402 



Journal of Agricultural Research 



Vol. XIII, No. 8 



RELATION BETWEEN THE QUALITY OF THE VARIOUS GLUTENS AND 

 THEIR DEGREE OF HYDRATION 



A study of the preceding tables and graphs confirms certain of the 

 findings of Upson and Calvin, that — 



gluten is an emulsoid colloid and shows all the properties of this class of compounds 

 and that — 



gluten absorbs water from dilute acid solutions, thereby losing its tenacity and 

 ductility, becoming soft and gelatinous. The presence of small amounts of neutral 

 salts in the dilute acid solutions inhibits water absorption by gluten. 



The data, however, do not support the latter part of their third state- 

 ment that — 



the bread-making qualities of dough made from wheat flours are dependent on the 

 quantity and quality of the contained gluten. Quality of gluten is regulated by the 



COA/C£Arr/?AT/OA/ or AC/D 



Fig. 8. — Graph showing the imbibition curves for W's gluten in lactic add and in lactic add plus certain salts. 



kind and concentration of the acids and salts present in the dough. If the kinds 

 and amounts of the acids and salts are such as to favor water absorption, the quality 

 of the gluten will be poor, whereas the presence of acids and salts in such amounts as 

 tend to inhibit water absorption makes for an improved gluten, 



but, on the contrary, all the evidence is directly opposed to such a 

 conclusion. 



The above statements by Upson and Calvin seem to have only one 

 interpretation: that a weak gluten is weak because it is hydrated to a 

 greater extent than is a strong gluten, and that in this respect, and in 

 this respect only, does a weak gluten differ from a strong gluten. Upson 

 and Calvin present data in their own bulletin which would have refuted 

 this idea had they made the necessary calculations. 



