Tolerance of Lactobacillus to Organic Acids and Their Fermentation Performances in Fruit and Vegetable Juices

In this study, the effects of different concentrations and types of organic acids in the medium on the fermentation characteristics of three high-performance strains of Lactobacillus isolated from fermented grains for vinegar brewing were investigated, and their fermentation performances in 12 typical fruit and vegetable juices were compared. The results showed that L. rhamnosus LR-S, L. plantarum LP-D and L. plantarum LP-F had good tolerance to malic acid, citric acid and tartaric acid, respectively, and were consequently superior in fermenting fruit and vegetable juices containing each of these organic acids as the major one. Sequential inoculation of two strains was suitable for raw materials with complicated organic acid composition such as mulberry juice. These results prove the necessity of developing targeted stress-resistant strains according to the characteristics of fruits and vegetables, and that sequential inoculation is an effective method to improve the fermentation performance of lactic acid bacteria on fruits and vegetables.