THE ETHICS OF FOOD— BREAD 543 



What is quite clear is that it is not the high percentage of 

 nutriment in a food but the ease with which it can be digested 

 and assimilated and then made use of by the individual that is 

 of importance. Extra protein is of little use if the body simply 

 burn it up in the same way that it burns the inexpensive 

 carbohydrate starch. 



Gluten is an excessively complex material consisting in 

 the main of two proteins named gliadin and glutenin, both 

 of which are characterised by the fact that they are built up 

 of a large proportion of a particular amino-acid named glutamic 

 acid which is characteristic of other cereal proteins. These 

 cereal proteins as a class are very different in their composition 

 from animal proteins. The germ of wheat contains another 

 protein named leucosine which is intermediate in character 

 between the cereal and animal proteins and it is possible that 

 the addition of the i'5 per cent, of germ to flour does add 

 to bread a minute quantity of constituents which it otherwise 

 lacks and so renders it a more complete food. As a matter of 

 fact less than 30 per cent, of the germ is protein, so that the 

 addition of the whole of the germ to flour does not increase 

 the amount of protein by 0*5 per cent. But at present no one 

 can say that these fragments of protein digestion are of such 

 special value as to make their presence of consequence and it 

 is a fallacy to claim that their presence would compensate for 

 other proved disadvantages of wholemeal bread. 



Numerous careful studies have been made on the digesti- 

 bility and nutritive value of bread, particularly those of 

 Rubner (1879), Pappenheim (1890), Constantinidi (1887), 

 Raudnitz (1892) and Moeller (1897). 



The most recent and systematic investigation is that of 

 Professor H. Snyder carried on at the University of Minnesota 

 in 1890-2, under the immediate supervision of the late Professor 

 W. O. Atwater, whose reputation as an authority on the 

 nutritive value of food is beyond question. These investiga- 

 tions were published by the United States Department of 

 Agriculture in 1903 (Bulletin 126). 



The flours compared were 72 per cent, patents ; entire 

 wheat flour obtained by removing about one-half of the bran 

 before grinding, i.e. equivalent to about 85 per cent. ; and loo- 

 per-cent. flour, representing the entire wheat kernel or much 

 the same as standard flour. 



