Effects of medium variation and fermentation time on the antioxidant and antimicrobial properties of Kombucha
Batul Moiz Vohra, Shazrul Fazry, Fareed Sairi, Othman Babul-Airianah
Kombucha is a traditional fermented drink and has recently gained popularity due to its numerous claims on therapeutic effects. It is prepared by
sweetening black tea and fermenting using a symbiotic culture of acetic acid bacteria and yeasts known as SCOBY. The drink can also be brewed using different types of tea and carbon sources. An investigation was conducted to characterize the
antioxidant and antimicrobial properties of kombucha by using variation of carbon sources: white sugar (S), jaggery (J) and Kelulut honey (H) in black tea (BT) and green tea (GT) media over a period of 7, 14, 28 and 60 days. The antioxidant and antimicrobial efficacies were tested post fermentation. All samples shown the highest value of 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition for antioxidant activity at 7 days of fermentation but subsequent decrease was observed with longer fermentation time except for the combination of green tea with jaggery (GT+J). Fermentation of green tea with white sugar (GT+S) showed the highest value with 84%. On the other hand, black tea with jaggery (BT+J) showed least DPPH activity of 9%. Fermentation with green tea demonstrated a higher antioxidant activity compared to black tea, whereas fermentation of any tea with jaggery showed the least antioxidant activity in comparison to white sugar and honey. Thus, it could be said that extended periods of fermentation would reduce the DPPH inhibition of kombucha and jaggery itself as carbon source showed an interesting property. Antimicrobial activity was tested using disk diffusion method against E.
coli, S. aureus, P. aeruginosa, B. subtilis and S. marcescens. The efficacy was increased with time of
fermentation for all combinations. Combination of black tea with all carbon sources was found to exhibit good antimicrobial activity.
Keywords: antioxidan, antimicrobial, sugar types
Citation: Malaysian Journal of Fundamental and Applied Sciences 15.2-1 (2019): 298-302
Study Mailing Address:
Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor
Date Updated: June 23, 2020