64 MAINE) AGRICULTURAL EXPERIMENT STATION. I904. 



While all these divisions may be distinguished in the immature 

 grain, in the ripened and dried kernel the cells composing them 

 collapse and adhere so closely to one another that the minor dis- 

 tinctions become largely obliterated. 



Since a close separation of these coatings is impossible, we can 

 not determine with exactness their relative food values. It is 

 generally conceded, however, that both the pericarp and the true 

 seed coatings (episperm and perisperm) consist almost wholly 

 of woody and mineral matter, with but little protein. The 

 nitrogenous matter of the bran of commerce is -for the most part 

 contained in the adhering aleurone cells. 



The simplest method of milling wheat consists in crushing the 

 berry, thus reducing it more or less completely to a powder. 

 The wheat meal thus prepared will always contain coarse parti- 

 cles of bran. Bread made from this wheat meal will obviously 

 contain all of the nutrients of the original wheat, but the bread 

 will be coarse in texture, dark in color and rather strong in 

 flavor. These objectionable features are much more pronounced 

 in wheat meal made from hard spring wheat than in soft winter 

 wheat meal. Graham flour* or wheat meal is usually made 

 from soft wheats relatively low in protein and high in starch con- 

 tent. Because of this, graham flour, as found in the market, is 

 usually lower in protein than is high grade patent flour. Sifting 

 wheat meal, to remove the coarser particles, was the first step 

 toward the making of white flour. As explained above, the 

 ovary walls and the true seed coats adhere very firmly to the 

 floury part of the wheat berry, and can at best be only imper- 

 fectly separated. Up to the middle of the last century even the 

 best milling involved grinding the wheat in a set of stones with 

 cut faces run not quite touching each other, and the fine flour 

 was obtained by sifting by means of bolts, i. e., sieves, of vary- 

 ing fineness. As fine grinding would reduce some of the outer 

 coatings to a fine powder, with a resulting dark flour and still 

 darker loaf, only soft wheats, which would readily crush and 

 reduce the soft starchy interior to flour without powdering the 

 germ and outer layers, were employed in making the first grades 

 of flour. This method of manufacture of fine flour from starchy 



* So called from Graham, the temperance reformer of the early part of the 

 nineteenth century, who based his cure for alcoholism upon certain radical 

 changes in diet, laying especial stress upon abstinence from meats, and the use 

 of bread made from unbolted wheat meal. 



