101 



proteid 2.29 per cent, total proteid 17.81 per cent, nitrogenous organic 

 extractives l.os per cent, noiinitrogenous organic extractives 1.02 per 

 cent, total organic extractives 2.70 per cent, fat 10.95 per cent, and 

 ash 1.03 per cent. The average amount of nitrogen in different forms 

 for the same samples was: Total nitrogen 3.195 per cent, proteid 

 nitrogen 2.849 per cent, and nonproteid nitrogen 0.3-ir) per cent. The 

 ratio of the nonproteid to proteid nitrogen was 1:8.3. The average 

 results obtained in the analysis of 2 samples of fresh veal were: 

 Water 75.75 per cent, insohdjle proteid 1«).23 per cent, soluble proteid 

 2.37 per cent, total proteid 18.60 per cent, nitrogenous organic extract- 

 ives 1.17 per cent, nonnitrogenous organic extractives 1.6<) per cent, 

 total organic extractives 2.83 per cent, fat 2.48 per cent, and ash 1.13 

 per cent. The average values for nitrogen were: Total nitrogen 3.350 

 per cent, proteid nitrogen 2.975 per cent, and nonproteid nitrogen, 

 0. 375 per cent. The ratio of the non])roteid to proteid nitrogen was 1 : 8. 



It will be seen that the soluble proteid in uncooked meat forms, 

 approximately, 12.80 per cent, or about one-eighth, of the total pro- 

 teid. The nonnitrogenous extractives are in all cases somewhat more 

 abundant than are the nitrogenous extractives. In general, the soluble 

 albumin and the nitrogenous and nonnitrogenous extractives vary 

 inversely with the fat; that is to say, the meats which contain the 

 most fat have, as a rule, the lower percentage of soluble albumin and 

 organic extractives, and vice versa. However, the amount of extract- 

 ives in corresponding cuts of meat from different animals may vary 

 considerably even when the fat content is about the same. For exam- 

 ple, lean beef round (sample No. 1775), containing 4.91 per cent of fat, 

 has only 2.53 per cent of organic extractives, while lean beef round 

 (sample No, 1647) contains 4.28 per cent of fat and has 3.36 of organic 

 extractives. 



The usual method of calculating the percentage of proteid in meats 

 by multiplying the total nitrogen by the factor 6.25 evidently gives a 

 much higher figure for the true proteids than should be assigned to 

 them. For example, if the average total nitrogen (3.195 per cent) 

 found in the twelve samples of fresh beef is multiplied by the factor 

 6.25, the product obtained is 19.97 per cent. The proteid obtained by 

 actual analysis with the methods used in this investigation is only 17.81 

 per cent, or a difference of 2.16 per cent. The discrepancy is due to 

 the fact that the former value includes organic extractives. Since the 

 nutritive value of the organic extractives is certainly much less than 

 that of the proteids, the usual method must necessarily lead to errors 

 in the determination of the nutritive value of meats and meat products. 



