Chemical analysis and antioxidant activity of polysaccharide extracted from rice bran.

Abstract

Three rice bran polysaccharide (RBP1, RBP2 and RBP3) fractions were successfully purified from the crude polysaccharide of rice bran by DEAE-Cellulose and Sephadex G-200 column chromatography. The average molecular weights (Mws) of these fractions were 51.5, 26.1 and 6.95 kDa, respectively. Monosaccharide components analysis indicated that RBP1 and RBP2 were composed of arabinose, xylose, mannose, glucose and galactose in a molar ratio of 1.00:2.82:57.11:140.82:7.76 and 1.00:1.62:1.18:77.5:7.79. RBP3 was composed of arabinose, mannose, glucose and galactose in a molar ratio of 1.00:1.03:8.84:2.00. On the basis of antioxidant test in vitro, RBP2 exhibited the highest antioxidant ability among these fractions.