Fermentation Process Optimization,Quality Analysis And Identification Of Lactic Acid Bacteria About JBFLAB

Jujube is China's unique economic fruit,currently the variety of jujube beverage is abundant,while jujube lactic acid fermented beverages are relatively rare.In this study,Xinjiang jujube is raw material,traditional fermented pickled Chinese cabbage juice in Shaanxi Guanzhong area is as the source of culture,analysis the colony composition and stability of seed bacteria liquid,optimize the process parameter of lactic acid fermentation,research on the clarification of gelatin,chitosan,PVPP effected on Jujube Beverage Fermented with Lactic Acid Bacteria(JBFLAB),research on antioxidant activity and the composition of organic acid of JBFLAB,separate and identify lactic acid bacteria in JBFLAB,The main research results are as follows:(1)Dominant bacterial community in seed bacteria liquid were Lactobacillus.The dominant bacterial community in the tenth generation of seed bacteria liquid was the same as the first generation,the opening subculture could retain dominant bacterial community preferable.The optimum technology parameter of JBFLAB were as follows:temperature 35?,time48h,seed bacteria liquid5%.The clarification effect on JBFLAB:PVPP>chitosan>gelatin.(2)The results indicated that JBFLAB exhibited the highest antioxidant activity,followed by jujube wine,while jujube yogurt juice and juice of wild jujube showed the lowest antioxidant capacity.Our results also showed a significant correlation between antioxidant capacity and total polyphenols content(p<0.05).Additionally,fermented prophase(0?12h)the antioxidant capacity of the fermenting mush along with the fermentation time increased significantly(p<0.05);12?72h,DPPH free radical scavenging activity and reducing power of the fermenting mush had no significant change(p<0.05);12-48h,ABTS+·scavenging activity of the fermenting mush had no significant change(p<0.05),48?72h,ABTS+·scavenging activity of the fermenting mush increased significantly(p<0.05).(3)7 kinds of organic acid were detected in JBFLAB and they were oxalic acid,tartaric acid,formic acid,L-malic acid,L-lactic acid,acetic acid,citric acid and they accounted for over 80%of the total organic acid content.The content of lactic acid in pickled Chinese cabbage juice,seed bacteria liquid and JBFLAB were high,the content of lactic acid in Unfermented jujube juice was rare.Citric acid was not detected in seed bacteria liquid and Unfermented jujube juice.0?48h,the lactic acid content in the fermenting mush along with the fermentation time increased high significantly(p<0.01);48?72h,the lactic acid content had no significant change(p<0.05).The content of other organic acids had on significant change(p<0.05).(4)Accroding to the 16S rDNA sequence analysis and phylogenetic tree analysis and physiological and biochemical analysis,strain L1 was identified to be Lactobacillus casei strain,and strain L2 was identified to be Lactobacillus rhamnosus strain.