Cereal Chem 65:86-94   |  VIEW ARTICLE

Wheat Hardness Determined by a Single Kernel Compression Instrument with Semiautomated Feeder.

Y. Pomeranz, C. R. Martin, R. Rousser, D. Brabec, and F. S. Lai. Copyright 1988 by the American Association of Cereal Chemists, Inc. 

Hardness was determined in 33 samples representing varieties from six wheat classes, in 16 samples from three classes representing wheats from the grain trade, in 24 laboratory-prepared blends (eight each of three pairs of various hard red winter and soft red winter varieties), and in 22 double-blind blends of hard red winter and soft red winter wheats. Individual kernels of various sizes and moisture contents were evaluated by a compression instrument equipped with a semiautomated kernel feeder. Software was developed to automatically compute, print, and analyze the data. Single-kernel hardness tests were related to determinations of hardness of bulk wheat samples and damaged starch of flours. Estimation of the amounts of soft and hard wheats in a blend was affected, among other things, by wide heterogeneity in hardness among individual kernels in a variety or a class. The range in hardness among kernels within a a variety or class may be larger than the difference between individual hard kernels of a soft wheat and soft kernels of a hard wheat. On the average, hard red spring wheat kernels were harder than those of hard red winter wheat. Distribution histograms of crushing scores were narrowest in soft winter wheats; crushing scores of soft white wheats from the midwest and east were lower than the average score for soft white wheats form the northwest.