556 EXPERIMENT STATION RECORD. 



time of rising in almost all cases. . . . The time for rising may be shortened 

 through two causes: Either the presence of a food which stimulates the ac- 

 tivity of the yeast, or a weakening of the gluten so that the same amount of 

 yeast activity will accomplish the same result in a comparatively shorter time. 

 In this latter case we are likely to have less maximum amount of rise in the 

 dough than in the former case where the substance stimulates the yeast activity 

 without affecting the quality of the gluten. An examination of the figures for 

 the time of rising and comparing them with the maximum rise of dough would 

 show that the amino compounds as a class, whether used as pure chemicals or 

 as found in germinated wheat products, affect the gluten in an unfavorable way. 

 On the other hand, substances which furnish food for the bacteria, such as the 

 ammonium compounds and the extracts from sound bran, stimulate yeast 

 activity without injuring the quality of the gluten. This opens up a very in- 

 teresting and profitable line of investigation in regard to the different ways 

 the gluten may be affected by the various methods of handling and storing 

 wheat, as well as the chemical compounds which are the ultimate cause of the 

 baking qualities of different flours." * 



The data reported with respect to spring in the oven and loaf volume do not 

 show any concordance and are not uniform enough so that definite conclusions 

 can be drawn from them, though they do not contradict the conclusions noted 

 above. 



With respect to the texture of the crumb the amino compounds, with few ex- 

 ceptions, had an unfavorable effect. " The amino compounds present in modi- 

 fied wheat products were the most pronounced in this respect. On the other 

 hand, with a few exceptions, the ammonium compounds as well as the extracts 

 from sound bran had no unfavorable effect on texture, Amino compounds as 

 a class are unfavorable to the baking qualities of the flour. As a group they 

 are more pronounced in their effects than the proteins such as gliadin, glutenin, 

 edestiu, or leucosin. It seems safe to conclude that a study of wheat flour 

 along these lines would be more profitable than many of the methods hitherto 

 used." 



Tests were also made to ascertain the effects of adding starch, bran, or bran 

 extract to flour in bread making. The addition of starch, it is noted, would 

 act in a way as a diluent, neither increasing or decreasing the amount of 

 gluten and has the same effect as a decrease of the percentage of protein with- 

 out any change in its quality. 



"There was a regular shortening of the total time for rising, being longest 

 for the check loaf and shortest for the loaf where bran extract was used. . . . 

 The presence of starch diminished the total expansion, oven spring, and loaf 

 volume as compared with the check loaf. The texture was not impaired by 

 the presence of starch but was equal to the check loaf. The use of bran dimin- 

 ished in a larger measure the total expansion, oven spring, and loaf volume. 

 This loaf had the least total expansion and loaf volume. The texture was also 

 poorest in this loaf. It is remarkable that the cold extracted bran should 

 differ in so marked a degree from the nonextracted bran. The oven spring, 

 total expansion, and loaf volume were so much larger in every case that the 

 result can not be due to accidents, and the same results were obtained in the 

 second trial. The total expansion, oven spring, and loaf volume were some- 

 what less with the hot extracted bran than with the cold extracted bran. The 

 effect of the cold bran extract was. in the main, the same as when this sub- 

 stance was tried before. It had the shortest total time for rising, the largest 

 total expansion, oven spring, and loaf volume in this test [and a little better 

 texture]. 



