Screening of lactic acid bacteria strains with high production-exopolysaccharide and their application in Cottage Cheese

Three strains with high EPS-producing capacity were screened from total 16 lactic acid bacteria, and their productions of EPS were measured by Phenol-H2SO4 method. Among of them, three strains, named S7, L6 and LTM were identified to be Streptococcus thermophilus and Lactobacillus delbruecckii ssp. bulgaricus, respectively. It was detected that 56. 25, 51. 53 and 51. 48mg/L EPS production by Phenol-H2SO4 method. Strains S7, L6 and LTM were used to make cottage cheese, with the sensory value as the main index, combining with moisture content, protein content and the hardness indexes. The results showed that the optimal adding quantity of cream was 5. 2%. The best level of heat treatment skim milk was 72℃, 15min and the optimal addition of CaCl2 was 0. 01%. Cottage Cheese produced by above conditions had the highest quality. This method could be applied to the production of Cottage Cheese.