152 Physiology. 



Cooking. Cooking is designed to make food more pala- 

 table and more digestible. Some foods, such as eggs, are 

 as digestible before they are cooked as after. But many 

 foods in the raw state are unattractive, or even repellent, 

 whereas cooking usually develops an agreeable odor and 

 taste. Cooking should soften the harder and tougher tis- 

 sues, such as cellulose in vegetables and the connective 

 tissue of animal foods. Cooking starch causes the starch 

 grains to swell and burst, and makes the starch much more 

 digestible. 



Making Soup. If meat be cut into small pieces and 

 put into cold water, and the water gradually warmed, the 

 soluble material of the meat may be extracted, and this is 

 the principle followed in making soups. 



Boiling Meat. If we wish to cook the meat itself, the 

 juices should be retained instead of withdrawn. For this 

 purpose boiling water is poured over the meat to coagulate 

 the outer layer and prevent the extraction of the juices. 



Baking, Roasting, and Broiling. The same principle 

 applies to baking, roasting, and broiling. The outside is 

 subjected to high heat at the beginning of the cooking, 

 which forms a sort of crust through which the nutritious 

 juices cannot escape. In these modes of cooking it is very 

 desirable to reduce the heat applied after the first few 

 minutes, so that the interior may be cooked enough with- 

 out over-cooking the outside; this is especially true in 

 broiling. 



Frying. Frying, as ordinarily done, is not a good mode 

 of cooking ; in fact, is often very bad, as the food is fre- 

 quently soaked with fat and rendered very indigestible. 

 But true frying, that is, by immersion in boiling fat, is a 

 good mode of cooking. This coagulates the albuminous 



