Antimicrobial Activity of Fermented Green Tea Liquid


Green tea kombucha made of sugar and single yeast was investigated for its antimicrobial
activity and composition changes during fermentation. Individual and total tea polyphenols,
caffeine, sucrose, reducing sugar, total sugar, pH, acetic acid and total acids, ethanol
concentration, superoxide dismutase and hexokinase activities, yeast yield and antimicrobial
activity were measured systematically at the intervals of 12 to 24 hours of fermentation.
Results shown that a 36-hour sample had total growth inhibition on Escherichia coli and
Staphylococcus aureus, but almost no effects on Bifidobacterium and Lactobacillus
delbrueckii subspecies bulgaricus. In order to see the effects of the main components on
the microbial growth, a mixture of tea polyphenols, a mixture of acids and ethanol were
tested respectively and showed various degrees of antimicrobial activities which weremuch
less than the activity of the 36-hour kombucha, suggesting that there was a synergy effect
among the components.

Keywords: antimicrobial, green tea, polyphenols, e. coli, ethanol, sugar content, caffeine, ph

Country: China

Citation: Original Report--citation is simply authors and title.

Study Mailing Address:
aDepartment of Tea Science, Zhejiang University, Hangzhou, China
bCollege of Environmental Science and Engineering, Zhejiang
Gongshang University, Hangzhou, China

Date Updated: May 1, 2019

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