Antioxidant and antibacterial activity of a beverage obtained by fermentation of yerba-mate (Ilex paraguariensis) with symbiotic kombucha culture

摘要

This study aimed to characterize yerba-mate kombucha by showing its oxidativestress inhibitory property with Saccharomyces cerevisiae yeast as the model and todetermine its antibacterial activity against Staphylococcus aureus and Escherichia coli.Different yerba-mate concentrations and fermentation temperatures were analyzedby an experimental design. Sucrose was used as the carbon source and green teakombucha was used as the control. Yerba-mate beverage, which was fermented for12 days had pH levels between 1.8 and 2.3; acidity from 4.8% to 6.0% acetic acid;total reducing sugars between 15.9 and 23.1 g/L; and total phenolic compounds(TPC) between 444.2 and 844.8 mg/L eq. gallic acid. Antioxidant activity, measuredby the ABTS~+ method, was from 16.1% to 31.3% higher than unfermented extracts.Yerba-mate kombucha exhibited antibacterial activity and was also effective to preventthe oxidative stress in S. cerevisiae.