Vitamin E Profiles and Triacylglycerol Molecular Species of Colored Rice Bran Cultivars at Different Degree of Milling

Abstract

The objective of this study was to evalute the tocochromanol distributions, lipid components and molecular species of triacylglycerols (TAG) in three colored rice bran cultivars. The dominant tocochromanol were -tocotrienol, -tocopherol and -tocotrienol with smaller amounts of -tocopherol, -tocopherol and -tocotrienol. These lipids comprised mainly TAG (78.0-81.6 wt%), free fatty acids (FFA: 5.6-8.8 wt%), and phospholipids (PL: 6.3-7.0 wt%), while other components were present in minor proportions (0.4-2.3 wt%). Sixteen different TAG molecular species were detected and quantified by successive applications of AgNO 3 -TLC and GC. The major TAG molecular species were SM 2 (6.1-9.8%), S 2 D (4.8-7.3%)，M 3 (16.4-18.7%), SMD (6.2-9.2%), SD 2 (6.5-9.5%), SMT (6.3-7.7%), M 2 D (12.3-15.5%.), MD 2 (8.4-10.4%), SDT (4.3-5.4%) and D 3 (10.2-15.2%) (where S, M, D, and T denote saturated FA, monoene, diene, and triene, respectively). The results showed that colored rice bran lipids contain large amounts of nutraceutical with proven positive health effects.

Classified processing of different rice bran fractions according to their component distributions

“…The aim of rice milling is to remove the inedible husk and then transfer the rice grain into a suitable form for human consumption (Tuncel & Yilmaz, 2011). After hulling, rice with the bran is called ‘brown rice’ and rice without the bran is called ‘white rice’ (Yoshida et al ., 2013). Before rice milling, the hydrolysis reaction cannot occur because the rice bran lipase cannot get in touch with oil.…”