PROVISIONAL METHODS FOR THE ANALYSIS OF FOODS, ADOPTED 

 BY THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS, 

 NOVEMBER 14-16, 1901. 



I. MEAT AND MEAT PRODUCTS. 



By W. D. BIGELOW, 

 In Charge of Food Laboratory, Bureau of Chemistry, U. S. Department of Agriculture. 



A. MEAT. 



1. IDENTIFICATION OF SPECIES. 



When dealing with large pieces of meat, and especially with fresh meat, the deter- 

 mination of the species of animal from which it was taken is the work of the veterina- 

 rian rather than the chemist, although the data obtained by the latter are often 

 conclusive as to the variety of meat present. The physical appearance of the meat, 

 its luster, grain, compactness, the presence or absence of the marbled appearance 

 due to intermuscular fat, the size and shape of the bones, and the color and consist- 

 ency of the fatty tissue must all be taken into account. Many of these characteristics 

 are destroyed by curing or smoking, and none of them are retained by chopped meat, 

 sausage, potted meat, or other preparations of like nature. 



In such cases we must depend mainly on the results of chemical examination. 

 The percentage of glycogen, added to the percentage of reducing sugar, is often of 

 value in detecting horse meat in preparations which are supposed to consist of beef. 

 Certain results obtained in the examination of fat separated from the meat by heat 

 or by extraction with organic solvents also afford valuable data. Among the factors 

 which are of value for this purpose may be mentioned the iodin number, melting 

 point, freezing point, index of refraction, and to a less extent the specific gravity, 

 acetyl number, and Maumen4 value." The meat from embryonic animals and from 

 animals killed before they are suitable for food may often be detected by its moist, 

 clammy nature and high water content. 



2. EXAMINATION OF POISONOUS MEAT AND OTHER FOODS. b 



From a hygienic standpoint the recognition of diseased meat is a matter of prime 

 importance. The inspection of fresh meats for the purpose of detecting animal 

 parasites such as trichime and vegetable parasites such as the lumpy-jaw fungus, the 

 bacillus of tuberculosis, and other disease-producing bacteria, need not concern the 

 analyst. It is only when a food, presumably wholesome, is found to have poisoned 

 one or more individuals that the analyst must, to some degree at least, distinguish 

 between the agents that may play a causative role. 



The ordinary foods of man are liable to become poisonous from either of the three 

 causes: (1) Trichime in pork, (2) metals, and (3) bacterial products. 



See Appendix, p. 1 19. 



t>The matter under this heading was written for this bulk-tin by Dr. F. G. Novy, of Ann Arbor, 



Mich. 



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