THE CONSUMPTION OF WHEAT 285 



Self -Raising Flour is produced by mixing leavening agents 

 with flour, such as form the essential constituents of ordinary 

 baking powder. The addition of water liberates the carbon 

 dioxide, and a spongy dough results. Self-raising flour has had 

 little commercial importance. 



The Comparative Value of Different Flours. The nourish- 

 ment that can be obtained from flour depends upon its chemical 

 composition and digestibility. Of the different flours that can 

 be made from the same lot of wheat, graham flour contains the 

 greatest proportion of protein and phosphates. Experiments 

 have shown, however, that patent flour has the greatest amount 

 of available or digestible protein and other food elements. More 

 phosphates are present in white bread than are needed or ab- 

 sorbed by the body. The lower digestibility of graham flour 

 is due to the bran, both because of its resistance to digestion, 

 and because of its physiological action. The lower grades of 

 flour, although not of such a fine white color, are yet highly 

 nutritious, and yield a bread that is quite thoroughly digested. 

 Since nitrogenous foods are proportionately more expensive 

 than starchy foods, and since wheat is cheaper than lean meat, 

 all wheat products are economical food, and those containing a 

 high percentage of gluten are especially so. 



Commercial Brands or Grades of Flour. To a greater or less 

 extent each miller manufactures a flour that, on account of the 

 closeness of grinding, the proportions of the different kinds of 

 wheat, or for other causes, is peculiar to his mill. His flour is 

 branded, and a trade arises for his particular brand. As he has 

 a monopoly of this brand, his business is largely non-competitive. 

 While the brands of flour reduce competition for the wholesaler, 

 they increase competition for the retailer, who must meet in 

 the brands that he handles the prices of all other brands. The 

 wholesale baking trade generally demands a sharp granular 

 flour with a great capacity for absorbing water, whereas the 

 household trade requires a finer granulation and a whiter color. 

 'The foreign trade prefers a strong granular flour with little re- 

 gard to color, for the flour bleaches during the time consumed 

 in transportation. In some of the larger markets, authorized 

 flour inspectors stamp the packages with a brand which indi- 

 cates the date of the inspection, the weight of the package, and 



