Profiles of Lipid Components, Fatty Acids and Triacylglycerol Molecular Species in Lipids of Rice Bran Cultivars

抄録

Tocochromanols in the lipids extracted from five rice bran cultivars were analyzed by high-performance liquid chromatography. The molecular species and fatty acid (FA) distribution of triacylglycerols (TAG) isolated from the total lipids were investigated among five different cultivars by a combination of AgNO₃ thin-layer chromatography and gas chromatography. The dominant tocols were γ-tocotrienol, α-tocopherol and α-tocotrienol with smaller amounts of δ-tocotrienol and γ-tocopherol. The lipids of the rice bran cultivars comprised mainly TAG (84.7 − 86.0%), free FA (4.2 − 4.6%), and phospholipids (6.5 − 6.7%), while other components were present in minor proportions (0.2 − 1.8%). Comparison of the different cultivars showed no substantial differences (P > 0.05) in their FA distributions among the same lipid subfraction. The major TAG molecular species were M₃ (17.1 − 18.5%), SMD (7.6 − 8.2%), M₂D (14.8 − 15.4%), MD₂ (9.3 − 10.6%) and D₃ (12.3 − 13.5%) (where S, M and D denote saturated FA, monoene and diene, respectively). The results showed that rice bran lipids contain large amounts of nutraceutical, which has proven positive health effects.