Class / 4 StDr r ) Book il Copyright^ . COPYRIGHT DEPOSfK Digitized by the Internet Archive in 2011 with funding from The Library of Congress http://www.archive.org/details/foodindustriesOOvult FOOD INDUSTRIES An Elementary Text-book on the Produc- tion and Manufacture of Staple Foods DESIGNED FOR USE IN HIGH SCHOOLS AND COLLEGES by HERMANN T. VULTE, Ph.D., F.C.S. Assistant Professor Household Arts, Teachers College, Columbia University SADIE B. VANDERBILT, B.S. Instructor Household Arts, Teachers College, Columbia University E ASTON, PA.: THE CHEMICAL PUBLISHING CO. 1914 \X 3 53 Copyright, 1914, by H. T. Vui/ris ;£K 29 1914 ©CI.A380644 - PREFACE. After many years' experience in lecturing on the processes of food manufacture, the authors feel encouraged to submit the result of their labors as a guide to those who wish to study this most important and interesting subject. Certainly no branch of general manufacturing has undergone so many and such important changes in the past twenty-five years as the food industries. The public have largely benefitted from these changes both in pocket and health. Unfortunately there still lingers in the minds of many, the impression that food stuffs have not the same dietetic value they possessed in the past, and that manipulation gives them an appear- ance of quality they do not possess. It is the universal experi- ence of the authors that manufacturers have not only improved the quality of their products in every possible way, but having nothing to conceal except from competitors, are most anxious to enlighten the interested consumer in the processes involved. Some mistakes have certainly been made in the past, but with no evil intent and largely through ignorance. As time passes these errors are corrected and it can confidently be stated that the public receives to-day better and cleaner material at a lower price than formerly. The economic improvement is largely due to the general utilization of by-products, many of which do not appear in any list of foods. The following pages do not claim to deal with any industry from the purely technical standpoint, but aim to point out the most essential parts of each. A knowledge of chemistry and physics is not absolutely essential, but is very helpful. As a pioneer book on the subject, any suggestions furnished by teachers would be very gratefully received. The authors are greatly indebted to Dr. H. C. Humphrey, Dr. W. D. Home, Dr. W. E. J. Kirk, Mr. George S. Ward and Mr. Earl D. Babst for valuable suggestions in regard to the subject matter of this book and to Mrs. Ellen B. McGowan of Teachers College for reading the manuscript. They wish also to acknowledge the assistance of the many manufacturers who have thrown their plants open for inspection and who have allowed the use of photographs and cuts of machinery. September, 1914. TABLE OF CONTENTS. PAGE Introduction 1-4 Chapter I — Food Principles 5 -I 5 Functions. Conservation of Energy. Elements in Foods. Food Principles. Examples of Each Group. Functions of Each Group. Importance of Water. Carbohydrates. Classification. Formation. Occur- rence. Important Properties. Hydrolysis. Fats. Composition. Occurrence. Properties. Solubility. • Change of State. Crystallization. Drying and Non- drying. Emulsification. Saponification. Proteins. Composition. Classification. Occurrence. Protein Hydrolysis. Properties. Solubility. Curdling. Coagulation. Clotting. Chapter II — Water 16-35 Classification of Natural Waters. Water Supply. Historical. Classification of Potable Water. Atmos- > pheric. Surface Water. Subsoil Water. Pollution of Wells. Contamination of Public Supplies. Danger of Impure Water. Diseases from Water. Purifica- tion of Water. Public Methods. Bacterial Action. Filtration. Use of Chemical Agents. Household Methods. Boiling. Use of Domestic Filters. Manufacturers' Methods. Self-purification. Judg- ing a Water Supply. Ice Supply. Mineral Waters. Classification. Natural Mineral Springs. Occur- rence. Medicinal Power. Artificial Mineral Waters. Chapter III— The King of Cereals. Old Milling Processes 36-51 Wheat. Origin. Geographical Distribution. Culti- vation. Structure of the Wheat Grain. Value of Wheat. Varieties. Old Milling Processes. Hand- stones. The Pestle and Mortar. The Quern. The Grist Mill. Disadvantages of Old Processes. Chapter IV — Modern Milling and Mill Products 52-65 Dust Collectors. Fundamental Objects in Milling. Cleaning of the Wheat. Tempering. Separation of the Middlings. Reduction of the Middlings. Advan-- CONTENTS V PAGE tages of the New Process. Testing of Flour. Wheat Blends. Adulteration. Bleaching of Flour. Mill Products. Hard Wheat Flour. Soft Wheat Flour. Prepared Flour. Graham Flour. Entire Wheat Flour. Gluten Flour. Cereal Department. Seminola. Rye. Composition. Uses. Adulteration. Chapter V — Cereals 66-76 Biological Origin. Kinds. Geographical Distribution. Use in Our Country. Indian Corn or Maize. Origin. Early Cultivation. Varieties. Early Methods of Preparation. Old Milling Methods. Samp. Hominy and Cornmeal. Modern Milling. Uses. Adultera- tion. Rice. Origin. Geographical Distribution. Composition. Cultivation. Milling. Adulteration. Uses. Oats. Composition. Oatmeal. Milling. Adulteration. Barley. Origin. Cultivation. Com- position. Uses. Mill Products. Chapter VI — Breakfast Foods and Coffee Substitutes. . 77-83 Breakfast Foods. Classification. Uncooked. Partly Cooked. Cooked. Malted Preparations. Adultera- tion. Comparison of Old and New Cereals. Coffee Substitutes. Chapter VII — Utilization of Flour. Breadmaking. . . . 84-106 Primitive Breadmaking. Leavened Bread. Flour. Water. Salt. Yeast. Leavening Effect of Yeast. Yeast Preparations. Home Brew. Brewer's Yeast. Compressed Yeast. Dried Yeast. Object in Bread- making. Steps in Breadmaking. Fermentation. Straight or Off'-Hand Dough. Ferment and Dough. Sponge and Dough. Baking. Cooling. A Modern Bread Factory. Souring and Its Prevention. Adul- teration. Losses in Fermentation. Chemical Process. Aerated Bread. Crackers. Macaroni. Manufactur- ing Processes. Domestic Macaroni. Judging Quality. As a Food. Chapter VIII — Leavening Agents 107-116 Advantages of Yeast. Chemical Agents. Advan- tages. Disadvantages. Baking Powders. Tartrate VI CONTENTS Powder. Phosphate and Alum Powders. Compari- son of Tartrate, Phosphate and Alum Phosphate Powders. Relative Efficiency. Ammonia Powders. ' Cream of Tartar. Tartaric Acid. Acid Phosphate of Lime. Bicarbonate of Soda. LeBlanc Method. Solvay Process. Niagara Process. Chapter IX — Starch and Allied Industries 1 17-129 Starch. Composition and Formation. Physical Characteristics. Physical and Chemical Properties. Uses. Source of Supply. Potato Starch. Extrac- tion. Processes in Manufacture. Tapioca. Corn Products Industry. Processes in Manufacture. By- products and Their Uses. Dextrins. Uses. Corn Syrup or Glucose. Uses. Processes in Manufacture. Chapter X — The Sugar Industry. 130-152 Source. History of the Sugar Cane. Histor}' of the Sugan Beet. Comparison of Cane and Beet Sugar. Properties of Sugar. The Cane Sugar Industry. Growth of the Cane. Production of Raw Cane Sugar. The Beet Sugar Industry. Beet Culture. Production of Raw Beet Sugar. Refining of Raw Sugar. Granulated Sugar. Block Sugar. Powdered Sugar. Utilization of the By-products. Yellow Sugar. Maple Sugar. The Date-palm. Sorghum. Cane Syrup. Adulteration of Sugar. Chapter XI — Alcoholic Beverages 153-164 Classification. Historical. Fermentation. The Brew- ing of Beer. Raw Material. Processes in Manu- . facture. Composition of Beer. Adulteration. Sub- stitution. Kinds of Beer. Chapter XII — Alcoholic Beverages (Continued) 165-175 The Wine Industry. Processes in the Manufacture of Still Wine. Improving Wines. Champagne. Sophisticated Wines. Adulteration. By-products. Distilled Liquors. Distillation. Bonded Whiskey. Cider. Vinegar. Adulteration. Koumiss. Chapter XIII— Fats „ 176-186 Extraction. Purification. Butter. Composition. . CONTENTS Vll Processes in Butter-making. Renovated Butter. Oleomargarine. Material Used. Processes in Manu- facture. Olive Oil. Processes in Manufacture. Adulteration. Cottonseed Oil. Peanut Oil. Chapter XIV — Animal Foods 187-200 Meat. The Physical Structure and Chemical Con- stitution. Meat Inspection. Reasons for Cooking Meat. Changes in Cooking. Beef Extracts. Beef Juices. Internal Organs. Fish. Nutritive Value. Edible Portion. Adulteration. Shellfish. Eggs. Physical Structure. Composition of the Shell. Methods of Preservation. Composition of the Egg. Chapter XV — The Packing House 201-209 Historical. Growth and Breadth of the Industry. Processes in the Packing House. Inspection and Slaughtering. Use of By-products. Hides. Fat. . The Feet. Bone Products. Tankage. Blood. Mix- ing Fertilizers. Glue arid . Gelatin. Canning of Meat. Beef Extracts. Sausages. Minor Products. Chapter XVI— Milk 210-223 Source. Composition. Importance of the Milk Supply. Diseases from Milk. Necessity for Clean- liness. Safeguarding the Milk Supply. Our Duty to the Producer. Testing of Milk. Sterilization. Pasteurization. Certified Milk. Modified Milk. Chapter XVII— Milk Products 224-234 Condensed Milk. Evaporated Milk. Concentrated Milk. Milk Powders. By-products of the Butter Industry. Skim Milk. Dried Casein. Milk Sugar. Buttermilk. Artificially Soured Milk. Cheese. His- torical. Composition. Cheesemaking. Adulteration. Chapter XVIII — Preservation of Foods. . 235-246 Classification. Drying. Cooling. Sterilization and Exclusion of Air. Sugaring. Salting. Smoking. Use of Fats and Oils. Use of Spices. Alcohol. Use of Preservatives. Artificial Sweetening. Arti- ficial Coloring. Vlll CONTENTS Chapter XIX — The Canning Industry 247-254 Historical. Process. Success of Canning Fruits and Vegetables. Meat Products. Containers. Advan- tages and Disadvantages of Glass. Advantages and Disadvantages of Tin. Adulteration. Chapter XX — Tea, Coffee and Coco 255-276 Historical. Cultivation of the Tea Plant. General Classification. Processes in Manufacture. Black Tea. Green Tea. Adulteration. Tea as a Beverage. General Rules for Tea-making. Composition of the Beverage. Coffee. Historical. The Coffee Plant. Cultivation. Processes in Manufacture. Adultera- tion. Coffee as a Beverage. Coffee Extracts. Coco. Historical. Cultivation. Processes in Manufacture. Preparation of Chocolate. Preparation of Coco. Adulteration. As a Beverage. Chapter XXI — Spices and Condiments 2JJ-2&J Salt. Spices. Uses. Spices as Preservatives. Vanilla. Pepper. Mustard. Cinnamon and Cassia. Cloves. Allspice. Nutmeg and Mace. Ginger. Adulteration. Vinegar. Bibliography 288-294 Index 2 95- INTRODUCTION. In regard to the production and manufacture of our food material, there is a prevalent ignorance among woman to-day which is a marked contrast to the knowledge possessed on this subject by the old-fashioned housekeeper. The reason for this can readily be seen for in the early days, and in fact until com- paratively recent years, agriculture was very near the home and in the majority of cases the housewife herself was the manufac- turer. The spinning-wheel, now so highly prized as a memento of the olden times, testifies to the fact that our grandmothers knew full well how to manufacture the clothing for their fami- lies. A closer look at these same days will show that they knew equally well how to prepare many food products and materials needed for household work. As civilization has advanced the tendency toward the massing together of our population in towns and cities has gradually changed greatly the home life of the people. Agriculture no longer is carried on in proximity to the home, and large com- mercial establishments remote from the household now do the work that at one time was the daily duty of the housewife. Many such examples can be found. In our later study of the history of milling, we will find that among all primitive people, the woman was the miller, grinding each day the grain she was to make into bread; the preparation of the meal and breadmaking were practically one operation. Later on in the history of the human family, the making of meal and flour passed into the hands of the village miller, who ground the grain for the pro- ducers of his neighborhood, who in turn bought their sack of flour directly from him. As this business grew in size it grad- ually was moved further and further from the home, until the average housekeeper of to-day knows little of the mighty indus- try that is preparing the flour for her use. More and more each year, we find that the making of this flour into bread is in like manner passing into the hands of the modern manufacturer of bread. The old-time home-made loaf of bread is still found in 2 FOOD INDUSTRIES isolated districts, but seldom in city life. In the preparation of alcoholic beverages we again find this marked change. As late as our own colonial days, every housewife knew how to prepare beer and wines and her reputation as a homekeeper was judged as much by the beer that she could brew, as by the loaf of bread that she could bake. The curing of meat and fish by salting and smoking, the drying of fruits and vegetables now are known only to the housekeeper in isolated sections of our country, for the city woman must depend on the manufacturer's supply. Even the preservation of our food by canning is rapidly passing into the hands of the canning industry. These marked changes in our food preparation have brought new types of foods on the market and have greatly increased the variety. To the modern housekeeper, they have brought both advantages and disadvantages. Advantages. — I. There has been a great lessening of household drudgery, giving an opportunity for broader interests and for more recreation than was known to our grandmothers. II. In the majority of cases better products can be obtained for the methods of preparation used by the housekeeper were necessarily very crude. Manufacturers for financial reasons must give much study to their particular industry and new and better methods are constantly being sought. This has led to improved sanitary conditions and a standardizing of the quality of the product. III. In recent years there has been a great extension of the open season ; fresh fruits and vegetables are now quite common in the city markets the year round. The variety of food has been also increased by canning. IV. Great improvements have taken place in the science of agriculture leading gradually to the raising not only of better products but to the increase in the area of production, of prod- ucts which formerly were obtainable only from a limited section, as oranges and other fruits, sugar from the beet and wines. V. New and improved methods of food preservation have been largelv studied as canning and the use of cold storage. FOOD INDUSTRIES 3 VI. The co-operation with scientists has led to protection against certain diseases as tuberculosis from meat and milk, typhoid from the oyster, trachina from pork, etc. VII. Articles of food are now put up in better and more sani- tary packages and better packing material is being used. Disadvantages. — I. The cost of living has been greatly increased. a. Foods may be roughly divided into permanent and perish- able material. Among the permanent foods, the cost has de- creased, as sugar and flour. The great advance in price of our food material is found entirely in the perishable foods. Such material is now often brought from a long distance, thus adding cost of freight and many times the cost of preservation during transportation. The many hands through which food material must pass also increases the cost. b. Packages are sometimes used without enhancing the value. Many times this means that the actual weight of the food material is less than the housekeeper supposes as the weight of the box or package is included. c. The open market has led to expensive tastes. Luxuries look attractive and the cost is great where such products have been brought from a distance. II. The women of our country represent about 90 per cent, of the retail buyers in food products. A lack of knowledge and many times of interest have led to great deception on the part of some manufacturers. a. Until the Pure Food Law went into effect, there was a great amount of adulterated material put on the market and preserva- tives were most freely used. b. The substitution of cheaper products with intent to deceive the purchaser was also a common practice. Butter substitutes were sold as butter, cottonseed oil as olive oil, apple jelly as currant, canned herring as sardines, potted veal for chicken, and the like. c. Following these evils there gradually crept in the custom of printing misleading statements on the outside wrappers as to the 4 FOOD INDUSTRIES effect and food value of the contents. Much advertising was done also giving these false impressions. Had the modern housekeeper possessed the knowledge of her grandmother as to the production and manufacture of food material she was buying, manufacturers would not have found it advantageous to practice such frauds for so long a period. The United States Government has for many years been study- ing and experimenting along these lines, and bulletins have been printed which can be procured free or at a very small cost, yet comparatively few housekeepers seek such information. This lack of knowledge and interest led the faculty of the School of Practical Arts, Columbia University, to introduce many years •ago, into its domestic science course, a study of the manufacture of food material, hoping that a more extended knowledge of this subject would lead to greater interest and more intelligent buying on the part of the modern housekeeper. In connection with the following course of lectures, excursions should be taken as frequently as possible to manufacturing estab- lishments, where processes and methods can be studied and sani- tary conditions noted. Wherever such excursions are not prac- tical, illustrative material and demonstrations should be most freely used, accompanied whenever possible by the use of the stereopticon and moving picture slides. CHAPTER I. FOOD PRINCIPLES. Food principles are types of chemical compounds differing in exact composition but of equal energy value. They are reducible to similar forms by the process of digestion. Functions. — Food has two important functions : first, to supply tissue for the growth of the young child, and since life's processes are continually breaking down this body structure, to supply needed material for its repair; second, to. furnish the organism with fuel which in burning gives power to carry on life's activi- ties ; the heat produced is utilized to maintain the temperature necessary to the organism. Conservation of Energy. — Locked up in the resources of nature is a vast wealth of energy. Man has only to seize this energy and convert it into a form which he needs. Thus we find wood, coal, petroleum and natural gas being utilized to give heat and light. Should the energy be contained in a compound which can be finally assimilated by the human body he can accept it as a food. Elements in Food. — Nature does not always give us these foods in a simple state ; many of them are quite complex in their nature. When analyzed, however, it has been found that even the complicated forms are composed of the most common ele- ments as carbon, hydrogen, oxygen, nitrogen, with a small amount of sulphur, phosphorus, iron, calcium, etc. Food Principles. — Although these elements may be differently combined, they can be divided into groups which are called the five food principles : i. Water composed of hydrogen and oxygen. 