Abstract:
This study was based on two strains of exopolysaccharide-producing
Kazachstania unispora from Tibetan kefir as object. The exopolysaccharide content, fermentability and rheological properties of two strains were evaluated. The results showed that
Kazachstania unispora of two strains had high ability to produce exopolysaccharide, and exopolysaccharide content of J
7 was 350.02 mg/L, which was higher than J
5. The fermentation characteristic of strain J
7 was better than that of strain J
5, and the fermented milk of strain J
7 had better organization status and flavor and sensory score was 84. The result of rheological properties showed that the fermented milk of strain J
7 had relatively higher apparent viscosity which was compared with strain J
5.Fermented milk of two strains were the thixotropic fluid, and thixotropic loop area of fermented milk of J
5 and J
7 was 377.63(1/s Pa)and 346.96(1/s Pa), which illustrated that the fermented milk of J
7 had stronger ability of structural resilience. The values of G' were higher than G″of fermented milk from two strains which showed similar solid properties, and fermented milk of J
7 had higher viscous and elastic. By comparing their exopolysaccharide-producing, fermentability and rheological properties, the result showed that the strain J
7 had higher fermentability and rheological properties, which could lay a foundation for the application of strains.