370 AGRICULTURAL CHEMISTRY 



489. Proteids of Meat. Lean meat, fat- free, is a con- 

 centrated nitrogenous material composed mainly of pro- 

 teids but containing also small amounts of amides, albu- 

 minoids and in some cases, alkaloidal bodies. The pro- 

 teids are present mainly in insoluble forms ; a small 

 amount, however, is soluble. The principal soluble meat 

 proteids are albumin and syntonin. 



490. Albumin. The formula C 72 H 112 N 18 SO 22 has been 

 tentatively assigned to albumin. The amount of albu- 

 min in meats ranges from 0.6 to 5 per cent. Liebig gives 

 as a mean 2.96 per cent. The lean meat of the pig as 

 well as that of poultry contains a relatively large amount. 

 Albumin is soluble in cold water, and is coagulated at a 

 temperature of 157 to 163 F. and of 69 to 75 C. 

 Dilute acids convert albumins into acid albuminates while 

 alkalies produce alkali albuminates. The albuminates 

 are proteids derived from albumins and other proteids 

 by the action of acids or alkalies. 



491. Hyosin. Myosin is obtained from meat by extrac- 

 tion with a weak solution of common salt. The myosin 

 dissolves in the salt solution and is precipitated by heat 

 and chemicals (see Experiments 60 and 61). Myosin is 

 a globulin and in the living animal is present largely in 

 soluble forms. 



492. Syntonin has the same general relationship to 

 myosin as dextrin has to starch. Dextrin is derived 

 from starch and syntonin is derived from myosin. Syn- 

 tonin is an acid albuminate formed by the action of dilute 

 acids. The amount of syntonin and myosin in meats is 