2. Carbohydrates composed of carbon, hydrogen and oxygen. 3. Fats composed of carbon, hydrogen and oxygen. 4. Protein composed of carbon, hydrogen, oxygen, nitrogen, sulphur, generally phosphorus, sometimes iron, etc. 5. Mineral matter — as sodium, potassium, calcium, magnesium, iron, sulphur, phosphorus, chlorine, and minute quanti- ties of iodine, fluorine and silicon. 6 FOOD INDUSTRIES Examples of Each Group. — Among the carbohydrates we find such well-known foods as starch, sugar, cereals and vegetables. Fats may appear in different forms as liquids, semi-solids and solids, represented by olive oil, butter and suet. Protein in its most concentrated form occurs in the white of egg, large amounts being also found in meat, fish, cheese, eggs and milk. Usually we look to animal life for our protein supply, although it occurs also in the vegetable kingdom, relatively large amounts being found in beans, cottonseed meal, peas, lentils and smaller amounts in wheat, maize and other cereals. The vegetable king- dom supplies mankind with most of his carbohydrate food, animal carbohydrate occurring only in such forms as milk-sugar, glycogen and glucose. Fat occurs frequently in both animal and vegetable life. Function of Each Group. — Although all of the food principles have nutritive value each group has its own special function. This work may be : first, directly building tissue ; second, giving energy and heat; third, making it possible for other groups to carry out their special function. The great work of building tissue and gradually repairing it as it wears away can be per- formed by protein and inorganic matter, water always assisting in this work. The other food principles cannot build tissue; therefore, protein, mineral matter and water are absolutely essen- tial to life. None of the three is alone sufficient. The work of producing energy is done by all the food principles, although only in a very limited sense by mineral matter. Tissue Builders : Protein. Mineral matter. Water. Energy Producers : Protein. Carbohydrate. Fat. Protein alone is able to fulfil both of these functions of foods ; for this reason it is of vast importance in the diet. Without FOOD INDUSTRIES 7 protein life is impossible for any length of time for the wear and tear on the tissue must be replaced. With protein assisted by- water life can be maintained for some time. In many classifica- tions only four food principles are given, protein, carbohydrate, fat and mineral matter, water being omitted. It is claimed that water cannot build tissue, neither does it supply the organism with fuel from which to produce heat and energy; therefore, it cannot be called a food principle. Importance of Water. — Whether this statement be true or not, tissue building and, in fact most of life's processes, cannot go on without the presence of water. Blood is the gr,eat carrier of the system and there water is essential. It acts as an eliminator, washing out the tissues and carrying away waste matter loitering there. Water acts as a chemical agent. It has the power, of dis- solving substances, is essential to hydrolysis and can, therefore, assist in bringing about such chemical changes that otherwise useless food can eventually become part of the living organism. Its services to all forms of life cannot be over-estimated. Whether we regard it as merely a chemical agent or as a true food, next to the atmosphere we breathe it is the most essential thing in life. CARBOHYDRATES. In order to obtain the necessary amount of heat, and muscular energy it is necessary to supply the body with fuel. This work is done largely by the carbohydrates, a group containing carbon, hydrogen and oxygen. The hydrogen and oxygen occur in the same proportion as in water, and the carbon as six or some mul- tiple of six in most of those forms utilized as human food. The carbohydrates owe their value as a fuel very largely to the carbon which on oxidation gives off much heat energy. They are found in a large variety of foods : flour, meal, cereals, sugar, starch, vegetables and fruits. Sometimes they appear in simple forms which can easily be made use of by the organism ; at other times so complicated is the. molecule, that only after many chemical changes do they assume a form simple enough to pass through the membrane of the intestines. From the standpoint of nutri- 2 b FOOD INDUSTRIES tion the alimentary canal must be looked upon as outside the body, the lining of this canal being the outer coating of the body proper. All foods, therefore, must be reduced to chemical com- pounds which are capable of passing through the walls of the intestines before assimilation. The most important properties for assimilation are solubility and osmotic power. Those carbo- hydrates which cannot be reduced to forms having these proper- ties cannot be utilized as food'. Classification. — I. Monosaccharids or Simple Sugars, C 6 H 12 6 . Glucose or grape sugar, formerly called dextrose. Fructose or fruit sugar, formerly called levulose. Galactose. II. Disaccharids or Double Sugars," C^H^O^. Sucrose or sugar. Maltose. Lactose or milk sugar. III. Po^saccharids or Complex Sugars, (C 6 H Irt 5 )„. Cellulose. Starch. Dextrin. Glycogen. Formation of Carbohydrates. — The monosaccharids or simple sugars are built up in the leaf of the plant, by the absorption of the carbon dioxide and water of the atmosphere. With the assistance of the chlorophyll cells of green plants and the energy of the sun's rays, the following compounds are formed in the leaf : H 2 + C0 2 — HCHO + 2 6HCHO — C 6 H 12 O g Glucose, C 6 H 12 6 , is soluble and diffusible so it can pass from one part of the plant to another. When this material is to be stored as reserve food for the plant, water is withdrawn and starch, an insoluble and colloidal compound, is formed: *C 6 H 12 6 ^ (C.H 10 O B )» + H A FOOD INDUSTRIES 9 Occurrence. — Glucose is an important simple sugar widely dis- tributed in nature, and is found to a great extent in the same plants as contain sucrose. Grapes contain about 20 per cent., hence the common name grape sugar. It occurs also in sweet corn and most of the garden vegetables and fruits. In animal life it occurs in small quantities in the blood, 0.1 per cent., where it is constantly being burned to produce energy. Where the body has more or less lost the power to burn glucose as with diabetes, it accumulates and is finally eliminated by the kidneys. Fructose is usually found associated with glucose. It occurs in the juices of sweet fruits, the largest amount being found in honey. Galactose is not found in nature. It occurs only in the splitting of lactose or milk-sugar during the process of digestion. Sucrose is the most important of the sugars as it is the ordinary crystallized sugar of commerce. It is found widely distributed in the vegetable kingdom in the fruit and juices of a variety of plants, many times occurring in relatively large amounts as in the pineapple, strawberry and carrot. It is ex- tracted commercially from the sugar cane, the sugar beet, the sorghum cane, the date palm and the sugar maple. Maltose never occurs in nature in large quantities. It is the carbohydrate which is formed from starch during the germina- tion of seeds. As a commercial product it plays an important part in the brewing industry, in the so-called malted breakfast foods and in malted milk. Lactose occurs in the milk of all mammals usually from 3 to 7 per cent. It is the most abundant of the animal carbohydrates. Cellulose or crude fiber constitutes the framework of all vege- table tissue, so we find it widely distributed throughout the vegetable kingdom. It occurs in wood, linen, cotton, hemp, flax and paper. Much of our food as cereals, vegetables and fruit contain cellulose, but as it cannot be made soluble in the organism it has no food value. Other forms of life can utilize it, however, and we find it serving as food for insects and bacteria. Starch as it is found in nature is also insoluble and indiffusible, 10 FOOD INDUSTRIES but here we find a carbohydrate which can be changed to a simpler form within the alimentary canal. It is found largely in vegetables where it is stored as food for the plant. Dextrin or, as it is commonly called gum, is formed from starch by the process of hydrolysis. In nature it occurs in ger- minating cereals. Glycogen is often spoken of as the animal starch, although it more closely resembles dextrin. It is found to the largest extent in shell-fish, especially the scallop. It is also abundant in the muscle and liver of both higher and lower animals, where it is stored and ultimately utilized as a source of muscular energy. Important Properties. — Among the most important properties of the carbohydrates are found solubility, diffusibility, hydrolysis, crystallization and action on polarized light. Hydrolysis. — This important property occurs repeatedly in the changing of complicated forms of food material, to such simple forms that they can be utilized by the organism. It has been defined by Alexander Smith 'as "A double decomposition involv- ing water" and by other well-known chemists as "A simplification with absorption of water." Changes taking place during hydroly- sis are always brought about by certain agents, which do not themselves enter in any way into the compound being formed. These agents may be heat, dilute acid, bacterial action, enzyme action, etc. The action always takes place in the presence of water, both the water molecule and the complex carbohydrate molecule breaking down to form a new carbohydrate molecule in which the hydrogen and oxygen appear in the proportion as in water. 2 C 6 H 10 O 5 + Starch H 2 ^ '-'12-"-22^-'ll> Maltose C 12 H, 2 O n + H 2 Maltose — 2C 6 H 12 6 . Glucose Sucrose is a double sugar. When it breaks down under the influence of a catalytic agent it yields two simple sugars as C 12 H 22 O n + H 2 ^ C 6 H 12 6 glucose, C.H^CX fructose. FOOD INDUSTRIES II A special name lias been given to these two molecules, glucose and fructose. They are called invert sugar. This name has been given to them on account of their peculiar behavior toward polarized light. Before hydrolysis a sugar solution will rotate the plane of polarized light to the right, after hydrolysis to the left, hence the name invert sugar and the term inversion. Hydrolysis also occurs in the digestion of fats and proteins. FATS. Composition. — True fats are composed of the elements carbon, hydrogen and oxygen. Little was known of how these elements were combined in the formation of fats, until the investigation by Chevreul in the early part of the nineteenth century. He dis- covered that they were essentially salt-like bodies formed together with water by the combination of an acid and a base. With the exception of some of the waxes the base is always the same, the triatomic alcohol glycerine, C 3 H 5 (OH) 3 . The acid usually belongs to a series termed fatty acids and varies accord- ing to the fat. The three most common fatty acids are oleic, palmitic and stearic acid. Unless a fat or oil contains both glycerine and a fatty acid, it is not a true fat. C.H.COH), + 3 C 17 H 3:s COOH ^ C 3 H 5 (C 18 H 33 2 ) 3 + 3 H 2 0, Glycerine Oleic acid Olein Water C 3 H 5 (OH) 3 + 3 C 15 H 31 COOH ^ C 3 H 5 (C 16 H 31 2 ) 3 + 3 H 2 0, Glycerine Palmitic acid Palmitin Water C 3 H 5 (OH) 3 + 3 C 17 H 35 COOH ^ C 3 H 5 (C 18 H 35 Q 2 ) 3 + 3 H 2 0. Glycerine Stearic acid Stearin Water ' Two or more of these fatty acids are generally present in all fats — mixed, not chemically combined. They differ in their physical nature. Olein is liquid at ordinary temperature and whenever this acid predominates, the fat appears in the liquid form as in olive oil. Palmitin is semi-solid; it predominates in butter and lard and is the largest part of the human fat. When- ever stearin is present in a relatively large amount, the fat is a solid as in suet and tallow. Occurrence. — Fats are found widely distributed throughout both the animal and vegetable kingdoms. In plants the percent- 12 FOOD INDUSTRIES age varies to a great extent, approximately i per cent, being found in barley and 67 per cent, in Brazilian nuts. Fat usually occurs in inverse ratio to the starch. It is often difficult to extract as it is deposited throughout the plant; no part seems to be entirely wanting in fat. In animal life fats are present in all tissues and organs and in all fluids, with the exception of the normal urine. Large quantities are found in the abdominal cavity surrounding the kidneys, and beneath the skin of marine animals or those living in cold climates. Being present often in large quantities, it is very easy to extract. Properties. — The most important properties are solubility, change of state, crystallization, drying and non-drying, emulsifi- cation and saponification. Solubility. — Fats are soluble in gasolene, ether, chloroform, warm alcohol and carbon disulphide. These solvents may be used for cleansing purposes, for extraction and removal of grease stains. Change of State. — All fats have a definite melting point. They exist as liquids, semi-solids and solids according to the tempera- ture. This property is taken advantage of in the extraction of fats and as a means of identification. Crystallization.— All fats are highly crystalline. They form definite crystals and can be readily identified under a microscope. This has been of great value in detecting adulteration. Drying and Non-drying. — Certain oils are oxidized when exposed to the air and are converted into thick gummy masses. These drying oils when applied in thin layers on a surface form a dry, hard, transparent film. They are used extensively in paints and varnishes as linseed oil. Some oils such as cotton- seed possess this property to a limited extent, while others as olive oil show no sign of drying even when exposed to the air for an indefinite period. Emulsification. — Fats can be broken up in small globules by mechanical agitation. If these globules can be coated with a sub- stance which will prevent them from running together, they will remain in suspension. Egg albumin is very frequently the agent FOOD INDUSTRIES 13 used in making an emulsion ; example — mayonnaise dressing. This property is taken advantage of in soap-making and in the cleansing of fatty material by means of soap. It always occurs as an early stage in the digestion of fats. Saponification. — The process of splitting a fat into its con- stituents, fatty acid and glycerine, is termed saponification. It may be brought about by such agents as heat, mechanical agita- tion, bacterial action and use of an alkali. Saponification always occurs in the digestion of fats and in the process of soap-making. PROTEINS. Composition. — The proteins are very complex compounds differing greatly in composition and properties, but all are of high molecular weight. They are composed of carbon, hydrogen, oxygen, nitrogen, sulphur usually phosphorus, sometimes iron, lime, etc. As nitrogen compounds they play an important part in human nutrition, for they are essential to the growth of the living cells which make up the tissue. Classification. — The following is a modification of the classifi- cation recommended by the American Physiological Society and the American Society of Biological Chemists. { Simple Proteins J Conjugated I Derived • • f Albumins Globulins Glutelins Alcohol solubles Albuminoids Nucleoprotein Phosphoprotein Primary . , ^ Secondary f Coagulated proteins I Meta proteins ! Protean s Proteoses Peptones [ Peptids Non-protein r Extractives -{ Amides I Amino-acids 14 FOOD INDUSTRIES Occurrence. — Albumin is found in both plant and animal life. It occurs most abundantly in the white of egg, where it coagu- lates on being cooked in boiling water and becomes a hard white mass. It appears in milk as lact-albumin, in egg as ova-albumin, in fluids of the animal body such as muscle and blood as serum albumin. A small proportion of the protein of plant life occurs as albumin. Globulin is very similar to albumin, but differs from it in solu- bility. It occurs in both plant and animal life, but is far more abundant and wide-spread in plant tissue. Globulin is found in large proportion in hemp-seed, flax-seed, and in the seeds of the legumens. Animal globulin occurs in muscle and blood. Glutelins are nitrogenous compounds found in the cereal grains. The most familiar example is the glutenin of wheat. Alcohol solubles is a form of protein also found in cereals. The prin- cipal one is the gliadin of wheat. Glutenin and gliadin in the presence of water form the well-known substance gluten. Albuminoids occur in the skeleton of the body as the connec- tive tissue, bones, hair, nails, hoofs and horns. It is that form of protein which yields gelatin on cooking. Nucleo-proteins are complex proteins which are believed to be combinations of one or more protein molecules with nucleic acid. They are closely associated with the nuclei of cells in both plant and animal life and occur most abundantly in asparagus tips, the hearts of lettuce and internal organs such as liver, heart, kidney and pancreas. In the clearage of the molecule during digestion true nucleo-proteins are believed to yield uric acid. Phospho-proteins are proteins closely combined with mineral matter as phosphorus and sulphur. The most familiar examples are the caseinogen of milk and the vitellin of egg. Protein Hydrolysis. — As in the carbohydrates, protein must undergo hydrolysis or a simplification before such compounds can be assimilated by the body. This change involves a breaking down of the protein molecule, and the taking up of the elements of water, under the influence of agents such as heat, dilute acids or alkalis, bacterial action and enzyme action. The products FOOD INDUSTRIES 15 formed are known as derived proteins. Primary derived pro- teins are those which have been only slightly modified, secondary derived forms those having been more completely acted upon by the hydrolytic agent. In this way are formed coagulated proteins, meta-proteins, proteoses, peptones and peptids. Peptones for a long period were believed to be the final product of enzyme action in digestion, but that action is now believed to be continued to the amino-acid. Extractives. — The name extractives has been given to a body of substances which can be extracted from meat by the action of cold water. The most important are creatin and creatinin. Although nitrogen compounds, they are not capable of building tissue and it is believed that they have little or no food value. Properties.