Chemical and Physical Papers. 203 



A considerable number of observations are made in connection 

 with each baking test, and a detailed study of any set of these 

 would involve considerable time and the inspection of many figures 

 — a proceeding that would be wearisome to all not especially in- 

 terested in this line of work. In most cases, therefore, only the 

 figures for loaf volume are presented. 



In addition to the experiments using amino acids, others have 

 been made with salts such as might be present in the flour or that 

 are related to them. 



The accompanying table exhibits the results obtained with bran, 

 etc. If bran were merely a diluent, and without active effect on 

 the gluten, we should expect that the quality of the loaf would be 

 affected by incorporating a considerable percentage of it with the 

 flour. To offset this effect of dilution a loaf was made in which an 

 equal weight of starch was used instead of bran, starch being pre- 

 sumed to be without specific influence, or, at least, without much 

 influence except as a diluent. In all of our baking tests a check 

 loaf is baked from the untreated standard flour, and with this, as a 

 rale, all others are to be compared. The difficulty of conducting 

 exactly comparable baking tests is such that, without such a test 

 loaf produced by a parallel treatment in each baking, it would be 

 impossible to draw any conclusions. Of the results obtained with 

 the bran, in addition to loaf volume, there is presented the scoring 

 as to texture, and total time in minutes required for the rising. 



The bran used in these tests was free from scourings or screen- 

 ings of any kind. In preparing the extracts, 500 grams were 

 treated with 2000 cc. of water. The bran was allowed to soak over 

 night, and then placed on linen and the extract squeezed out. The 

 residue was treated several times with additional portions of water 

 in preparing the washed bran. In extracting hot, the bran was 

 boiled about ten minutes with water, then washed several times on 

 linen with hot water, the water being squeezed out. 



The table shows that the unextracted bran had a notable deteri- 

 orating effect on the loaf, in respect to both volume and texture, 

 as compared with the check loaf or with the loaf to which an equal 

 weight of starch was added. The extracted bran was less marked 

 in its effect on loaf texture, and the loaf volume exceeded that of 

 the loaf in which starch was used. The loaf in which the extract 

 from 40 grams of bran was used was the best of all. The fact that 

 extracted bran and bran extract each produces better results than 

 Avhen the two coexist in the enextracted bran is something that 



