still largely followed in isolated sections. Small smoke-houses are frequently found in many parts of the country, where meat or fish can be laid across slats near the roof and smoke from a wood fire allowed to pass over it. The preservative action is now known to be due to certain products present in the smoke, such as creosote, which contains a bactericidal substance known as guaiacol. Formaldehyde and acetic acid are also present in smoke, but as they are extremely volatile, they are of little use. Creosote being less volatile re- mains on the exterior of the meat and acts as a violent germi- cide, while being perfectly harmless to the human consumer of the product. Since many woods also yield turpentine on burn- ing it is necessary to select beech, hickory, oak or such woods as yield creosote and not terpene compounds which would affect the flavor. Water plays an important part in the production of creosote so generally the wood is used in the green state (Fig. 64). Smoking does not protect against all forms of micro-organ- isms. Mold can attack food preserved in this way, but it is usually only on the surface and can readily be removed with a cloth dampened with lard or sweet oil. Canvas-covered meats are less likely to be attacked by mold. As smoking does not 266 FOOD INDUSTRIES reach the interior only material free from contamination should be used. It is quite customary to combine salting and sugaring with smoking as in sugar cured hams. If such products are of a high grade they are immersed in a pickle composed of salt, salt-petre, sugar and spices for forty to sixty days, after which they are placed in a smoke-house for three days. This process is excellent but it is long and increases the cost so a quicker, Fig. 64.— The Sausage Smoke House. (Courtesy of Armour & Co., Chicago, 111.) cheaper method is occasionally substituted. Brine is pumped into the ham and the product is then treated with smokine. This preservative contains minute particles of creosote in solution and may be applied by a brush or by dipping meat quickly into the solution and afterwards drying it. This method is not as effective as the use of the old-fashioned smoke-house and the creosote is more likely to penetrate. FOOD INDUSTRIES 267 USE OF FATS AND OILS. Foods which do not contain a large amount of fat are excellent when put up in oil, sterilized and sealed to prevent the oil from becoming rancid. A coating of oil is also frequently used to preserve foods by the exclusion of air. This method has been used largely abroad where birds are dried and saturated with oil ; goose-livers similarly treated are sold as "pate-de-foie- gras." These products are considered great delicacies. In Italy wine is often covered with oil to prevent bacterial action, and in Arctic regions many kinds of meat are preserved in this way. Possibly the most common food on our market put up in oil is the sardine although tuna fish, salmon, mushrooms, truffles and arti- chokes are also important products. The name sardine was originally given to a variety of fish found in the Mediterranean near the Island of Sardinia but the commercial usage now includes several varieties, the French sardine being the young of the pilchard, and the American, young herring. During the process of manufacture the fish are carefully sorted into sizes, cleaned, placed in brine, washed in fresh water, dried in the open on trays, immersed in oil, boxed and sterilized. Olive and peanut oils are largely used abroad while cottonseed is frequently substituted, especially in the United States. As a rule the French sardine receives greater care in the manufacture and is supposed to improve with age caused by the blending of fish, oil and flavoring. This method of preservation is used in Germany in the manu- facture of sausages. In the German market, two types of sau- sage can be found : those so rich in fat that they can be kept for some time; and those which are lean and must depend upon the preservative influence of the high content of spices. The casing in both types is more or less impervious to any material. USE OF SPICES. Spices were originally added to food to change or modify the flavor, but it has been found that they exercise a powerful pre- servative effect. See Chapter XXII. Spices. 268 FOOD INDUSTRIES ALCOHOL. Alcohol makes protein matter insoluble thus killing bacterial life. For this reason it is used largely in preserving biological specimens. To a slight extent it is also used for foods. Fruits of all seasons can be put up in an alcohol solution and preserved indefinitely. USE OF PRESERVATIVES. It is well known that certain chemicals when added to food have a restraining influence upon bacteria, yeast and molds which are associated with its decomposition. Some simply pre- vent the further development, others act as strong bactericidal agents. In the early days of the canning industry, they were largely used but modern methods of sanitation and sterilization by heat have proved so much more reliable and less expensive, that manufacturers of legitimate products have now almost en- tirely abandoned their use, regardless of the Pure Food Law. The harmful nature of these chemical compounds has been ar- gued for and against for a long period. At the present time prob- ably all agree that their use is absolutely unnecessary for goods that are to be consumed within a short period. There is still, however, much discussion as to using them in such products as chili-sauce, ketchup, apple butter and other foods classed as rel- ishes. These products have been cooked thus making them more susceptible to bacterial action after being opened. The claim is made that the housekeeper through careless handling frequently spoils food that the manufacturer has taken so much trouble to preserve. The prohibition of all preservatives would be as un- satisfactory to the consumer as to the producer. At the present time benzoate of soda is allowed by the Federal Government, it having been determined as not being poisonous or deleterious to health. When used each container must bear a label stating the amount. Although the government does not limit the quantity, one-tenth of I per cent, is employed by manufacturers. The use of salicylic acid or its salts is now forbidden. Rideal claims that the salts are irritating to the kidneys and distinctly antagonistic to most enzymes, especially starch digesting ferments. Neither FOOD INDUSTRIES 269 can one part in a thousand always be relied upon as experiments have proved. Arguments advanced in favor of their use are : 1st, These antiseptics are harmless when used in small amounts. One part benzoate of soda in 1,000 is not injurious and may be beneficial in warding off intestinal diseases ; 2nd, they are found occurring naturally in many of our fruits, such as currants, cranberries, raspberries and crab-apples; 3rd, these antiseptics are frequently developed during manufacturing processes es- pecially where sterilization by high temperatures is necessary. Arguments against their use : 1 st, They are not violent poisons, but some are believed to be undesirable as they are antif ermentatives so interfere with the digestive ferments ; 2nd, they are irritants so are apt to injure the mucous membrane of the stomach and intestinal canal; 3rd, the blood has for its chief function oxidation. These compounds interfere with the oxidizing function of the blood; 4th, the amount is not always small. Possibly the strongest reasons for prohibiting their use are that it may lead to carelessness in manufacturing processes and to the use of inferior material. Neither can they be regarded as "cure-alls" for they do not affect ptomaines which cause disease. Artificial Stveetening. — Saccharine has been largely used for sweetening syrups, preserves, jams, jellies, canned goods and similar products. It is a glistening white powder resembling sugar, but with a much greater sweetening power, thus making it a cheaper agent to use. Saccharine is obtained by the oxida- tion of one of the coal tar products and has no food value. It is believed to be an irritant so its use has been forbidden. Artificial Coloring. — The employment of artificial coloring in connection with food has been practiced for the past fifty years. The colors have included animal, vegetable and mineral dyes for a long period and recent years have added an innumerable num- ber of coal tar dyes to the list. The animal and vegetable dyes have included cochineal, annatto, turmeric, logwood, saffron and carrot juice, which are generally supposed to be harmless. At present the only mineral dyes being used to any extent are copper 27O FOOD INDUSTRIES sulphate in green vegetables and fruit, oxide of iron in cocoa, confectionery, condiments, sausages and the like and Prussian blue in sugar refining. Copper sulphate is generally considered to have a deleterious effect on the consumer. There seems to be reason for the belief that copper is a cumulative poison similar to lead and mercury, hence it is wise to abstain from these products. The use of copper is prohibited in Germany, Austria-Hungary and is limited in many other European nations. Since the report of the Referee Board of Consulting Scientific Experts the importation of cop- pered vegetables has been forbidden in the United States. The coal tar dyes are unlimited in variety and are used ex- tensively in confectionery, jellies, jams, meat, dairy products, wines and non-alcoholic beverages. Usually the amount is very small rarely exceeding one part in one hundred thousand and for this reason, it is almost impossible to form an opinion in regard to whether or not they are injurious to health. While such coloring matter may not be detrimental to the consumer, the use is unfortunate for it enables the manufacturer to place inferior goods upon the market for high grade material. Articles of food are preferable in their natural color, and it is unfortu- nate that the housewife so frequently chooses highly colored goods thus encouraging the use of artificial coloring matter. CHAPTER XX. THE CANNING INDUSTRY. Historical. — The process of food preservation by canning- was invented in 1810 by Nicholas Appert of Paris. The underlying principle of this method, the destruction of all life by means of heat followed by the exclusion of air by hermetically sealing, was established by the experimental work of Spallanzani, in 1765. By placing various nutritive liquids in tubes, sealing, and boiling them for an hour, he discovered that the liquid remained unchanged as long as the seal was unbroken. During the wars of Napoleon, much dissatisfaction occurred in regard to the food that his army was obliged to eat while on the march. An investigation followed which led to the offering of a prize of 12,000 francs to any man who could keep food indefinitely in its natural condition without adding the preserva- tives then in use which included salt, sugar, vinegar and smoke. It was won by Appert who after long practical experience in confectionaries, kitchens, breweries and distilleries, had been working for many years along the line of food preservation. Food material was placed in air tight containers after it had been subjected to such a degree of heat that the contents had been thoroughly sterilized. The apparatus used by Appert was neces- sarily very crude but his discoveries laid the foundation for one of the greatest industries of modern times. About the same time, Peter Durand obtained a patent in Eng- land for preserving meat, fruit and vegetables in tin cans, and shortly after several other manufacturers introduced similar methods. The theory upon which these men worked was, that the oxygen contained in air was the destructive agent and its exclusion alone would preserve food which had been cooked. It was not until the time of Tyndall and Pasteur that the real cause of putrefaction was understood. The industry was estab- lished in the United States by Ezra Daggett, who after learning the trade abroad, canned salmon, lobsters and oysters in New York in 1819. Shortly afterward William Underwood started 2J2. FOOD INDUSTRIES to pack tomatoes, and in 1837 Isaac Winslow began experiment- ing with the canning of corn in Portland, Maine. Spreading gradually throughout the east, canneries were finally introduced into the middle west about the time of the breaking out of the Civil War and within a year or two, we find their establishment in California. The discovery of gold in the west gave the first impetus to this industry for canned goods were used largely by the 49ers, who found them a convenient form in which to carry food material across the country. Again the industry was af- fected in the early sixties by the discovery that canned goods were vastly superior to dried food in palatability for army use. The growth of the industry since that time has been very rapid and at the present time canneries are scattered throughout the United States. Along the Atlantic Coast large quantities of vegetables, meat and fish are preserved. Oregon and Washing- ton supply much of the salmon, Chicago packs largely meat, while California furnishes fruit and vegetables of the highest grade. The rapid growth resulted in the formation of Associations of Canners the development of which led to new and better methods of making cans, great improvements in machinery, skilled workers and much experimentation in regard to the best methods of sterilization. In the latter work manufacturers have been greatly assisted by scientific investigation. While the United States puts out enormous quantities of certain products, such as corn, tomatoes and salmon, European coun- tries have a considerably larger variety of articles. Numerous combination of mixed vegetables, meat and vegetables and meat delicacies are placed on the market, one country alone having canneries whose output includes several hundred different items. The future possibilities of this industry both at home and abroad are very great, if by rigid inspection only canned foods consisting of good wholesome material, packed with proper care under sani- tary conditions are placed upon the market. Process. — As before stated the two principal points to be borne in mind in the preservation of foods by canning are: — 1st, the FOOD INDUSTRIES 273 destruction of all micro-organisms and their spores by means of heat ; 2nd, the exclusion of air by hermetically sealing. As a rule the can and food are sterilized at the same time but the details of the process necessarily vary with different products and in various canneries. Fruit and vegetables should be selected when at their best, transported as quickly as possible to the factory and immediately sorted for quality. They are washed, treated according to the product and placed at once in cans. Care is given that the cans are filled full, then closely covered with the exception of a small hole for exit of steam. They are then subjected to the temperature of boiling water or higher according to the material. The hole is immediately closed with solder, the cans reheated and allowed to cool. Some factories accomplish Fig. 65.