- — Among the more important properties of the pro- teins are solubility, curdling, coagulation and clotting. Solubility. — Albumin is soluble in cold water; gelatin swells and all other proteins are insoluble. All proteins are soluble in dilute sodium chloride, and with the exception of albumin, all are insoluble in saturated sodium chloride. All proteins are insoluble in saturated solutions of ammonium sulphate. Curdling. — Curdling is a change which occurs in connection with conjugated proteins such as the caseinogen of milk. It is the precipitation of a soluble matter by means of an acid, without serious chemical change. Coagulation. — Albumins and globulins are made insoluble by heating to about 158 F. In concentrated solution such as the white of egg, solidification is caused throughout the mass. This is a chemical change always brought about by (1) heat some- times with the aid of dilute acid or (2) the action of alcohol. Clotting. — The term clotting is applied to conjugated proteins, when the molecule is split by means of an enzyme into two simpler proteins, for example, — caseinogen under the action of rennet is split into casein and para or pseudo-nuclein. CHAPTER II. WATER. In chemical language we speak of water as a compound con- taining the elements hydrogen and oxygen, in the proportion of 2 to i by volume and i to 8 by weight. Such a compound, however, is never found in nature and the term as repeatedly used "pure water" is generally accepted, as meaning a water free from harmful ingredients and which can, therefore, be utilized for drinking and other household purposes ; contaminated or pol- luted water contains material injurious to health. Classification of Natural Waters. I. Atmospheric f Rain — Contains very little dissolved solids but dust and gases of the atmosphere. j Snow I Fog II. Terrestrial f Surface— Cloudy, usually a large amount of ' suspended matter, minimum of dissolved. j Underground — Clear, minimum of suspended i matter, maximum of dissolved. [ Salt f Brines — Over 5 per cent, soluble salts. I Sea water — 3.6 per cent, solids. j Mineral — Excess of unusual mineral matter [ and gases. It is known as the universal solvent ; there is .scarcely a sub- stance existing which is not more or less soluble in water. Hard rock can be gradually worn away by its action, and glass, one of the hardest of known substances, will gradually dissolve. All natural waters are found, therefore, to contain foreign matter, gases and solid material of the atmosphere and earth, either dissolved or in suspension. Sometimes these materials occur in small amounts, at other times in relatively large proportions. The nature and amount of these gases and solids have a con- siderable influence on the effect of water to be used for household purposes. The two great uses for water in the household are for drink- FOOD INDUSTRIES 17 ing and for cleansing purposes. There is a standard to estimate the purity of each. For detergent purposes, the amount of mineral matter present plays an important part, while for drink- ing, organic matter received directly or indirectly from sewage or industrial waste, constitutes the chief danger. A safe water supply should be reasonably free from objectionable mineral and organic matter. WATER SUPPLY. Historical. — Even in remote antiquity a high value seemed to have been placed on an abundant water supply, and a keen appre- ciation existed of the danger should such a supply become con- taminated. Settlements were made and communities grew near the source of available water, which many times was looked upon as a blessing bestowed by the gods. In districts where water was not abundant courses were constructed with much expenditure of time, money and labor to carry it from a distance where water was found to be pure and naturally plentiful. Such courses were built by the ancient Romans, where water could proceed by gravity from the distant mountains to the city where great reser- voirs were built for its storage. These reservoirs were still in use during the middle ages and the ruins to-day show how well they had been constructed. Methods of irrigation were used early in the history of the world, for reservoirs were known to have existed in Egypt before 2,000 B. C. They were utilized for the purpose of receiv- ing and storing the surplus water during the annual inundation of the Nile, the stored water being used for irrigation during seasons when the river failed to reach the crops. Pumping as it exists to-day was unknown among the ancients, but curious devices were constructed for the elevation of water, the ruins of which can still be seen in some parts of the Old World. One of the greatest curiosities of Zurich is the pump invented and erected by a tin-plate worker of that city. It con- sists of a hollow cylinder like a very large grindstone turning on a horizontal axis, and so constructed as to be partly plunged in a cistern of water. This cylinder is formed into a spiral canal by l8 FOOD INDUSTRIES a plate coiled up within it like the main-spring of a watch in its box. Bucket lifts in different forms seemed to have been employed the world over from 'the remotest historical times. In oriental countries an earthen pot attached to a rope wound around a windlass was used. Another form was the scoop-wheel composed of a series of curved blades, terminating in a hollow axle into which they discharged the water scooped up by the revolution of the wheel. A series of buckets was sometimes arranged around a huge wheel which in revolving scooped up the water. The well sweep or bucket and balanced pole, still frequently seen in certain rural sections of America, were water elevators of the same simple construction and principle. The displacement pump acting on the principle that two bodies cannot occupy the same space at the same time finally took the place of the bucket lifts, and in the sixteenth century we find pumps being introduced into Germany and France. A little later than this Paris constructed a filtering plant. Methods of puri- fication, however, had been studied much earlier for we read that 400 years before the Christian Era, Hippocrates had advised boiling and filtering drinking water should the supply become contaminated. Classification of Potable Waters. — I. Atmospheric. II. Surface. f shallow, III. Sub-soilj dee I. Atmospheric. — Rain is the original source of all natural water. It results from the water-vapor rising from the earth, being condensed in the upper air and again falling to earth. In its descent it to a great extent purifies the atmosphere by taking up ammonia, carbon dioxide and other soluble gases and by washing down solid matter as dust, soot, industrial waste and disease germs. Near the seacoast, rain water is found to contain an appreciable amount of salt dissolved in it. In districts con- taining a number of inhabitants and factories rain water is never FOOD INDUSTRIES 19 pure, for even after prolonged washing the atmosphere is still more or less impure. This is not true in the open country for there after the air has been purified by the first rain that falls, the water can be collected and stored. This is the purest form of natural water known. Stored rain should only be used where natural water cannot be obtained pure enough for household purposes. In collecting rain the first flow should run to waste, thus avoiding contamina- tion by dirt, soot and other impurities washed from the atmos- phere and from the surface on which the water is collected. Such water should be filtered and great care should be given to the storage. Cisterns should be so constructed that they will be absolutely impervious to surface drainage, and so that they can easily be inspected and frequently cleaned. The best materials for building are brick, stone, cement and slate. They should be kept covered to prevent impurities from falling in and to exclude light. This will prevent the development of low forms of plant life. II. Surface Water. — After reaching the earth a portion of rain water runs over the ground to join streams or larger bodies of water. Of these waters lakes and rivers form an important source of our water supply. They are known as surface waters. The composition varies greatly according to the character of the soil over which they flow. Should the soil be rocky a por- tion of the mineral salts would undoubtedly be added to the water, but it would be more or less free from organic impurities. If the water comes in contact with swampy land it will be very rich in organic matter. The character of these waters varies also according to the uninhabited or settled condition of the locality. Water from a clear lake or river, exposed to the sun- light and air, is one of the safest of water supplies in a thinly populated region. Such bodies of water, however, become highly polluted should they receive the drainage of city or town life. From every point of view running streams should be kept free from organic matter if they are to be used as a water supply. III. Subsoil Water.— The portion of rain water which sinks 20 FOOD INDUSTRIES into the ground is known as subsoil or ground water. It is used as spring water and shallow or deep well water. Subsoil water is greatly changed by the character of the earth through which it percolates. It passes to various depths according to the porosity of the soil and the arrangement of the strata. When it reaches an impervious formation it accumulates upon the level. In its descent to the earth and again in the soil, water dissolves more or less carbon dioxide. The presence of this gas greatly assists in dissolving mineral constituents of the soil. Thus we find in limestone regions a large amount of calcium carbonate in the water supply, making the so-called hard water. This greatly influences water to be used for detergent purposes. Rain water percolating through the ground may be changed also in regard to its purity as a drinking water. As it enters the soil it carries with it whatever organic matter it has dissolved from, the atmos- phere. In the upper layer, it again dissolves organic ingredients and becomes impregnated with micro-organisms, through the agency of which the organic matter undergoes very important chemical changes, gradually bringing about the purification of the water. Water which has percolated through the earth makes a very safe drinking supply, unless there is special contamination due to admixture with sewer drainage which contains excretory products. Shallow wells are much more likely to be subject to pollution of this kind. As a rule deep wells, 700 feet or more, are not apt to be dangerous, but they are usually higher in mineral sub- stances than surface waters. Pollution of Wells. — The chief danger to the water supply comes from earth closets, cesspools and house-drainages. To avoid expense in construction, too often the well and cesspool are built comparatively near together. The bottoms and sides of the old-fashioned cesspool were usually left open; to allow the house sewage to drain into the surrounding soil. Such condi- tions are a great source of danger and it is hoped that the septic cesspool will be more universally constructed in the future. In the septic cesspool, purification takes place by bacterial action and FOOD INDUSTRIES 21 the water is not allowed to drain from it until it has been more or less freed from dangerous material. As regards location it is a common belief, that if the well is built on slightly higher ground than the earth closet or open cesspool there can be no danger of pollution. This is a false impression, however, for it is not so much the location that determines the possibility of pollution, as the relative position of the cesspool and the point where the water enters the well. Great carelessness has very often been shown in this direction by the property owner, who has little regard for the rights of his neighbors unless compelled by legal restrictions. His own water supply may be carefully guarded, but the cesspool may be so located as to be a serious source of danger to neighboring wells. Contamination of Public Supplies. — Much trouble has been caused in the past by the same carelessness in regard to larger supplies, that is, the location of earth closets and cesspools along the watershed of a public water course. This utter disregard of the rights of others has been practiced by communities as well as individuals. The municipal supply furnished to the larger cities and towns is often drawn from great bodies of surface water, as lakes and rivers. Here there is great opportunity for gross neglect of sanitary conditions. Steamships and sailing vessels make a practice- of discharging their waste matter into the water. Manufacturing establishments along the banks add to the pollution. The greatest danger, however, comes from looking upon rivers as a convenient receptacle for the disposal of sewage, for as it has often been said by Mrs. Richards, "It is only after contamination with the waste of human life that danger comes to other beings." Many epidemics of typhoid in the New World and of cholera in the Old World have been caused by using the same body of water, as a water supply and as a means of disposing of refuse. One town may take its water from a point above and discharge its sewage at another point below, a second town farther down the river takes the already contaminated water for drinking purposes, and in its turn discharges the sewage at another convenient point. 22 FOOD INDUSTRIES Danger of Impure Water.- — Hutchison in his "Foods and Dietetics" tells us that water is not absorbed by the mucous membrane of the stomach ; it begins to flow into the intestines at once. The rapidity with which water passes through the stomach causes it to be a very dangerous vehicle of infection, for the hydrochloric acid of the gastric juice has not the oppor- tunity to act upon any disease bacteria which it may contain. Once in the intestines pathogenic bacteria find an alkaline medium which is most favorable for their growth and reproduction. For this reason it is quoted that "Contaminated water is a more obnoxious carrier of disease than impure milk." Too much care cannot be given that our water supply be above suspicion. While it is the duty of a city or town to supply a safe drinking water, to properly construct and maintain reservoirs and filter- ing plants, and to provide police surveillance for the water shed, it is also the duty of every citizen in such a community to cheer- fully pay the necessary expense for its maintenance, and to guard his neighbors' rights as his own. Education of the people at large on this subject is one of the essentials of modern life. Diseases from Water. — The presence of mineral matter quite frequently causes temporary intestinal derangement. This is more apt to be true with the visiting stranger to a community than with those accustomed to its use. The change from a soft to a hard water disturbs digestion and frequently causes con- stipation, while the change from a hard to a soft water may bring about diarrhoea. Organic pollution from vegetable origin has also been the cause of many mild epidemics of diarrhceal troubles. It is, however, to the typhoid and cholera bacteria that the world has owed its death destroying epidemics. Cholera has its home in India and has been largely kept alive and scattered in all directions, by the pilgrimages taken to such sacred rivers as the Ganges. The pilgrims from all parts of India travel in large companies for hundreds and even thousands of miles. Exhausted, filthy and many times diseased at the end of their journey, it is their custom to bathe in and drink of the sacred waters. Poorly fed and sheltered in the midst, of the FOOD INDUSTRIES 23 most insanitary conditions, it is little wonder that a cholera epidemic is soon started and by returning pilgrims is carried to all parts of the country. The European and American nations hear with horror tales told of cholera in India, and yet although more enlightened and understanding more fully sanitary condi- tions, Europe and America have repeatedly been visited with typhoid epidemics. It has been said that we have not advanced far in civilization, when we have not yet learned as a nation to take care of the excreta from our own bodies. Not until the end of the nineteenth century were authorities fully awakened to this subject, and there is still much work to be done in this direction. PURIFICATION OF WATER. Public Methods. — With the constant increase in our population and the modern tendency toward city and town life, a pure water Fig. 1. — Sedimentation Basin. supply has become almost an impossibility. The most that we can demand now is a safe water. Large sums of money have been used and much experimentation has been carried on of late years to determine the best methods of purification. Several very effi- 3 24 FOOD INDUSTRIES cient methods have been discovered and are now in use, but which is best seems to depend on local conditions. The most important public methods are bacterial action, filtration and the use of chemical agents. Bacterial Action. — This method is used largely in England and is commonly spoken of as the English Filtering System. It con- Fig 2— Section of an English Filter Bed. (Courtesy of John Wiley & Sons.) sists of a filtration through sand-beds which are filled with putre- factive bacteria. Water to be filtered is usually run into a sedi- mentation basin first, in order to allow suspended matter to settle (Fig. i). This will prevent a too rapid clogging of the filtering beds if the water is materially turbid. After sedimen- tation has taken place, the water is delivered into the top of the FOOD INDUSTRIES 25 26 FOOD INDUSTRIES beds which are built of stone or concrete and have drainage pipes at the bottom, to discharge the filtered water into wells. In the beds are placed from the bottom upward layers of coarse gravel, fine gravel, coarse sand and fine sand (Fig. 2). The water percolates through the layers of sand and gravel to the drainage pipes which carry it away to the reservoir. Soon a slimy growth containing bacteria occurs on top of the filter beds ; these bacteria are the true purifying agents. For a long period after this system was put in operation, the purification was supposed to be entirely mechanical, then it was thought to be due to oxidation. It was discovered eventually that the filter beds failed to work thoroughly until the layer of slime had formed, and after much experimentation the purification was traced to bacterial action. The slimy mass acts as a mechanical agent, and through its bac- teria causes the oxidation of organic matter and destruction of pathogenic bacteria. When the sediment layer becomes so dense that the required amount of water fails to pass through, it becomes necessary to clean the bed by the removal of the top layer (Fig. 3). The scraped-off sand can be washed by a machine and stored for future use. Several days are required for the formation of a new sediment layer before the filter bed once more becomes effective. Filtration. — A system much in use called "The American Filter System" depends on the use of alum and filtration through sand. As in the English System the water to be filtered is first run into a sedimentation basin, after which potash alum or aluminium sulphate is added, 1/10 to 1 grain per gallon. The water is then admitted to a filter which is cylindrical in shape, made of wood or iron and is filled three-quarters full of fine sand (Fig. 4). Alum will readily ionize in water forming a heavy white floccu- lent precipitate of aluminium hydrate, jelly-like in appearance. K 2 A1 2 (SCU + 3 H 2 -> Al 2 (OH) 6 + K 2 SO, + 3H 2 S0 4 . The precipitate collects on the top of the sand as the water filters through. The action of this mass closely resembles the clarifying of coffee with egg albumin. It entangles all suspended matter which may be purely inorganic or living organisms and FOOD INDUSTRIES 27 deposits them on the surface of the sand. The jelly-like layer then acts mechanically much as the bacterial layer of the English filter-beds. Use of Chemical Agents. — Chemical treatment has been long used as a means of purifying water and has been found very efficient in periods of epidemics. Permanganate of potassium has been used in India during cholera epidemics. This acts as an Fig. 4. — View of the Interior of the East Albany, N. Y., Filter-plant. (Courtesy of John Wiley & Sons.) oxidizer of the organic matter in water and then attacks the bacteria. Sodium hypochlorite, chlorine and bromine are also effective in destroying micro-organisms. Perhaps alum is the agent most commonly employed for purifying water. It was first used in Egypt during the time of Napoleon to clarify the muddy water used by his army. As it has been previously described, alum will form a precipitate carrying down all sus- pended matter and will greatly improve the appearance of water. 