470 COMPOSITION OF FLESH. 



In 100 parts ASH there is 



The amount Of fat in flesh varies very much according to the condition of the 

 animal. After removal of the visible fat, human flesh contains 7'15, ox 1T12, 

 calf 10 '4, sheep 3 '9, wild goose 8 '8, fowl 2-5 per cent. 



The amount of extractives is most abundant in those animals which exhibit 

 energetic muscular action; hence it is largest in wild animals. The extract is 

 increased after vigorous muscular action, when sarcolactic acid is developed, and 

 the flesh becomes more tender and is more palatable. Some of the extractives 

 excite the nervous system, e.g., kreatin and kreatinin ; and others give to flesh its 

 characteristic agreeable taste (" osmasome "), but this is also partly due to the 

 different fats of the flesh, and is best developed when the flesh is cooked. The 

 extractives in 100 parts of flesh in man and pigeon, 3 ; deer and duck, 4 ; swallow, 

 7 per cent. 



Preparation, or Cooking Of Flesh. As a general rule, the flesh of young 

 animals, owing to the sarcolemma, connective-tissue, and elastic constituents 

 being less tough, is more tender and more easily digested than the flesh of old 

 animals; after flesh has been kept for a time it is more friable and tender, as the 

 inosit becomes changed into sarcolactic acid and the glycogeu into sugar, and 

 this again into lactic acid, whereby the elements of the flesh undergo a kind of 

 maceration. Finely-divided flesh is more digestible than when it is eaten in large 

 pieces. In cooking meat, the heat ought not to be too intense, and ought not to 

 be continued too long, as the muscular fibres thereby become hard and shrink very 

 much. Those parts are most digestible which are obtained from the centre of a 

 roast where they have been heated to 60-70^0. , as this temperature is sufficient, 

 with the aid of the acids of the flesh, to change the connective-tissue into gelatin, 

 whereby the fibres are loosened, so that the gastric juice readily attacks them. 

 In roasting beef, apply heat suddenly at first, to coagulate a layer on the surface, 

 which prevents the exit of the juice. 



Meat Soup is best prepared by cutting the flesh into pieces and placing them 

 for several hours in cold water, and afterwards boiling. Liebig found that 6 

 parts per 100 of ox flesh were dissolved by cold water. When this cold extract 

 was boiled, 2 '95 parts were precipitated as coagulated albumin, which is chiefly 

 removed by "skimming," so that only 3 '05 parts remain in solution. From 100 

 parts of flesh of fowl, 8 parts were extracted, and of these 4 '7 coagulated and 3 '3 



