Fermentability and rheologic properties of three strains of exopolysaccharide- producing Leuconostoc pseudomesenteroides from Tibetan kefir

In this study,the exopolysaccharide content,fermentability and rheological properties of three srains with exopolysaccharide produced were evaluated. The results showed that Leuconostoc peudomesenteroides of three srains produce exopolysaccharide,exopolysaccharide content of R5 was 454.67 mg / L.The growth process three srains was typical bacterial growth,acid production period mainly was logarithmic phase of strain,they were suitable for fermented dairy production,R5 of them had better organization status and flavor and sensory score was 86. The result of rheological properties showed that apparent viscosity was reduced with the shearing time of fermented dairy products from three strains,they presented flow characteristics of the shear thinning,viscosity size was R5 > R2 > R1.Fermented milk of three strains could form the thixotropic loop,they were the thixotropic fluid,hixotropic loop area of fermented milk of R1 and R5 was 2301.72( 1 / s Pa) and 2924.09( 1 /s Pa).R2 was 4697.82( 1 /s Pa).G' values were higher than G" of fermented milk from three strains and elastic modulus was preferred,fermented milk of R5 has higher elastic and viscous.By comparing their fermentability and rheological properties,strain of R5 had higher exopolysaccharide content,its fermented milk revealed the highest apparent viscosity,viscoelasticity and strongest stability,strain of R5 had potential applications.The result illustrated that exopolysaccharide producing strains could give good texture for fermented milk.