28 FOOD INDUSTRIES This method of purification is used quite extensively in public baths. For drinking purposes it should only be used in small amounts. Where alum has been used to throw down coagulated matter, it increases the hardness of a naturally hard water. In order to overcome this hardness, sodium carbonate is added in amount calculated to precipitate all as carbonate of lime. Household Methods. — Where public methods cannot be depended upon or in times of special contamination, it is often necessary for the householder to purify his water supply. The most common methods are boiling and the use of domestic filters. Boiling.— Boiling is the oldest and simplest way of purifying water. It has been used from the earliest times and is still one of the most effective methods that we have. As the chief danger of a polluted water comes from the typhoid bacillus, whose thermal death point is below the boiling point of water, prolonged boiling is not necessary. Boiled water is not palatable as the air has been driven out. It is well to cool and pass it from one vessel to another or to agitate it in contact with the air to restore the original taste. Use of Domestic Filters. — Most of the many varieties of house filters remove only dirt, iron rust and other coarse particles in suspension. They are usually small in size and contain a com- paratively small amount of sand or charcoal. While sand is effective on a large scale and charcoal is a well-known deodorizer and clarifier, the amount is not enough to affect a large quantity of water run through them, with the pressure of the ordinary city supply. In a very short time these filters become impreg- nated with bacterial life, the growth and development of which soon make them a dangerous medium through which to pass water. Effective filters, however, can be bought, but at a much higher price than the ordinary house filter. The Berkefeld (Fig. 5), Pasteur-Chamberland and Aqua Pura are filters of this type. The filtering medium in the first two is unglazed, well- baked porcelain, and in the latter, sandstone. Both of these media are capable of holding back micro-organisms as well as suspended matter. Great care must be given these filters to have FOOD INDUSTRIES 2 9 them work effectively. Bacteria soon cover the filtering surface and must be cleaned off by scraping or scrubbing. Most filters of this type also require sterilization by baking, boiling or sub- Fig. 5.— The Berkefeld Filter. jecting them to live steam. Unless the housekeeper is willing to give the filter proper care it is far safer to simply boil the water. Manufacturers' Method. — Boiling on a large scale has been Fig. 6.— Distillation Apparatus. (Courtesy of Carl H. Schultz Co.) 30 FOOD INDUSTRIES found so troublesome, that most manufacturers who must purify water before Using it prefer the method of distillation (Fig. 6). Here water is raised to the boiling point, passes off as steam to another receptacle where it is condensed. This produces a sterile water as bacteria do not pass over in the distillate. It, however, is tasteless and needs aeration. Self-purification. — In the examination of surface waters, it has frequently been found that water taken from a river at a given point contains a certain amount of impurities ; at another point farther down there is considerably less, while at a still greater distance it is practically pure. This is supposed to be due to the fact that water can in time bring about its own purification. It is accounted for in several ways : first, the water becomes diluted ; second, changes take place due to oxidation and bacterial action; third, sedimentation; fourth, purifying influence of algae and other low forms of vegetable life. Could these agents always be relied upon there would be no need of constructing and maintaining expensive filtration plants. Undoubtedly they produce great results in many cases, but at other times the purification is only partial while at times it is of no special value. There is great danger, therefore, in relying on water to purify itself. Conditions might exist or arise which would prevent these agents from doing their work. Where self- purification is used, every precaution should be taken by the local authorities to guard the entire water-shed from all possible contamination. Judging a Water Supply. — In regard to a drinking water the world at large still retains the primitive idea, that purity in appearance alone is necessary in judging a safe water. Expert examination has shown that appearance alone is of little value. A pure water is generally bright and sparkling, but it has been found that some highly contaminated waters show remarkable brilliancy. On the other hand water may be distinctly muddy, owing to minute particles of clay or turbid from the effect of iron, and still not be dangerous. Neither can safety be judged by color and odor. Color may be due to traces of iron or to leaves FOOD INDUSTRIES 3 1 and other such color imparting substances. The presence of color does not indicate that water is unfit for domestic use, neither does the absence of color indicate purity, for many polluted waters are colorless. Repulsive odors in water usually mean stagnation, presence of dead animals or other decomposing organic matter which makes it unfit for drinking purposes, but many odors may be present in water which are perfectly harmless as grassy or peaty odors. The only safe way of judging the purity of a water supply is by chemical and bacterial tests. The chem- ical examination usually made is for the presence of organic matter, and consists of the quantitative examination for the total solids, free ammonia, albuminoid ammonia, nitrites, chlorides and oxygen consuming power. Such tests to be reliable should not be made by the amateur, but by an expert chemist in a room set apart for this purpose. Great care should be given in collecting a sample of water to be sent for examination, since careless, handling would make the analysis worthless. If the bottles have not been provided by the chemist, a glass bottle or a demijohn which has been thoroughly cleaned and fitted with a glass stopper or new cork can be used. Details in regard to further directions for collecting samples, the significance of the tests and analytical methods can be found in "Air, Water and Food" by Richards and Woodman or other standard works on water analysis. Ice Supply. — The taking of ice from polluted waters has been a subject much discussed of late years. Many micro-organisms including typhoid are not killed by freezing, and it is claimed by many scientists that such ice is dangerous if put into drinking water for cooling purposes. It is a well-known fact that cold storage food will deteriorate rapidly when taken from ice. This would not be true if bacterial life had been destroyed. It has been discovered, however, that after prolonged freezing most germs are practically harmless, and for that reason some scien- tists claim that ice is safe to use even if taken from a con- taminated water. If there is any doubt of the ice supply, it is 2,2 FOOD INDUSTRIES far safer to chill drinking water by placing it in bottles on ice, rather than by putting the ice directly into the water. MINERAL WATERS. The term mineral water is usually applied to spring water which contains a larger volume of gases dissolved in it, or more solid matter in solution than ordinary drinking water. It may, therefore, exert a different effect on the human body. Classification. — Acidulous. Alkaline. Bitter. Sulphur. Chalybeate. Acid. Alum. Borax. Saline. Lithia. These mineral waters may be either natural or artificial. Natural Mineral Springs. — Mineral springs have been found in many countries of both the Old and New World, and from the early ages have attracted much attention. They often present remarkable appearances when relieved from subterranean pres- sure by losing their gases with great rapidity. This often causes them to be thrown upward to a height of 20-40 feet* accompanied by a hissing or rumbling noise. Some waters are icy cold while others are at a boiling heat. These and other phenomena led to many superstitious beliefs in the early ages, and these waters were supposed to possess supernatural properties. There is, however, nothing unnatural about their origin. Subsoil water containing a considerable amount of carbon dioxide may sink to great depths, and may be subjected to great pressure or even heat. Should such water find an outlet it would tend to escape with considerable force. Much of the dissolved matter undoubt- edly is obtained from rocky soil through which the water has percolated. The solvent action of water, greatly increased by FOOD INDUSTRIES 33 the presence of carbon dioxide and sometimes heat, may take from one type of rock certain acids which later react with basic elements dissolved from another rock, thus producing salts. Salts of lime, magnesium and iron are quite frequently found in these waters. Occurrence. — Mineral springs have been found to occur most frequently in volcanic districts where there is much carbon dioxide and many mineral compounds. They also occur in many other parts of the world and there are but few countries where they have not been found. France, Germany, Italy, Spain, Greece, Asia Minor, United States, and Canada are rich in min- eral springs, while they can also be found in Great Britain, Sweden, Norway and in many parts of Africa and the Orient. Medicinal Pozver. — Mineral waters have been used as medic- inal agents from very early periods. The pages of ancient authors frequently contain wonderful tales of their curative power, and records speak of resorts where the sick bathed in healing waters or drank of medicinal fountains. These mineral springs seemed to have played an important part in the religion of some nations, for the Greeks frequently erected their temples near such places, where their gods could be worshiped and their sick healed of whatsoever disease they had. In the pages of Latin writers we meet often with allusions to medicinal springs, and the splendor of the buildings erected in their vicinity in Italy testify to the esteem in which they were held by the Romans. This faith in the curative power has come down from these early times to the present day. How much they do really affect disease is a question of much interest to the modern phy- sician. Great difficulty is experienced by investigators of the subject for it is hard to eliminate other circumstances which con- tribute to the cure of the patient. A different climate, possibly a change in altitude alone has a remarkable effect in many dis- eases. Different diet, complete rest, change in hours of going to bed and getting up, new and possibly cheerful society, relief from the harassing cares of business or demands of social life are obtained. Patients after a short period at these springs return 34 FOOD INDUSTRIES to their homes much improved, many times entirely due to rest, recreation, more open-air exercise, regular habits, etc. It is hardly fair, however, to state that the waters have had no part Carbonic Acid Gas Generator. Fig. 7- — Carbon Dioxide Generator. By allowing sulphuric acid to flow drop by drop" |J from the upper container into the lower tank which is filled with, a solution of bicarbonate of soda, carbon dioxide gas is obtained. (Courtesy of Carl H. Schultz Co.) in the benefits obtained. The feeling against these mineral springs or spas as they are frequently called has come largely from the quackery surrounding the resorts. The superstition of FOOD INDUSTRIES 35 past ages gave to them the power of curing all diseases. This same "cure-all" style of advertisement is still largely used by proprietors of springs and local physicians in the hope of attract- ing large crowds, and has done much to bring odium on the spas and to disgust the modern scientist. Before taking these waters care should be given that the water is effective for the specific disease, and that sanitary conditions surrounding the springs have been carefully guarded. There is no reason to believe that min- eral water will not become as highly contaminated as ordinary drinking water if exposed to sewage. It has long been a custom also to bottle and sell mineral waters, and should they be con- taminated, disease can readily be carried to all parts of the country. Artificial Mineral Waters. — In the latter part of the eighteenth century, Joseph Priestly suggested that an artificial aerated water could be made by charging water with carbon dioxide. The gas was obtained by the action of oil of vitriol on chalk. H 2 SO, -f CaC0 3 ~- C0 2 + H 2 + CaSO,. This carbonated water is still largely used, but most manufac- turers at the present time prefer to use bicarbonate of soda as a means of generating the gas, as the soda compound being soluble is less troublesome (Fig. 7). H 2 SO + + 2NaHC0 3 — 2C0 2 + 2H 2 + Na 2 S0 4 . From this simple suggestion of Priestly has grown an industry for making not only carbonated water, but mineral waters closely resembling the natural mineral springs. By careful analysis of the spas, chemists have been able to combine mineral salts in the same proportions, thus giving an artificial water claimed by many to be as beneficial as the natural water. Care should be given, however, in the use of these waters that the firm placing them on the market is thoroughly reliable. CHAPTER III. THE KING OF CEREALS. OLD MILLING PROCESSES. Taking the civilized world as a whole, both in the quantity produced and in its value as a human food, wheat has won the name of the world's King of Cereals. It is the cereal best adapted for bread-making and appears to meet the needs of civilized life more than the other grain foods. As the standard of living advances in a nation, wheat has grown steadily in com- mercial importance. If there were time to look thoroughly into the history of this cereal, we should find that the growth and development of wheat has been interwoven with the very life history of the human race. Origin. — It is impossible to tell how long it has been utilized as a food by mankind, for archaeologists claim that its record began in prehistoric times. The most ancient languages mention it and the fact that it has been found in the earliest habitations of man is a proof of its antiquity.' Specimens have been dis- covered in the Swiss lake dwellings and among the remains of Egyptian civilization. The Chinese claim that it was grown in their Empire over 3,000 years before the Christian Era and the Bible mentions its use as early as the Book of Genesis. If these accounts be true, wheat must have kept its place in man's diet for nearly 6,000 years. Such a record of long, faithful service could not be unless the grain of wheat had locked up within its kernel the elements which are most needed to maintain heat, and replace the energy and tissue which are constantly being worn away during life's processes. ;The savage in his hunger seemed to have instinctively turned to it as a food, and the wis- dom of his choice can readily be seen by a study of its composi- tion as given by Dr. H. W. Wiley, formerly of the United States Department of Agriculture. Water 10.60 Protein 12.25 Fat s 1.75 Fiber 2.40 Starch, etc 71.25 Ash 1.75 J?OOD INDUSTRIES 2)7 Geographical Distribution. — The raising of wheat has so long been a practice with man that the geographical origin is unknown. Egyptians attribute its discovery to Isis and the Chinese claim to have received the seed as a direct gift from Heaven. It was at one time the custom for the Chinese Emperor to drive the plow in order to do homage to the dignity of agriculture. The belief that it originated in the Valley of the Euphrates and Tigris is more widely accepted than any other theory. Early it spread into Phoenicia and Egypt, finding a most suitable lodging place along the shore of the Mediterranean. The climate there was suited to its cultivation, dry and hot during the summer months. Italians as far back as the early Roman days obtained part of their wheat supply from the north of Africa, for that war-like nation was unable to produce enough wheat for its own con- sumption. Many of their warfares were for the purpose of capturing the harvest from their more successful wheat growing neighbors. ' The migration of wheat from those early days was closely connected with the migration of the human race. Gradually spreading throughout Europe, it finally reached Germany, France and Great Britain, although this latter country has never been able to grow enough wheat to supply its population. Great Britain still obtains much of its wheat from countries where con- ditions are more favorable for the growth of this cereal. Extend- ing into Russia, wheat once more found a suitable soil and climate which in time produced so large a supply, that Russia became known as "The Granary of Europe." That title she continued to keep until the famine of 1891-92 swept the country with a terrible scourge and from which she has never fully recov- ered. \ The failure of the crops