Isolation And Identification Of Lactic Acid Bacteria For The Use Of Fermentation In Low Temperature From Pickles And Study Of Fermentation Technology

In the paper four strains Leu.1, Leu.2, Lact.l and Lact.2 were isolated from many sorts of pickles for their excellent characteristics in acid production and fermentation flavor. With API 50 CH system, Leu.l and Leu.2 were identified as Leuconostoc mesenteroides subsp. mesenteroides. Lact.l and Lact.2 were identified as Lactobacillus casei subsp. casei and Lactobacillus plantarum respectively. The growths of Leu.l and Leu.2 were both prevented in the condition in which the pH was lower than 4.0 or the salty concentration was higher than 8%, while Lact.l and Lact.2 could grow in the condition in which the pH was higher than 2.5 or the salty concentration was lower than 14%.The most appropriate temperature for the growth of Leu.l and Leu.2 was 30℃,while that of Lact.l and Lact.2 was 37℃ .During the fermenting of cabbage inoculated with different compound bacteria as fermentation agent, the compounds contained Leu.l produced acid more quickly than other compounds in the prophase of fermentation, while the compounds contained Lact.l or Lact.2 produced acid more and more quickly in the anaphase of fermentation. The flavor of cabbage fermented with Leu.l solely was best, that with the compounds of three strains were the next. Compound A(Leu.1) and compound B(Leu.l : Lact.l : Lact.2=l : 1 : 2) were selected as excellent fermentation agent. When cabbage was fermented with compound A or compound B at 10℃,the fermentation was best. The nitrite contents of cabbage fermented with two compounds were lower than that of cabbage during spontaneous fermentation, and the nitrite content of cabbage inoculated with compound B was lower than that of compound A.At 4% salty concentration, 5% inoculation level and 1-3% sucrose concentration, the quality of cabbage fermented with Leu.l solely was the best Pepper powder could accelerate the fermenting of cabbage, while garlic prevented it, and ginger had little effect on it. When some apple and Lycium Barbarum were added during the cabbage fermenting, the pH decreased more quickly, and the total acid content increased. In the cabbage brine added with apple, the main organic acids whose contents were increase were malic acid and acetic acid, while in the cabbage brine added Lycium Barbarum were citric acid and acetic acid. The sensory quality of fermented cabbage added apple and Lycium Barbarum were better than that of cabbage without apple and Lycium Barbarum.