RELATION OF KERNEL TEXTURE TO WHEAT 13 
protein content and the kernel texture of these samples corresponded 
very closely in kind and extent to that noted in connection with the 
water absorption of the flour milled from them. The differences 
between the protein contents of the various separations of each of the 
samples is shown graphicly in Figure 5. 
The nitrogen-free extract — that is, constituents of the wheat such 
as starches, sugars, gums, etc. — is determined by subtracting the sum 
of the other analyses from 100. With every sample studied, except 
No. 7066, this factor increased progressively with the degree of 
starchiness. 
NITROGEN COMPOUNDS OF THE WHEAT 
Since it is the gluten-forming compounds of wheat which give flour 
its bread-making qualities, special attention was paid to the nitrogen 
compounds in the various types of kernel textures. Tests were made 
to determine the amounts of albumin, globulin, and gliadin present 
in the samples under study. The methods employed for determining 
the gliadin in both the wheat and flour were those recommended by 
Bailey 1 and Blish. 
Tests were first made relative to the nitrogen compounds. A study 
of the data for this factor, given in Table 5, shows that there was a 
progressive decrease in the quantit}^ of salt-soluble protein, albumins, 
and globulins, as the degree of starchiness or softness increased. This 
fact was the same with all the samples studied. It was found also 
that the gliadin, or alcohol-soluble protein, decreased in percentage as 
the percentage of starchiness increased. 
Comparing the physical characteristics of the various types of 
separations with the baking strength of the flour milled from them, 
it was found that there was a positive correlation between the volume 
of the loaf and the percentage of salt-soluble and alcohol-soluble pro- 
teins, exception to this being noted with the two samples of durum 
wheats tested. 
CHEMICAL COMPOSITION OF FLOURS FROM WHEAT KERNELS OF 
DIFFERENT TEXTURES 
Data obtained regarding the chemical composition of the flours are 
of more interest than those obtained from a study of the wheats from 
which they were milled. The data on this phase of the subject are 
given in Table 5. 
The tests made upon the flours included moisture, ash, total pro- 
tein, gliadin, wet and dry gluten, hydration capacity of the gluten 
protein, and the acidity of the flour. The results are expressed on a 
13.5 per cent moisture basis. As with the wheats, the protein of the 
flour decreased progressively as the percentage of starchiness in- 
creased. This is true likewise of the gliadin. There was a decided 
decrease in the percentage of wet gluten of flour from the dark kernel 
separations down to the starchy kernel separations. This factor 
likewise decreased as the starchiness of the samples increased. What 
is true of the wet gluten was likewise true of the dry gluten analyses. 
Hydration capacity of the gluten decreased as the texture changed 
from vitreous to starchy in almost every instance. 
1 Bailey, O. H., and Blish, M. J. concerning the identity of the proteins extracted from 
WHEAT FLOUR BY THE USUAL SOLVENTS. Jour. BiocHem., vol. 22, no. 1, p. 345. 
