Appearance and Alkali Solubility of the Brown Rice of Aromatic Rice Cultivars Collected in Japan and Other Countries

Japanese Journal of Crop Science

Tomio ITANI¹ 

关键词: Alkali solubility;    アルカリ崩壊度;    Aromatic rice;    イネ;    Chalky rice;    香り米;    Oryza sativa L.;    玄米品質;    Rice quality;    白亜質米;    Whiteness;    白度;   

DOI  :  10.1626/jcs.71.178

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

To clarify the quality of aromatic rice, we evaluated the grain appearance and alkali solubility of the brown rice of 69 Japanese native aromatic rice cultivars, 18 foreign aromatic rice cultivars and 18 Japanese non-aromatic leading rice cultivars, which were used to determine the inspection grade by the Japanese Food Agency. We also examined the percentages of chalky rice grains and whiteness using a whiteness tester. Alkali solubility was classified into 10 grades from 1 (no change) to 10 (perfectly disintegrated or dissolved) after soaking half-cut brown rice grains in 1.25 and 1.5 % potassium hydroxide solutions for 24 hours. The Japanese aromatic rice showed the worst appearance, low inspection grade, high percentage of chalky rice grains and high whiteness, but the non-aromatic leading cultivars showed the opposite characters. On the other hand, the foreign aromatic rice showed intermediate values between Japanese aromatic rice and non-aromatic leading cultivars in the inspection grade, percentage of chalky rice grains, and whiteness. The Japanese aromatic rice showed higher alkali solubility than non-aromatic leading cultivars and the solubility greatly varied with the cultivation area; Tohoku (North-East Japan) < Kanto and Hokuriku (Central Japan) < West Japan. Alkali solubility showed a positive, high correlation coefficient with the heading date. The foreign aromatic rice showed a lower alkali solubility than non-aromatic leading cultivars and a very large variation in the solubility. The quality of the rice grain such as hardness (or softness) should be considered when we use aromatic rice as blending or breeding materials.

【 授权许可】

Unknown