Isolation and Identification of Lactic Acid Bacteria from Zha-chili and Screening of Lactic Acid Bacteria Suitable for Jujube Juice Fermentation

To identify lactic acid bacteria (LAB) strains with excellent fermentation properties of jujube juice, this study used traditional fermented food, Zha-chili, as the source of lactic acid bacteria isolation, followed by initial and re-screening of the strains using bionic equipment and sensory evaluation, respectively, and finally, the growth characteristics of the optimal strains of the re-screening were investigated. The results of isolation and identification showed that a total of 38 strains of Lactobacillus were isolated from the samples of Zha-chili, and 29 strains of Lactobacillus under 6 species were selected for the preparation of fermented jujube juice according to the study on the list of microbial strains used for traditional fermented foods in China (second edition); the results of the preliminary screening of strains showed that the fermented jujube juice samples prepared with different strains of Lactobacillus were classified into 3 clusters by the clustering analysis, in which the samples belonging to cluster 1 exhibiting higher a^* value, b^* value, saltiness, umami, richness, and response values for W3C, W5C, and W1C; the results of strain re-screening showed that the fermented jujube juice sample prepared by Lactiplantibacillus plantarum ES7-1 had the highest sensory score of 94.7; the results of growth characterization showed that L. plantarum ES7-1 strain showed good growth kinetics and reached the stabilization period at 12 h. It was also able to utilize 19 common carbon sources such as D-galactose, glucose and D-fructose, and in addition, the fermented jujube juice prepared by this strain had good product stability. In conclusion, L. plantarum ES7-1 has the potential to be used in fermented jujube juice, so as to expand the strain resources for the processing of fermented jujube juice.