— Stock Boilers. (Courtesy of the Franco-American Food Co.) the same result by means of a steam heated "exhaust box," which withdraws part of the air in the filled cans before they are sent to the capping department. With either method a partial vacuum is formed within the can which causes the end to be depressed. Should the process of sterilization be imperfect and bacteria or spores be left within the can, fermentation soon begins and 18 274 FOOD INDUSTRIES the formation of gas causes the top to bulge. Canned goods are usually kept for one month and are then tested by striking with the finger. Expert examiners are able to tell by the sound if a partial vacuum still remains. With the best manufacturers all cans which show the presence of gas are thrown away. In some factories, however, they are resterilized. This practice is dangerous as injurious products may have developed which are not affected by reheating (Figs. 65 and 66). Success of Canning. — There has been a great difference with various foods in regard to successful canning:. Fruits are more Fig. 66.— Sterilizing Process. (Courtesy of the Franco-American Food Co.) subject to the attack of yeast and molds which are killed at a com- paratively low temperature, so have given little trouble. Toma- toes, corn and peas, however, have been successfully canned only after much experimentation. Even after careful treatment and sealing, these products have frequently undergone the putrefactive changes that it was the purpose of canning to prevent. Through FOOD INDUSTRIES 275 scientific investigation, the discovery was made that these vege- tables are invaded with bacteria, the spores of which will resist heat for a length of time. If when the can is sealed a single spore remains capable of action complete destruction of the prod- uct follows in the course of time. For a long period it 'was thought impossible to can green corn, for that vegetable had given the manufacturer more trouble than any other product. With the aid of the bacteriologist the problem has been completely solved. Corn is not only invaded by extremely resistant spore bearing bacteria but the kernels are not easily penetrated by heat. Those which lie next to the can are easily sterilized but the interior layers do not heat readily. For this reason a thermometer is usually put in the center of a test-can and the temperature is carefully registered. It has been found necessary to use 250 F. for 65 minutes in order to render all spores inert. Regardless of the product the. success of canning depends on the sanitary conditions which prevail throughout the factory, the quality of the material and the rapidity with which it is handled. Meat Products. — In the canning of meat the fore-quarter as a rule is used, the hind-quarter selling better as fresh meat. Al- though this may mean a poorer grade meat, it does not necessarily indicate that it is any less healthy. Before sterilization meat is usually cut into uniform pieces, as different sizes would mean disintegration of the smaller pieces, before the larger ones are cooked, thus giving a bad appearance to the finished product. The meat is then par-boiled for 8-20 minutes to secure shrinkage before being put in cans. The further processes of sterilization and exclusion of air are quite similar to those used in other canning industries. A large variety of potted and deviled meat can also be found on the market. As the process of manufacture is usually a trade secret their exact composition is difficult to determine, but they are largely composed of beef or pork, mixed with spices and flavoring, the larger amount of condiments being used with the deviled varieties. Containers. — Manufacturers use either glass or tin in preserv- ing. The preference usually is in favor of glass but it is a ques- 276 FOOD INDUSTRIES tion whether this is warranted, except in certain products which cannot be preserved to the best advantage in tin. Advantages of Glass. — 1st, Food material such as fruit or vege- tables look very attractive; 2nd, it contains no lead or other dangerous material; 3rd, in the household it is much easier to handle. Disadvantages of Glass. — 1st, The jars to be strong must be made of thick glass which is likely to break with a sudden change of temperature. They also break easily if struck with a blow; 2nd, they cannot be handled with automatic machinery ; 3rd, transportation is difficult on account of the weight and liability to break. They occupy too much space; 4th, it is frequently necessary to cover the glass with paper as light has a bleaching effect on some products. Caution. — When glass jars are used in the home they must be made air tight. This is a difficult thing to do especially where rubber bands are used. Old rubber bands have lost their elas- ticity so are not safe to use. It pays to buy new ones. As sul- phur has been used to impart elasticity and to keep the rubber from sticking, the new bands should be moistened before using. Advantages of Tin Containers. — 1st, They are light to handle and occupy less space in storing and during transportation; 2nd, they are less likely to break; 3rd, products are protected from light; 5th, they are much easier to make air-tight; 5th, tin cans cannot be refilled ; 6th, if a good quality of tin has been used and the can carefully made there is no danger of poisoning. Disadvantages of Tin Containers. — 1st, Tin cans are not prac- tical for use in the household ; 2nd, they are dangerous if a poor grade of tin has been used or the process of manufacture has not been thoroughly carried out; 3rd, with such products as raspberries, cherries, plums and beets, they are not desirable as the tin coating is attacked resulting in a loss of color, flavor and quality. Salts of tin are also formed which are objectionable. For the protection of these products a recent improvement has been made by coating or lacquering the inside of the can. While such coatings are not perfect, they are a step in advance and further improvement will undoubtedly be made in the near future. FOOD INDUSTRIES 277 According to work done by the United States Department of Agriculture,* such products as corn, peas, beans and tomatoes have little action on tin so a coating is unnecessary. On the whole there is practically little risk now in the use of tin as the manufacture of cans has greatly improved. They are made of sheet iron which has been cleaned and rolled out to the proper thickness, dipped into acid to remove oxide, put quickly Fig. 67. — Can Closing Machines. (Courtesy of the Franco-American Food Co.) into water then dried, after which the sheet is dipped quickly into melted tin. Before being made into cans by machinery they are carefully examined. If the oxide has not been removed the tin will not stick, thus leaving the iron exposed to the action of organic acids occurring in fruits and vegetables. All imperfectly made sheets are rejected. The modern can is made with lock seams and outside soldering (Fig. 67). As the sealing in many cases is done by double seaming on the top no solder is used * The Canning of Foods. Bulletin No. 151. Bureau of Chemistry. 278 FOOD INDUSTRIES except on the side seam. This overcomes possible contamination by solder in contact with food material. By a recent process the so-called sanitary can is formed by machine, filled and closed without the use of solder. To insure the safe usage of products packed in tin, it is abso- lutely necessary that the contents be removed from the tin after the can has been opened, to avoid the effects of oxidation. Adulteration. — Since modern methods of sterilization have been employed, the use of preservatives in the canning industry has been practically abandoned, as they simply add to the cost. Saccha- rine, bleaches and coloring matter now constitute the chief adul- terants. Saccharine has been frequently added to corn, toma- toes and peas to disguise the fact that sweet varieties of the garden vegetable were not used. A bleaching agent is frequently employed to whiten corn, and peas and other green vegetables are given a brighter green shade by the addition of copper salts. Dur- ing canning and on standing peas are apt to lose part of the chlorophyl through oxidation processes, which give them a yellow- ish appearance. Copper salts will unite with the nitrogenous constituents of the peas to form a compound with a brilliant green, thus restoring the original color, although the shade lacks the delicacy of the natural green. The coloring of peas is largely practiced in France, but as a rule is not used by American can- ners (see page 270). Very little adulteration has been found in tomatoes except the addition of coloring matter, such as coch- ineal or coal tar dye. The artificial coloring has been used to make inferior material appear as mature and high grade tomatoes. The adulteration of canned meat is probably more often prac- ticed than with vegetables, but it has been found by no means common by the Bureau of Chemistry. It consists largely in the substitution of cheaper meats and fat and the addition of starch to increase bulk and weight. Coloring matter and preservatives as borax and boracic acid are still occasionally found. CHAPTER XXI. TEA, COFFEE AND COCOA. TEA. Historical. — According to the writings of an ancient Chinese author, the virtues of tea were known in the Orient some 2,700 years before the Christian era. Many legends exist as to the original home, some claiming that it was first grown in China, while others speak of its introduction into that kingdom from one of the neighboring provinces of India. For a long period it seems to have been used as a medicine rather than as a beverage. Gradually growing in popularity, however, it eventually became a national drink and the cultiva- tion of the tea plant for this purpose grew to be an important in- dustry in China, Japan, India and Ceylon. It was not until the latter part of the 16th century that the ships of the Dutch East India Co., in their voyages to the Orient, carried back to Holland some of the curiosities of the Eastern World, one of them being Chinese tea. Knowledge of it finally passed over to England and in 1657, we hear of the first tea-house being opened in Exchange Alley, London. For many years the price per pound was so high that tea was looked upon as a rare luxury, but by the latter part of the 17th century it was being imported from China in such large amounts, that it "ceased to be a rarity. As the price lowered the annual consumption grew until at the present time Great Britain uses considerably more than one-half of the world's total production. Tea was intro- duced into the colonies as early as 1680, the price at that time being five or six dollars per pound for the cheapest varieties. Cultivation of the Tea Plant. — The tea plant is a hardy ever- green shrub, which grows to a height of from twelve to fifteen feet in the wild state, but under cultivation it is usually dwarfed in order to stimulate the greatest possible growth of the young shoots. These yield the tender new leaves so desirable in tea- making. It will grow in a variety of climates, but the sub-trop- 28o FOOD INDUSTRIES ical appears to be the best, especially in sections where the rain- fall approximates fifty inches annually. The plant is usually Fig. 68.