4(^ 



present is removed in milling; and, furthermore, unless 15 per cent of 

 tiie bran is removed, the decorticated yrain, either finely or coarsely 

 ground, gives a bread of inferior dioestibility. 



In a study of the relation of decortication and grinding to digesti- 

 bility Lehmann" reports data which have to do with the effect of bran 

 on the digestibility of bread. The data are summarized in Table 34. 



Table 34. — Coefficients of digestibility of different sorts of bread. 



Kind of flour used 'for making bread. 



Coari=ely ground decorticated rye flour, Steinmctz process, 9 1 per cent of the grain. 



Finely ground rye flour, old jiroeess, 70 per cent of the grain 



Rather coarsely ground decorticated rye flour, Steinnietz process, 82 per cent of 



the grain 



Finely ground rye flour, old process, 62 per cent of the grain 



Finely ground commercial rye flour, 75 per cent of the grain 



Dry 



matter. 



Protein. 



Per cent. 

 85. 73 

 8'.». 25 



87.71 

 88.66 

 87. 52 



Per cent. 

 45. 30 

 44. 25 



54.08 

 61.70 

 53.37 



In the author's opinion the flour specially ground by the Steinnietz 

 process, which contained not less than 15 per vent of bran, was about 

 as dige.stible as ordinary rye-flour bread when it forms a part of a 

 mixed diet, and, in general, he concludes that there was no marked 

 and regular difierence in the digestibility of flour from which 18 to 38 

 per cent of the ])ran was removed. 



Lehmann's conclusions are not in accord with the others cited, and 

 it seems fair to say that the consensus of opinion is unfavorable to 

 bran as a constituent of flour. 



EXPEEIMENTS WITH BREAD FROM "GERM FLOUR." 



Experiments simihir to those with bran were also made to determine 

 the influence of the addition of germ to white flour. A sample of 

 germ (No. 1:11:, obtained in milling flour No. 276) containing 29.88 

 per cent of protein and 11.23 per cent fat was ground in the same 

 manner as the bran. A mixture, designated as "germ flour," was 

 then made, containing 93 per cent of Oklahoma straight-grade 

 flour (No. 276) and 7 per cent of the finely ground germ, the germ 

 being added in about the same proportion as is removed during the 

 milling process. Bread was made fiom this mixture as previously 

 described, and a digestion experiment with each of the three subjects 

 of the preceding experiments was conducted in the usual manner. 

 The data of these experiments are given in Tables 35 to 37 following. 



DIGESTION EXPERIMENT NO. 490. 



Kind of food. — Milk, and bread made from germ flour. 

 Suhject. — Man No. 1. Conditions as in experiment No. 469. 

 Wci(/ht. — At the beginning of the experiment ISO pounds; at the 

 close 178 pounds. 



«Arch. Hyg., 45 (1902), p. 177. 



