*]2. MAINE AGRICULTURAL EXPERIMENT STATION. I904. 



carries about half and the patent flour about one-fourth as much 

 ash as the wheat from which they were made. The greater part 

 of wheat ash consists of potassium phosphate, and the ash re- 

 jected in the bran and other offals is as rich in this constituent 

 as that saved for food in the flour. Potassium phosphate is sol- 

 uble in water, and hence is probably readily assimilated. While 

 comparatively little is known of the function of mineral con- 

 stituents of the food in nutrition, it is known that they are of 

 importance, and where bread is almost the sole article of diet, 

 the removal of the phosphates in the processes of milling dimin- 

 ishes its value in nutrition. In ordinary mixed diet, where 

 several articles of food are eaten, this removal of the ash would 

 not be of very great importance, as the food of a mixed diet 

 would contain, so far as present knowledge of the function of 

 minerals can be taken as a guide, ample soluble ash constituents 

 for the needs of the body. 



The entire wheat flour carries 1 per cent and the standard pat- 

 ent more than 2 per cent more carbohydrates than the wheat 

 from which they are milled. Starch is the most important car- 

 bohydrate in wheat. There are also present small amounts of 

 dextrin and sugar. There is also always present in the wheat 

 itself about 2.5 per cent woody fiber, which is valueless in nutri- 

 tion. The entire wheat flour carries about .75 per cent and the 

 standard patent about .3 per cent of woody matter, or crude fiber, 

 as the chemist terms it. 



The heats of combustion of wheat and of the flours differ but 

 slightly from one another. From the available data, the compo- 

 sition of the three classes of flour milled from a wheat carrying 

 14.50 per cent protein would be approximately as given in the 

 table below. A hard, high grade wheat is used for illustration. 

 If a soft wheat had been used, practically the same relations 

 would have existed. 