— The Tea Plant. (Courtesy of McCorraick & Co., Baltimore, Md.) placed on a southern exposure, so the sunshine will protect it from cold, and in soil which has a certain water-retaining prop- erty. In China most of the tea gardens are small, each farmer FOOD INDUSTRIES 28 1 producing - enough for the consumption of his own family, while the surplus is sent to the market. Following this idea, the United States Department of Agriculture has strongly recommended the growing of tea on the farms of the South Atlantic and Gulf States. With very little trouble and expense the southern farmer could at least raise enough tea for his own use, while the plant itself makes a hedge well worth cultivating for purely ornamen- tal purposes. Farmers Bulletin, No. 301, "Home Grown Tea" gives many ideas as to the successful cultivation and manufac- ture of tea in the United States. In modern methods of cultivation, the plants are raised from seeds in nurseries and are set out in their permanent home in the open when about twelve inches high. According to climate, soil, etc., the first crop is borne in three or four years, and from that time, the shrub may be picked at regular intervals. It is customary to occasionally allow the plant to rest thus insuring a longer life. General Classification. — The differences in the tea appearing on the market do not depend upon the variety of shrub, but rather on the size of the leaf and the way in which it is treated during manufacturing processes. According to the method of curing it is designated as : — Black tea, which has a dark, dull appearance. Green tea, which has a rather brilliant tinge due to the retention of part of the chlorophyl. For a long period, China so jealously guarded her tea gardens, that her green and black teas were supposed by foreign nations, to be produced from different species of shrub. That this idea was false was finally proved by Robert Fortune, who traveled in China on behalf of the Horticultural Society of Great Britain. Tea is also classified according to the size of the leaf (Fig. 69). 1 st. Pekoe, which consists of the three young shoots at the tip and are known as flowery pekoe, orange pekoe and pekoe acord- ing to their size. As these leaves contain the least fiber and the most juice, they produce the finest grade of tea. 2nd. Souchong is prepared from the leaves immediately below 282 FOOD INDUSTRIES the pekoe variety and makes a tea of popular price. Pekoe and souchong are sometimes mixed when the product is known as pekoe-souchong. 3rd. Congou is a cheaper variety prepared from the more fully developed leaves below the souchong size. In the American 2l // C, /^e/foc c/, "SlscAo-rro (f irsf J of & (rrr/xcc/J fe/(x>c j c?.£>,c.c/. e a on /e/*Coe - *5o 'oc/c /? o r? <9 Fig. 69. market this term is sometimes used as a general name for China black teas and souchong for China green teas. 4th. Bohea is a name frequently applied to any larger leaf used for tea-making than the congou variety. This tea is no longer found on our market. FOOD INDUSTRIES 283 Processes of Manufacture.- Black Tea Leaves picked. Withered in the sun. Rolled until soft. Fermented. Fired. Sorted. Picking. — The tea leaves are operation generally being carried Green Tea Leaves picked. Withered in pans. Rolled until soft. Withered again. Sweated in bags. Slowly roasted, plucked entirely by hand, the on by women and children. In Fig. 70.— Withering Tea Reaves. (Courtesy of The Spice Mill Publishing Co.) China and Japan there are several harvests. The first picking commences about the middle of April and gives delicate pale green leaves, which usually command a high price. About two weeks later, the bush is again ready to be plucked and again a third and fourth picking follow, each harvest yielding leaves a little lower in quality. In Ceylon where there is practically no winter, picking takes place about every ten or twelve days the year round. Withering. — Whether small or large the leaves are of the same 284 FOOD INDUSTRIES general structure. All consist of a certain amount of fibrous material which must be softened by rolling. In order to make this operation easier the leaves are first withered, either indoors or by exposure to the sun, until part of the moisture has evap- orated (Fig. 70). In good weather this operation takes about eighteen to twenty-four hours but when cloudy or rainy, artificial heat must be used and a longer time is required. Withering not only softens the leaves, but assists in the production of the greatest amount of enzyme which is needed in the later operation of fermentation. Fig. 71.— Rolling Tea L,eaves. (Courtesy of The Tea and Coffee Trade Jout nal.) Rolling. — In China, rolling is still done very largely by hand (Fig. 71). The worker gathers a quantity of leaves in his hands and rolls and kneads the mass with a very similar motion to that used in the kneading of dough. In India the withered leaves are rolled almost entirely by machinery. This operation bruises the leaves, takes out excess moisture, and gives the characteristic twist to the leaf. FOOD INDUSTRIES 285 Fermentation. — Fermentation is the most important part of the preparation of black tea, for its influence on the quality and character of the tea is very great. The rolled leaves are piled in heaps on mats or frames and allowed to ferment until they turn a bright copper tint. During this period, the tea leaves are sub- jected to the influence of enzyme action and important chemical changes take place. The green color of the leaves and the dis- agreeable odor disappear, and a fine flavor due to the development of essential oils is acquired in proportion to the amount of enzyme in the leaf. According to the investigations of Dr. H. H. Mann "The tannin is oxidized during fermentation and combines with other substances in the leaf-forming compounds, some of which are insoluble in water; there is, therefore, a decrease in soluble tannin." Experienced judgment is necessary to determine how far fermentation should proceed; too little means rawness and if carried too far, much of the delicate flavor is lost. Firing. — Fermentation is checked by the application of heat. The leaves are sometimes exposed to the sun then fired or they may be immediately fired, care being taken that the temperature is sufficiently high to remove moisture, but not high enough to drive off the volatile oils which have been developed during curing. Sorting. — After cooling, tea is sorted into grades by sifting, packed into lead-lined chests and is ready for transportation. Green Tea. — The preparation of green tea differs from that of black tea in several important operations. 1st, The method of drying is different. While black tea is withered in the sun, the leaves for green tea in Japan are steamed until they lose their elasticity and in China are heated in pans over charcoal fires. In a few minutes the leaves become soft and pliable and are ready to be rolled. 2nd, After rolling, the leaves are again subjected to the action of a slow, steady fire, the process of fermentation being omitted. The chlorophyl is therefore more or less retained and tannins are not oxidized to insoluble forms. This means that a larger amount of tannic acid is found in green tea when used as a 286 FOOD INDUSTRIES beverage. The difference in flavor is entirely due to fermenta- tion. Adulteration. — In former years when tea was expensive and investigation slack there was much fraud practiced, especially in the Chinese varieties. The adulteration consisted chiefly in the addition of foreign leaves and in facing. The leaves of the ash, beech, willow, rose and buckthorn were frequently mixed with those of the tea plant. Substitution of this kind can readily be detected with the microscope as tea leaves have a characteristic appearance. Facing consisted in treating the leaves with various coloring matter, such as Prussian blue, indigo or plumbago. By such means leaves which were inferior or had been damaged in manufacturing processes or during a sea voyage, could be im- proved in color and general appearance. As black tea does not need as much care in preparation for the market, attempts were also made to face such tea and sell it for green tea. Since laws have been passed prohibiting the importation of faced tea, there is practically no adulteration to be found in the tea sold in the United States. Tea growers are more carefully watched, government inspection is more rigid and competition is much greater than in the past. For a long period the Chinese were the chief exporters to this country, but the rapid growth in the popularity of the India and Ceylon teas has forced China to send better grades to hold her place in the American market. Tea as a Beverage. — The main constituents of tea to be con- sidered in the preparation of the beverage are caffein and tannic acid. Caffein is the ingredient which gives the stimulating prop- erty. It belongs to a class of substances known as alkaloids. Just below the boiling point of water it is remarkably soluble. Tannic acid is not particularly soluble at the boiling point but will become so on prolonged boiling. These two facts must be taken into account when preparing the beverage. Caffein is ■ a mild stimulant and is desired while tannic acid so far as possible should be avoided. General Eules for Tea-Making. — Heat freshly drawn water to the boiling point. Pour it on the requisite amount of tea, which has been placed in a previously scalded pot, made of non-con- FOOD INDUSTRIES 287 ducting material. Allow to stand in contact with the leaves from three to five minutes. The spent leaves should not be used again. Practically all the stimulating ingredient has been removed and that which is left is deleterious to health. Tea should never be boiled; the delicate aroma is lost as the essential oils volatilize. Boiling also makes soluble the tannin, too much of which is un- desirable. Composition of the Beverage. — Beside caffein, tannic acid and volatile oil, tea contains minute amounts of nitrogenous matter, fat, dextrin, fiber and mineral matter. COFFEE. Historical. — The early history of the cultivation of the coffee bean is lost in antiquity, but it is to Arabia that the civilized world is indebted for the knowledge of its use as a beverage. Tradition gives various tales of the introduction of coffee into Arabia, one of which places the original home in the province of Caffa, Abyssinia, from which it is supposed to have received its name. The Ethiopians were known to have used coffee in very early ages, but with that nation it appears to have served as a food rather than a beverage. Wherever the origin may have been Europeans discovered its use in Arabia during the 15th century. Undoubtedly the knowledge of it spread very largely through the Arabian merchantmen who added the coffee bean to other orien- tal luxuries, and to the Mohammedan pilgrims who flocked an- nually to Mecca. Learning to drink coffee while in the "Sacred City," these pilgrims carried back with them saddle-bags of the coffee bean to all parts of the globe professing the faith of Islam. Coffee reached Constantinople in the 16th century and spread from there to the countries bordering on the Mediterannean, fin- ally being introduced into London, Paris and other European cities during the 17th century. Originally all of the coffee used in Europe was grown in Arabia. As much of it passed through the port of Mocha it was known under the name of Mocha coffee. Later coffee was grown in the European colonies, in the French West Indies and on the island of Java. Its cultivation soon spread to Sumatra, the 288 FOOD INDUSTRIES Malay Archipelago, Ceylon, the Philippine and Hawaiian Islands and in the Western World to Cuba, Porto Rico, Mexico, and parts of Central and South America. About 1740 it was planted in Brazil where it gradually grew to be so important an industry, that at the present time Brazilian plantations produce three- quarters of the total supply and that government controls the coffee market of the world. The Coffee Plant. — The coffee plant is a very beautiful tree attaining a native growth of some 18-20 feet, but under culti- vation it is rarely allowed .to exceed 4-6 feet in height. This dwarfing the plant increases the crop and facilitates picking. The leaves are a fresh green color expanding outward and down- Fig. 72.