EXAMINATION OF FROZEN EGG PRODUCTS. 95 



Salicylic acid. — Use the method for the detection of salicylic acid 

 in preserved eggs. 1 



MISCELLANEOUS CHEMICAL TESTS. 



The chemical tests described are those which up to the present 

 time have been found most useful in detecting the presence of decom- 

 posed egg material. With advances in knowledge it is probable 

 that these will be supplemented and possibly displaced by new and 

 even better methods. The following methods, upon which some 

 work has already been done, seem to offer possibilities : 



Inorganic phosphoric acid. — R. M. Chapin and W. C. Powick have 

 discussed "An Improved Method for the Estimation of Inorganic 

 Phosphoric Acid in Certain Tissues and Food Products," in the 

 Journal of Biological Chemistry (1915), volume 20, number 2, page 97. 



Separation and quantitative determination of the lower alkylamines 

 in the presence of ammonia. — A method for this separation and deter- 

 mination has been published by F. C. Weber and J. B. Wilson in the 

 Journal of Biological Chemistry (1918), volume 35, number 2, 

 page 385. 



Catalase. — Tests for this determination are discussed by Hull man 

 in Centralblatt fur Bakteriologie, Parasitenkunde und Infections- 

 krankheiten. II Albteilung (1915), volume 45, page 219, and by 

 M. E. Pennington and EL C. Robertson, jr., in U. S. Department of 

 Agriculture, Bureau of Chemistry Circular 104. 



Determination of degree of putrefaction. — F. W. Foreman and G. S. 

 Graham-Smith have reported their method in the Journal of Hygiene 

 (1917), volume 16, page 109. 



Physical and Microscopical Examination. 



Note the odor of frozen egg products while the jxroduct is frozen 

 and again after thawing. For this purpose remove a small amount 

 from the can and immediately thaw it. Allow the remainder of the 

 contents of the can to thaw in running cold water, which takes about 

 12 hours for a 30-pound can. Examine the sample for mold, em- 

 bryos, eggshells, dirt, larva?, and other foreign material by the follow- 

 ing methods : 



PHYSICAL. 



Note the odor of the eggs. Good eggs have a characteristic eggy 

 odor, which must be distinguished from a sour, a musty, and a rotten 

 odor of bad eggs. Then make a physical examination to detect 

 the presence of mold, embryos, eggshells, dirt, larvae, and any foreign 

 material, as follows : 



Dip out a small amount into a large, flat pan, the one most satis- 

 factory being white enamel, 2 inches deep and measuring 12 by 17 

 inches. Add enough water to theeggtomakea thinmbrture, aboutone- 



i Chem. Abs. (1914), 8: 3331. 



