WniGin. -Chemistr// of Flesh Foods. S' 



study a comparison of the composition of tlie frozen ; ample was made 

 with that of the ''resh meat ; there appeared to be no general tendency 

 for the free ammonia, coaguable proteids, or the albumoses to increase 

 or decrease, and hence chemically the products of bacterial growth, if there 

 were any, were inappreciable. 



The authors concluded from their results that frozen meats can be held 

 in cold storage under proper conditions for a period of 554 days or 

 longer. 



It must be noted that in the above investigation the fresh samples were 

 not examined chemically until an average of 3-7 days had elapsed after 

 slaughter, and that in comparing the fresh and frozen results they are 

 from material from diiferent animals. In a second paper Richardson and 

 Scherubel have made a study of beef stored at 2° to 4° C. — that is, above 

 freezing-point. Tests were also made to ascertain whether chemical 

 methods could dt^tect any change", due to known bacterial decomposition 

 of meat. It was found that the total nitrogen, the total solids in the cold- 

 water extract, the coaguable proteids, albumoses, meat-bases, and free 

 ammonia all increased. 



The experiments with samples kept at 2° to 4° C. were not, on the 

 whole, satisfactory, but showed that decomposition took phice. 



In 1909 Emmett and Grindley investigated the effect of cold storage 

 on beef and poultry stored twenty-two to forty-three days, and concluded 

 that the slight changes that occurred did not alter the nutritive value of 

 the meat. 



In 1911 Houghton found that chicken meat stored for five months at 

 — 21° to —14° C. showed certain physical and chemical changes which 

 demoiTstrated that it is not identical with the fresh material ; they also 

 detected the enzymes peroxydase, catalase, protase similar to trypsin, 

 invertase, and a nitrate-reducing enzyme. 



From a review of the above work it would appear that, with the 

 exception of the investigations of Wiley and his associates, Richardson 

 and Scherubel, Emmett and Grindley, and of Houghton, either the con- 

 ditions as to temperature and methods of preparing meats for cold storage 

 do not correspond with those in common usage of refrigeration, or else in 

 most comparable cases the chemical constituents determined and reported 

 are few; and outside of Emmett and Grindley's and Houghton's work no 

 one, as far as can be discerned, has published any results where fresh and 

 frozen meats were all procured from the same animal, and hence, as far as 

 our present knovs^ledge shows, the differences reported could have been 

 still more, les ., or of a different nature, and therefore, outside the work 

 of Emmett and Grindley on beef and of Houghton on poultry, the 

 influen'^e of cold storage upon the chemical composition of flesh has not 

 been defiiiitely determined. 



Experimental. 



A carcase each of lamb and of mutton, weighing respectively 34 lb, and 

 48 lb., and graded C.M.C. 2 and 7, was chosen by the author immediately 

 after slaughter ; each carcase was split, and, from one half of each, portions 

 of the flesh were removed ; the excessive fat was trimmed off, and all bone 

 removed ; the portions of the resulting lean meat were finely minced to 

 obtain a uniform sample, and then analysed. The remainder of the carcases 

 were placed in cold storage, and similar samples drawn from time to time 

 up to 160 days, when the experiment ceased. 

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