Metabolic engineering of blueberry juice by Lactiplantibacillus plantarum JM065: Fermentation optimization

Blueberry juice is rich in glycosylated polyphenols with limited bioavailability. We hypothesized that fermentation with Lactiplantibacillus plantarum JM065 could enhance the biotransformation of these compounds into more bioactive aglycones, thereby improving functionality. Using response surface methodology and genetic algorithms-backpropagation neural network approach, fermentation conditions were optimized (0.7 % inoculum, 12 h, 29 °C), resulting in significant increases in total phenolic content and antioxidant capacity. The process also reduced the pH, increased the viable bacterial count, promoted sugar consumption, and elevated mild organic acids (lactic and succinic acids), resulting in improved sensory properties. Metabolomic analysis further confirmed substantial accumulation of aglycone-type polyphenols, such as quercetin, kaempferol, and gossypetin, especially during the first half of fermentation. These results validate our hypothesis and underscore the potential of L. plantarum JM065 for producing functional fermented beverages with enhanced bioactivity. The optimized framework offers a viable strategy for industrial-scale applications.