FOODS N UTRITI ON. 



771 



amount of bread and milk, and of a large and a small amount of oatmeal and milk; 

 (3) the digestibility of bread made from flour in Avhich the proportion of starch is 

 increased; and (4) the quality of the bread as affected by increasing or diminishing 

 the proportion of starch, by raising or lowering the temperature of the flour, by 

 prolonged heating of the flours, and I)y blending different types of flour. 



The digestion experiments with standard patent white bread, entire-wheat bread, 

 and graham bread, gave the following average coefficients of digestibility: 



Digestibility of different sorts of bread. 



Protein. 



Fat. 



Carbo- 

 hydrates. 



Energy. 



Standard patent white bread 



Entire-wheat bread 



Graham bread 



Per cent. 

 8.5.3 

 80.4 

 77.6 



Per cent. 

 56.4 

 55.8 

 58.0 



Per cent. 

 97.5 

 94.1 



88.4 



Per cent. 

 <J0. 1 

 8.3. 5 

 80.7 



The principal results of all of the experiments follow : 



Chemical analysis showed that the patent flour contained a little less protein than 

 the graham and entire-wheat flours, but its protein was more thoroughly digested 

 than that of the coarser flours. The digestibility of first and second patent flours 

 was not appreciably different from that of standard patent flour. In every case the 

 digestibility was high, doubtless owing to the fact that the flours were finely ground. 

 Generally speaking, small rations were somewhat more thoroughly digested than 

 larger rations, and bread and milk a little more thoroughly than oatmeal and milk. 

 This the author believes is due to the fact that the oatmeal was much coarser than 

 the flour from which the bread was made. 



An increase in the proportion of starch in flour caused a slight decrease in the 

 digestibility of protein. When starch was added to flour with a high percentage of 

 gluten containing 37.2 per cent glutenin and 62.8 per cent gliadin, the size of the loaf 

 was not reduced. The physical qualities of the bread, however, were materially 

 altered. It contained less moisture than bread made from normal flour. When the 

 proportion of starch in flour was diminished by the addition of moist gluten, the size 

 of the loaf was not increased. These experiments indicate that the character of 

 gluten rather than the starch content of flour affects its bread-making qualities, the 

 size of the loaf being determined by the ratio of gliadin to glutenin rather than by 

 the percentage of gluten present. 



The effect of the temperature of the flour used for bread making was most notice- 

 able in the rate of expansion of the dough and the physical quality of the bread, the 

 best bread being obtained when the temperature of the flour was about 70° F. Pro- 

 longed heating of flour impaired its bread-making qualities, affecting both color and 

 lightness. 



By blending hard and soft wheats the undesirable properties of each were counter- 

 balanced. When flour containing a high percentage of glutenin was mixed in equal 

 proportions with flour containing a high percentage of gliadin, the loaf produced was 

 larger and of better quality than that from either flour alone, but was not equal in 

 (juality to that i)roduced from wheat containing a normal, well-l)alanced glut«n. 



A further study of the losses in the process of making bread, L. A. Voor- 

 HEEs {Xi'w Jirxiii Stax. Rpt. 1000, ]>p. 1.J4-176). — A number of experiments are 

 reported on the losses of material involved in bread making and related topics. A 

 part of this work has been abstracted from a previous publication (E. S. R., 11, p. 768). 

 The experiments not previously noted, ac^cording to the author, "have shown that 

 the variability in the lo.ss of dry matter, as ob.served in the results of different inves- 

 tigators, may occur as readily in the experimonts of a single investigator, and at a 



