May 20, 191S Hydration Capacity of Gluten 409 



RATE OF HYDRATION 



It will be observed that the different glutens, prepared and treated in 

 exactly the same manner and for exactly the same interval of time, differ 

 widely in their rate of hydration. For example, in Table I it is shown 

 that I gm. of moist gluten from P flour in NI50 lactic acid imbibed i.io 

 gm. of water, while W^ gluten absorbed only 0.47 gm.; in N/^oo acid the 

 figures are, respectively, 0.63 and 0.12 gm. These examples are typical 

 of other experiments in the tables, and when the graphs are inspected, 

 they are so convincing that only one conclusion seems possible — that is. 



Aadon/y 



Ac/dfO. OOJ/^/r^eflOt 

 Aoc/*0.00£A7CaC/f^ihiO 



Acidfa00.5A7/i/s(''S0*)3 

 - /Qc/cffOOOSAf /$rC4 



Fig. 15— Graph showing the knbibition curves for P gluten in hydrochloric acid and in hydrochloric acid 



plus certain salts. 



that a weak gluten has a much lower rate of hydration than a strong 

 gluten. 



MAXIMUM CAPACITY FOR HYDRATION 



There is, moreover, a marked difference in the maximum degree of hy- 

 dration of the different glutens. In preliminary experiments it was found 

 that disks of P gluten would retain their coherency and plasticity for as 

 long as two hours in the different concentrations of lactic acid and still 

 be so cohesive that they could be easily removed from the acid solutions 

 by means of small forceps, although they had swelled to three or four 

 times their former size and had imbibed as much as 2.22 gm. of water 

 per gram of moist gluten. 



On the other hand, the weak glutens W^, Wj, and W3 became so badly 

 dispersed when immersed in the concentrations of acids causing maxi- 

 mum imbibition that in many instances they could not be collected for 

 weighing in even so short a time as one hour, although even at this point 



