Effect of Fermentation on Phenolic Composition and Antioxidant Capacity of Blackcurrant Juice usingLactobacilluswith Different ß-Glucosidase Activities

The objective of this research was to evaluate the impact of lactobacilli fermentation of blackcurrant juice on phenolic compounds and antioxidant capacity. Seven lactobacilli bacteria strains were analyzed for tannase and β-glucosidase activities, and the phenolics composition and antioxidant capacity of blackcurrant juices were measured before and after fermentation. β-Glucosidase and tannase activities were detected in all strains. After 24 h of fermentation, anthocyanins decreased but had no significant change from the control. Condensed tannins decreased significantly (182- 265%), antioxidant capacity significantly increased with Lactiplantibacillus plantarum strains (502%-445% for HEAL19 and LB7, respectively), and polyphenols significantly increased with Lacticaseibacillus paracasei 8700:2 (94%) compared to the control. L. paracasei 8700:2 had a clear effect on the increase in phenolic acids. In conclusion, L. plantarum HEAL19 or L. paracasei 8700:2 are the most promising strains for increasing antioxidant capacity or total polyphenols after fermentation of blackcurrant juice under the specified conditions.