Cereal Chem 65:503-508   |  VIEW ARTICLE

A Rapid Single-Kernel Wheat Hardness Tester.

S. R. Eckhoff, W. A. Supak, and A. B. Davis. Copyright 1988 by the American Association of Cereal Chemists, Inc. 

The design of an instrument to differentiate hard from soft wheat on an individual kernel basis and its initial evaluation are presented. The unit is an automated system capable of sampling rates up to 200 kernels per minute. Hardness evaluation is achieved by shearing individual kernels and recording the associated force breakage curves. The tester was found to have an 80% classification accuracy for the five hard and five soft varieties tested. Initial testing showed that a discriminant model combining peak force, peak sharpness, and a Fourier transformation of data collected produced a useful classification system. However, peak force as a single criterion was almost as effective. A sharp cutting edge supplied the greatest differentiation between brittle and ductile materials when compared with square-edged and radius blades. Peak force readings collected were affected by variations in kernel moisture content, size, and orientation during cutting.