Lipid Components and Distribution in Brown Rice

Abstract

Most components of rice polar lipids were separated, identified and determined; then lipid distribution in rice grains was investigated. The rice bran contained 80% of the total extracted lipids, and the endosperm had the residual 20%. The endosperm lipids were composed of similar amounts of both phospholipids and glycolipids, while the bran was rich in glycolipids. A fractionation of the endosperm through mechanical and enzymic disintegration gave protein body fractions, which contained about 80% of total lipids and 76% of total proteins. Other fractionation of the endosperm by solvent extractions suggested liberation and redistribution of lipid components, which seem to occur through intermolecular association of lipids with proteins and polysaccharides. The lipid components of “fat by hydrolysis” in starch granules were also examined, showing the presence of free fatty acids with lysolecithin and lysoglycolipids.