Cereal Chem 69:397-400   |  VIEW ARTICLE

Physical, Chemical, and Dry-Milling Properties of Corn of Varying Density and Breakage Susceptibility.

A. J. Peplinski, M. R. Paulsen, and A. Bouzaher. Copyright 1992 by the American Association of Cereal Chemists, Inc. 

Seven lots of yellow dent corn varying in kernel density and breakage susceptibility were tested for chemical composition, physical properties, and dry-milling response. Whole-kernel nitrogen content varied among lots from 1.35 to 1.48%, fat content ranged from 4.3 to 5.6%, starch from 70 to 78%, and ash from 1.3 to 1.6%. Physical analyses showed test weights of 732-762 kg/m3 (56.9-59.2 lb/bu), 100-kernel weights from 29.0 to 32.2 g, 11-64% floating kernels, and 14-33% broken kernels. Kernel breakage susceptibility correlated statistically (P less than or equal to 0.05) with test weight, percentage of floating kernels,and percentage of stress-cracked kernels. Percentage of floating kernels was a more precise indicator of kernel density, breakage susceptibility, and hardness than was test weight. Dry-milling response showed that first- break grit yield was higher for corn with test weight above 747 kg/m3 (58.0 lb/bu), percentage of floating kernels below 36%, and percentage of broken kernels below 16% as measured by the Stein breakage test. Hull (pericarp) yield was positively correlated (P less than or equal to 0.05) with breakage susceptibility, stress cracks, floating kernels, and degermer throughput. The results indicate that corn is less susceptible to breakage when its density is high, as measured by low flotation and high test weight, and when the percentage of stress-cracked kernels is low.