10 STUDIES OF POULTRY. 



cago, where the chickens were killed, is a market in which scalded 

 chickens prevail almost exclusively and the bird is killed by breaking 

 the spinal column near the head and bleeding is accomplished by 

 gashing the throat from the outside, hoping thereby to cut both jugu- 

 lar veins, the animal heat being removed by soaking in cold water, 

 or finally ice water, it is fair to assume, in the absence of specific state- 

 ments, that this was the method employed. 



Light and dark meat were analyzed together. The nitrogen of the 

 flesh was determined as nitrogen soluble in cold water and coagulable 

 by heat; noncoagulable (proteoses and peptones), and nonprotein 

 nitrogen (amino bodies). The total nitrogen soluble in water is the 

 sum of these constituents; the total nitrogen in the meat itself, less 

 the nitrogen soluble in water, being considered as insoluble protein 

 nitrogen. 



While the analyses of the flesh both by Pennington and by Emmett 

 and Grindley were for essentially the same constituents, the different 

 methods of stating results make comparisons difficult. Emmett and 

 Grindley do not calculate results to a water-free basis, but they do 

 recalculate the findings in the case of the storage chickens to the 

 water content of the one lot of fresh chickens examined, taking this 

 as the original water content for all. Since the water content of the 

 flesh of fresh fowls is quite variable, 6 this is a doubtful procedure for 

 the drawing of very accurate conclusions. It has been shown (loc. 

 cit.) that there may be a maximum variation of at least 2.2 per cent 

 in the moisture content of light meat and of 4.2 per cent in the dark 

 meat, which would make a decided difference in such calculations. 



While the methods for the study of flesh protein used by Emmett 

 and Grindley and by Wiley and Pennington were based upon the same 

 general plan, the latter adopted certain mechanical devices in the 

 interest of thoroughness and speed (since enzym action during long 

 extraction periods must be reckoned with), such as shaking machines 

 and centrifuges, which rendered extraction and filtration rapid and 

 completed 



It has been shown (Pennington, address before the American Warehouse- 

 men's Association, December, 1909) that of all the methods, so far studied, of 

 preparing poultry for cold storage, the above procedure gave the most irregular 

 and most unsatisfactory results. 



6 Pennington, Proc. First Int. Cong. Ref . Ind., 1909, 2 : 243. 



c Later work on 82 fresh broiling chickens gave a maximum water content of 

 the light meat as 75.76, a minimum of 73.32, and a mean value of 74.79. For 

 the dark meat the maximum was 75.94, the minimum 71.75, and the mean 74.84. 

 Twenty roasting chickens gave a maximum for the light meat of 75.73, a 

 minimum of 73.30, and a mean of 74.14. For the dark meat the maximum was 

 75.86, the minimum was 73.02, and the mean 74.30. 



d U. S. Dept Agr., Bureau of Chemistry Bui. 115. 

 [Cir. 64] 



