Abstract:
In order to screen the excellent lactic acid bacteria suitable for plant substrate fermentation. In this paper, rice koji was used as the donor of target lactic acid bacteria, to screen lactic acid bacteria with high acid yield and good tolerance to gastrointestinal environment. And the antioxidant activity of lactic acid bacteria and its fermentation ability in chestnut glutinous rice beverage were evalutated. The results showed that 84 strains of lactic acid bacteria were isolated from Jiuqu, of which 38 strains produced acid≥10 g/L. In further acid-tolerant, bile salt-tolerant and simulated gastrointestinal tests, three target strains were screened. All the three strains of lactic acid bacteria were identified as
Pediococcus pentosaceus though 16S rDNA. In the fermentation supernatant, the DPPH radical scavenging rate, hydroxyl radical scavenging rate and SOD enzyme activity of strain DH16 were the highest, which were 98.56%, 42.27% and 20.3 U/mL respectively. In the intact cell suspension, the DPPH radical scavenging rate of strain DH20 was the highest (22.49%), and the hydroxyl radical scavenging rate of strain DH16 was the highest (22.77%). The chestnut glutinous rice beverage separately fermented by three strains of lactic acid bacteria has a balanced taste and strong antioxidant capacity. Therefore, the three strains of lactic acid bacteria screened in this paper have a good application prospect in the development of plant-based beverages.