Fermentation of Bergamot (Citrus bergamia Risso) Fruit with Lactobacillus plantarum: Phenolic Compound Content, Antioxidant Capacity, and Prebiotic Potential

Bergamot (Citrus bergamia Risso) fruit is rich in flavonoids and health-promoting compounds.However, it is not widely consumed unprocessed because of its bitter taste.In this study, the potential of fermenting the entire bergamot fruit, including its non-consumable fractions, with Lactobacillus plantarum was evaluated with respect to bacterial viability, antioxidant capacity, and phenolic compound content.A bergamot homogenate was inoculated with L. plantarum and incubated at 30°C for 6 days.Simultaneously, an uninoculated homogenate was incubated as a control.Samples collected on days 0, 2, 3, 4, and 6 were analyzed for total phenolic content, DPPH • and ABTS • + scavenging activity, and contents of individual phenolic compounds, including neoeriocitrin, naringin, neoeriocitrin dioxalate, neohesperidin, neohesperidin dioxalate, and melitidin.The total phenolic content increased from 20.17 to 21.74 mg GAE/mL in the fermentation group, whereas an insignificant change was found in the sample without L. plantarum inoculation on day 6.Antioxidant capacity in the ABTS assay increased from 8.56 to 9.72 mmol Trolox/L following fermentation, while it decreased to 7.63 mmol Trolox/L in the control group.The contents of neoeriocitrin, naringin, and neoeriocitrin dioxalate increased significantly on the 4th day, to 297.23 µg/L, 160.37 µg/L, and 55.86 µg/L, respectively.Melitidin content, on the other hand, decreased over the fermentation period.This study provides the first evidence of a change in neoeriocitrin content during bergamot fermentation and demonstrates that the 4th day of fermentation represents the optimal stage for increasing bioactive compound content, while maintaining antioxidant capacity.