— Coffee Bean. ward giving a very pleasing appearance. The flowers occurring in clusters are white in color and have an odor strongly resem- bling jasmine. The flowers and fruit which are frequently called "the cherries" are found on the tree at the same time and in all seasons, in various stages of development. It is from these cherries which turn a dark crimson color on ripening, that the coffee bean is obtained. The outer part of the cherry is fleshy similar to other fruit, while within are usually two seeds, laid face to face, covered by a very delicate membrane known as the "silver skin" and an outer straw colored husk called "the parch- ment" (Fig. 72). The main processes of manufacture consist in freeing the fruit from the pulpy matter and removing the two inner skins which surround the seeds. These seeds are in reality the unroasted coffee bean of commerce. Occasionally a single bean occurs, common to all varieties of coffee, in which case it Food industries 289 is called "pea-berry" and is supposedly of finer quality than the split beans. Cultivation. — The coffee trees thrive best in rich, well-irri- gated soil and in tropical climate where the rainfall exceeds 75 inches per annum. They are propagated from seeds, which are planted directly in the fields or grown in wicker baskets in nur- series until 18 inches high, when they are transferred to their permanent homes in the open. An absence of frost is essential to the growth of the plant and protection from wind and sun is commonly given by planting shade trees between the young coffee trees. The first crop of any importance is born when the plant is from 4 to 5 years old, and with care harvesting may be con- tinued at regular seasons for 20 years or more. The fruit is ready to be picked when it is dark red in color strongly resemb- ling a ripe, red cherry. Processes of Manufacture. — Harvesting. — In Arabia the fruit is allowed to remain on the tree until it falls off of its own accord, but on Brazilian plantations, which are by far the largest in the world, the cherries are usually picked by hand. They are allowed to fall directly on the ground or on sheets from which they are later raked together, and a first rough sorting is given before they are packed in bags to be removed to where further treatment is given. There a more careful sorting, sifting and winnowing take place, and the berries are at once treated with the dry or wet method for removal of the pulp. Dry Method. — The berries are spread out on drying grounds; where they are left exposed to the sun for two or three weeks, during which time fermentation takes place and the pulpy mass, gradually dries. It can then be removed by pounding in a mortar or by passing through a hulling machine. This method is still' used in Arabia and to some extent on the modern plantations of Brazil, many planters claiming that it has advantages over the- modern wet process. Wet Method. — Where the wet process is used inclined canal's are frequently built, where the cherries can be dumped and carried by gravity to the pulping machine. While floating down 19 290 FOOD INDUSTRIES imperfect and unripe berries rise to the top and can readily be removed, after which the well developed berries are washed with fresh water. Pulping. — The pulping machines are of various types, but as a rule they consist of a revolving cylinder with a rough surface which faces a curved metal plate. The berry is crushed between the two surfaces in such a manner that the pulp only is separated. The interior consisting of the coffee beans with the two coverings must not be injured. A separation is made by sifting and all im- perfectly pulped must be reprocessed. Fig. 73.— Views of Coffee Cultivation and Industry of Brazil. Washing Tanks. (Courtesy of The Spice Mill Publishing Co.) Fermentation. — The beans are next allowed to ferment for twenty-four to seventy-two hours in order to soften and loosen any adherent pulp. The essential part of this process is enzyme action on the adhesive substance, but as to its effect on the flavor of the coffee, no full investigation has as yet been made. FOOD INDUSTRIES 29 1 Washing and Drying. — Successive rinsings with water finally leave the parchment covering quite free from adherent pulp. It is now known as "parchment coffee" and must be subjected to a drying process in order to remove the two inner coats by friction. Coffee is dried in most places out-of-doors on the ground, during which time it is carefully watched. Too slow or too rapid drying greatly injures the flavor of the coffee. Peeling. — The two coverings can now be readily loosened by an ingenious machine which cracks the parchment and inner skin without injuring the beans. The hulls and dust are separated by winnowing, leaving the coffee 'beans clean and ready for sorting. Sorting and Packing. — In order to secure uniformity the beans are separated into six to eight grades. They are sorted first, according to size, by sifting through various mesh sieves ; second, according to weight by being subjected to strong currents of air blowing upward. The coffee is then bagged ready for removal to the shipping port, at which place it is frequently blended and repacked before shipment. As coffee deteriorates after roasting that process is usually carried on in the country where it is to be consumed. On arrival at the coffee-house the raw bean is subjected to a thorough cleans- ing process to remove all foreign matter. Roasting. — The cleaned beans are run into a revolving oven and are subjected to a temperature of 200 C. In the production of a good coffee this is one of the most important steps. Count Rumford in an essay published in 1812 says — "Great care must be taken in roasting coffee, not to roast it too much ; as soon as it has acquired a deep cinnamon color, it should be taken from the fire and cooled; otherwise much of its aromatic flavor will be dissipated and its taste will become disagreeably bitter. The progress of the operation and the moment most proper to put an end to it, may be judged and determined with great certainty; not only by the changes which take place in the color of the grain but also by the peculiar fragrance which will first begin to be diffused by it when it is nearly roasted enough. This fragrance is certainly owing to the escape of a volatile, aromatic substance 292 FOOD INDUSTRIES which did not originally exist as such in the grain, but which is formed in the process of roasting it." When a light cinnamon brown is desired, coffee is allowed to remain in the oven for thirty minutes and from thirty-five to forty minutes, if a heavy chocolate color is wanted. It is then quickly cooled by blasts of cold air and is ready to be bagged or boxed for the market (Fig. 74). The effect of roasting is both physical and chemical. The physical state of the bean is changed to a brittle form, in which Fig. 74. — General View of Coffee Roasting Room. (Courtesy of the Spice Mill Publishing Co.) it can more easily be ground or pulverized. Two very important chemical changes also take place; first, the formation of caramel which greatly improves the taste — this flavor can readily be imitated in the production of coffee substitutes ; second, the pro- duction of an oil known as caffeol to which the aroma of roasted coffee is due. As this oil is volatile, coffee should be consumed as quickly as possible after roasting and should never be pulver- ized until the time of the preparation of the beverage. During the roasting operation there is also an appreciable FOOD INDUSTRIES 293 amount of the alkaloid caffein which volatilizes, consequently, in some of the most improved coffee roasting establishments, the vapor developed during the operation is thoroughly cooled for the purpose of recovering the caffein. By subjecting coffee to a long continued roasting at low temperatures, practically all of the caffein present in the bean volatilizes and is recoverable. Coffee roasted by this method has been sold in the bean under the name of caffein-free coffee. When treated in this manner, however, it lacks some of the flavor of the ordinary product. Adulteration. — Adulteration of coffee has consisted in the ad- dition of foreign matter, the substitution of cheaper substances, in facing and glazing. As with tea facing, the addition of color- ing matter has been used largely to conceal poor or damaged coffee or to make inferior varieties appear as high grade material Glazing consists in the addition of graphite, charcoal, ultra-ma- rine, Prussian blue, talc, shellac and similar substances for the purpose of preventing the loss of aroma. It must be remembered, however, that such material adds weight to the coffee. Liebig suggested the use of sugar which if added when hot would glaze and protect it. In former years an imitation bean was manufac- tured and occasionally mixed with coffee, but the price of coffee is too low at present to make such substitution profitable. The addition of foreign substances was much more practiced with ground coffee than that sold in the bean form, since they could be less readily detected. Cereals of various kinds, peas, beans, acorns and the like have from time to time been added, but the chief adulterant has been found to be chicory which is the kiln dried root of the wild endive. In recent years misbranding has been found more frequently than adulteration. The early coffee market drew its supply almost entirely from Arabia and from the islands of Java and Sumatra. These coffees were known on the market as Mocha and Java. As the coffee industry spread, there was a strong tendency to label the product from new coffee fields as Mocha and Java, since those two names had taken a firm hold in the minds of the housewife. The passing of the Food and Drugs Act of June 30, 1906, has made this also a misdemeanor. Al- 294 FOOD INDUSTRIES though undoubtedly much coffee is still on the market not prop- erly labeled, there is a strong tendency now on the part of the manufacturers, as well as the government, to have coffee im- ported under its own name. Coffee as a Beverage. — One of the most important constituents of coffee and the ingredient to which it owes its stimulating effect, is the alkaloid caffein. It is the same substance as is found in tea but occurs in a rather smaller proportion, approxi- mately i to 2 per cent, being found in the unroasted bean. Tannic acid is also found with a larger amount of other substances such as fat, gum, fiber, sucrose, dextrin, reducing sugar and mineral matter. As coffee contains volatile oils, every effort should be made to retain them, in the preparation of the beverage, or much of the aroma and flavor will be lost. Coffee Extracts. — In recent years, products have been found on the market called coffee extracts. They consist essentially of a coffee solution from which the water has been evaporated in vacuo and the resulting mass, dried and ground. When added to boiling water they are supposed to have the original consis- tency of coffee solution. Coffee Substitutes. — See Chapter VI, page 85. COCOA. Historical. — Cocoa was not known to the European nations until after the discovery of the Western World. On his return from the third voyage to America, Columbus was supposed to have carried back with him to Spain the cocoa bean, as a curiosity from the newly discovered land. It was introduced into Europe in 1528 by Cortez after his conquest of Mexico. The explorer found the natives of the new land using the roasted bean, ground and mixed with maize meal, moistened with the sweet juice of the maize stalk and flavored with vanilla and various spices. It was known to them as chocolatl and was considered to be highly nutritious as well as a beverage of great delicacy. Evidently it was also held in high esteem by the Europeans for the tree from which the fruit is obtained, was known to them as "Theo- broma, — food for the Gods." Although so highly prized, the use FOOD INDUSTRIES 295 of cocoa spread very gradually in Europe and it is not until recent years, that it has grown considerably in popularity. Possibly this is due to the fact that tea is used so extensively in the British Isles and coffee in the continental countries. Cocoa was first introduced into the States by the fishermen of Gloucester, and its use has increased to so great an extent that one-fifth of the world's crop is now consumed in the United States. Cultivation. — Cocoa is the fruit of a tropical tree commonly known as the cocoa tree although it belongs botanically to the Fig- 75-— Pods and Reaves. (Copyrighted by Walter Baker & Co., and used with their permission.) species cacao, the most commonly used being the variety theo- broma cacao. Thriving only in tropical climate, 20 both north and south of the equator, its cultivation is very limited. Only those localities of America and Africa with their neighboring islands that have well-watered, well-drained soils and plenty of rainfall, can be utilized for the growing of the tree. The West- ern World produces by far the largest part of the world's crop, Venezuela, Ecuador and Brazil being the largest exporting coun- tries. Mexico still produces the greatest amount of cocoa but uses most of it for her own consumption. 