404 



Journal of Agricultural Research 



Vol. XIII, No. 8 



these three glutens, although differing widely in "quality" and in 

 physical properties from P, were hydrated to almost exactly the same 

 extent as was P. However, the difference in moisture content of W3 

 gluten is probably significant. It is necessary, therefore, to consider 

 what effect this increased moisture content should have in the experi- 

 ments in Tables I to V, provided that the gluten had originally possessed 

 the same physical properties as P. W3 contains 7.28 per cent of dry 

 gluten. The dry gluten of P composes 33.15 per cent of the wet gluten; 

 therefore the wet gluten of W3 should weigh 21.96 gm. at the same 

 hydration as the gluten of P. It actually did weigh 25.45 g™-. or an 

 excess of 3.49 gm. of water based on a weight of 21.96 gm. of moist 

 gluten, this indicating an imbibition of 0.16 gm. of water per gram of 

 moist gluten (of P quality). This amount is entirely too small to account 



y^c/if on/y 



Fig. 10. — Graph showing the imbibition curves for C gluten in acetic acid and in acetic acid plus certain 



salts. 



for the very marked differences in the physical properties of the two 

 glutens and the only conclusion which remains possible is that there is 

 an inherent difference in the glutens from strong and weak flours, that 

 the colloidal properties of the glutens from the different flours are not 

 identical and would not be identical even if the flours had the same salt 

 and acid content. 



These data are substantiated by the moist and dry gluten figures pre- 

 sented by Upson and Calvin, although these authors, as noted above, 

 expressed the opinion that the difference between a strong and a weak 

 gluten was due to its degree of hydration. Under Table XII on page 

 23 of their bulletin (15) are given the percentages of wet and dry gluten 

 from several different mill streams of flour. Using carbon-dioxid-free 

 water as the washing agent, they give the percentages of wet and dry 

 gluten as follows: 



