Quality enhancement of Dendrobium officinale and banana juice through probiotic fermentation using beneficial lactic acid-producing bacteria

Abstract

Abstract Consumption of functional juice is becoming increasingly popular. This study aimed to evaluate the effect of probiotic fermentation with Bacillus sp. DU-106; Lactobacillus planturum Lp-43 and Lactobacillus rhamnosus Lr-156 on the biochemical and functional characteristics, antioxidant activities and storage stability of Dendrobium officinale and banana (DOB) juice. The cell levels of the lactic acid bacteria reached near 9 log copies/mL after fermentation at 32 °C for 36 h and could keep in this level after storage at 4 °C for 28 days. After fermentation, total acidity, flavonoids and polysaccharide contents of DOB juice increased, while pH, dissolved oxygen, nitrite, nitrate, vitamin C, β-carotene, sugar contents and antioxidant capacity slightly decreased. Compared with nonfermented DOB juice, polyphenol oxidase (PPO) and peroxidase (POD) activities of fermented DOB decreased significantly, but the color value and the content of total phenols and vitamin C decreased slightly in fermented DOB juice during storage. Overall, the probiotic fermentation with selected strains could improve the quality the DOB juice, enhance antioxidant capacity and storage stability, and destroy accumulation of nitrite and nitrate during storage. Findings of this study would help in the development of beneficial beverages in industrial production.