THE WHEAT GRAIN AND PLANT 27 



Total 100.015 100.485 



Deduct 0=C1 015 .485 



Total 100.00 100.00 



There is great uniformity in the ash constituents of the grain 

 of wheat when it is not subject to irregularities in ripening, 

 and there is but slight deviation under normal variations in 

 soil composition. 



PROTEIN. Osborne and Voorhees 1 recognized and investi- 

 gated five proteids. Approximately they form the following 

 per cent of the grain: A globulin, 0.65; an albumin, 0.35; a 

 proteose, 0.30 ; gliadin, 4.25 ; and glutenin, 4.25. Gluten is com- 

 posed of several nitrogenous compounds, chiefly gliadin and 

 glutenin. Wheat bread owes its excellence to the peculiar 

 properties of gluten, which makes it lighter and more digestible 

 than bread made from the other cereals. The amount and 

 quality of gluten determine the baking qualities of a flour. It 

 is now claimed that 55 to 65 per cent of the total gluten should 

 be in the form of gliadin. Hard wheats have a higher gluten 

 content than soft wheats, and consequently yield better flour. 

 Gluten generally forms from 12 to 14 per cent of the wheat 

 grain. Dough washed with water will retain only the crude 

 gluten. A short growing period or a season unfavorable to full 

 maturity of the grain increases the amount of protein. The 

 nitrogenous compounds are the most desirable part of the 

 nourishment found in wheat, but they tend to give a yellowish 

 tint to the bread, "against which fashion rebels/' for the 

 "unnatural demand of the times " is for a starchy, snow white 

 flour. 



NITROGEN FREE EXTRACT. This forms the larger portion of 

 both grain and flour, and is composed very largely of starch, 

 the amount of which is easily influenced by the irregularity of 

 seasons. 



Composition Influenced by Seasons and Fertilizers. A favor- 

 able season seems to give a high weight per bushel, a large per- 

 centage of starch, and a low ash and nitrogen content. The 

 following table gives the results of the observations of Lawes 

 and Gilbert at Rothamsted. 2 



1 Amer. Chem. Jour., 15:392-471. 



2 Hunt, Cereals in Amer. (1904), p. 43. 



