Screening of Fermentation Strains of Lychee Lactobacillus Beverage and Analysis on Its Fermentation Characteristics

In order to screen the strains suitable for the fermentation of lychee Lactobacillus beverage, eight kinds of Lactobacillus (Lactobacillus rhamnosus FJAT-13807, Lactobacillus brevis FJAT-43776, Lactobacillus fermentum FJAT-13771, Lactobacillus delbrueckii FJAT-43773, Lactobacillus paracasei FJAT-13741, Lactobacillus plantarum FJAT-13737, Lactobacillus acidophilus FJAT-13772, and Streptococcus thermophilus FJAT-43774) were selected, of which the inoculation amount was 3%. The formula of fermentation medium was 50% lychee juice+48% soybean protein+2% granulated sugar, and the fermentation medium was fermented at 37℃ for 48 h. The viable count was measured every 6 h. The diversity indexes (such as the dominant index, Shannon index, and evenness index) of the viable count distribution and the cluster analysis were introduced to evaluate the fermentation ability of lactic acid bacteria from the aspects of strain fermentation ability, fermentation cycle difference, and time distribution uniformity of viable count. The results showed that: Lactobacillus rhamnosus FJAT-13807 had the highest fermentation level (the total viable count in the fermentation process was 562.90×10⁷ cfu·mL^-1). It entered the logarithmic phase of fermentation quickly and maintained for a long time (12-30 h). The diversity indexes of the viable count distribution were high, with the dominant index of 0.86, Shannon index of 2.00, and the evenness index of 0.91. The comprehensive evaluation results of cluster analysis showed that Lactobacillus rhamnosus FJAT-13807 had strong growth ability and the time distribution of viable count was more uniform, which was the most suitable for the fermentation of lychee Lactobacillus beverage.