高产EPS乳酸菌株的筛选及在农家干酪中的应用

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

摘要: 从16株乳酸菌中筛选出三株高产胞外多糖菌种,分别为嗜热链球菌S7和保加利亚乳杆菌L6及LTM,应用苯酚—硫酸法测定其胞外多糖的产量分别为56.25、51.53、51.48mg/L,产量相对较高且稳定。利用菌株S7、L6和LTM制作农家干酪的研究表明,以感官评定值为主指标,结合农家干酪的含水量、蛋白质含量和硬度进行分析,确定当稀奶油添加量为5.2%、72℃热处理15min、氯化钙添加量为0.01%时,生产的农家干酪品质最佳。

Abstract: 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.