Evaluation of physiochemical composition, phenolic compounds, and antioxidant activity of Kombucha produced from <i>Thunbergia laurifolia</i> as a potential functional food

Abstract Kombucha has gained global attention for its beneficial bioactive compounds. This study aimed to evaluate Thunbergia laurifolia tea as a potential substrate for Kombucha production due to its rich polyphenol content and biological properties, including antioxidant and anticancer properties, through monoculture and simultaneous mixed coculture fermentation. The pH and brix of the teas decreased significantly during fermentation, indicating sugar hydrolysis and organic acid synthesis by fermenting microbes. The alcohol content was higher in yeast monocultures (45.80 ± 0.00¬50.23 ± 0.08 g L−1) compared to mixed coculture fermented (CBY) tea (20.16 ± 0.00 g L−1). Total phenolic and flavonoid contents and antioxidant activity increased significantly in CBY tea compared to non-fermented and monoculture teas. CBY also exhibited the highest cumulative phenolic compound content, including rosmarinic acid, caffeic acid, gallic acid, rutin, catechin, and quercetin, compared to monoculture teas. Overall, Thunbergia laurifolia tea shows promise as a substrate for kombucha production, with improved bioactive constituents and antioxidant activity.