296 FOOD INDUSTRIES The cocoa tree is grown from seeds either planted directly in the fields or in nurseries. It attains an average height of about 20-30 feet and bears small, red, wax-like flowers which appear either singly or in clusters, along the trunk and main branches of the tree. The fruit is a pod some 8-10 inches long, 3-4 inches thick (Fig. 75). It is when ripe, either lemon color or chocolate brown, according to the variety, and has a thick tough rind en- closing a mass of cellular tissue. Embedded in the pulpy matrix are .some forty or more cocoa beans which are covered with a thin shell greatly resembling an almond (Fig. 76). The beans Fig. 76. — Section Cocoa Fruit. are arranged in five longitudinal rows. The tree begins to bear fruit when four or five years old and continues to the age of forty. While blossoms and fruit are to be found on the tree at the same time and in all seasons, there are two main crops gathered yearly, generally in June and December, although this condition varies in different localities. Processes of Manufacture. — Picking. — The pods are picked when fully ripe, either by hand or with a knife fastened to a long, bamboo pole. Great care is necessary that the buds and blossoms which lie next the fruit are not injured. FOOD INDUSTRIES 297 Decomposition of Pod. — As the rind of the pods when picked is exceedingly woody and tough and would be difficult to cut, they are laid on the ground in heaps and allowed to decompose for twenty-four hours, or until the rind has become leathery. They are then sorted according to the degree of ripeness and are cut open with a sharp cutlass. The pulp and cocoa beans still within their shell can readily be removed. Fermentation. — As a considerable amount of the soft pulp still clings to the beans, it is necessary in order to free them, to allow fermentation to take place. This process is carried out by heaping the beans on the floor where they are allowed to sweat, by burying them, or by the use of enclosed sweating boxes where they remain for several days. The seeds are frequently turned to insure regular sweating, great care being also given to keep the temperature from rising too high. Both alcoholic and acetic fermentation take place and several important changes occur. The germinating power of the seed is arrested; the adherent pulp is loosened; color develops and an exceedingly bitter taste is modified so the flavor is greatly improved; the beans are less liable to be attacked by mold and are in the best form for dry- ing. Washing and Drying.— When fermentation is complete the beans are sometimes washed before drying. Washing is carried out by placing them in sieves or troughs, where they are thor- oughly scrubbed and rinsed, to remove all pulpy matter that may be clinging to them. Whether they are washed or not, the cocoa bean must pass through a drying process. This is accom- plished by the heat of the sun, whenever possible, or in drying houses which are heated by artificial means. In out-of-door drying some ten days or more are required, indoor drying is complete in less time. In some countries coloring matter is used and the practice of polishing the bean after drying is frequently performed. The cocoa is now ready to be bagged and shipped to the markets of the world. When received by the manufacturer cocoa is cleaned, sorted and roasted. 298 FOOD INDUSTRIES Roasting. — As in the case of coffee, this process must be care- fully guarded to insure the development of the desired flavor; too much heat means bitterness and too little leaves the cocoa with a crude undeveloped taste. The process is usually carried out in large iron drums, heated to I25°-I45° C. and con- stantly kept in motion. During the roasting the thin husks of the seeds become brittle and are so loosened, that afterwards they can easily be removed ; the aroma is increased ; the bitter taste is still further modified and the starch is partially dextrinized. When sufficiently roasted cocoa is quickly cooled in order to prevent the loss of the aroma. Fig. 77. — Grinding Room. (Copyrighted by Walter Baker & Co. and used with their permission.) Crushing. — The roasted seeds are next run through a machine called the cracker. This frees the outer shell from the inner parts which are known as cocoa nibs. A separation of shells, nibs and germs is effected by sieves and a machine of special device. As the shells retain the flavor they are sold and used for the preparation of a cheap beverage. The nutritive value is FOOD INDUSTRIES 299 not great but they make a satisfactory drink for people of weak digestion. The cocoa nibs are used for the preparation of the commercial chocolate and cocoa. Preparation of Chocolate. — The cocoa nibs are ground into a paste by a series of revolving stones, arranged in pairs and slightly heated to assist in liquefying the cocoa. While in a semi- fluid condition, the paste is moulded into cakes and allowed to harden. It may be sold in this form as plain chocolate or the ground nibs may be passed into a mixer and finely ground sugar, spices, vanilla and other flavors may be incorporated. After moulding, the product is placed on the market as sweet chocolate or as milk chocolate, if condensed or powdered milk has also been added. Preparation of Cocoa. — As the cocoa nib is too rich in fat for ordinary purposes, sometimes approximately one-half of the total weight, it is customary to remove a portion of it. The product is then known as cocoa. In the United States this is chiefly car- ried on by running the ground nibs, while in the semi-liquid form, directly from the grinder into an hydraulic press, which removes some 60-70 per cent, of the fat. The mass is then allowed to cool after which it is reduced to a powder and boxed. Foreign manufacturers remove further amounts of fat from cocoa by treatment with a watery alkali after which it is thoroughly washed and neutralized. The use of alkali is generally defended on the plea that it makes cocoa soluble but this statement is not borne out by the facts. No market cocoa or chocolate is com- pletely soluble but owing to the fine state of division of the particles, it does not readily settle in the hot, thick liquid. Ameri- can manufacturers do not generally favor this process. The ex- tracted fat is clarified and made into cocoa-butter. As cocoa- butter does not readily turn rancid if carefully stored, it is used largely in pharmacy, for candy-making and in the preparation of cosmetics, perfumes, pomades and soft toilet soaps. Adulteration. — Cocoa preparations have been much subject to adulteration. In order to increase the bulk and weight, sugar and various starches have been frequently added, while sand, 300 FOOD INDUSTRIES clay, the ground shells of the cocoa-bean, powdered roasted acorns, chestnuts and other substances of organic and inorganic origin have, from time to time, been found. Fats of cheaper variety, such as lard or coconut oil, are used to restore the normal percentage of fat after cocoa-butter has been removed. In cheaper grades of chocolate, glucose is sometimes used in place of sugar, while inferior flavorings and coloring matter are fre- quently added. As a Beverage. — Cocoa not only furnishes the material for a refreshing and exhilarating beverage, but is a food of great nutritive value. This may readily be seen by the average com- position of the cocoa bean as given by Payen. Fat '.'..' 50 Starch 10 Protein 20 Water 12 Cellulose 2 Mineral matter 4 Theobromine 2 Theobromine which is responsible for the stimulating effect of cocoa is closely related chemically to the alkaloid caffein, which occurs in tea and coffee and has a similar physiological effect. The presence of so high a percentage of fat, protein and car- bohydrate not only makes cocoa of greater nutritive value than tea or coffee, but both soluble and insoluble portions become a part of the beverage. This is not true of tea or coffee where only the constituents soluble in hot water are obtained. As chocolate is a concentrated food it frequently causes bili- ousness when indulged in too freely. Physiological Effect of Tea, Coffee and Cocoa. — The stimulating effect of tea and coffee is due to the presence of caffein a pow- erful drug which acts on the nervous system. The excessive use of these beverages frequently results in nervousness, insomnia, headache and indigestion ; disturbances of other organs may fol- low. A limited use appears, however, to be harmless or may even be beneficial to some people but they should never be given to young children. Cocoa and chocolate contain a substance similar to the caffein of tea and coffee, but is milder in its effects. CHAPTER XXII. SPICES AND CONDIMENTS. The terms condiments and spices are applied to products which possess no nutritive value, but are added to food to make it more palatable and to stimulate digestion. They may be either organic or inorganic. The words are confusing for the reason that many of the bodies included under these headings are similar in chemi- cal composition but all do not belong to the same series of chemical compounds. Actually, the terms as employed describe conditions of usage rather than composition. The word condi- ment describes material which is used commonly in the daily diet and covers all varieties of foods while spices are not so commonly employed, being restricted largely to pastry, puddings, cakes and the like. Condiments are represented by salt, pepper, mustard and vinegar; spices, by cinnamon, nutmeg, ginger, etc. CONDIMENTS. Sodium Chloride. — Sodium chloride or common salt, the most necessary to man and used to the largest extent, is inorganic. It appears to be the one item of food found in the diet of all nations and every race from the earliest times, the chlorine being utilized by the system in the formation of hydrochloric acid of the gastric juice, while the sodium is needed in the production of the bile. Its use is particularly important among people whose diet consists largely of vegetables and vegetable products. Salt is procured from natural deposits of sodium chloride in the form of solid crystals, from natural or artificial brine wells and from the sea by the process of evaporation. Formerly much of our salt came from the Bahama Islands. These islands are of coral origin and possess comparatively little vegetation. Small pools can be found in many places where the sun in time evap- orates the water, leaving a deposit of salt which could be sent to the market. The product was known as Turks Island Brand. Natural brine wells are underground streams which may be the result of sweet water percolating through salt soil, or they may have come from a body of salt water. Artificial brine wells have 302 FOOD INDUSTRIES been made by man by running water into a salt deposit. The brine may then be pumped to the surface which is an easier method of obtaining the salt than by digging. A large part of the salt on the American market to-day comes from natural brine wells in the vicinity of Syracuse, New York, and along the borders of Lake Erie. They were discovered as early as 1654 by the French Jesuits, who found the Iroquois and other Indian tribes making use of the salt. Michigan in the southern part, Ohio and Kansas are also rich in saline deposits, and much is procured from Utah on the shores of Great Salt Lake. The process of preparing salt for the market necessarily differs according to its source. Where natural deposits occur salt is mined by sinking a shaft and working similar to a coal mine. The salt can be sent to the market just as it is mined, under the name of rock-salt or it can be ground and screened. When salt has been obtained by evaporation from the ocean or other body of salt water it is usually quite impure so must be washed and recrystallized. The method used to the greatest extent to-day, consists in evaporating brine obtained from salt beds. The brine is generally purified by concentrating until the less soluble con- stituents, such as calcium sulphate, crystallize when .they can readily be removed. The brine is then concentrated in pans either by the sun's rays, direct heat or exhaust steam and sometimes in vacuo. However obtained the crystals are drained, dried, sifted into grades and packed. Pepper. — Various spices can be found on the market under the general head of pepper, but the most common forms are black and white pepper. Pepper is one of the oldest spices known to mankind and is still used in enormous quantities. Although it now sells at so low a price that it may be utilized by comparatively poor people, it was worth its weight in gold during the days of the Roman Empire. The high price in the Middle Ages led the Portuguese to seek a water route to the far east, and the first vessel that sailed around the Cape of Good Hope had for its object the finding of a cheaper way to procure pepper. The black variety is prepared from the dried, unripe berry FOOD INDUSTRIES 303 of a vine which was grown first in Southern India, the East Indies, Siam, Cochin China and in later ages in the West Indies. For a long period the Dutch nation controlled the trade and tried to confine its cultivation to the Island of Java and other Dutch possessions. The berry is gathered before it is fully matured, is spread out on mats for several days, after which the outer skin is removed by rubbing with the hand. It is then cleaned by sifting and is Fig 78.