Herbal kombucha vinegar: Biotechnological perspective, biological potential and sensory evaluation

Increasing consumer preference for natural and organic products, along with recognition of the multifunctionality and health benefits of vinegar, are key drivers of the global vinegar market growth. This growing demand gives vinegar producers a great opportunity to diversify their product offerings. In this study, the possibility of kombucha vinegar production on sucrose-sweetened black tea and infusions based on different herbs (peppermint, chamomile, stinging nettle, thyme, echinacea, lemon balm, yarrow, lavender, basil, and valerian) through prolonged fermentation by the autochthonous symbiotic culture of bacteria and yeasts was examined. The fermented media were analyzed regarding bioprocess success indicators to determine the fermentation capability of the used kombucha culture under the applied conditions. The quality of the obtained products was evaluated based on their chemical composition, bioactivity, and sensory properties. All experimental data were statistically processed to establish the effect of the medium composition variation on the prolonged kombucha fermentation efficacy. Summarizing all the results and findings, the basil was selected as the herb with the greatest utilization potential in the production of herbal kombucha vinegar, an innovative food product with promising health-promoting effects. The basil-based kombucha product created in this study is an acidic product (pH value of 2.66) rich in nutrients and bioactive compounds (sugars content of 32.78 g/L, total acids content of 55.52 g/L, total phenols content of 29.32 mg GAE/L, vitamin C content of 3.85 mg/L, RSC_DPPH of 85.59 %, and RSC_ABTS of 58.89 %), and with highly acceptable sensory quality (mean liking scores for the evaluated sensory attributes ≥8.3).