35o 



FLESH AND ITS PREPARATIONS. 



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, 11-12 ; 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, whereby 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 flavour [" osmasome,"] but this is also partly 

 due to the different fats of the flesh, and is best developed when the flesh is cooked. The ex- 

 tractives in 100 parts of flesh are in man and pigeon, 3 ; deer and duck, 4 ; swallow, 7 percent. 



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 glycogen 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 to 70 C, 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 escape 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 1 00 parts of flesh of fowl, 8 parts were extracted, and of these 4 7 was coagulated 

 and 3 *3 remained dissolved in the soup. By boiling for a very long time, part of the albumin 

 may be redissolved. The dissolved substances are : (1) Inorganic salts of the meat, of which 

 82-27 per cent, pass into the soup ; the earthy phosphates chiefly remain in the cooked meat. 

 (2) Kreatin, kreatinin, the inosinates and lactates which give to broth or beef-tea their stimu- 

 lating qualities, and a small amount of aromatic extractives. (3) Gelatin, more abundantly 

 extracted from the flesh of young animals. According to these facts, therefore, flesh broth or 

 beef-tea is a powerful stimulant, supplying muscle with restoratives, but is not a food in the 

 ordinary sense of the term, as kreatin in general leaves the body unchanged (v. Voit). The 

 flesh, especially if it be cooked in a large mass, after the extraction of the broth is still avail- 

 able as a food. 



Liebig's Extract of Meat is an extract of flesh evaporated to a thick syrupy consistence. It 

 contains no fat or gelatin, and is chiefly a solution of the extractives and salts of flesh. 



[Extract of Fish. A similar extract is now prepared from fish, and such extract has no fishy 

 flavour, but presents much the same appearance, odour, and properties as extract of flesh.] 



234. VEGETABLE FOODS. The nitrogenous constituents of plants are not 

 so easily absorbed as animal food {Rubner). Carbohydrates, starch, and sugar are 

 very completely absorbed, and even a not inconsiderable proportion of cellulose may 

 be digested. The more fats that are contained in the vegetable food, the less are 

 the carbohydrates digested and absorbed. 



