Effects of different herbal teas on the fermentation and functional properties of kombucha symbiotic culture of bacteria and yeasts (SCOBY)
Seda Akçay, Gülden Başyiğit Kılıç, Damla Bilecen ŞenAbstract
BACKGROUND
Kombucha is a fermented beverage traditionally produced from sweetened tea by a symbiotic culture of bacteria and yeasts (SCOBY), forming a bacterial cellulose layer during fermentation. Alternative herbal substrates have attracted attention for their potential to influence the composition and characteristics of kombucha. Therefore, this study investigated the effects of black tea, green tea, Echinacea purpurea , and lavender on the microbiological, physicochemical, antioxidant, organic acid, sugar, volatile aroma compound, and ethanol profiles of kombucha cultures.
RESULTS
Significant substrate‐dependent differences were observed in most microbiological and biochemical parameters ( P < 0.05). Green tea and echinacea SCOBY exhibited higher microbial counts than black tea SCOBY, whereas lactic acid bacteria were not detected in black tea samples. Echinacea SCOBY showed the highest total phenolic content (219.36 mg gallic acid equivalents g −1 ) and strong antioxidant activity. Lavender SCOBY was characterized by the highest concentrations of volatile aroma compounds and ethanol, indicating enhanced fermentative activity. Organic acid profiles differed among substrates; echinacea SCOBY contained the highest levels of malic and ascorbic acids, while green tea SCOBY showed elevated lactic and citric acid concentrations. Sugar analysis showed greater glucose utilization in lavender SCOBY, consistent with increased ethanol and metabolite production.
CONCLUSION
The type of fermentation substrate significantly influenced microbial growth, metabolite formation, antioxidant potential, and fermentation characteristics of SCOBY. Echinacea SCOBY showed the highest phenolic content and high antioxidant capacity, whereas lavender promoted aroma development. These findings demonstrate that alternative herbal substrates can be successfully utilized to diversify kombucha products. © 2026 Society of Chemical Industry.