Yoshida, H; Tomiyama, Y; Mizushina, Y
Extracted lipids obtained from black and red rices were analysed by high-performance liquid chromatography (HPLC), for endogenous tocochromanols. The molecular species and fatty acid (FA) distribution of triacylglycerols (TAG) isolated from these total lipids were analysed by a combination of AgNO(3) thin-layer chromatography (TLC) and gas chromatography (GC), and were investigated in relation to the content of endogenous tocochromanols. With a few exceptions, the predominant tocols were γ-tocotrienol and α-tocopherol, followed by α-tocotrienol (red) and γ-tocopherol (black) with much smaller amounts of ß-, d-tocopherols and d-tocotrienol. The lipids of these rices were comprised mainly of TAG (76.4-80.5%), free FA (7.2-9.8%), and phospholipids (3.5-3.6%), whilst other components were present in minor proportions (0.1-4.1%). The principal FA components were palmitic (16:0), oleic (18:1n -9) and linoleic (18:2n -6) acids. Fifteen different TAG molecular species were detected and quantified by successive applications of AgNO(3)-TLC and GC. The major TAG components were S(2)M (7.0-7.8%), SM(2) (12.6-12.9%), M(3) (15.7-16.5%), SMD (23.5-23.7%), SD(2) (5.7-5.8%), M(2)D (9.3-9.8%), MD(2) (8.1-8.6%) and D(3) (5.8-7.4%) (where S, M, D, and T denote a saturated FA, a monene, a diene, and a triene, respectively). The results suggested that these rice lipids contain large amounts of nutraceuticals with proven positive health effects.