RATIONAL FEEDING OF MEN 385 



albumins are coagulated, the globulins also are coagulated, 

 and if the heat is sufficiently intense, molecular changes 

 take place, in which the elements composing the proteid 

 molecule are rearranged in a different way forming, prac- 

 tically, a new molecule with different chemical and phys- 

 ical properties. Since the proteid compounds contain 

 fatty acid radicals, carbohydrate- like bodies, amides and 

 radicals of other compounds, a number of chemical 

 changes may take place, varying with the degree of heat 

 employed. 



The chemical changes which take place in the process 

 of cooking influence, to a limited extent, the digestibility 

 of the foods. As a rule, the total digestibility of the 

 carbohydrate nutrients is changed but little by the action 

 of heat. For example, experiments have shown that the 

 carbohydrates in toast are no more completely digested 

 than the carbohydrates in bread, but the action of heat 

 in the preparation of toast produces chemical and phys- 

 ical changes which render the nutrients more susceptible 

 to the action of the digestive fluids, and while toast is no 

 more completely digested than bread, it is more readily 

 acted upon by the digestive fluids. Experiments show 

 that prolonged heat has a tendency to decrease the di- 

 gestibility of the proteid compounds as a class. In toast, 

 the proteid nutrients are slightly less digestible than in 

 bread. 



In general, it can be said that cooking effects ease of 

 digestion rather than completeness of the process, that 

 the carbohydrates are practically as digestible before the 

 action of heat as after and that the proteids are slightly 



