Cereal Chem 72:488-490  |  VIEW ARTICLE

Measuring Desirable and Undesirable Color in White and Yellow Food Corn.

C. D. Floyd, L. W. Rooney, and A. J. Bockholt. Copyright 1995 by the American Association of Cereal Chemists, Inc. 

Subjective field and objective nondestructive laboratory measure- ments of color in white and yellow corn were compared. L, a, b, and E color values were correlated to subjective field color grades by a trained observer. Physical factors that affect the variability of L, a, b, and E color values such as position of the germ and adhering colored cob material were examined. Variability of objective measurements decreased when colored cob material was removed or the kernels were positioned with the germ facing away from the light source during color measurements. Pearson correlation coefficients between field color grades and L, a, b, and E color values were less than 0.54. Differences in endosperm hardness, pericarp thickness, and pericarp gloss between cultivars with the same subjective field ratings contributed to the low correlation values. The L, a, b, and E color values provide a general index of color especially for yellow corn. Important subtle differences in color, particularly in white corn, were not accurately determined by these indices. Subjective evaluation of corn on the cob viewed in the field is the most effective method for selecting appropriate color corn.