Screening of Probiotic Strains and Process Optimization for Synergistic Fermentation of Grape Juice

In order to improve the health promoting effects of grape juice, 21 kinds of probiotic strains were used for fermentation of grape juice producing with ‘Jumeigui’ grape berries. By comparing the fermentation ability of each probiotic strain as well as phenolic content and sensory properties of fermented grape juices, Lactobacillus plantarum 21802 and Lactobacillus brevis 6239 were selected as the most suitable probiotic strains for fermentation of grape juice. Then, based on viable count and score of sensory evaluation, the process was optimized by using Lactobacillus plantarum 21802 and Lactobacillus brevis 6239 for synergistic fermentation of grape juice. Results showed that the optimum conditions for synergistic fermentation of grape juice by compound probiotics were as follows:The ratio of Lactobacillus plantarum 21802 to Lactobacillus brevis 6239 was 1:2, the ratio of grape juice to water was 2:1, the inoculation amount was 5%, the fermentation temperature was 36℃, and the fermentation time was 60 h. Under these optimal conditions, the viable count of probiotics in fermented grape juice achieved to 8.98×10⁹ CFU/mL, and the score of sensory evaluation was 91.1.