— Pepper Plantation near Singapore. (Courtesy of The Spice Mill Publishing Co.) usually ground before being placed on the market. White pepper is generally supposed to be produced from a different spice but is in reality the same fruit, prepared by a different method. This variety is obtained by decorticating or removing the dark skin from the fully ripened black peppercorn, leaving a light colored kernel which is pulverized, and forms the white pepper of com- merce. White pepper is more expensive but has a more delicate flavor than the whole pepper ground. There are several varieties of red peppers, the cayennes which have a sharp, acrid taste and the paprikas which are sweet and 304 FOOD INDUSTRIES mild. Paprika is used in cooking for its color as well as flavor. It is rapidly finding favor among American housewives. Mustard. — The mustard most commonly used is obtained by grinding to a flour the small seeds of the mustard plant. The plant which may be found either in the wild state or under cul- tivation has a wide distribution in Europe, northern Africa,, Asia, the United States, the West Indies and South America. It has been used for medicinal purposes from remote antiquity, but appears to have been unknown as a condiment until 1829, when a resident of Durham, England, placed it upon the market, keeping the manufacturing process a secret. The product was given the name of Durham Mustard, a brand which is still found in the markets. The two most common varieties of seeds used at the present are brown and yellow in color, the brown yielding the highest grade product. Mustard is prepared by passing the interior of the seed through a winnowing machine, for the removal of foreign material and crushing the grain between rollers, after which the oil is removed by hydraulic pressure. The cake is then dried, powdered and bottled. The powder is frequently mixed with spices and oil when it is known as prepared mustard. Much adulteration has been practiced in the preparation of mustard, principally in the addition of wheat flour, cayenne pepper, etc. Curry Powder. — Curry or curre powder is a very highly seasoned condiment which has been used for many generations in East India but has come into favor in the Western World only in recent years. It consists chiefly of ground turmeric roots highly flavored with cayenne pepper, ginger, and similar pungent spices. Curry is usually applied to cooked dishes just before serving. Vinegar. — Vinegar is used very largely in connection with food, the same as spices, to give flavor and as a preservative. Such articles as pickles depend largely upon vinegar for their keeping quality. It does not contain antiseptics as do the spices, but owes its preservative value to the acetic acid which inhibits the growth of putrefactive bacteria. FOOD INDUSTRIES 305 The manufacture of vinegar has been treated under the Fer- mentation Industries. See Chapter XIII. SPICES. Spices comprise all aromatic vegetable substances which may be added to food, principally to make it more palatable. They have been used from the earliest known eras of civilization and have played an important part in the discovery of a water pas- sage to the far east, in the colonization of the East Indies, and in the opening up of these countries to western civilization and to western trade. The tropical parts of Asia have given to the world by far the greatest variety and quantity of spices, such as pepper, cinna- mon, nutmeg, mace, cloves, turmeric, ginger and cassia. The tropical countries of America have added several new varieties to the list, cayenne pepper being the most important. The West Indies is celebrated for ginger and is also the home of the pi- mento. From Africa, grains of Paradise are obtained. All spice plants are grown in tropical climates, latitude 25 ° N. and 25 ° S. of the equator, where there is considerable rainfall and soil with water absorbing properties. Most of' these flavoring plants are found on islands in close proximity to the sea. Spices are obtained from different parts of the plant; dried fruit as pepper, pimento, nutmeg, mace; dried bark as cinnamon and cassia; flower buds as cloves; the root as ginger; seeds as cara- way; leaves as sage, thyme, etc. Many of these owe their power to essential oils which in some cases are extracted and used as flavoring extracts. The flavor of others is due to esters and to alkaloids. Uses. — While the principal use of spices is to add flavor to food and beverages this is by no means their only service to man. Many are used in perfumery, in soap making and in the manu- facture of incense. Several varieties are utilized in medicine chiefly to disguise a disagreeable flavor; turmeric is used in dye- ing and others in the various arts. In Egyptian days they were utilized for embalming all the distinguished dead. While spices have been used from early ages in connection 20 306 FOOD INDUSTRIES with food for the sake of the various flavors that they yield, it has been left to modern science to discover, that they also assist in the preservation of the material to which they have been added. This is due to the fact that they contain antiseptic prin- ciples. Spices as Preservatives. — That spices are useful as preservatives may readily be detected with such food products as sausages and mince meat. Mince meat as a rule has for its chief con- stituents chopped meat and apples. Meat is subject to decay by bacterial action and apples furnish an excellent food for mold and yeast, yet it is a well known fact that mince meat will keep for many months. Sausage meat is subject to rapid putrefaction but in winter weather, it can be kept for a length of time on account of the high content of spices. Fruit cake furnishes another example, as it can be held for an indefinite period and even improves with age. Spices do not furnish a complete pro- tection, however, and food material to which they have been added should not be allowed to stand in a warm place or fermen- tation and decay will set in. Although these facts have been common knowledge for many years, very little experimental work has been done, as to the varieties which contain the best antiseptic properties and the amount which should be used. Unfortunately many of them are irritating to the mucous membrane, and when used in excess are harmful. It is very important therefore that the manu- facturer and housewife should know which spices may be used for their antiseptic properties and what the physiological effect is of such condiments. To the experimental work of Conrad Hoffman and Alice Evans, the authors are indebted for the fol- lowing information.* That ginger, black pepper and cayenne pepper do not prevent the growth of micro-organisms but that cinnamon, cloves and mustard are valuable preservatives. Nutmeg and allspice delay growth but cannot be considered of any practical importance, since the amount used in cooking is too small to preserve food for any * The Use of Spices as Preservatives, by Conrad Hoffman & Alice Evans. Published in Journal of Industrial & Engineering Chemistry. FOOD INDUSTRIES 307 length of time. Cinnamon, cloves and mustard are almost equal in their efficiency. Cloves when used in large enough amounts to prevent growth have a burning taste to the palate, but cinnamon and mustard are particularly valuable as they are palatable even when used in proportions that prevent all growth. The active antiseptic constituents of mustard, cinnamon and cloves are their aromatic or essential oils. Cinnamon contains cinnamic aldehyde which is more effective if pure than benzoate of soda. Commonly Used Spices. — Cinnamon and Cassia. — Cinnamon is Fig. 79. —Rolling Cinnamon Bark into Quills. (Courtesy of the Spice Mill Publishing Co.) the inner bark of young shoots of certain species of cinnamon tree, which is particularly rich in a volatile oil known as oil of cinnamon. It is apparently one of the oldest of the spices used by man and was the first sought after in the oriental voyages of the early merchantmen. The shoots are cut very carefully from the tree, the bark is slit longitudinally and removed in strips by special knives. The strips are piled in heaps and allowed to fer- 308 FOOD INDUSTRIES ment, after which the epidermis is removed. The bark shrinks on drying and is known as "the quills." When put up in bundles they are ready for exportation (Fig. 79). Cinnamon contains an essential oil which consists largely of cinnamic aldehyde. A syn- thetic cinnamic aldehyde, prepared from coal tar, is frequently used in flavoring extracts to replace the genuine oil. Cassia in olden times was obtained entirely from the bark of other varieties of cinnamon trees. It was thick, comparatively coarse and was generally considered inferior to cinnamon. Much of the cassia of to-day, however, is obtained from China and the Dutch West Indies, from the fragrant bark of a plant known as the cassia. It has a much more pronounced flavor than cinnamon and is frequently used as an adulterant. Cloves. — Cloves are the unopened flower buds of an exceed- ingly beautiful evergreen tree, which grows mainly in the Spice Islands. They were known to the ancients and were considered an important article of trade in the Middle Ages. The curing process is very simple. After picking, the buds are thrown on the ground on grass mats and are allowed to dry in the sun, care being taken to shelter them from the dew at night. In about one week, they are ready to be packed for export. Cloves contain about 16 per cent, of a volatile oil, which can easily be removed and is of considerable value. It consists largely of a substance known as eugenol. The oil is used largely in perfumery and in soaps (Fig. 80). Allspice. — Allspice, known to the Spaniards as pimento, is the dried, unripe fruit of an evergreen tree native to the West Indies. Mexico and South America. The chief supply conies from Jamaica. The name allspice has been given on account of the fact that its very fragrant odor and flavor appears to be a com- bination of those obtained from cinnamon, cloves and nutmeg. The fruit is picked before it is ripe, dried in the sun and usually ground on common burr-stones. It is used frequently for medicinal purposes to disguise the taste of nauseous drugs, and in the tanning of some kinds of leather. Allspice yields ? volatile oil on distillation which is used as a flavoring in alcoholic solutions. FOOD INDUSTRIES 309 Fig. 80.— Clove Tree of Zanzibar. (Courtesy of The Spice Mill Publishing Co.) 3io FOOD INDUSTRIES Nutmeg and Mace. — Nutmeg is the dried kernel of the fruit of a tropical tree somewhat resembling an orange tree. It is native to the Malay Archipelago, but is also grown largely in Asia, Africa, South America and the -West Indies. The fruit is gathered when fully ripe and the outer part is discarded. The seeds are then dried in the sun or by artificial means. When the thin outer seed coat is broken, the kernel or nutmeg is removed, cleaned and packed. Nutmegs are exported in the unground state in order to retain the flavor, and usually lime coated for preservation. The inner envelope which surrounds the nut is also dried, and exported under the name of mace. Ginger. — Ginger is the only spice taken from the root. The original home of the plant is supposed to be China, but it is now Fig. 81. — Digging and Peeling Ginger in the Fields — Ginger Plantation, Jamaica. (Courtesy of The Spice Mill Publishing Co.) grown in many tropical countries. The West Indies produce an excellent quality, that from Jamaica usually being considered the best. The root may be left unpeeled when it is simply dried in the sun or it may be peeled after having been scalded. Preserved FOOD INDUSTRIES 31 1 ginger is prepared very largely in China, especially Canton. After being peeled, the ginger is treated with a boiling solution of sugar, after which it is packed in jars or sent to the market in the dry state (Fig. 81). Adulteration. — In former years, no article connected with our food supply was more largely subject to adulteration than spices, especially when they were placed on the market in the ground condition. Spices of a good quality were usually high in price, and many cheap materials could be found which to some extent resembled the real article. They were used frequently as dil- uents and to some extent as complete substitutes. According to Bulletin 13 of the United States Department of Agriculture, a profitable business for many years was carried on in the manufac- ture of products known as spice mixtures. They consisted of a combination of various materials, such as ground cocoanut shells, wheat flour, crackers, charcoal, coloring and mineral matter, yel- low cornmeal, mustard, husks, sawdust and other odds and ends. Much misbranding has also been found especially among flav- oring extracts. Vanilla and Lemon Extracts. — Vanilla is obtained from the fruit of a climbing orchid, native of tropical America, but now grown in Java, Ceylon and other parts of the Orient. It was used by the Aztecs as a flavoring agent for their favorite beverage chocolate, before the discovery of America, and was taken to Europe by the explorers as early as 15 10. The fruit is a pod which must be dried and cured with great care in order to obtain the desired flavor. The characteristic odor is developed during the process of fermentation which takes place while drying. The aroma and flavor are due to a substance known as vanillin which gradually crystallizes from the fluid of the pod. The well cured pods, either whole or powdered, may be found on the market as the vanilla bean or powder, but a more common form is the ex- tract of vanilla. Modern science has furnished a commercial rival to vanilla extract in the production of a synthetic product. Vanillin has been largely prepared from eugenol, a substance to which oil of cloves. 