Physicochemical properties of exopolysaccharide produced by Lactobacillus kefiranofaciens ZW3 isolated from Tibet kefir

An exopolysaccharide (EPS) producing strain, ZW3, was isolated from Tibet kefir grain and was identified as Lactobacillus kefiranofaciens. FT-IR spectroscopy revealed the presence of carboxyl, hydroxyl, and amide groups, which correspond to a typical heteropolymeric polysaccharide. The GC analysis of ZW3 EPS revealed that it was glucogalactan in nature. Exopolymer showed similar flocculation stability like xanthan gum but better than guar gum with a melting point of 93.38 °C which is lower than xanthan gum (153.4 °C) and guar gum (490.11 °C). Compared with other commercially available hydrocolloids like xanthan gum, guar gum and locust gum ZW3 EPS showed much better emulsifying capability.