during those years was caused not only by bad weather, but by the continued use of crude agri- cultural methods which in time thoroughly impoverished the soil. Should she use more up-to-date methods in regard to fertilizing, she might again regain that title, but the yield per acre at present is very small. The peasantry still cling to old methods slightly in advance of the Middle Ages. In Russia, there are still 3& FOOD INDUSTRIES immense undeveloped areas that would make ideal wheat fields and much is being looked for in the Siberian wheat-growing area. It is difficult to predict, however, what part the Russian Empire will play in the wheat market of the future. The possi- bilities are very great, but many changes must first be brought about in the political and social condition of the people, for Russia is still sadly lacking in the institutions that are necessary to bring about progress and prosperity. Even with these great drawbacks Russia is still one of the greatest wheat producing countries of the world, largely due to the Siberian wheat fields. When civilization moved westward, it was found that wheat could be grown in the New World for that cereal readily adapts itself to new environments. Starting along the Atlantic coast, it pushed farther and farther westward with the march of civili- zation, flourishing wheat fields shortly replacing the primeval forest. When the wheat line had reached Ohio it was thought by many European nations to have reached its limit on American soil. Warning was given to the Ohio farmer to care for the soil, for with the rapid growth of the United States it was feared that the population would soon outrun its wheat production. But the wheat line was not to stop; in the opening up of the northwest, this cereal was again to find favorable conditions for its growth. With fertile soil, intellectual farming, American enterprise and capital, the United States advanced to one of the leading wheat producing nations of the world. Still farther north the wheat line was to travel, for it has been found in recent years that thousands of acres of land in Canada, which were considered waste land, can be utilized for wheat growing. This area is nearly three times as great as that used for wheat in the United States and the yield per acre is larger. As yet only about 5 per cent, of the land is under cultivation. In Canada the United States has found a powerful rival. The virgin soil is capable of producing enormous crops of superb spring wheat, much needed to blend with softer varieties, and the men behind the plow in this new wheat-producing country both read and think. FOOD INDUSTRIES 39 \ It would seem that with the development of the northwest area that wheat had at last reached its limit of cultivation on American soil, but agriculturalists prophesy that the line of march will next turn eastward, and that much land now lying idle in the eastern and southern sections will in time be utilized for the growing of wheat. With the development of drought resistant varieties, it is also hoped that more of the semi-arid land of the west can be used.; Of the South American countries, Argentine Republic has taken the first place as a producer and exporter of wheat. Here are found great natural advantages, extensive prairies very sim- ilar to those of Minnesota and the Dakotas, and a moderate climate which enables the farmer to work the land almost any time of the year. Cheap land, cheap labor and its nearness to the sea are also important factors. As in Russia, however, agri- cultural methods are still very crude. Land is not well cared for and the crops are not properly stored. This latter deficiency sometimes affects wheat to be used for milling. With improved conditions, Argentina promises to be an important wheat pro- ducer. At the present time more wheat is being raised than is necessary for home consumption, and large quantities are being shipped to Europe. While Russia, United States, Canada and Argentina have been the most important wheat-producing countries, this cereal can be cultivated in a variety of climates. Regions having cold winters produce most of the world's wheat, but marked exceptions are found in Egypt arid India. While Egyptian wheat is of little commercial importance to-day, in the age of the Pharaohs and during the Roman civilization, Egypt was the wheat center of the world. Cultivation. — Wheat has always been a cereal that has needed the care of mankind; wild varieties are practically unknown. Little is told us in history of how the farmer of antiquity tilled, sowed and harvested his crop and it was not until the days of the Roman Censor, Cato (234-149 B. C), that any written work can be found on the subject of agriculture. The tillers of the 4 40 FOOD INDUSTRIES soil have always been marked by their independence, and it was not until modern times that we found co-operation among this class of workers. The early farmer worked many times in a more or less isolated position, independent and non-progressive, teaching his son and grandson to follow in his footsteps. For information as to the time of sowing, he had only the deities and medicine-men to consult. For centuries the farmer was left to work out his own salvation, but with the advance of civilization very gradually there arose the botanist, the physicist and chemist, the agriculturist and the bacteriologist to assist him in his work. So important is the work of the scientist in modern times that a single government has been known to spend many millions of dollars in the solution of a problem of great importance. Shortly after the colonists had established their independence, the sug- gestion was made to establish a national board of agriculture, but it was not until the days of Lincoln that the National Depart- ment of Agriculture was established. The experimentation car- ried on by Liebig and other scientists of his time led the way to the foundation of experiment stations, and in time to agricul- tural colleges both in Europe and America. Farmers' institutes and societies followed which have now grown to be of national importance. Hand in hand with the progress of agricultural methods is found the progress in motor power. For centuries, undoubtedly only the muscular energy of man was used, and hand labor is still employed to a large extent in India, China, Japan, Egypt, Mexico and among many of the Eastern and South American nations. Animal power was the first that relieved man from the drudgeries of agricultural life, the oxen and the horse being almost universally employed. This power is still largely used, although as early as 1832 steam power was introduced into Eng- land, and is now used to a great extent in the Western United States and in parts of Germany and Hungary. Much experi- menting is being done along the lines of electricity. As in motor power, so in implements can the progress of the world be seen by a comparison of the early plow as seen on Egyptian monu- FOOD INDUSTRIES 41 merits with the modern combined harvester of the great north- west. Structure of the Wheat Grain. — (Figs. 8 and 9.) I. Husk. — The husk is the outer layer and serves as a covering, thus protect- ing the grain from the attack of its enemies in much the same way as the shell does the nut. It is composed largely of cellulose, a woody fibrous material not available as human food. II. Bran coats lie directly under the outer covering and are S^sf/V ^fwr? olt/^zt ^^r G> ~! « < o , "J J (i u III u >> 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 IOO FOOD INDUSTRIES dough. Alum will cause it once more to become insoluble and a better gluten will he 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.— Machine for Wrapping Bread with Paraffin Paper. (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 taken and as a rule it has been found to be approximately 2 per cent, although it may be much higher under unfavorable con- ditions. Liebig 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 IOI 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 : V; ,,-:;,.,*» - Fig. 23.— Bread After Leaving Wrapping Machine. (Courtesy of Ward Baking Co.) England and the United States, only two have met a slight suc- cess. I. Chemical Process. — Use of baking powders. See Chapter VIII. II. Aerated Bread. — In this process water is saturated with C0 2 prepared by chemical reaction. This highly charged water is then mixed with flour under pressure in air-tight chambers. 102 FOOD INDUSTRIES When the pressure is lowered 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 ma- terial but unfortunately it has an insipid taste due to the absence of the by-products of yeast, so has never met with great success. 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 industry until it now includes many articles formerly considered cakes, pastry and confectionery. In both this country and in England the manufacture of bis- cuit has been greatly improved and the output tremendously in- creased, one American firm alone manufacturing some four hun- dred or more different 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 insanitary cracker bin and barrel of the grocery store, such as was fomerly 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 air-tight, 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. Raw Material. — For the most part, flour made from winter wheat is used in the preparation of biscuit, although different varieties will contain Graham, whole wheat and cereal flours. Butter, lard and specially prepared, refined fats from vegetable sources shorten the goods, and pure water or high grade milk furnishes the moisture, while yeast, bi-carbonate of soda, baking FOOD INDUSTRIES IO3 powder or aeration, assisted by the presence of eggs and fatty matter, serves as a leavening agent. There are many varieties of fancy biscuit in which are used refined sugar, fruits, spices, cheese, eggs, chocolate, nuts and confectionery. The ingredients, as above set forth, are carefully measured and weighed, then placed in a mixer, usually a large steel receptacle with revolving arms, and are thoroughly mixed by machinery for a definite time. If the leavening agent be yeast, a period of incubation at a properly fixed temperature must follow. The dough, now Fig. 24.— A Baking Floor showing Ovens. (Courtesy of The National Biscuit Co.) thoroughly mixed and having been allowed to rise the proper length of time, is wheeled in its clean steel car to the dough- breaks where, by being rolled and folded between great rollers, it is kneaded into the proper thinness and ready for the machine which further shapes and stamps it into the form in which it is baked with the design and trade mark impressed on the dough. The ovens used to bake biscuit are generally direct heat with 8 104 FOOD INDUSTRIES rotating shelves and are kept at a temperature approximating 500° F. After being .baked and taken from the oven, the biscuits are cooled and immediately packed in their moisture and dust- proof packages, in which they start their journey, often the same day they are packed, to the ultimate consumer (Fig. 24). 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 its 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 equaled 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- 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 FOOD INDUSTRIES IO5 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 out leaving the light amber, glutenous part resembling 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 for about 7 minutes or until the dough has a smooth and tough appearance. The mass is kneaded 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 character 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 mac- aroni and smaller holes produce 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 store- houses where they remain until the strings have a horn-like tough- ness. They are now ready to be inspected, sorted, weighed and packed for shipment. In case of bad weather the macaroni is dried under cover for a longer period. The yellow color is pro- duced by the use of saffron or of a coal tar dye. Domestic Macaroni. — There is a constant increasing demand for macaroni made in the United States. The hardest variety of wheat is Used especially the hard wheat of Kansas and that 106 FOOD INDUSTRIES grown in the semi-arid land. 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 can readily replace 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. C0 2 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. II. The slow liberation of the gas causes it to have its full effect as a leavening agent. III. The by-products produced during fermentation give a pleasant taste. IV. Bread made by yeast is more easily digested. Disadvantages. — I. The time required for leavening is long. II. Careful watching and studying of favorable conditions for the growth of yeast are necessary or the result will be sour or sodden bread. III. It involves a loss of carbohydrate in the formation of products which are volatile at the baking temperature. IV. 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 carbonate, usually in the form of a bicarbonate. The salt resulting from the chem- ical action of the acid and base remains in the dough. Advantages. — -I. 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. II. No loss of the carbohydrate is involved. IOS FOOD INDUSTRIES III. It is possible to calculate the amount of gas which may be produced if the composition of the chemical reagents is known. Disadvantages.- — I. The taste is not as good as that of bread raised by yeast. II. The product is not as readily digestible. III. The residue resulting from the chemical reaction remains in the loaf. As these residues have no nutritive value, they can only be regarded as waste products. 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: I. 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. C 12 H 22 O u -H 2 0- 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,, but a cheaper and stronger compound NaHCO s , 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 j4 of the amount suggested. 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 CO s and H 2 S0 4 , but this proved too troublesome to be practical. Liebig suggested the use of the NaHCO, 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 HCl almost invariably contains traces of arsenic, minute quantities of FOOD INDUSTRIES IO9 which could be found in the dough. Another acid was sought, one which could be effective, comparatively cheap, with good keeping qualities and which would give a harmless residue. Tar- taric acid was finally chosen. It was expensive and difficult to keep but it was effective and harmless. Bicarbonate of soda and tartaric acid were tried, both in the powder form. For the sake of convenience these powders could be mixed together. When dry, they did not exert any effect on each other but atmospheric moisture was so quickly absorbed, that chemical action took place and much carbon dioxide was lost. An early improvement was the addition of starch or some other substance having hygro- scopic property. Starch absorbs moisture readily and will also tend to keep apart the particles of the acid and base. Another improvement was soon made. Tartaric acid was found to be harmless and efficient but it was expensive and objectionable from a practical standpoint. On account of its great solubility, too rapid evolution of gas occurred. The acid potassium salt, cream of tartar, was less expensive, very effective and perfectly harmless. As it was not so soluble, less loss occurred. These were known as the tartrate powders. Tartrate Pozvders. — The first powder of commercial impor- tance contained three ingredients, bicarbonate of soda, cream of tartar and starch as a filler. Much advertising led to a rapid growth in the use of these powders and in a short time they became very popular. The method of manufacture was simple and the profits were enormous. Chemistry was searched for other combinations which could be used for leavening bread. Two acid salts were soon discovered which could be substituted for cream of tartar. 1. Phosphate and Alum Pozvders. — Calcium acid phosphate, a salt of about the same strength as cream of tartar, but cheaper in price. 2. Potash alum, a salt of great leavening power and very low in cost. Formulae were devised by chemists which made possible the use of either one or both of these salts in combination with bi- IIO FOOD INDUSTRIES carbonate of soda, starch being added as a filler. The powders were known as the ' phosphate, the alum phosphate and the straight alum powders. The introduction of less expensive salts and the simplicity of the process of manufacture led hundreds of individuals and com- panies into the baking powder business and great competition followed. 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 ef- fective but were found so objectionable, on account of the amount of alum present that their sale has been practically abolished. The powders on the market at the present time are tartrate, phosphate and alum phosphate. There has been much contro- versy 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?" A glance at the following reactions and table will give some idea of the relative value. TARTRATE POWDER. 188 84 54 282 44 KHC 4 H 4 6 + NaHCO, + 3H 2 — NaKC 4 H 4 6 ,4H 2 + C0 2 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 cubic centimeters at o° C, which becomes 273 cubic centi- meters at ioo° C. the highest temperature of the oven. The residue of crystallized Rochelle Salts amounts to 2.5 grams. PHOSPHATE POWDER. 234 168 180 CaH 4 (P0 4 ) 2 + 2NaHCO, + ioH 2 — . 136 358 88 CaHP0 4 + Na 2 HP0 4 .i2H 2 + 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 CO., or FOOD INDUSTRIES III 355 cubic centimeters at o° C. which becomes 485 cubic centi- meters at ioo° C. the highest point of the oven. The residue of phosphates weighs 4.05 grams. ALUM PHOSPHATE POWDER. 475 234 336 (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 + 132 644 176 (NH 4 ) 2 S0 4 + 2Na 2 S0 4 ,ioH 2 + 4C0 2 1 level T. of powder weighs 2.85 grams and contains 33^3 per cent, of starch. This yields approximately 0.32 gram C0 2 or 160 cubic centimeters at d° C. which becomes 218 cubic centi- meters at ioo° C. the highest point of the oven. Residue weighs 2.17 grams. Weight of 1 T. of powder Weight of 1 T. of powder less the filler Weight of COo Volume of COo at o° C. Volume of COo at the oven tempera- ture Weight of the residue Remarks Tartrate . . 3 grams 2.4 grams 0.4 gram 200 c.c. 273 c.c. 2.5 grams All soluble in water. Residue contains water of crys- tallization. Phosphate 4.4 grams 3.3 grams 0.72 gram 355 c.c. 485 c.c. 4.05 grams 27.55b insol- uble in water. Residue contains water of crys- tallization. Alum phosphate 2.85 grams 1. g grams 0.32 gram 160 c.c. 218 c.c. 2.17 grams 36.6 fo insol- uble in water. Residue contains water of crys- tallization. Eelative Efficiency. — I. Alum phosphate powders are the cheapest, but they do not keep well. They contain alum which is supposed to have a deleterious effect on the system and leave a residue which is partly insoluble in water. II. Phosphate powders are cheap, but they do not keep well and leave a residue which to some extent is insoluble. 