Insights into the improvement of bioactive phytochemicals, antioxidant activities and flavor profiles in Chinese wolfberry juice by select lactic acid bacteria

The effects of six commercial lactic acid bacteria (LAB) fermentation on bioactive phytochemicals, antioxidant activities and flavor profiles in Chinese wolfberry juice were investigated. All the strains exhibited satisfactory proliferative capacities in Chinese wolfberry juice with viable counts above 7 log CFU/mL at the end of fermentation. Bioactive phytochemicals were significantly increased by LAB, especially for Lactobacillus paracasei, Lactobacillus acidophilus and Bifidobacterium lactis increasing betaine from 8237.77 to ca. 20000 mg/L. Furthermore, antioxidant activities based on DPPH, ABTS and FRAP methods were significantly enhanced after LAB fermentation due to the accumulation of phenolics. In addition, 68 volatile compounds including 20 alcohols, 18 esters, 13 ketones, 10 aldehydes, three acids, three terpenes and theaspirane were detected. LAB fermentation resulted in significant decrease in aldehydes content and increase in esters production, suggesting that LAB could be employed to remove off-flavor and enrich pleasant flavor of Chinese wolfberry juice.