312 FOOD INDUSTRIES owes its characteristic odor, and in recent years much has also been obtained electrolytically from sugar. In the preparation of vanilla extract the flavor is obtained from the bean by a mixture of alcohol and water as the resins in the bean will not impart their flavor to either alcohol or water alone. (From 40-60 per cent, alcohol is the strength used according to the character of the bean.) The method of extraction is prefer- ably that of percolation. At least 13.35 oz - °f extracted matter in one gallon of the finished product is required by the United States Department of Agriculture. The best vanilla extracts are kept from six months to two years in white oak casks or vats in order to have them acquire a fine dainty bouquet which cannot be obtained by any other known process. Storage, however, raises the cost of the product 12-15 P er cent, owing to losses from evaporation and interest on the money invested and to insurance rates. The partly extracted beans are dried, ground and used in the powdered state by ice cream manufacturers. Lemon extract contains at least 5 per cent, by volume of lemon oil in alcohol of proper strength. The lemon oil industry has been carried on largely in Sicily. A very small quantity is pre- pared in the West Indies and experimental quantities in Cali- fornia, but the Sicilian lemons have so much finer bouquet and flavor that 99 per cent, used in this country comes from that section. In the best extracts 8 per cent, of the oil is used, the maximum amount that can be held in solution by 95 per cent, alcohol. A higher percentage would become cloudy if sub- jected to changes in temperature especially cold, and would ap- pear unsightly although the product would be in no way in- jured. Alcohol is necessary in the manufacture of lemon ex- tract not only to hold the oil in permanent solution, but to pro- tect it from the action of oxygen, since that element combines chemically with certain constituents of the oil known as ter- penes, resulting in a turpentine-like odor and a bitter, disagree- able taste. Fresh lemons are frequently added to give a fine aroma and zest to the oil. Much adulteration, substitution and misbranding has been practiced with vanilla and lemon extracts. In the former an FOOD INDUSTRIES 313 extract made from the tonka bean, the active principle of which is coumarin, is frequently used in inferior extracts to replace the more expensive vanilla. Imitation products from oil of cloves have also been largely employed. Such extracts have a strong pungent odor which will not volatilize in cooking as quickly as the genuine vanilla. They are often used for flavor- ing the ice cream and cakes on the market. Coloring matter and a low alcoholic strength are frequently found in both vanilla and lemon extracts. In the later imitation lemon prepared from lemon grass oil and citric acid have been much used. The flavoring extract business to a large extent passed into the hands of unscrupulous men, mail-order and premium-giving houses who put most inferior goods upon the market. As a result the Flavoring Extract Manufacturers Association of the United States was organized the object of which is to do away with all evil practices, to place the industry on a firmer basis and to secure uniform Pure Food Laws in the various states, which will be in accordance with those adopted by the National Gov- ernment. BIBLIOGRAPHY. CHAPTER I.— FOOD PRINCIPLES. Sherman, Henry C. — Chemistry of Foods and Nutrition. Jordan, Whitman H. — Principles of Human Nutrition. Vulte, H. T. — Household Chemistry. Perkin and Kipping. — Organic Chemistry. Thorpe. — Dictionary of Applied Chemistry. Haas and Hill.— An Introduction to the Chemistry of Plant Products. CHAPTER II.— WATER. Mason, William P.— Our Water Supply. Woodman and Norton.— Air, Water and Food. Leffmann, Henry. — Examination of Water. Frankland, E. — Water Analysis. Wanklyn and Chapman. — Water Analysis. Harrington, Charles. — Practical Hygiene. Thorpe.— Dictionary of Applied Chemistry. Buchanan, E. D. and R. E. — Household Bacteriology. Schultz, Carl H.— Mineral Waters. CHAPTER III.— CEREALS. Burtt-Davy, Joseph. — Maize : Its History, Cultivation, Handling and Uses. Freeman and Chandler. — The World's Commercial Products. Sherman, Henry C. — Food Products. Bailey, E. H. S. — The Source, Chemistry and Use of Food Products. Harrington, Charles. — Practical Hygiene. Wiley, Harvey W. — Foods and Their Adulteration. Ward, Artemas. — The Grocers Encyclopedia. Bulletin No. 131, Agricultural Experiment Station, Orono, Maine. — Indian Corn as Food for Man. Farmers Bulletin No. 417, U. S. Department of Agriculture, Washington, D. C— Rice Culture. Farmers Bulletin No. 45, U. S. Department of Agriculture, Washington, D. C. — Some Insects Injurious to Stored Grain. Farmers Bulletin No. 565, U. S. Department of Agriculture, Washington, D. C. — Cornmeal as a Food and Ways of Using It. Encyclopedias. — Britannica, International. CHAPTERS IV AND V.— OLD AND MODERN MILLING PROCESSES. Dondlinger, Peter Tracy. — The Book of Wheat. Smith, Rollin E— Wheat Fields and Markets of the World. FOOD INDUSTRIES 315 Edgar, William C. — Story of a Grain of Wheat Amos, Percy A. — Processes of Flour Manufacture. Grant, James. — The Chemistry of Breadmaking. Wiley, Harvey W. — Foods and Their Adulteration. Bulletin No. 57, Agricultural Experiment Station, Ottawa, Canada. — Quality in Wheat. Trade Paper. — The Northwestern Miller, Chicago, 111. Encyclopedias. — Britannica, International. CHAPTER VI.— BREAKFAST FOODS. Bulletin No. 118, Agricultural Experiment Station, Orono, Maine. — Cereal Foods. Bulletin No. 13, U. S. Department of Agriculture, Bureau of Chemistry — Cereals and Cereal Products. Bulletin No. 65, Agricultural Experiment Station, Orono, Maine. — Coffee Substitutes. Bulletin No. 211, State Agricultural College Experiment Station, Michi- gan. — -Breakfast Foods. Bulletin No. 162, Dept. of Agriculture, Ontario Agricultural College, Ontario, Canada. — Breakfast Foods. Farmers Bulletin No. 249, U. S. Department of Agriculture, Washington, D. C. — Cereal Breakfast Foods. CHAPTER VII.— UTILIZATION OF FLOUR. Jago, W. and W. C. — Technology of Breadmaking. Simmons. — Book of Bread. Grant, James. — The chemistry of Breadmaking. Buchanan, E. D. and R. E. — Household Bacteriology. Conn, H. W. — Bacteria, Yeasts and Molds in the Home. Jordan, E. O. — General Bacteriology. Farmers Bulletin No. 389, U. S. Department of Agriculture, Washington, D. C. — Bread and Breadmaking. The National Geographic Magazine, March, 1908. — Making Bread in Different Parts of the World. Trade Paper. — The Baker's Review. New York City. CHAPTER VIII.— LEAVENING AGENTS. Hart, Richard N. — Leavening Agents. Thorpe. — Dictionary of Applied Chemistry. Smith, Alexander. — General Inorganic Chemistry. Harrington, Charles. — Practical Hygiene. Bulletin No. 13, Part Fifth, U. S. Department of Agriculture, Division of Chemistry. — Baking Powders. 316 FOOD INDUSTRIES Bulletin No. 52, Agricultural Experiment Station, Florida. — Baking Powders. Bulletin No. 103, U. S. Department of Agriculture.— Alum in Foods. CHAPTER IX.— STARCH AND ALLIED INDUSTRIES. Sadtler, Samuel. — Handbook of Industrial Organic Chemistry. Thorp, Frank H. — Outlines of Industrial Chemistry. Thorpe. — Dictionary of Applied Chemistry. Olsen, John C. — Pure Foods. Humphrey, H. C. — Descriptive Paper — The Corn Products Refining Industry. Bulletin No. 202, U. S. Department of Agriculture, Washington, D. C. — ■ Digestibility of Starch of Different Sorts as Affected by Cooking. CHAPTER X.— THE SUGAR INDUSTRY. Geerlings, H. C. Prinsen. — The World's Cane Sugar Industry, Past and Present. Sadtler, Samuel P. — Handbook of Industrial Organic Chemistry. Thorp, Frank H. — Outlines of Industrial Chemistry. Thorpe. — Dictionary of Applied Chemistry. Wiley, Harvey W. — Foods and Their Adulteration. Deerr, Noel. — Sugar and the Sugar Cane. Deerr, Noel. — Cane Sugar Manufacture. International Library of Technology. — Manufacture of Sugar. The School of Mines Quarterly, Columbia University, April, 191 1. — The Chemistry of Raw Sugar Production; Sugar Refining. The School of Mines Quarterly, Columbia University, January, 1913. — Manufacture of Raw Sugar in the Philippine and Hawaiian Islands. The School of Mines Quarterly, Columbia University, July, 1913. — By-Products of Sugar Manufacture, and Methods for Their Utili- zation. Farmers Bulletin, No. 52, U. S. Department of Agriculture, Washington, D. C— The Sugar Beet. Report of the Eighth International Congress of Applied Chemistry, Vol. 27-29. — The Status of Cane Sugar and Manufacture in the Hawaiian Islands. Trade Paper. — Sugar, Chicago, 111. CHAPTER XL— FRUITS, VEGETABLES AND NUTS. Ward, Artemas. — The Grocers Encyclopedia. Wiley, Harvey W. — Foods and Their Adulteration. Sherman, Henry. — Food Products. Bailey, E. H. S. — The Source, Chemistry and Use of Food Products. FOOD INDUSTRIES 317 Fisher and Fisk. — How to Live. Bulletin by C. F. Langworthy. — Green Vegetables and Their Use in the Diet. Bulletin by C. F. Langworthy. — Raisins, Figs and Other Dried Fruits and Their Uses. Bulletin, University of Illinois, Department of Household Science. — Prin- ciples of Jelly Making. Bulletin No. 172, The Agricultural Experiment Station, Fort Collins, Colo. — Garden Notes. Farmers Bulletin, No. 121, U. S. Department of Agriculture, Washington, D. C. — Beans, Peas and Other Legumes as Food. Farmers Bulletin No. 256, U. S. Department of Agriculture, Washington, D. C. — Preparation of Vegetables for the Table. Farmers Bulletin, No. 295, U. S. Department of Agriculture, Washington, D. C. — Potatoes and Other Root Crops as Food. Farmers Bulletin, No. 324, U. S. Department of Agriculture, Washington, D. C. — Sweet Potatoes. Farmers Bulletin, No. 433, U. S. Department of Agriculture, Washington, D. C— Cabbage. Farmers Bulletin, No. 282, U. S. Department of Agriculture, Washington, D. C. — Celery. Farmers Bulletin, No. 220, U. S. Department of Agriculture, Washington, D. C. — Tomatoes. Farmers Bulletin, No. 293, U. S. Department of Agriculture, Washington, D. C. — Use of Fruit as Food. Farmers Bulletin, No. 203, U. S. Department of Agriculture, Washington, D. C. — Canned Fruit, Preserves and Jellies. Farmers Bulletin, No. 332, U. S. Department of Agriculture, Washington, D. C. — Nuts and Their Use as Food. Trade Paper. — Green's Fruit Grower. CHAPTERS XII AND XIII.— ALCOHOLIC BEVERAGES. Thorpe. — Dictionary of Applied Chemistry. Sadtler, Samuel. — Handbook of Industrial Organic Chemistry. Thorp, Frank H. — Outlines of Industrial Chemistry. Harrington, Charles. — Practical Hygiene. Accum, Frederick. — A Treatise of Adulteration of Food and Culinary Poisons. Fisher and Fisk. — How to Live. Buchanan, E. D. and R. E. — Household Bacteriology. Conn, H. W. — Bacteria, Yeasts and Molds in the Home. Fowler, G. J. — Bacteriological and Enzyme Chemistry. Osborn's Annual Guide, December, 1903. — Vintage and Production of Wines and Liquor. 318 FOOD INDUSTRIES Bulletin No. 13, Part Third, U. S. Department of Agriculture, Division of Chemistry.- — Fermented Alcoholic Beverages. Bulletin No. 239, Agricultural Experiment Station, Ottawa, Canada. Trade Paper. — The American Brewer. CHAPTER XIV.— FATS. Sadtler, Samuel P. — Handbook of Industrial Organic Chemistry. Thorp, Frank H. — Outlines of Industrial Chemistry. Thorpe. — Dictionary of Applied Chemistry. Wing, Henry W. — Milk and Its Products. Bailey, E. H. S. — The Source, Chemistry and Use of Food Products. Sherman, H. C. — Food Products. Lewkowitsch. — Chemical Technology and Analysis of Oils, Fats and Waxes. Ward, Artemas. — The Grocers Encyclopedia. Leffmann and Beam. — Food Analysis. Wiley, Harvey W. — Foods and Their Adulterations. International Library of Technology. — Cottonseed Oil and Products. Bulletin No. 13, Part First, U. S. Department of Agriculture, Division of Chemistry. — Dairy Products. Bulletin No. 163, Agricultural Experiment Station, Fort Collins, Colo.— Farm Butter Making. Farmers Bulletin, No. 241, U. S. Department of Agriculture, Washington, D. C. — Butter Making on the Farm. Farmers Bulletin, No. 131, U. S. Department of Agriculture, Washington, D. C. — Household Tests for the Detection of Oleomargarine and Renovated Butter. CHAPTER XV.— ANIMAL FOODS. Sherman, Henry C. — Food Products. Wiley, Harvey W. — Foods and Their Adulterations. Harrington, Charles. — Practical Hygiene. Hutchison, Robert. — Foods and Dietetics. Jordan, Whitman H. — Principles of Human Nutrition. Wilder, F. W. — The Modern Packing House. Ward, Artemas. — The Grocers Encyclopedia. The National Geographic Magazine, March, 1913. — Oysters : The World's , Most Valuable Water Crop. Bulletin No. 114, U. S. Department of Agriculture, Bureau of Chemistry. — Meat Extracts and Similar Preparations. Bulletin No. 13, U. S. Department of Agriculture, Bureau of Chemistry. — Preserved Meats. Farmers Bulletin, No. 391, U. S. Department of Agriculture, Washington, D. C. — Economical LTse of Meat in the Home. FOOD INDUSTRIES 319 Farmers Bulletin, No. 183, U. S. Department of Agriculture, Washington, D. C— Meat on the Farm. Farmers Bulletin, No. 85, U. S. Department of Agriculture, Washington, D. C. — Fish as Food. Farmers Bulletin, No. 128, U. S. Department of Agriculture, Washington, D. C. — Eggs and Their Uses as Food. CHAPTER XVI.