Antifungal Potential of Hibiscus Tea and Fermented Kombucha

Abstract

Kombucha is a beverage fermented by a symbiosis of bacteria and yeast from teas. Secondary fermentations can be made using vegetables, such as hibiscus for example. In addition to providing a different flavor, the kombucha fermented with hibiscus can provide functional properties such as antimicrobial and antioxidant action. Botrytis cinerea causes gray rot in fruits and is difficult to control due to resistance to chemicals. The objective of this work was to evaluate the antifungal activity of the 1st fermentation of kombucha (F1), the 2nd fermentation of kombucha with hibiscus (F2H) and hibiscus tea against the fungus Botrytis cinerea for a possible alternative for fungal control in strawberries. B. cinerea was inoculated in PDA medium at concentrations of 50 %, 25 %, 12.5 %, and 6.25 % of hibiscus tea and fermented kombucha and evaluated after seven days for mycelial growth, verified by its diameter. PDA without added tea or kombucha was used as a control. Strawberries were steeped in an aqueous solution of hibiscus tea and fermented into kombucha. The results showed inhibition of the mycelial growth of B. cinerea in the media with concentrations of 50 % and 25 % of kombucha (F1 and F2H) and hibiscus tea, where the inhibition for F1 was 88.9 % and 46.7 %. For F2H, it was 58.9 % and 20 %. And for hibiscus tea, it was 21.1 % and 12.2 %, respectively. When these pure compounds were applied by immersion on strawberries and stored at 15 °C, there were signs of reduced external deterioration, with hibiscus tea showing better control.