Study on the screening of fine strains of yoghurt
Fermentation property and lactose hydrolytic percentage of 6 lactic acid bacteria strains (GZY2, GHH6, CW102, CW80, CW81 和 CW97) which were isolated from the fermented yoghurt in the Qinghai region were studied in this article. The results of the experiments showed that the fermentation property of lactobacillus CW97, CW81 and lactococcus GZY2 was significantly better than other strains, and the optimal fermentation temperature was 37 ℃ and 42 ℃. The mixture fermentation condition was: proportion was 1∶1, inoculation amount 3% , fermentation temperature 42 ℃ . Under the condition, CW97 and GZY2 mixed fermentation, both the acid-producing and the aroma-producing were very well, and comprehensive evaluation was best. CW97 and GZY2 were selected as optimum combination.