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An exopolysaccharide (EPS) was produced by Leuconostoc pseudomesenteroides DRP-5 isolated from homemade wine. The EPS was obtained with ethanol extraction, which was further purified by chromatography of Sephadex G-100 to get a purified fraction. The monosaccharide composition of the EPS was glucose, and its molecular weight (Mw) was 6.23 × 10 6 Da, as determined by gas chromatography (GC) and high-performance size-exclusion chromatography (HPSEC). Fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance spectra (NMR) showed that the EPS was a linear glucan with α-(1→6)-linked glucosidic bonds. The water holding capacity (WHC), water solubility index (WSI) and emulsifying activity (EA) of DRP-5 EPS were 296.76 ± 18.93%, 98.62 ± 3.57% and 87.22 ± 2.18%, respectively. DRP-5 EPS have a higher degradation temperature of 278.36 °C, suggesting high thermal stability of the EPS. Also, DRP-5 EPS was found to have moderate 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical, superoxide anion radical, 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical, Fe 2+ scavenging activities and reducing power. All these characteristics suggest that DRP-5 EPS might have potential applications in the pharmaceutical, cosmetic and food industries. [ABSTRACT FROM AUTHOR]

A water-soluble exopolysaccharide (EPS) was produced by Leuconostoc ctireum NM105 from homemade manchurian sauerkraut. After culturing the strain in Man–Rogosa–Sharpe medium containing 5% sucrose at 25 °C for 48 h, the EPS was purified and a yield of 23.5 g/L was achieved. The EPS consisted exclusively of glucose and the weight-average molecular weight was 1.01 × 10 8 Da. The structural characterization of the purified EPS determined by FT-IR, 1 H, 13 C and two-dimensional NMR spectroscopy demonstrated that the glucan contained α-(1 → 6)-linked d -glucopyranose units, 2,6-linked d -glucopyranose units and terminal α- d -glucopyranose units at a ratio of 1:1:1. The microstructure of the dried dextran appeared a sheet-like smooth glittering and highly branched surface. The NM105 dextran showed high water solubility and excellent water retention. All the results suggested that the highly α-(1 → 2) branched dextran might have the potential to serve as valuable polymers applied in foods, cosmetics and other fields. [ABSTRACT FROM AUTHOR]