摘要
Abstract
Red rice is the largest yield of colored rice in China,with biological activities such as antioxidant and anti-inflammatory.But its water-soluble polysaccharide resources have not been exploited.Non-starch polysaccharides from red rice bran were prepared from red rice bran as raw material,by extracting with hot water,decoloring,deproteinizing,alcohol precipitation,and dialysis.Different frac-tions of extractive polysaccharides were isolated and purified using DEAE-52 Cellulose and Sephadex G-200,with the largest proportion being the RRBP4 component.Molecular weight,monosaccharide composition,main and side chains,glycosidic bonds,branching degree,and triple helix conformation of RRBP4 were identified by using HPLC,FT-IR,complete acid hydrolysis,partial acid hydrolysis,[3-elimi-nation,I2-KI experiment,and Congo red test methods.Result showed that the relative molecular weight of RRBP4 was 1.65 x 105 Da.RRBP4 was composed of mannose,ribose,rhamnose,galacturonic acid,glucuronic acid,glucose,galactose,xylose,and arabinose,the mole ratio of them was 0.29∶1.93∶0.35∶1.41∶0.50∶1.00∶5.58∶1.67∶2.56.RRBP4 was an acidic heteroglycan dominated by galactose.There were 62.40％polysaccharides located in the side chain,which was a highly branched polysaccharide.RRBP4 was a polysaccharide with α-glycosidic bonds and amino acids and had a triple helix structure.The structural analysis of water-soluble non-starch polysaccha-rides from red rice bran provided a scientific essential data for the development of their application in the food industry.关键词
红米米糠/多糖/提取/纯化/结构Key words
red rice bran/polysaccharides/extraction/purification/structure
