Insights into changes in functional properties of strawberry juice induced by different types of probiotic fermentation: From molecular to regulatory mechanisms

Lactic acid bacteria (LAB) fermentation is an effective strategy for enhancing the functional properties of foods. In this study, strawberry juice was fermented with different types of probiotics, Limosilactobacillus fermentum , Lacticaseibacillus rhamnosu s, and Lactiplantibacillus plantarum , and then their corresponding physicochemical, metabolic, and functional properties were investigated. The results showed that all tested LAB strains proliferated in strawberry juice and formed their own unique taste and flavor by depleting amino acids and hydrocarbons. Concurrently, all LAB fermentations significantly increased total flavonoid and phenolic contents and promoted anthocyanin conversion. Correlation analyses revealed that these changes in bioactive constituents were positively correlated with enhanced antioxidant activity and improved inhibition of α-amylase and lipase. Notably, different LAB fermentations induced different metabolic profiles, but they still shared pathways related to biosynthesis of folate, alkaloids, and isoflavones, and metabolism of certain amino acids and sugars. Overall, these results provide insights into LAB fermentations to enhance nutritional value and bioactivity of fruit-based foods.