112 FOOD INDUSTRIES III. 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 ^2-pound of cream of tartar, x 4-pound of bicarbonate of soda and %■ -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. Ammonia Powders. — Bakers are now using ammonia carbonate very effectively as a leavening agent. It has the great advantage of leaving no residue, but must be used in very small quantities or the product will taste of ammonia. (NH 4 ) 2 C0 3 — 2NH 3 +,C0 2 + H 2 0. Cream of Tartar. — Almost all of the cream of tartar and tar- taric acid used in this country is imported, the largest amount 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 passes out with the juice. There is no tendency for it to become insoluble and pre- cipitate out 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 "argol." There are usually from one to three inches of 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 argol, cream of tartar is made. "Lees" contains a larger amount of calcium tartrate and is used more extensively for the production of tartaric acid. Argol is not pure cream of tartar as it carries down in pre- cipitating, other constituents of the grape. These impurities FOOD INDUSTRIES 113 must be removed. In the process of refining, the crystals of argol 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 out 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 O s + H,S0 4 -~ H. 2 C 4 H 4 O t; + 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. — Acid phosphate of lime occurs in different forms. The soluble acid phosphate as used in the bak- ing powder industry does not occur in nature, but must be manu- factured. The skeletons of animal life are largely employed for this purpose. Here calcium phosphate Ca 3 (P0 4 ) 2 appears in a form insoluble in water, but which can be readily made soluble by treatment with an acid. Ca,(P0 4 ) 2 + 2 H 2 S0 4 — CaH 4 (P0 4 ) 2 + 2 CaS0 4 insoluble soluble The material utilized in this industry is usually obtained from certain sections of the country where large deposits of phos- phate of lime have been found. This has been caused by sharks and other forms of animal life having been deposited in past ages, and through the process of weathering all organic matter has disappeared, leaving only the material which has constituted the frame work. This material is dug up and changed to a form which can be utilized in the baking powder industry. Bicarbonate of Soda. — The preparation of soda constitutes to-day one of our largest and most important industries. An 114 FOOD INDUSTRIES alkali has been used for cleaning purposes by the housewife, for many centuries, but this represents only about one per cent, of the soda manufactured. It is also needed in many industries 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 life. The early housewife 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 could be used for cleansing purposes. For many years, the manufacturer was forced to depend, also, on the leaching of wood ashes or on natural deposits of potash which have been found in certain parts of the world. The largest deposits occur on the western coast of South America and in the region of North Germany which has Starsfurt 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 sodium carbonate. Everything used in the manufacture, how- ever, must be obtained in France. Many chemists worked at this problem 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 sulphuric acid. 2 NaCl + H a S0 4 — Na 2 S0 4 -f 2HCI FOOD INDUSTRIES 115 Na 2 S0 4 was known as the salt cake. It was broken up and mixed with powdered coal and limestone and was then treated in a reverberatory furnace. Na 2 SO, + 2C — Na 2 S + 2 CO, Na 2 S + CaC0 3 — * Na 2 CO„ + CaS Na 2 C0 3 an impure form, known as soda ash, could be dissolved out and the water afterwards evaporated. To obtain pure Na 2 CO s , the soda ash must be again heated with coal and other soda compounds be changed to the carbonate form. Bicarbonate of soda can be easily obtained from sodium car- bonate. Na 2 CO s -(- H 2 + C0 2 — 2NaHCO :s 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 Le Blanc Process. — I. The raw materials salt, coal, limestone and sulphuric acid are common and inexpensive. II. The furnace and plant can be put up at a fairly low price. III. The by-products are important and have done much toward keeping this process in existence. Solvay Process. — The Solvay method of preparing sodium carbonate was invented in i860 by a Belgian named Solvay, and is a serious rival of 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 Il6 FOOD INDUSTRIES the Le Blanc method required dry salt, it was found very trouble- some 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 + C() 2 — NaHC0 3 + NH 4 C1. NaHC0 3 is separated out 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 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 here run into partitioned tanks containing electrodes. When the current is turned on ionization 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 CO s + H 2 -f C0 2 — 2 NaHCO. s 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. STAECH 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. — I. Insoluble in cold water. II. With iodine, starch gives a characteristic blue color. III. 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. IV. When heated dry to 200 ° C. or more it is converted into dextrin. V. 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 Il8 FOOD INDUSTRIES important article of commerce, the manufacturer finds many another market for his" product. It is used : - In laundries. For food such as puddings, sauces and jellies. For candies such as gum drops and lozenges. In baking powders. In the textile industry for stiffening and finishing fabrics. In wall paper manufacture 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 makes 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 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 such FOOD INDUSTRIES IIO, as Germany, England, Scotland and Ireland. In the United States, Maine is noted for the production of a high quality po- tato and Wisconsin and Colorado grow the potato largely for the starch industry. The following 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. — I. Cleaning. — The washing of po- tatoes must be thorough or the quality of the starch will suffer. 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. II. 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. ill. Sifting. — Shaking tables covered with gauze separate the starch grains from the potato pulp. The pulp can be pressed and dried. It is 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. 120 FOOD INDUSTRIES 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 grown largely in Brazil and other 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- 1^ ! VL , ."'- ip '0/00 * *-r. wm ^PS§ tt& * 1. IF* » ; ..." 1 Z &>■-' -■< ■■>_ . gqjp^g^^ ^§lj j |^ ■:^ ? ; : Mt: m^'- \_\ __ Fig. 25.— Sheds and Board Used for Drying the Tapioca. (Courtesy of The Spice Mill Publishing Co.) 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 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. ) FOOD INDUSTRIES 121 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. Outline of the Corn Products Industry. — I. Cleaned. II. Kernel softened by steeping. III. Crushed. IV. Separated by gravity. (i) 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 •< ( Gluten, which with corn sol- ubles obtained from steep- ing water, becomes part of the gluten feed. Starch is purified and sold as I. Starch — laundry lump, crystal, pearl powder etc. 1. By process of roasting. II. Dextrin 2. By use of a dilute acid. Boiled with dilute III. Glucose by process of hydrolysis { acid 0.06 of 1% Neutralized. Filtered^. Decolorized. I. Concentrated, 122 FOOD INDUSTRIES 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 which contains a comparatively large amount of oil, and the endosperm, where are found starch and protein. When received at the factory, the corn contains some impuri- ties and the kernel is in a dry, hard condition. Fig. 26. — Steeped Corn Running to Crushers. (Courtesy of Corn Products Refiniug Co.) Processes in Manufacture. — I. 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 re- moved by screening, while magnets are used for drawing out bits of iron, nails and the like. II. Steeping.— In order to separate the kernel into its com- FOOD INDUSTRIES 123 ponent parts, the hard, dry grain must first be softened. This is accomplished by steeping it 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, 6.005 P er cent. H 2 S0 3 , is added to prevent fermentation. This is afterwards removed by thorough washing. When the grain has absorbed sufficient moisture to cause a loosening and softening of the various parts, the water is drawn off, leaving the kernel of corn in a moist, soft condition. Fig. 27.— Crushers. (Courtesy of Corn Products Refining Co.) 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. 26). III. Crushing. — The softened grain is passed through a mill called the crusher (Fig. 27). It consists of two large disks set face to face having projecting teeth and rotating in opposite di- rections. It is supposed to grind only to a coarse meal, thus leaving the germ and hull intact. 124 FOOD INDUSTRIES s j . m ." ||--jj: Ok £. *s ^Hl '^^^■■i ■' '.'^.*. S J^"' •1 '«fc ^a.&! r^\ '■•■> rt % J $4$~vB* Fig. 28. — Separators. (Courtesy of Corn Products Refining Co.) Fig. 29. — Hydraulic Presses for Oil. (Courtesy of Corn Products Refining Co. FOOD INDUSTRIES 1 25 IV. Separation. — The resulting mass is fed to a long, narrow tank about 25 feet long, 4 feet wide and 8 feet deep, where tak- ing advantage of the difference in the specific gravity, a separa- tion of the various parts is effected. The germ being the light- est 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. 28). The germs are passed over screens or shakers. They are then washed to free them from adhering starch, dried, ground fine, heated, wrapped in cloth and pressed (Fig. 29). 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 press. It may be used for the manufac- ture of soap, soap powders, oil cloth, leather, paints and var- nishes. 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 automobile tires. V. 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 running the starch liquor from the germs, hulls and ground hulls, directly upon tables from 60-120 feet long, 3 feet wide with a decline of about 4 inches. As there is a difference in specific gravity, the 126 FOOD INDUSTRIES 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 be repeated, until all foreign matter such as traces of fat and Fig. 30. — Dripping Boxes. (Courtesy of Corn Products Refining Co.) 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 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. 30). The boxes are allowed to stand until the water runs off, then turned over and the thick FOOD INDUSTRIES 127 slab of starch is broken up into cubes (Fig. 31 ). 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. Fig. 31. — Emptying Starch from Drip Boxes. Breaking into Cubes. (Courtesy of Corn Products Refining Co.) DEXTRINS. 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 for Dextrins.— For the manufacture of gums, glues, muci- lage and other adhesives. For cloth, carpets and twine. For leather 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. 128 FOOD INDUSTRIES 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 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 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. Uses for G-lucose. — 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. 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 FOOD INDUSTRIES 1 29 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 which with the acid forms an insoluble precipitate. During the process of refining this precipitate is removed. H 2 S0 4 + CaC0 3 — CaS0 4 + 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 a — 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 a characteristic taste 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. — The sugar cane is by far the earliest plant from which sugar was extracted. Prior to its discovery, many centuries before the Christian era, mankind was largely dependent Upon honey as a sweetening 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 Hin- doos and Chinese. Its cultivation was gradually carried west- ward, by the Persians and Arabs, and at the time of the cru- sades, sugar factories were found in operation in Syria and Pales- tine. Carried still further westward by the Saracens and Moors, it 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 I3I 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 by the English fleet. 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 followed 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 cam- paign. 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 importance. Undoubtedly, the great progress in this industry was largely due to the invention of the polariscope, which greatly assisted 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 12 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 132 FOOD INDUSTRIES the household and for commercial purposes. Any differences 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 ; 1 st, 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, all 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. — I. Cane cut in the green stage. II. Cane crushed { ^e^uice. III. Crude juice screened -] . . y J (juice. IV. Juice treated with milk of lime; residue removed. V. Juice concentrated. a. Boiled down in open kettles. ( TTlolclSSCS Drained in hogsheads or casks j muscovado sugar b. Boiled down in vacuum. Separated in centrifuge j molasses - ( raw sugar. FOOD INDUSTRIES 133 Cutting. — The sugar cane, when the crop is ready, is harvested by cutting the stalks as close to the ground as possible. Consid- erable care must be given that the plant be 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. 32. — 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 the crushing process by means of heavy mills. The cane-mills of to-day are of various types ranging from the crude ox-driven mill of primitive countries (Fig. 32) 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 i34 FOOD INDUSTRIES carriers to high crushers (Fig. 33), which reduce 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 itfl'ifc -, n ; ■■■- ■ r .^ ' ■' ". ■'•;: : Tffe'S . lliii^ +P*> x w - Y '- I " l r _J?s. «* * Fig. 33. — 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 of cane in 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 FOOD INDUSTRIES 135 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 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 Fig. 34. — Open Pan Evaporators, Philippines. (Courtesy of the School of Mines Quarterly, Columbia University.) 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 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- 10 136 FOOD INDUSTRIES lated plantations (Fig.. 34). 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 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 line perfor- ated bottoms, through which the molasses gradually drained out. Fig- 35- — Vacuum Pans, Hawaii. (Courtesy of the School of Mines Quarterly, Columbia University. The light brown sugar obtained as a result of this process was known as "muscovado" sugar. The molasses was very dark in 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 181 3 is a large closed vessel usually made of cop- per containing steam-coils for heating, the vacuum being, main- FOOD INDUSTRIES 137 tained by a pump (Fig. 35). 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 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. 36). When arranged in series, a low Fig. 36.— Multiple-effect Evaporating Apparatus. 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 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 133 FOOD INDUSTRIES of vacuum is maintained (Fig. 37). 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 Fig' 37- — Vacuum Strike Pan. mixture of crystals and syrup is known as "massecuite." The 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 FOOD INDUSTRIES 139 still warm, the mixture is passed to a centrifugal machine which causes a separation of the crystallized sugar and the molasses. Centrifugal. — The centrifugal or centrifuge is a hollow iron drum containing a perforated basket (Fig. 38). 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. The sugar is then bagged and shipped to the country where it is to be refined. Fig. 38. — Centrifugal Machines. (Courtesy of Sugar, Chicago, 111.) 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 sugar and a second molasses are obtained. The second molasses may again be boiled down for a third sugar and molasses. While 140 FOOD INDUSTRIES the third molasses still contains about 30 per cent, sugar, it con- tains so many impurities that the sugar will not crystallize out. THE BEET SUGAR INDUSTRY. Growth. — Unlike the cane, the sugar beet reaches its highest Fig. 39. — The Wild Beet. (Courtesy of Sugar, Chicago, 111.) development in a north temperate climate, although where the soil has exceptionally good qualities, it has been grown success- FOOD INDUSTRIES 141 fully in sub-tropical regions. It is not apt, however, to contain as much sugar. Moisture also plays an important part in the Fig. 40. — The Sugar Beet of To-day. (Courtesy of Sugar, Chicago, 111.) production 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 142 FOOD INDUSTRIES FOOD INDUSTRIES I43 can also be grown successfully in irrigated areas and much waste land, it is hoped, may be utilized in this way. Much experiment- 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. 39 and 40). The average percentage of the sugar is 13-14 per cent., while on the irrigated area it has been increased to 16-18 per cent. The yield per acre is still low, however, not exceeding eight tons, while in Europe twelve to thirteen tons are obtained (Fig. 41). Outline; of the: Production of Raw Sugar. — I. Beets are grown, harvested, topped. II. Washed. III. Sliced. IV. Diffused { P ul g- • • ( crude juice. V. Crude juice is screened. VI. Defecated. VII Filtered { albuminous matter, etc. ( juice. VIII. Concentrated in vacuum. IX. Centrifugedj mola K SSe f- & ( raw beet 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 is 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. 144 FOOD INDUSTRIES 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 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 IO-15 4-6 II-16 I2-l6 Q-5-I-5 0.0-0.3 0.5-1.0 0.S-I.5 0.4-0.6 1 -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 slices 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. 