Structural characterisation and physicochemical properties of exopolysaccharide produced by <i>Weissella confusa</i> P2

Structural characterisation and physicochemical properties of purified <i>Weissella confusa</i> P2 exopolysaccharide (EPS) were analysed. It contained C, H, N, S, uronic acid, protein and sulphate. Gel permeation chromatography (GPC), high performance liquid chromatography (HPLC), Fourier transform infra-red spectroscopy (FT-IR), nuclear magnetic resonance (NMR) and methylation were all used for the analysis of P2 EPS. The congo red test confirmed the presence of random coil conformation of P2 EPS in aqueous solution. Scanning electron microscope (SEM) and atomic force microscope (AFM) revealed that the P2 EPS exhibited a smooth, glossy, compact sheet and reticular configuration. In addition, P2 EPS exhibited high water solubility index (WSI), water holding capacity (WHC), strong emulsifying ability (EA) for gasoline, benzene and soybean oil and possessed high thermal stability. It had significant adsorption capacities for three heavy metal ions. These results support its use as an additive in the functional food and environmental protection fields.