Change in Lipid Content and Fatty Acid Composition of Rice Kernel from Dough Ripening to Over Ripening

Abstract

Investigations have been carried out to determine the lipid content and the fatty acid composition of lowland non-glutinous rice kernel of one line for Sake brewing and three varieties at intervals of 10 days from dough ripening (20 to 25 days before full ripening) to over ripening (35 to 45 days after full ripening). From dough ripening to full ripening, the lipid content and the fatty acid composition varied widely. The lipid content decreased especially until 10 or 15 days before full ripening on dry basis and decreased after increasing until 3 or 15 days before full ripening in 1000 kernels. As to the fatty acid composition, the myristic acid, olelic acid, and linolenic acid content increased and the palmitic acid, stearic acid, and linoleic acid content decreased. After full ripening, the lipid content had a tendency to decrease slightly on dry basis and in 1000 kernels. However, the fatty acid composition was little varied. With respect to each of one line and three varieties, the lipid content on dry basis showed significantly positive correlations with the palmitic acid and linoleic acid content and negative correlation with the oleic acid content. The oleic acid content showed significantly negative correlations with the palmitic acid and linoleic acid content.