On the Whiteness of Rice Grains

[摘要] The whiteness values for hulled rice and milled rice were measured by the whiteness meter in relation to the rice quality. The values measured by the whiteness meter are propotionated to the values of light reflected by rice grains. The values for hulled rice were influenced by color of bran layer and opacity of starch-cell layer. As compared with normal grain, rusty grain and green grain showed low values according to the degree of deepness of color. White-belly grain, milky-white grain and the other grains which have chalky parts in their endosperm showed high values in proportion to the grade of opacity. Among normal grains, the values were rather low for the grains of good quality as they were more translucent than the grains of bad quality. The values for milled rice were affected by the degree of milling and the grade lof opacity of endosperm. They became higher with progress of milling. Among fully milled grains, the grains of bad quality showed higher value than the grains of good quality for the formers had somewhat opaque endosperm.

[学科分类] 农业科学（综合）