UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1420 
Washington, D. C. 
Ausust. 1926 
RELATION OF KERNEL TEXTURE TO THE PHYSICAL CHARACTERISTICS, 
MILLING AND BAKING QUALITIES, AND CHEMICAL COMPOSITION OF 
WHEAT 
By J. H. Shollenberger, Milling Investigations, and D. A. Coleman, Chemical 
Research Laboratory, Grain Division, Bureau of Agricultural Economics 
CONTENTS 
Page 
Introduction 1 
Source and description of samples used 1 
Physical characteristics of different kernel 
textures 3 
Test weight per bushel 4 
Weight per 1,000 kernels 5 
Specific gravity of kernels 5 
Milling yields 5 
Baking results 6 
Water absorption of flour 7 
Volume of loaf 7 
Texture of bread 8 
Color of bread 9 
Page 
Chemical composition of wheat kernels of 
different textures 9 
Ash, crude fiber, and fat content 10 
Crude protein content 11 
Nitrogen compounds of the wheat 13 
Chemical composition of flours from wheat 
kernels of different textures 13 
Comparison of average results for each of the 
three different separations 15 
Summary 15 
INTRODUCTION 
Wheats of certain classes containing a high percentage of hard and 
vitreous kernels usually command a premium over the price paid 
for the yellower or more starchy appearing wheats of the same class. 
The reason is that the hard vitreous kernels are more glutenous and 
are generally believed to have superior bread-making qualities. This 
belief has existed in the minds of the grain trade for many years, and 
because of it when the official United States grain standards were 
promulgated, the percentage of hard and vitreous kernels present was 
taken as the basis for establishing subclasses for the hard red spring, 
hard red winter, durum, and white wheat classes. 
In the official grade requirements for the hard red spring and hard 
red winter wheat subclasses, these kernels are referred to as "dark, 
hard, and vitreous"; for the durum wheat subclasses as "hard and 
vitreous kernels of amber color"; and for the white wheat subclasses 
as "hard (not soft and chalky)". 
SOURCE AND DESCRIPTION OF SAMPLES USED 
To establish definitely whether a relationship exists between kernel 
texture and milling and baking quality, the following special studies 
on the hard red spring, hard red winter, and durum classes were made. 
96085°— 26 
