394 



Journal of A gricultural Research voL xni, no. s 



the two other flours, so greatly was it lacking in coherency. The gluten 

 from each of these flours was then pressed out to a nearly uniform thick- 

 ness of about 3 mm. between glass plates, and after draining for a few 

 minutes (this interval of time was kept as nearly constant as possible), 

 was cut into small disks by means of a large cork borer. These disks, 

 which were fairly uniform as to size, shape, and weight, were weighed 

 out to an accuracy of 5 mgm., placed in acid solutions of varying compo- 

 sitions and concentrations, and left for exactly 50 minutes. They were 

 then removed, drained for about 10 minutes on a perforated porcelain 

 plate and re weighed. The change in weight was calculated to the 

 change per gram of moist gluten. Preliminary experiments were un- 

 dertaken in order to determine the maximum time during which glutens 



Fig. I . — Graph showing the imbibition curves for the various glutens in different concentrations of lactic acid. 



from all the flours could remain submerged in the different concentra- 

 tions of the various acids and still retain their coherence sufficiently to 

 make weighing possible. This time was found to be 50 minutes. In 

 order that the results with the different flours might be comparable, this 

 time interv^al was kept exactly the same in all the experiments reported 

 in the following tables. The glutens for any given set of experiments 

 were prepared at the same time and placed in acids at the same temper- 

 ature. Every possible precaution was taken to eliminate variations in 

 experimental conditions, and we believe that any appreciable difference 

 between the recorded constants may be attributed to intrinsic differences 

 in the various glutens themselves. 



This method of measuring water imbibition or "hydration capacity" 

 is obviously somewhat crude when compared with the usual chemical 



