A I A Journal of Agricultural Research voi. xiii, no. s 



Here again the differences in the stronger acids do not appear very- 

 striking. Those for lactic acid are, however, very consistent. In every 

 instance the W3 gluten shows lower imbibition than P gluten, and the 

 antagonistic action of salts on imbibition by the P gluten is very much 

 more pronounced than with either C or W3 gluten. 



There is a certain similarity between the curves for the P gluten and 

 salt and those for the weaker glutens in acid alone. There is, however, 

 no necessary correlation, for a flat, slowly rising curve means only that 

 the imbibing power of the gluten is low. In one instance this is due to 

 the antagonistic action of the salts upon the action of the acid and in 

 the other instance to an inherently, weaker tendency on the part of the 

 colloid to imbibe water. That these differences actually do exist in the 

 two instances is shown by the fact that the presence of salts in the acid 

 solution causes the gluten to retain its coherence and become more firm 

 and elastic than controls in the same concentration of acid lacking the 

 salts. This does not hold for the weak glutens with the flat imbibition 

 curves, for these lose their coherence, become weak and inelastic and 

 disperse at a much lower degree of hydration than do those glutens whose 

 curves rise sharply. 



We can therefore definitely state that a weak gluten does not owe its 

 "weakness", nor its imbibition curve its "flatness", to either the acid or 

 the salt content of the flour from which it is derived, but rather to the 

 fact that a weak gluten has inherently inferior colloidal properties. 



BAKING TESTS AND FLOUR ANALYSES 



In the foregoing experiments and discussion, considerable attention 

 has been directed to the effect of acids and salts upon glutens prepared 

 from strong and weak flours, and we believe that it has been clearly 

 shown that the determining factor in flour strength is not the concentra- 

 tion of soluble acids and salts which are present in the flour. 



Further evidence, however, that "quality" in flours is not determined 

 by the soluble-acid and salt content is again presented in Table VI. 

 From the data therein given, it is to be observed that the patent flour 

 ranks first in baking quality. It absorbs more water in the doughing 

 process, producing a dough much more coherent and elastic, as is shown 

 by the maximum expansion of the dough during the process of fermenta- 

 tion, and produces a loaf of the largest size and of the best texture. 



It will also be noted that the patent flour is somewhat lower in its 

 total and soluble ash content, and electrical conductivity. However, the 

 differences between the patent flour, the flour with the strong gluten, and 

 the W3 flour, the flour with much weaker gluten, give values for ash on 

 dry flour, soluble ash, and specific conductivity of the flour extract, all 

 of which are within experimental error of each other, an observation 

 which confirms the previously expressed idea that strength or weakness 

 of gluten is due to the colloidal condition of the flour proteins, and is not 



