VALUE OF COOKING 71 



mon method in modern times, was probably also of later 

 development since it required the use of grease in an 

 earthen or metal receptacle. 



Effects of cooking. Cooking has won favor because 

 the added flavor and delicacy which it imparts to food 

 stimulate the appetite and promote digestion. By 



Boiled 

 starch 



llulose 

 envelope 



starch 

 grain 



FIG. 52. Mashed boiled potato. (Bulletin of Agricultural Department.) 



means of it, meat becomes tender, hard grains are 

 softened, and fruits which were unwholesome because 

 of their bitterness or acidity are made wholesome and 

 pleasant. Moreover, through the destruction of disease- 

 producing microbes, 1 the food is made safe and much 

 disease thereby avoided. 



From the standpoint of cooking, foods fall into two 

 distinct classes, animal and vegetable. In animal tis- 

 sues, the strengthening framework of connective tissue, 

 to which their toughness is largely due, is changed by 

 the cooking to tender soluble gelatine. 2 In vegetable 

 foods, the binding structure is largely tough hard cellu- 

 lose, which resists chewing and digestion. This becomes 



1 See p. 282. 



2 Gelatine itself has little food value. 



