# 5F Ui .Di ..¥' HoUinger Corp. pH8.5 [Reprinted from thf Journal of the American, Chemical Society, Vol. XVIII., No. 2. February 1S96.] THE USE OF THE CALORIMETER IN DETECTING ADUL- TERATIONS OF BUTTER AND LARD.' By E- a. de Schweinitz and James A. Emery. i\ t Received January 3, 1896. WHILE engaged in a study of the comparative value of butters and oleomargarines, it occurred to one of us that possibly the determinations of their respective heats of combustion might be useful if taken in connection with other data. Prof. Atwater, who has for some time been conducting experiments with an improved calorimeter, ver}^ kindly con- sented to burn such samples as might be sent to him. The first results were so interesting that it occurred to us at once that this method might be useful in detecting the adulteration of but- ter with oleomargarine, and also perhaps in distinguishing between lards of different sources and compound lards. Accord- ingly, some specially selected samples of which duplicates were kept in our laboratory, w^ere sent to Prof. Atwater, and in the case of the butters and oleomargarines the results confirmed our first suppositions. In the use of the lards, however, the results were not so sharply distinctive, but taken in conjunction wnth other analytical data will prove, as we will endeavor to show, 1 Read at the Cleveland meeting, Dec. 31, 1895. 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C, sam ha a 3- Q a ^a ca C8 a a * 5d?i c (u a- .t! a^. en M'f'g Creame s. Va., ur & Co. 03 > •0- •0 a-a- 0) u 03 > ^1 a ta ^0 Gosh Elgir Plain Armc I to "^ >0^ M CI to ^ io>o t^OO Ov O M w e* to -^ »o CALORIMETER FOR BUTTER AND LARD. 3 exceedingly useful. The samples were forwarded to Prof. Atwater, prepared for combustion, without any description of their character being given except that they were fats. It is well understood that the estimation of the calories is of consider- able use in a determination of the molecular weights of complex molecules and the results which we will report will serve to show, we think, practical application of the use of the bomb calorimeter. This is best seen by a study of the following tables, which give in detail the examinations that are ordinarily made for oleomargarine and butter (Table I.), and accompanying these examinations the calories per gram. The samples were pre- pared for these latter determinations by washing, melting, filter- ing, and drying the samples at 100° C. The figures given by different authorities for butter fat, vary slightly. Stohman gives the heat equivalent as determined by the potassium chlorate method as 9.192 small calories per gram, while by the oxygen method it was 9.231 calories per gram. The three samples of pure butter burned were from the follow- ing sources : No. 28, the best butter used by Armour & Co., in the manufacture of butterine. No. 26, was Elgin Creamery butter, and No. 27, obtained from a Virginia gentleman, who sent it as a sample of the best butter made on his place. Nos. 31, 32, and 33, were mixtures of Elgin butter and oleomargarine. The figures obtained for butter fat are a little higher than those Stohman gives for pure butter. Table II. The steady increase in the calories of the mixtures is in proportion to the amount of oleomargarine added to the butter and this taken in conjunction with the iodine number gives additional confirmatory evidence of the character of the sample. TABLE II. Mixture Composed of Definite Proportions of Elgin and Wood- lawn No. 2^. Sample. I E and \ W, No. 2^ \ Fand I W, No. 2^ ^Eand f W, No. 2=^. Actual iodine equivalent. Theoretical iodine equivalent. Actual combustion calories per gram. Theoretical combustion calories per gram. • 43-90 43-76 9-391 9.412 . 48.01 49-77 9.416 9.498 • 5540 55.78 9.491 9-584 4 E. A. DE SCHWEINITZ AND JAMES A. EMERY. The theoretical calories per gram for the above mixtures as compared with those found are, Theory. Found. No. 31 9-412 9-391 No. 32 9-498 9-4i6 No. 33 9.584 9.491 The actual combustion of the sample containing a small admixture of oleomargarine falls a little lower than theory requires, but is sufficiently high to indicate at once that there is adulteration of the normal butter. The other two samples give results still more distinctive and characteristic. The determina- tion of the calories would be sufficient, therefore, to detect oleo- margarine. If not relied upon entirely it still furnishes very satisfactory evidence. One point to which attention should be called is the exceedingly low temperature at which the oleomar- garines melted. They were purchased at the end of winter and probably made to suit the winter trade. If left in an open dish in the laboratory for a few hours they became soft and semi- fluid. In the case of the lards from various sources the results are somewhat different and are not so distinctive as compared with compound lard, as the butter and oleomargarine. (Table III.) Still even here the determination of the calories taken in con- junction with other determinations, as the iodine absorption, will also be of use. Should the determination of the calories show a low figure one could conclude that the lard was either a compound or a lard from the caul, intestines, or head of the ani- mals, while the determination of the iodine number and cotton- seed-oil test, would show at once whether the sample was a lard or a compound lard. The error of experiment in calorimetric work is usually counted at twenty-five calories per gram, but by careful work can be made less and a number of experiments in the same line as the above, would probably give data that would make the determination of the calories of still more practical value. E. A. DE SCHWEINITZ AND JAMES A. EMERY. 5 TABIvE III. Analvses of Specimens from Armour & Co. Combustion Cotton-seed oil, Melting Iodine calories Bechi's Quality. point, equivalent, per gram. test. Lard, leaf 56.85 9.621 none. " caul fat 40.0° 58.61 9.573 Slightly darken " intestinal fat 40.7° 54.74 9.581 " " " heads 29.5" 68.79 9-503 None. " mixture of all fats 63.86 9.654 " " trimmings 65.57 9.606 " " compound, 1st grade 86.18 9.583 Purple brown. " compound, 2nd grade 86.57 9.530 " " shield 61.01 9.598 x