Correlation between flour color of Japanese domestic wheats and their mineral contents

Abstract

Four cultivars of wheat (Bandohwase, Norin 61, Tsurupikari, Ayahikari) were cultivated in various cultural conditions or harvest times. These grains were ground to 60% extraction flour (A flour), and color value (L*, a*, b*) and mineral contents (Ca, K, Mg, Cu, Fe, Mn, and Zn) were analyzed. There were two types of correlations between mineral contents of flours and their color values. In first case, increasing of Mg, Cu, and Zn contents in flours were observed according to the decrease of the L* value caused by increasing an application of nitrogen fertilizer. In another case, decreasing of Ca, K, Mg, Zn contents and increasing of Fe contents in flours were observed according to the decrease of the L* value of as a harvest time was delayed. Decreasing of the L* value was observed according to the increase of iron contents in flours. Correlation between the iron content and the L* value was observed, the range of coefficient of correlation being 0.70-0.84. Therefore, it is suggested that iron was related to the color of wheat flour.