372 AGRICULTURAL CHEMISTRY 



juices in small amounts; 100 pounds of meat contain from 

 0.07 to 0.32 of a pound. Like other amides, it pos- 

 sesses less food value than protein. Keratin, sarkin 

 and allied bodies are not coagulated by heat, but 

 are gradually decomposed and give off characteristic 

 odors when meat is being cooked. Keratin and sarkin 

 are present in large amounts in beef extracts and although 

 they possess no direct food value, they impart palatabil- 

 ity and are mainly valuable on this account. 



497. Albuminoids, Gelatin. When bone or muscular 

 tissue is subjected to the action of boiling water, 

 gelatin separates upon cooling and standing. Gelatin 

 is quite different in chemical composition from albumin, 

 muscular fiber and other proteids. Hoffmeister gives the 

 formula as C 102 H 151 O 39 . It contains no sulfur, while pro- 

 teids contain from i to 2 per cent. Gelatin may prevent 

 the rapid depletion of the protein of the body but cannot 

 take its place as a nutrient. The approximate amounts 

 of the nitrogenous compounds in lean meat are given in 

 the following table from which it will be observed that 

 only a small part is present in the meat juices. 

 THE NITROGENOUS COMPOUNDS OF MEAT. 



Per cent. 



f Muscular fiber 12 to 18 



I Albumin 0.5 to 2.0 



' Proteids iMyosin 0.4 to 0.6 



[ Sy ntonin 



2. Albuminoids Gelatin, etc 2.0 to 5.0 



r Keratin 0.07 to 0.34 



3. Amides < Sarkin o.oi to 0.03 



lUrea 



4. Alkaloids (ptomaines) Occasionally traces. 



