XVII. METHODS FOR THE ANALYSIS OF MEAT AND MEAT 



PRODUCTS/ 1 



MEAT. 

 1. Identification of Species. Provisional. 



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

 often of value in detecting horse meat. Certain results obtained in the exam- 

 ination of the fat also afford valuable data. Among the factors which are of 

 value for this purpose may be mentioned the iodin number, melting point, con- 

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

 number, and Maurnene 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. The subject of the determina- 

 tion of the species of animal from which meat is taken is well treated in works 

 on meat inspection and is not discussed here. 



2. Injurious and Poisonous Products. 6 Provisional. 



The ordinary foods of man are liable to become unwholesome or poisonous 

 from any of the following causes: (1) Trichinae in pork, (2) metals, and (3) 

 bacterial products. 



(a) TRICHINAE. 



Examine immediately for trichinae pork, or sn usage containing pork, which 

 has caused sickness. 



(b) POISONOUS METALS. 



Examine for arsenic, antimony, tin, lead, copper, and zinc. For the deter- 

 mination of these metals proceed as directed under " IX. Canned Vegetables," 

 page 61. 



(c) BACTERIAL PRODUCTS. 



As bacteria are the most common cause of poisonous meat the examination 

 should primarily be made from that point of view. Given a poisonous meat, the 

 first procedure is to examine for trichinae. If they are not found, the bac- 

 teriological examination should next be undertaken and the chemical examina- 

 tion reserved until the last. 



The bacteriological examination should first consist in feeding a number of 

 different species of animals the larger the number the better for a day or 

 two exclusively upon the food. White mice, house mice, white rats, young dogs, 



"See Appendix, p. 252, for method for the determination of acidity. 



'The material under this heading was originally prepared by Dr. E. C. Novy. of Ann 

 Arbor, Mich. 



r Fishchoder, Leitfaden der praktischen Fleischtx'selmu ; Ostert;ii:. Ilnntlbmh <lrr 

 Fleischbeschau ; Walley, A Practical Guide to Meat Inspection, pp. 233-245. 



106 



