May 20, 1918 Hydration Capacity of Gluten 393 



It should be noted that this finding is in many respects similar to that 

 of Wood (17) : 



The variations in coherence, elasticity, and water content, observed in gluten 

 extracted from different flours, are due rather to varying concentrations of acid and 

 soluble salts in the natural surroundings of the gluten than to any intrinsic difference 

 in the glutens themselves. 



There are, however, marked differences between these two statements; 

 these Vsdll be considered later in this paper. 



EXPERIMENTAL WORK 



THE PROBLEM 



In the experiments reported by Wood and in those recorded by Upson 

 and Calvin it would appear that in each instance the action of acids and 

 salts had been tested upon gluten derived from only one flour, and this 

 presumably a "strong" flour, and that the application of such data to 

 the problem of flour strength was made by analogy rather than actual 

 observation. It v/as thought v/orth while, therefore, to repeat the work 

 of Upson and Calvin {14, 15) , with glutens derived from flours of widely 

 differing baking strength in order to determine what correlation, if any, 

 exists between the baking qualities of the flour and the hydration capacity 

 of the gluten. 



MATERIAL USED 



Five different flours were used. The first, a typical Minneapolis 

 patent grade milled from No. i northern hard spring wheat from the 191 6 

 crop. The second was a first clear grade milled from the 191 5 crop. 

 The three other samples were milled in the State of Oregon from typical 

 soft wheats grown in that section, and are "straight-grade" flours. It 

 is to be regretted that sufficient amounts of two of the western flours, 

 Wj and W2, were not available for all of the experimental work. 



METHOD OF EXPERIMENTATION 



The method used in studying these flours was the same as that used by 

 Hofmeister in his work on the swelling of gelatin and, as mentioned 

 above, by Upson and Calvin. Briefly, it consisted in first doughing 

 200 gm. of flour by adding the required amount of distilled water. The 

 dough was then permitted to stand for from 30 minutes to an hour under 

 distilled water, after which it was washed for 1 5 minutes under a stream 

 of distilled water. Almost all of the starch was washed out in this 

 manner. The gluten was then submerged under distilled water until 

 all the desired samples of gluten had been prepared. 



It was interesting to note the difference in the character of the gluten 

 prepared from the different samples. The patent flour, from No. i 

 northern grade of wheat, called "P," gave a rather firm coherent gluten, 

 as did the first clear grade, "C." The three western flours, designated 

 "W," "W^," and "W^" gave a more friable, sticky, and less coherent 

 gluten which was much more difficult to obtain than was the gluten from 