42). They are usually arranged in a series of 10-12 upright iron cylinders FOOD INDUSTRIES 145 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. 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 Fig. 42.— The Circular Diffusion Battery. (Courtesy of Sugar, Chicago, 111.) 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 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- I46 FOOD INDUSTRIES 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 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 or 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. FOOD INDUSTRIES 147 REFINING OF RAW SUGAR. Raw sugars, with the exception of maple, are now refined before being placed upon the market. The refining of sugar was not practiced until about 500 A. D. It first appeared in Mesopo- tamia and gradually traveled westward, refineries being erected in many of the European countries in the 15th and 16th cen- turies. In 1689 the first refinery of the Western Continent was built in New York City. This industry has gradually grown until public taste now demands a pure white sugar. As before stated, so far as the beet sugar is concerned, refining is a neces- sity since the raw product has a disagreeable odor and taste. Cane sugar, however, possesses in the raw state a more fragrant 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 process 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; Rffining Procfss. — ■ I. Raw sugar washed. II. Centrifugedj waS l: S / rU P- & ( washed raw sugar. III. Washed raw sugar melted. IV. Defecated. V. Filtered through bags j J^^ 6 °" VI. Iyiquor bone-blacked. VII. Boiled down in vacuum. , ( syrup. VIII. Centrifuged \ 5™£ \ yellow sugar. (. sugar Washing. — The raw sugar after being weighed is mixed with 148 FOOD INDUSTRIES 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. 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 Melt er. — 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. 43. — Filter Bags. Defecators. — Here the solution is treated for the removal of such impurities as organic acid and fine suspended matter. Different 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 out, 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 FOOD INDUSTRIES . 1 49 open end is tied tightly around a metallic nipple by which the bag is suspended (Fig. 43). 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 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 its power of removing color, and must be revivified. It is 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. 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. I50 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. 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. 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 by 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 begasse has been utilized mainly, in the past, for fuel purposes. In recent years, it has been discov- ered that an excellent quality of paper may be manufactured from begasse. 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. FOOD INDUSTRIES 151 Molasses constitutes the most valuable by-product. As it contains a large percentage of sugar which cannot be crystallized out with ordinary methods, chemical means are being devised for its extraction. Beet sugar molasses contains 50 per cent, of sucrose. By treatment with calcium, strontium or barium hydroxides, it is possible to precipitate the sucrose as insoluble saccharate which, after filtration, may be decomposed and re- covered as sucrose. Beet sugar molasses being rich in nitro- genous and mineral 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 begasse 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 n 152 FOOD INDUSTRIES 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. 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 has been found in the United States on account of the cheapness of the product. Sugar sold in the powdered form, however, has been adulterated from time to time with flour, glucose, chalk, silica and gypsum. CHAPTER XL 2. ALCOHOLIC BEVERAGES. Alcoholic beverages may be classified as follows : f Beer. I Ale I. Malted fermented s -n 1 J Porter. L Stout. II. Malted distilled \ Whiskey. ' i. Sweet or dry. P , f Red, Claret, Burgundy, etc. { White, Sauterm, Rhine, etc. (' Still, most of the natural wines. III. Wines -j 3. CO, -n' Sparkling, Champagne and Sparkling ( Moselle. ( Natural, containing not more than Alcohol s 15%. Most of the natural wines. [_ (_ Fortified, Sherry, Port and Maderia. IV. Distilled Wines , c. g/ e fe/Co - ~5o&c r? o r? c? can market this term is sometimes used as a general name for China Black Teas. IV. Bohea is a name frequently applied to any larger leaf used for tea-making than the congou variety. This tea is no longer found in our market. POOD INDUSTRIES 259 v Processes of Manufacture. Beack Tea Leaves picked. Withered in the sun Rolled until soft. Fermented. Fired. Sorted. Green Tea Leaves picked. Withered in pans. Rolled until soft. Withered again. Sweated in bags. Slowly roasted. Picking. — The tea leaves are plucked entirely by hand, the operation generally being carried on by women and children. In Fig. 67.— 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 260 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. 67). In good weather this operation takes about eighteen to twenty-four hours but when cloudy or rainy, artificial heat must be used. 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. 68. — Rolling Tea Leaves. (Courtesy of The Tea and Coffee Trade Journal.) Rolling. — In China, rolling is still done very largely by hand (Fig. 68). 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. Per mentation. — Fermentation is the most important part of the FOOD INDUSTRIES 26l 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 it turns 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, is packed into lead-lined chests and is ready for transportation. GrFEn Tea. — The preparation of green tea differs from that of black tea in several important operations. I. 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. II. 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 262 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. Such substitution can readily be detected with the microscope as tea leaves have a characteristic appear- ance. Facing consisted in treating the leaves with various color- ing matter, such as Prussian blue, indigo or plumbago. By such means leaves which were inferior or had been damaged in manu- facturing processes or during a sea voyage, could be improved 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 lqng 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. Caffein is not present in the leaf but is probably developed during fermentation. 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 Kules for Tea-Making. — Heat freshly drawn water to FOOD INDUSTRIES 263 the boiling point. Pour it on the requisite amount of tea, which has been placed in a previously scalded pot, made of a non-con- 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 undesirable. 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 its introduction into Arabia, one of which places its original home in Abyssinia, province of Caffa, 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 its origin may have been, Europeans discovered its use in Arabia during the 15th century. Undoubt- edly the knowledge of it spread very largely through the Arabian merchantmen, who added the coffee bean to other oriental lux- uries, and to the Mohammedan pilgrims who flocked annually 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. It reached Constantinople in the 16th century and spread from there to the countries bordering on the Mediterranean, finally 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 264 FOOD INDUSTRIES in the European colonies, in the French West Indies and on the island of Java. Its cultivation soon spread to Sumatra, the 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 shrub 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. 69. — 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 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 parchment" (Fig. 69). The main processes of manufacture consist in free- ing 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. FOOD INDUSTRIES 265 Cultivation. — The coffee shrubs 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 shrubs. 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 modern plantations of Brazil, many planters claiming that it has advantages over the modern wet process. Wet Method. — Where the wet proces's is used inclined canals are frequently built, where the cherries can be dumped and carried by gravity to the pulping machine. While floating down, imperfect and unripe berries rise to the top and can readily be 266 FOOD INDUSTRIES removed, after which the well developed berries are washed with fresh water (Fig. 70). 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. 70. — 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. Washing and Drying. — Successive rinsings with water finally FOOD INDUSTRIES 267 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 out by winnowing, leaving the coffee beans clean and ready for sort- ing. 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 cleansing 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 268 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. 71). The effect of roasting is both physical and chemical. The physical state of the bean is changed to a brittle form, in which Fig. 71.— General View of Coffee Roasting Room. Publishing Co.) (Courtesy of The Spice Mill 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 posible after roasting and should never be pulver- ized until at the time of the preparation of the beverage. Adulteraton. — Adulteration of coffee has consisted in the ad- FOOD INDUSTRIES 269 dition of foreign matter, the substitution of cheaper substances, and in facing. As with tea facing, the addition of coloring matter has been used largely to conceal poor or damaged coffee or to make inferior varieties appear as high grade material. In former years an imitation bean was manufactured and occasion- ally 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 Drug Act of June 30, 1906, has made this, also, a misdemeanor. Al- 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 imported 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, approximately 1 to 2 per cent, being found in the unroasted bean. Tannic acid is also found with a larger amount of other substances 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. 27O FOOD INDUSTRIES 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 consistency of coffee solution. COCO. Historical. — Coco 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 coco 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, its use 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. Coco 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. v Cultivation. — Coco is the fruit of a tropical tree commonly known as the coco tree although it belongs botanically to the 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- FOOD INDUSTRIES 271 ern World produces by far the largest part of the world's crop, Ecuador and Brazil being the largest exporting countries. Mexico still produces the greatest amount of coco, but uses most of it for her own consumption. \y The coco 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 Fig. 72.— Pods and L,eaves. (Copyrighted by Walter Baker & Co , and used with their permission.) the tree. The fruit is a pod some 8-10 inches long, 3-4 inches thick (Fig. 72). 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 coco beans which are covered with a thin shell greatly resembling an almond (Fig. y^). The beans 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 2/2 FOOD INDUSTRIES gathered yearly, generally in June and December, although this 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. 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 Fig. 73. — Section Coco Fruit are cut open with a sharp cutlass. The pulp and coco 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 FOOD INDUSTRIES 273 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 organic matter that may be clinging to them. Whether they are washed or not, the coco 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 coco is now ready to be bagged and shipped to the markets of the world. When received by the manufacturer coco is cleaned, sorted and roasted. 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 coco with a crude undeveloped taste. The process is usually carried out in large iron drums, heated to from 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, coco is quickly cooled in order to prevent the loss of the aroma. 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 coco nibs. A separation of shells, 274 FOOD INDUSTRIES 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 not great, but they make a satisfactory drink for people of weak digestion. The coco nibs are used for the preparation of the commercial chocolate and coco. Fig. 74. — Grinding Room. (Copyrighted by Walter Baker & Co., and used with their permission.) Preparation of Chocolate. — The coco nibs are ground into a paste by a series of revolving stones, arranged in pairs and slightly heated to assist in liquefying the coco. 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, it is placed on the market as sweet chocolate or as FOOD INDUSTRIES 275 milk chocolate, if condensed or powdered milk has also been added. Preparation of Coco. — As the coco 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 coco. 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. It is then allowed to cool after which it is reduced to a powder and boxed. The ex- tracted fat is clarified and made into coco-butter. As coco-butter does not readily turn rancid if carefully stored, it is used largely in pharmacy, for candy-making and in the preparation of cos- metics, perfumes, pomades and soft toilet soaps. Adulteration. — Coco 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, clay, the ground shells of the coco-bean, powdered roasted acorns, chestnuts and other substances of organic and inorganic origin have, from time to time, been found. Fats of cheaper variety, as lard or coconut oil, are used to restore the normal percentage of fat after coco-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. — Coco 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 coco bean as given by Payen. Fat 50 Starch to Albuminoids 20 Water • 12 Cellulose 2 Mineral matter 4 Theobromine 2 Theobromine which is responsible for the stimulating effect of 276 FOOD INDUSTRIES coco, 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 coco 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 biliousness when indulged in too freely. CHAPTER XXL SPICES AND CONDIMENTS. The word condiment is 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 in- organic. 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 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. VA 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, 278 FOOD INDUSTRIES and much is procured from Utah on the shores of Great Salt Lake. In the process of preparing salt for the market, the brine is passed through a succession of heaters with an increasing range of temperature. By this means many of the impurities are pre- cipitated and can be filtered off. The brine is then run into evaporators where the water volatilizes and the salt deposits. Since the salt still contains impurities it is purified by recrystalli- zation from water. It is then dried, sifted into grades and packed in bags, barrels or other packages. 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 colonizaton 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, as cayenne pepper and vanilla. The West Indies is celebrated for ginger and is also the home of the pimento. 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. FOOD INDUSTRIES 279 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 dyeing 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 with food for the sake of the various flavors that they yield, it has been left to modern times 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 also be kept for a length of time on account of the high content of spices. Fruit cake furnishes another example. 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 19 280 FOOD INDUSTRIES 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 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. — Vanilla. — 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 1510. 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 out 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 extract of vanilla. This is obtained by dissolving out the flavoring material by the use of alcohol. / Modern science has furnished a commercial rival to vanilla extract in the production of synthetic product. Vanillin has been largely prepared from engenol, a substance to which oil of cloves owes it characteristic odor, and in recent years much has also been obtained electrolytically from sugar. * The Use of Spices as Preservatives by Conrad Hoffman & Alice Evans. Published in Journal of Industrial & Engineering Chemistry. FOOD INDUSTRIES 28l V 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. Fig- 75- — Pepper Plantation near Singapore. (Courtesy of The Spice Mill Publishing Co.) The black variety is prepared from the dried, unripe berry of a vine which was gr.own 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 282 Food industries 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. It is generally considered better but the product has not as good a flavor and is more expensive, the only advantage being in the appearance (Fig. 75)./ V 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 market of to-day.) The two most common varieties of seeds used at 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, turmeric, cayenne pepper, etc. / Cinnamon and Cassia. — Cinnamon is the inner bark of young shoots of a 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 is removed in strips by special knives. The strips are piled in heaps and allowed to ferment, after which the FOOD INDUSTRIES 283 epidermis is removed. The bark shrinks on drying and is known as "the quills." These are then put up in bundles ready for ex- portation (Fig. 76). 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-dav, however, is obtained from China Fig. 76.— Rolling Cinnamon Bark into Quills. (Courtesy of the Spice Mill Publishing Co.) 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 ah adulterant. v 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 284 FOOD INDUSTRIES the ground on grass mats and are allowed to dry in the sun, care Fig. 77.