Fermentation by Multiple Bacterial Strains Improves the Production of Bioactive Compounds and Antioxidant Activity of Goji Juice

• Main Authors: Yuxuan Liu, Huan Cheng, Huiyan Liu, Ruoshuang Ma, Jiangtao Ma, Haitian Fang
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: Molecules
• Subjects: goji juice; fermentation; multiple bacterial strains; volatile compound; antioxidant capacity
• Online Access: https://www.mdpi.com/1420-3049/24/19/3519

Microorganisms can be used for enhancing flavors or metabolizing functional compounds. The fermented-food-derived bacterial strains comprising <i>Bacillus velezensis</i>, <i>Bacillus licheniformis</i>, and <i>Lactobacillus reuteri</i> mixed with <i>Lactobacillus rhamnosus</i> and <i>Lactobacillus plantarum</i> were used to ferment goji berry (<i>Lycium barbarum</i> L.) juice in this study. The fermentation abilities and antioxidant capacities of different mixtures of multiple strains in goji juice were compared. The results showed that the lactic acid contents increased 9.24&#8722;16.69 times from 25.30 &#177; 0.71 mg/100 mL in goji juice fermented using the SLV (<i>Lactobacillus rhamnosus</i>, <i>Lactobacillus reuteri</i>, and <i>Bacillus velezensis</i>), SZP (<i>Lactobacillus rhamnosus</i>, <i>Lactobacillus plantarum</i>, and <i>Bacillus licheniformis</i>), and SZVP (<i>Lactobacillus rhamnosus</i>, <i>Lactobacillus plantarum</i>, <i>Bacillus velezensis</i>, and <i>Bacillus licheniformis</i>) mixtures, and the protein contents increased 1.31&#8722;2.11 times from 39.23 &#177; 0.67 mg/100 mL. In addition, their contents of volatile compounds increased with positive effects on aroma in the fermented juices. Conversion of the free and bound forms of phenolic acids and flavonoids in juice was influenced by fermentation, and the antioxidant capacity improved significantly. Fermentation enhanced the contents of lactic acid, proteins, volatile compounds, and phenols. The antioxidant capacity was strongly correlated with the phenolic composition.