— THE PACKING HOUSE. Wilder, F. W— The Modern Packing House. International Library of Technology. — Packing House Industries. The Chemical Engineer, December, 1906. — Chemical Engineering in the Packing House. Morris & Co. — The Pictorial History of a Steer. Wiley, Harvey W. — Foods and Their Adulteration. Encyclopedia. — International. CHAPTER XVII.— MILK. Winslow, K. — The Production and Handling of Clean Milk. Ros ; nau, M. J.— The Milk Question. Wing, Henry H. — Milk and Its Products. Sherman, Henry C. — Food Products. Harrington, Charles. — Practical Hygiene. Buchanan, E. D. and R. E. — Household Bacteriology. Conn, H. W. — Agricultural Bacteriology. Conn, H. W. — Storrs Agricultural Experiment Station, Report 1895— Bacteria in the Dairy. Leffmann and Beam. — Food Analysis. Bulletin No. 161, U. S. Department of Agriculture, Bureau of Animal Industry. — A Study of the Bacteria which Survive Pasteurization. Bulletin No. 104, U. S. Department of Agriculture, Bureau of Animal Industry. — Medical Milk Commission and the Production of Cer- tified Milk in the United States. Bulletin No. 107, U. S. Department of Agriculture, Bureau of Animal Industry. — The Extra Cost of Producing Clean Milk. Farmers Bulletin, No. 363, U. S. Department of Agriculture, Washington, D. C— The Use of Milk as Food. Farmers Bulletin, No. 413, U. S. Department of Agriculture, Washington, D. C— The Care of Milk and Its Use in the Home. Farmers Bulletin, No. 63, U. S. Department of Agriculture, Washington, D. C. — The Care of Milk on the Farm. 320 FOOD INDUSTRIES CHAPTER XVIII.— MILK PRODUCTS. Van Slyke and Publow. — The Science and Practice of Cheese-making. Wing, Henry H. — Milk and Its Products. Wiley, Harvey W. — Foods and Their Adulteration. Leffmann and Beam. — Food Analysis. Luchsinger. — History of a Great Industry. Address at the State His- torical Society of Wisconsin. The National Geographic Magazine, December, 1910. — A North Holland Cheese Market. Bulletin No. 13, Part First, U. S. Department of Agriculture, Division of Chemistry. — Dairy Products. Bulletin No. 203, New York Agricultural Experiment Station, Geneva, N. Y. — A Study of Enzymes in Cheese. Bulletin No. 219, New York Agricultural Experiment Station, Geneva, N. Y. — Some of the Compounds Present in American Cheddar Cheese. Bulletin No. 236, New York Agricultural Experiment Station, Geneva,. N. Y. — Conditions Affecting Chemical Changes in Cheese-making, Bulletin No. 237, New York Agricultural Experiment Station, Geneva, N. Y.— The Role of the Lactic Acid Bacteria in the Manufacture and in the Early Stages of Ripening of Cheddar Cheese. Farmers Bulletin, No. 487, U. S. Department of Agriculture, Washington, D. C. — Cheese and Its Economical Uses in the Diet. CHAPTERS XIX AND XX.— PRESERVATION OF FOODS. Appert, Nicholas. — The Art of Preserving All Kinds of Animal and Veg- etable Substances. Duckwall, E. W. — Canning and Preserving. Thresh and Porter. — Preservatives in Food and Food Examination. Rideal, Samuel. — Disinfection and the Preservation of Foods. Wiley, Harvey W. — Foods and Their Adulteration. Green, Mary E. — Food Products of the World. Bulletin No. 13, Part Eighth, U. S. Department of Agriculture, Division of Chemistry. — Canned Vegetables. Bulletin No. 151, U. S. Department of Agriculture, Bureau of Chem- istry. — The Canning of Foods. Farmers Bulletin, No. 375, U. S. Department of Agriculture, Washington, D. C— The Care of Food in the Home. Farmers Bulletin, No. 359, U. S. Department of Agriculture, Washington, D. C. — Canning Vegetables in the Home. Farmers Bulletin, No. 521, U. S. Department of Agriculture, Washington, D. C. — Canning Tomatoes at Home and in Club Work. Farmers Bulletin, No. 203, U. S. Department of Agriculture, Washington, D. C. — Canned Fruit, Preserves and Jellies. FOOD INDUSTRIES 32 1 Farmers Bulletin, No. 291, U. S. Department of Agriculture, Washington, D. C. — Evaporation of Apples. CHAPTER XXL— TEA, COFFEE AND COCOA. Freeman and Chandler. — The World's Commercial Products. Thorpe. — Dictionary of Applied Chemistry. Ward, Artemas. — The Grocers Encyclopedia. Harrington, Charles. — Practical Hygiene. Fowler, E. J. — Bacteriological and Enzyme Chemistry. Whymper, R. — Cocoa and Chocolate ; Their Chemistry and Manufacture. Harris, W. B. — Paper on Coffee as Affected by the Food and Drugs Act. Count Rumford. — Essay on The Excellent Qualities of Coffee and the Art of Making it in the Highest Perfection. Leffmann and Beam. — Food Analysis. Pan-American Union Bulletin, 1912. — The Cacao of the World. The National Geographic Magazine, October, 191 1. — A Visit to a Brazilian Coffee Plantation. Bulletin No. 13, Part Seventh, U. S. Department of Agriculture, Wash- ington, D. C. — Tea, Coffee and Cocoa Preparations. Farmers Bulletin, No. 301, U. S. Department of Agriculture, Washington, D. C. — Home Grown Tea. Trade Paper. — The Tea and Coffee Trade Journal, New York. Trade Paper.— The Spice Mill. Spice Mill Publishing Co., New York. CHAPTER XXIL— SPICES AND CONDIMENTS. Ridley, Henry N. — Spices. Gibbs, W. M. — Spices and How to Know Them. Freeman and Chandler. — The World's Commercial Products. Bailey, E. H. S. — The Source, Chemistry and Use of Food Products. Leffmann and Beam.— Food Analysis. Wiley, Harvey W. — Foods and Their Adulteration. Ward, Artemas. — The Grocers Encyclopedia. Conn, H. W. — Bacteria, Yeasts and Molds in the Home. Hoffman and Evans. — Journal of Industrial and Engineering Chemistry. The Use of Spices as Preservatives. Bulletin No. 13, Part Second, U. S. Department of Agriculture, Division of Chemistry. — Spices and Condiments Trade Paper.— The Spice Mill. Spice Mill Publishing Co., New York. INDEX. Acid phosphate of lime 119 Adulteration. . . .44, 46, 48, 73, 78 84, 101, 158, 179, 191, 202, 215, 258, 278, 293, 299, 311 Albumins 13 Albuminoids 13, 14 Alcoholic beverages ..... .169-191 adulteration 179, 191 brewing 1 71-179 cider 189 classification 169 distilled liquors 186-189 koumiss 191 vinegar 190, 191 wine industry 181-186 Ale 180 Allspice 308 Alum 28, 29, 101, 117 Animal foods 205-223 beef extracts ....210-212,231 eggs 220-223 fish 213-215 internal organs 212-213 meat 205-210 poultry 218-220 shellfish 215-218 Baking powders ........ .114-118 Barley 48, 49 Beef extracts 210-212, 231 Beer (see Brewing) Bicarbonate of soda 1 19-122 Biscuit industry 104-110 Bolter 70 Bone-black filters 155 Brandy 187 Breadmaking 86-104 adulteration 101 aerated bread 103, 104 leavened bread 88 losses -in fermentation... 102 Breadmaking — (Continued) primitive methods 86-88 salt-rising bread 95 souring and its preven- tion 100, 101 steps in breadmaking. . .96-98 yeast preparations 93~95 Breakfast foods 79-84 Brewing 171-180 Butter 193-198 Caff ein 286, 294, 300 Cane syrup 1 58 Canning industry 271-278 adulteration 278 containers 275-277 historical 271, 272 meat products 275 processes 272-274 success of canning 274 Carbohydrates 7-10 classification 7 formation 8 occurrence 8 properties 9 Cassava 125, 126 Cassia 307 Caviar 214 Cellulose 9 Centrifuge 144 Cereals 38-49 barley 48-49 biological origin 38 composition 39 Indian corn 39~44 oats 47, 48 rice 44-47 use in our country 38 Champagne 185 Cheese 253-258 Chocolate 299 Cider 189 3^4 FOOD INDUSTRIES Cinnamon 307 Clams 217 Clotting 15 Cloves 308 Coagulation 15 Cocoa 294-300 adulteration 299 as a beverage 300 cultivation 295 historical 294 manufacture 296-299 physiological effect 300 Coconut oil 204 Coffee 287-294 adulteration 293 as a beverage 294 cultivation 289 extracts 294 historical 287 manufacture 280-293 physiological effect 300 substitutes 85 Cold storage 261-263 Condiments 301-305 Cordials 189 Cornmeal 42 Corn syrup (see Glucose) Cottonseed oil 202, 203 Crabs 218 Crackers (see Biscuit industry) Cream of tartar 1 18, 1 19 Curdling 15 Curry powder 304 Dextrin 9, 132, 133 Diffusion battery 150-152 Diseases from impure milk . . 230-240 Diseases from impure water 23 Diseases of animals 208,209 Distillation 30 Domestic filters 31 Drying 250-261 Eggs 220-223 Emulsification 12 Extractives 15 Fats 192-204 butter 193-198 butter substitutes 199-201 composition 10, 11 edible oils 201-204 extraction 192 occurrence 11, 12 properties 12 purification 193 Fermentation 177-179, 183, 184 Fish 213-215 Flour 64-77 adulteration 73 bleaching jt> entire wheat 75 gluten yy Graham 74, 75 hard wheat J2> prepared 74 soft wheat 73 testing 72 utilization of 86-112 Food principles 5-7 Foot-and-mouth disease 208 Fructose 8 Fruits and vegetables 159-166 composition 161 cultivation 162 definition and classification 160 handling on the farm. . . . 1162 importance in the diet... 159 marketing 165 transportation and storage 164 Galactose 8 Gelatin 230 Gin 189 Ginger 310 Globulin 13, 14 Glucose 8, 133-135 Glutelins 13, 14 FOOD INDUSTRIES 325 Glycogen 9 Glycoproteins 13, 14 Grist mill 61 Haemoglobins 13, 14 Hand-stones 58 Hominy 42 Hydrolysis 10, 14, 15 Ice cream 251 Ice supply 33 Indian corn 39~44 Jellies and jams 166 Koumiss 191 Lactose 9 Lard 228 Leavening agents 1 13-122 Lemon extract 311 Lobsters 218 Macaroni 1 10-1 12 Mace 310 Maize (see Indian corn) Malting 172-175 Maltose 9 Marmalade 166 Meat 205-210 Meat products 275 Milk 233-246 certified 245 composition 234, 235 diseases from milk 239 importance of supply .... 236 modified 246 necessity for cleanliness . . 240 pasteurization 245 producer 241 safeguarding the supply. . 240 source 233 sterilization 242 testing 242 Milk products 247-258 artificially soured milk. . . 253 butter 193-198 by-products of butter. 252, 253 cheese 253-258 concentrated milk 249 condensed milk 247 evaporated milk 249 ice cream 251 market cream 250, 251 milk powders 250 Milling- modern processes 64-77 old processes 58-63 Mineral waters 33~37 artificial 36 classification 33 natural 33-36 Molasses 156, 157 Mussels 218 Mustard 304 Nncleo-proteins 13, 14 Nutmeg 310 Nuts 166-168 Oatmeal 47 Oats 47, 48 Oleomargarine 199-201 Oleo oil 227 Olive oil .201, 202 Oysters 215-217 Packing house 224-232 growth and breadth 224 historical 224 processes and by-prod- ucts 225-232 Peanut oil 203 Pepper 302-304 Pestle and mortar 59 Phospho-proteins 13, 14 Porter 180 Poultry 218-220 326 FOOD INDUSTRIES Preservation of foods. .. .250-278 alcohol 268 canning 271-278 cooling 261-263 drying 259-261 preservatives 268 salting 264 smoking 265 sugaring 263 use of fats and oils 267 use of spices 267 Preservatives 268-270 Proteins 13-16 classification . . 13 composition 13 hydrolysis 14 occurrence 13 properties 15 Purifier 69 Quern 59 Renovated butter 199 Rice 44-47 Rum 187 Rye 77, 78 Saccharine 269 Salting 264 Salt rising bread 95 Samp 42 Saponification 12 Sausages 231 Scallops 217 Scalper 67 Semolina 77 Shellfish 215-218 Smoking 265, 266 Sodium chloride 301 Spices 305-311 Starch 123-132 corn 127-132 potato 124, 125 properties 123 Starch — (Continued) source of supply 124 tapioca 125, 126 uses 123, 124 Sucrose (see Sugar) Sugar 136-158 beet sugar industry. . .145-152 cane sugar industry. . .138-145 comparison of cane and beet 137 historical 136-138 refining 152-155 source 8, 9, 136 Sugaring 263 Sweetbreads 213 Tallow 227 Tartaric acid 119 Tea 279-287 adulteration 286 as a beverage 286 classification 281 composition of the bever- age 287 cultivation of the plant 270-281 historical 279 manufacture 283-286 physiological effect 300 rules for tea-making 286 Trichina 208 Tuberculosis 209 Vacuum pan 142-144 Vanilla extract 311 Vegetables (see Fruits) Vinegar 190, 191, 304 Water 17-37 atmospheric 19 classifications 17, 19 contamination 21, 22 danger of impure water. . 23 ice supply 33 importance of 15 FOOD INDUSTRIES 327 Water — (Continued) Wheat — (Continued) j udging a supply 32 origin 50 mineral waters 33 structure of grain 54-50 subsoil 20 value 56, 57 surface ... 20 varieties 57, 58 Wheat 50-77 Whiskey 187-189 cultivation 53, 54 Wine industry 181-186 distribution 51-53 milling 58-77 Yeast 80-95 Household Chemistry for the use of Students in Household Arts BY Hermann T. Vulte, Ph.D., F. C. S. Assistant Professor of Household Chemistry in Teachers College, Columbia University CONTENTS. — Introduction ; Chapter I. — Outline of Organic Chemistry; Chapter II. — Atmosphere and Ventilation; Chapter III— Water; Chapter IV.— Metals ; Chapter V.— Glass, Pottery and Porcelain; Chapter VI. — Fuels; Chapter VII. — Carbohy- drates ; Chapter VIII. — Fruit and Fruit Juices ; Chapter IX. — Fats ; Chapter X. — Proteins ; Chapter XI. — Baking Powders ; Chapter XII. — Tea, Coffee, Chocolate and Cocoa; Chapter XIII. — Ferments and Preservatives ; Chapter XIV. — Disinfect- ants and Disinfection; Chapter XV. — Cleansing Agents; Chapter XVI. — Volumetric and Gravimetric Analysis; Chapter XVII. — Reagents. Appendix. Useful Tables. Pages VI + 234 (12 mo.) Price, $1.50, Postpaid The Chemical Publishing Co. EASTON, PENNA. LAUNDERING BY L. Ray Balderston Instructor in Laundering, Teachers College, Columbia University, New York City. 2nd EDITION Useful to Housewives Helpful to Teachers Text Book to Classes "This manual on Laundering is by Miss Balderston, who is an authority the country over on this subject. How to remove stains; how to set colors; washing woolens, sweaters, etc; laundry equipment, various types of washing machines, cost, etc.; all these are discussed, and explicit directions given." — Philadelphia Public Ledger. Published by L. R. BALDERSTON 1224 Cherry Street, Philadelphia, Pa. Price: $1.25 postpaid For sale by all book dealers