Cereal Chem 39:171 - 182.  |  VIEW ARTICLE

Evaluation of Color Characteristics of Flours Obtained from Various Types and Varieties of Wheat.

T. Yasunaga and M. Uemura. Copyright 1962 by the American Association of Cereal Chemists, Inc. 

Colors of flours obtained from various types and varieties of wheat were studied spectrophotometrically. The samples represented western white and dark hard winter wheat from the U.S.A., red spring wheat from Canada, wheat from Western Australia, and some varieties of Japanese domestic wheat. Color characteristics are reported in C.I.E. chromaticity coordinates derived from spectral reflectance curves. At the same levels of ash content, western white flours showed the highest luminosity, and the lowest excitation purity, while Japanese domestic wheat flours showed the lowest luminosity and the highest excitation purity. Differences in hue were also observed among these types of wheat. Content of yellow pigments, and the amount of residual pigment when bleached, varied with type or variety of wheat. These factors have a major influence on the excitation purity. Addition of benzoyl peroxide brought little improvement to bran color. Variations in luminosity and hue are caused not only by the different degree of bran contamination but also by the difference in bran color among the various wheat sources. Two indices, derived from reflectances at some particular wave lengths, were proposed for evaluating flour color: one, for the content of yellow pigments, and the other, for the coloration by the contaminating bran. Using these indices, it is possible to show, regardless of the degree of bran contamination, the color characteristics of flours from different samples of wheat.