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The water-soluble polysaccharides from bamboo shoots ( Phyllostachys praecox ) (WBP) were isolated, and the characterizations as well as prebiotic activities were investigated. The yield of WBP was 7.58 ± 0.31% under optimal hot-water extraction conditions. Two fractions, i.e., WBP-1 and WBP-2 with molecular weight of 83.50 kDa and 80.08 kDa, respectively, were purified by chromatography. Both the polysaccharides fractions were identified as heteropolysaccharides-protein complexes composed of 15 kinds of common amino acids in protein part and rhamnose, arabinose, xylose, mannose, glucose and galactose in different molar ratios in polysaccharide part. The existence of α- and β-glycosidic linkages between the sugar units was confirmed by FTIR and NMR spectra. Compared with the blank control and the reference of FOS, WBP-1 and WBP-2 significantly increased the numbers of Bifidobacterium adolescentis and Bifidobacterium bifidum ( P < 0.05), which contributed to the production of organic acids, suggesting that the polysaccharides have potential prebiotic properties. [ABSTRACT FROM AUTHOR]

In vitro digestibility, prebiotic activity and chemical composition of polysaccharides from rapeseed were deliberately studied in this paper. After preliminary treatments, two fractions of polysaccharides (RP1 and RP2) were obtained after purification by DEAE-cellulose and Sephadex G-100. Their primary structural feature and molecule weights were characterized. Furthermore, their digestibility was also evaluated by artificial gastric juice and α-amylase. Finally, their proliferative effect on bifidobacteria and lactobacilli and acid production of the resulting probiotics in vitro were investigated. The results showed that RP1 and RP2 were homogeneously protein-bound polysaccharides with molecular weights of 28.51 and 6.55 kDa, respectively. They were resistant to hydrolysis by artificial gastric juice and α-amylase. Moreover, they could also significantly stimulate the tested probiotics to proliferate and produce organic acids. These findings clearly suggest the polysaccharides from rapeseed are potential to be exploited as novel prebiotics. [ABSTRACT FROM AUTHOR]