— Clove Tree of Zanzibar. (Courtesy of The Spice Mill Publishing Co. ) being taken to shelter them from the dew at night. In about one FOOD INDUSTRIES 285 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 is used largely in perfumery and in soaps (Fig. 77)'. ^ 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 comes 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, is 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 a volatile oil on distillation which is used as a flavoring in alcoholic solutions. * ^ 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. The thin outer seed coat is broken, and the kernal or nutmeg is ready to be cleaned and packed. Nutmeg is exported in the unground state in order to retain the flavor. 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 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 ginger is prepared very largely in China, especially Canton. After being peeled, the ginger is treated with a boiling solution 286 FOOD INDUSTRIES of sugar, after which it is packed in jars or sent to the market in the dry state (Fig. 78). 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- Fig. 78.— Digging and Peeling Ginger in the Fields— Ginger Plantation, Jamaica. (Courtesy of The Spice Mill Publishing Co.) 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 manufactur- ing of products known as spice mixtures. They consisted of a combination of various materials as ground coconut shells, wheat flour, crackers, charcoal, coloring and mineral matter, yellow cornmeal, mustard, husks, sawdust and other odds and ends. Much misbranding has also been found especially among flavoring extracts. FOOD INDUSTRIES 287 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 pre- servative value to the acetic acid which inhibits the growth of putrefactive bacteria. The manufacture of vinegar has been treated under the Fer- mentation Industries. See Chapter XII. BIBLIOGRAPHY. CHAPTER L— 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. Richards and Woodman. — 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. CHAPTERS III AND IV.— OLD AND MODERN MILLING PROCESSES. ,' Doudlinger, Peter Tracy.— The Book of Wheat. 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. Encyclopedias. — Britannia, International. CHAPTERS V AND VI.— CEREALS AND BREAKFAST FOODS. Burtt-Davy, Joseph. — Maize : Its History, Cultivation, Handling and Uses. Freeman and Chandler. — The World's Commercial Products. Harrington, Charles. — Practical Hygiene. Wiley, Harvey W. — Foods and Their Adulteration. Ward, Artemus. — The Grocers Encyclopedia. Bulletin No. 131, Agricultural Experiment Station, Orono, Maine. — Indian Corn as Food for Man. Bulletin No. 118, Agricultural Experiment Station, Orono, Maine. — Cereal Foods. FOOD INDUSTRIES 289 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. Farmers Bulletin No. 417, U. S. Department of Agriculture, Washington, D. C.^Rice Culture. Encyclopedias. — Britannia, International. CHAPTER VII.— UTILIZATION OF FLOUR. Jago, W. and W. C. — Technology of Breadmaking. 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. CHAPTER VIII.— 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. Bulletin No. 52, Agricultural Experiment Station, Florida. — Baking Powders. CHAPTER IX.— STARCH AND ALLIED INDUSTRIES. Sadtler, Samuel. — Handbook of Industrial Organic Chemistry. Thorp, Frank H. — Outlines of Industrial Chemistry. Thorp. — 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. Bulletin, Department of Agriculture, North Carolina. — Starches Used in Cotton Mills and Their Adulterations. 29O FOOD INDUSTRIES CHAPTER X.— THE SUGAR INDUSTRY. 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. Durr, Noel. — Sugar and the Sugar Cane. 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 Utiliza- tion. 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. CHAPTERS XI AND XII.— ALCOHOLIC BEVERAGES. Thorpe. — Dictionary of Applied Chemistry. Sadtler, Samuel. — Handbook of Industrial Organic Chemistry. Thorp, Frank H. — Outlines of Industrial Chemistry. Harrington, Charley. — Practical Hygiene. Accum, Frederick. — A Treatise of Adulteration of Food and Culinary Poisons. 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. 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 XIII.— 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. FOOD INDUSTRIES 29I Ward, Artemus. — 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 XIV.— ANIMAL FOODS. 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, Artemus. — 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. Farmers Bulletin, No. 391, U. S. Department of Agriculture, Washington, D. C. — Economical Use of Meat in the Home. 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 XV.— THE PACKING. HOUSE. V 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. 292 FOOD INDUSTRIES CHAPTER XVI.— MILK. Winslow, K. — The Production and Handling of Clean Milk. Rosenau, M. J. — The Milk Question. Wing, Henry H. — Milk and Its 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. Farmer's Bulletin, No. 363, U. S. Department of Agriculture, Washington. D. C— The Use of Milk as Food. CHAPTER XVII.— 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, New York. — A Study of Enzymes in Cheese. Bulletin No. 219, New York Agricultural Experiment Station, Geneva. New York. — Some of the Compounds Present in American Cheddar Cheese. Bulletin No. 236, New York Agricultural Experiment Station, Geneva, New York. — Conditions Affecting Chemical Changes in Cheese- making. Bulletin No. 237, New York Agricultural Experiment Station, Geneva, New York. — The Role of the Lactic Acid Bacteria in the Manu- facture and in the Early Stages of Ripening of Cheddar Cheese. Farmer's Bulletin, No. 487, U. S. Department of Agriculture, Washington, D. C. — Cheese and Its Economical Uses in the Diet. FOOD INDUSTRIES 293 CHAPTERS XVIII AND XIX.— 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. 1-3, 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. CHAPTER XX.— TEA, COFFEE AND COCO. V Freeman and Chandler. — The World's Commercial Products. Thorpe. — Dictionary of Applied Chemistry. Ward, Artemus. — The Grocers Encyclopedia. Harrington, Charles. — Practical Hygiene. Fowler, E. J. — Bacteriological and Enzyme Chemistry. Whymper, R. — Coco and Chocolate; Their Chemistry and Manufacture. Harris, W. B. — Paper on Coffee as Affected by the Food and Drug 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 Coco 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. \ 294 FOOD INDUSTRIES CHAPTER XXL— SPICES AND CONDIMENTS. Ridley, Henry N. — Spices. V Gibbs, W. M. — Spices and How to Know Them. Freeman and Chandler. — The World's Commercial Products. Leffmann and Beam. — Food Analysis. Wiley, Harvey W. — Foods and Their Adulteration. Ward, Artemus. — The Grocer's 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 PAGE Acetic ferment 98, 155, J 74 Acid phosphate of lime 113 Adulteration 59. 65, 71, 73, 75, 81, 99, 152, 163, 170, 185, 195, 234, 254, 262, 268, 275, 286 Albumins 12, 13, 148, 188, 190, 199, 212 Albuminoids 13, 14 Alcoholic beverages 153— J 75 brewing 155-164 champagne 169 cider 173 classification 153 distilled liquor 171-173 fermentation 154-155 historical 153 koumiss 175 vinegar 174 wine industry 165-171 Alcoholic solubles 13, 14 Ale 164 Allspice 209, 280, 285 Alum 26, 27, 32, 99, 109, 1 10 Amino-acid '. . . . 13, 15, 230 Animal foods 187-200 beef extracts 191 beef juices 192 eggs 197 fish 193 internal organs 193 meat 187 shellfish 195 Annatto 182, 245 Ash (see Mineral matter). Bacteria 22-31, 87, 88, 98, 99, 179-181, 196, 198, 213-224, 225-232, 233-239, 242, 247-251 Baking powders 108-1 12 alum phosphate 111 ammonia 112 phosphate no relative efficiency in tartrate : no 20 296 INDEX PAGE Barley 75, 76 composition ". 75 cultivation 75 mill products 76 origin 75 uses 75 Beef extracts 191, 208 Beef j uices 192 Beef viscera inspection 203 Beer (see Brewing). Beet sugar factories 142 Benzoate of soda 235, 244, 280 Berkef eld filter 29 Bicarbonate of soda 1 13-1 16 Le Blanc method 114 Solvay process 115 Niagara process 116 Biscuit industry 102-104 Blood 206, 207 Bolter 56 Bolting reel 57 Bonded whiskey 173 Bone-black 113, 129, 149, 206 Bone products 206 Boracic acid 163, 209, 217, 235, 254 Borax 32, 209, 217, 235. 254 Brandy 171 Breadmaking 84-102 adulteration 99 aerated bread 101 leavened bread 87-91 losses in fermentation 100, 101 modern bread factory 95-98 primitive methods 84-86 souring and its prevention 98, 99 steps in breadmaking 93-95 yeast preparations 91 Bread wrapping machine 100, 101 Breakfast foods 77-82 adulteration 81 classification - 77-8i comparison of old and new 82 Brewing 155-164 INDEX 297 PAGE Brewing {continued) adulteration 163 composition of beer 163 kinds of beer 164 processes in manufacture 156-163 raw material 155 substitution 163 Bromine 27 Butter 177-182 by-products 228, 229 composition •. 177 processes in manufacture , 178-182 renovated 182 substitutes '. 182, 204 Butterine (see Oleomargarine). Buttermilk 228 Butyric ferment 98, 212 By-products 112, 113, 122, 150, 170, 201, 203-209, 228, 229 Caff ein 262, 263, 269 Calves brains 193 Can closing machines 253 Cane crushers 134 Cane mill 133 Canning industry 247-254 adulteration 254 containers 25 1 historical 247 meat products 251 processes in manufacture 248 success of canning 250 Carbohydrates 7-1 1 classification 8 formation 8 important properties 10 occurrence 9 Carbon dioxide 35, 90, 101, no, in, 154 Carbonic acid gas generator 34 Cardine 209 Cassava ' 85, 118 Cassia 282 Caviar 197 Cellulose 9 298 INDEX PAGE Centrifuge 139 Cereals 66-76 adulteration 71 barley 75, 76 biological origin 66 composition 67 corn 67 geographical distribution 66 kinds 66 oats 74, 75 rice 71-74 use in our country 66 Cereal Department 63 Champagne 169 Cheese 229-234 adulteration 234 composition 230 historical 229 processes in manufacture 230-233 uncured 233 Chlorine 2"] Chocolate , 274 Cholera 22, 27 Cholera infantum 217 Churning 181 Cider 173 Cinnamic aldehyde 280 Cinnamon 209, 280, 282 Citrate of lime 213 Clotting 15 Cloves 209, 280, 283 Coagulated proteins 13, 15 Coagulation 15 Coal tar dyes 105, 182, 245, 254 Cochineal 245, 254 Cockle cylinder 53 Coco 270-276 adulteration 275 as a beverage 275 cultivation 270 historical 270 preparation of chocolate 274 preparation of coco 275 IND£X 299 Coco (continued) page processes of manufacture 272 Coffee 263-270 adulteration 268 as a beverage 269 cultivation 265 extracts 270 historical 263 processes of manufacture 265-268 the coffee plant 264 Coffee substitutes 82, 83 Cold storage 199, 237, 238 Collagen 187 Coloring matter 182, 209, 232, 245, 246, 254, 275 Condiments (see Spices). Copper boilers 160 Copper sulphate 245, 254 Corn (see Indian corn). Cornmeal 69 Corn oil '. 125 Corn syrup (see Glucose). Cottonseed oil 185, 186 Crackers (see Biscuit industry). Cream of tartar 112, 113 Cream separators 179, 180 Creatin 192 Creatinin 192 Creosote 241, 242 Crushers 123 Curdling '. 15 Dextrins 127, 128 production of 127 occurrence 10 uses for 127 Diastase 157, 158 Diffusion battery 144-146 Distillation 29, 172 Domestic filters 28, 29 Dough divider 98, 99 Dough mixing machine 97 Dripping boxes 126, 127 Eggs 197-200 300 INDEX Eggs {continued') page composition of the egg .-...- 199 composition of the shell 198 methods of preservation .• 198 physical structure 197 Elastin 187 Emulsification 12 Ensilage 150 Extractives 15, 192 Facing 262, 269 Fats 1 1-13, 176-186 butter 177-182 butter substitutes 182-184 composition 11 cottonseed oil •. 185 extraction 176 occurrence 11 olive oil 185 peanut oil 186 properties , 12 purification 176 utilization of .■ 204, 205 Fertilizer 150, 186, 207 Fermentation 88-90, 154, 161, 167, 260, 266, 272 Filter bags 148 Filter bed 24, 25, 26 Filter plant 27 Filter press 124, 125, 135, 146, 159, 162, 185, 186 Fish 193-195 adulteration 195 edible portion 195 nutritive value 195 shellfish 19S Flour 44-6i adulteration 59 bleaching of 59 composition : 67 entire wheat 61 gluten 63 Graham 60 hard wheat 60 milling of 44~59 prepared 60 INDEX 3OI Flour (continued) page soft wheat 60 sifter and blender 96 testing of 58 Food principles 5—15 Force 79 Formaldehyde 217, 219, 235, 241 Fructose 9 Galactose 9 Gelatin 187, 207 Ginger '. 280, 285 Globulin 13, 14, 212 Glucose . .' 128, 129 occurrence 9 processes of manufacture 128, 129 uses 128 Glue 207 Glutelins 13, 14 Gluten feed 125 Glycogen 8, 10, 188, 195 Grape-Nuts 80 Grape sugar (see Glucose). Hominy 69 Hops 156, 160 Hulled corn 68 Hydraulic presses ' 124 Hydrolysis 10 Ice supply 31 Indian corn 67-71 composition 67 earlj' cultivation 68 early methods of preparation 68 modern milling 69 old milling methods 69 origin 67 uses 70 varieties 68 Invert sugar 11 Jaggery 151 Kidney 14, 193 302 INDEX PAGE Koumiss 175 Lactic ferment 98, 155, 180, 212, 231 Lacto-chrome 213 Lactose or milk sugar 9, 212, 228 Lard 205, 234, 275 Lardine (see Oleomargarine). Leavening agents 107-1 16 acid phosphate of lime 113 alum phosphate powders in ammonia powders 1 12 baking powders 108 bicarbonate of soda 113 chemical agents 107 cream of tartar 112 early use of chemical agents 108 phosphate powders no relative efficiency in tartaric acid 113 tartrate powders no yeast 107 Lecithin 200 Liberwurst 193 Lithia 32 Liver 14, 193 Logwood 245 Macaroni 104-106 Mace 285 Maize (see Indian corn). Malic acid 165, 170 Malting 156-159 Maltose 9 Massecuite 138 Meat 187-191 canning 208 changes in cooking - 190 chemical constitution 187 extracts 19 1 inspection 189 internal organs 193 physical structure 187 reasons for cooking 190 INDEX 303 PAGE Medulline 209 Menhaden , 68 Meta-protein , 13, 15, 230 Middlings 50, 54-56, 63 Milk 21CK223 certified 222 composition 211 diseases from 216 importance of the supply 213 modified 223 necessity for cleanliness 217 our duty to the producer 219 pasteurization 222 source 210 sterilization 219 testing 219 Milk bottling machine 221 Milk coolers 221 Milk products 224-234 artificially soured milk 229 buttermilk 228 cheese 229-234 concentrated milk 227 condensed milk 224 dried casein 228 evaporated milk 226 milk powders 227 milk sugar 228 Milling 44-59 advantages of new processes 57 cleaning of wheat 52 diagram of modern processes 50 disadvantages of old processes 49 grist mills 47 hand-stones 44 mortar and pestle 45 quern 46 reduction of the middlings 55 roller mills 49, 53 separation of the middlings 53 tempering 53 wheat blends 59 Mill-pick 47 304 INDEX PAGE Mineral matter 5, 6, 22, 32, 70, 72, 74, 143, 150, 165, 188, 195, 198, 213, 230, 263 Mineral waters 32-35 artificial 35 medicinal power 33 natural springs 32," 33 water, classification 32 Mineral springs 33 Molasses 136, 146, 151 Molds 87, 88, 233, 235, 236, 239, 242 Multiple-effect evaporating apparatus 137 Musculine 209 Mustard 280, 282 Myosin 188, 190 Neats-f oot oil 206 Nucleo-protein , 14 Nutmeg 280, 285 Oats 74, 75 adulteration 75 composition 67, 74 milling . . . < 75 mill products 74 Oatmeal : 74 Oleomargarine 182-184, 204 Olive oil 184, 185 Open pan evaporators j 135 Oysters 195-197 Packing house 201-209 beef extracts 208 blood 206 bone products ■ 206 butterine 204 canning of meats 208 fertilizers 207 gelatin 207 glue 207 growth and breadth of the industry 201 hides, pelts and bristles 203 historical 201 INDSX 305 PAGE Packing house (continued) inspection and slaughtering 202 lard 205 minor products 209 neats-f oot oil 206 tallow 204 tankage 206 sausages 208, 241 Pancreas 14, i93> 209. Pancreatin 209 Paragol 125 Pasteurization 162, 220-222 Peanut oil . . .' 186 Pepper 209, 280, 281 Pepsin 209 Peptase 159 Peptone 13, 15, 163, 230 Phosphoprotein 14, 199 Plumping 196 Plastering 168 Porter 164 Preservation of foods 235-254 alcohol 243 canning 247-254 cooling 237 drying 235 salting 239 smoking 240 sterilization 219, 247, 250 sugaring 239 use of fats and oils 242 use of preservatives 243 use of spices 243 Preservatives '. 243-246 Proteins 13-15 classification 13 composition 13 occurrence 14 properties 15 Proteoses 13, 15 Prussian blue 245, 262 Puffed Rice 78 Purifier 56 306 INDEX PAGE Rennet 232 Renovated butter 182 Rice 71-74 adulteration 73 composition 67, 72 cultivation 72 geographical distribution 72 milling 72 origin 71 uses 73 Roller mills 53, 158 Rum 171 Rye 64-65 adulteration 65 composition 64, 67 uses 64 Saccharine 245, 254 Saffron 105, 182, 245 Salicylic acid 163, 174, 217, 235 Salt 86, 181, 184, 233, 277 Salting 239 Samp 69 Saponification 13 Sarco-lactic acid 188 Sausages 208, 241, 279 Sauteing '... 191 Scalper 53 Scourer ' 53 Scrapple 208 Sedimentation basin 23 Seminola 64 Separators 52, 124 Shellfish , 195-197 Shorts 63 Shredded Wheat Biscuit 80 Smoking 240 Sodium hypochlorite 27 Sodium silicate 199 Spices and condiments 277-287 adulteration 286 allspice 285 as preservatives 279 INDEX 307 . PAGE Spices and condiments (continued) pnnamon and cassia , 282 cloves 283 ginger 285 mustard 282 nutmeg and mace 285 pepper 209, 280, 281 salt 277 uses 279 vanilla 280 vinegar ; 174, 287 Sterilization 219, 226, 247, 250 Starch 1 17-129 composition and formation 8 corn starch industry 122-129 occurrence 9 outline of corn products industry , 121 physical characteristics 117 physical and chemical properties 117 potato starch 118, 1 19 source . of supply , 118 tapioca 120, 121 Stock boilers 249 Strike pan 138 ' Stout 164 Sucrose (see Sugar). Sugar 130-1S2 adulteration ■ 152 beet sugar industry 140-147 block sugar 149 cane sugar industry 132-140 cane syrup 152 comparison of cane and beet sugar 131 date palm sugar 151 history of the sugar beet 130 history of the sugar cane 130 maple sugar 151 powdered sugar 132 properties 132 refining 147-149 sorghum 151 source 130 utilization of the by-products 150 308 index PAGE Sugar (ccrntinued) yellow sugar 150 Sweetbreads 193 Tallow 204 Tannic acid .' 17c, 261, 262, 263, 269 Tartaric acid 113, 165, 170 Tea 255-263 adulteration 262 as a beverage 262 classification 257 composition 263 culture of the plant 255 green tea 261 historical 255 processes in manufacture 259-262 rules for tea making 262 Tea plant 256 Theobromine 275 Thymus gland 193, 209 Thyroidine 209 Tongue 193 Tortillas 85 Trachina 189 Tripe 193 Tuberculosis 189, 216 Turmeric 245 Typhoid fever 23, 196, 226 Vacuum pan 136-139, 226 Vanilla 280 Vanillin 280 Vinegar : 174, 175, 287 Vodka 172 Water 16-35 atmospheric 18 classification of natural water 16 classification of potable water 18 contamination of public supply 21 contamination of wells 20 danger of impure 22 diseases from 22 INDEX 309 PAGE Water (continued) history of the water supply • 17 ice supply 31 importance of 7 judging a supply 31 mineral 32-35 pollution of wells 20 purification 23-30 subsoil 19 surface 19 Water glass (see Sodium silicate). Wheat 36-64 composition ■ 36, • 67 cultivation 39 geographical distribution t>7 milling (old processes) 44~Si milling (new processes ) 52-59 origin 36 structure of the grain 41 value of 42 varieties 43 Whiskey 172, 173 Wild beet 140 Wine 165-171 adulteration > 170 champagne 169 composition 170 improving wines 168 preservation 171 processes in manufacture 166-168 sophisticated 170 Wort 160 Yeast 87-91, 154, 155 Yeast preparations 91-93 brewers , 91 compressed 92 dried ' 93