Verificação antifúngica frente ao chá de hibisco e fermentados de kombucha

Abstract

Kombucha is a beverage fermented by a symbiosis of bacteria and yeast from teas, and it is of Asian origin. Secondary fermentations can be made using fruits, teas, spices, leaves, such as hibiscus for example. Hibiscus sabdariffa L. is known for its deep red color, aroma and unique acidic taste, being an herbaceous plant of the genus Hibiscus of the Malvaceae family. The kombucha fermented with hibiscus, in addition to providing a different flavor, can provide functional properties such as antimicrobial and antioxidant action. Botrytis cinerea is a phytopathogenic fungus, which causes gray rot in fruits, in which strawberry stands out, which, due to its moisture content, sugars and acids, makes it susceptible to attack by the fungus. B. cinerea is a fungus that is difficult to control and may be resistant to the chemicals used to control it. Thus, techniques such as the application of natural compounds and physical treatments have been studied for use in the prevention of gray mold. 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 7 days for mycelial growth, verified by its diameter. PDA without added tea or kombucha were used as a control. Strawberries were steeped in an aqueous solution of hibiscus tea and fermented into kombucha. The results obtained 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 some signs of reduced external deterioration, with hibiscus tea showing better control.