Journal of Pure and Applied MicrobiologyVol. 7 No. 4

Assessment of the Antimicrobial and Antioxidant Activities of Green Tea and Black Tea

Arunachalam Chinnathambi1* and Sulaiman Ali Alharbi1

1Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia.

Received on 12 October 2013 and accepted on 30 November 2013



Tea and coffee have various biological properties including antimicrobial activity against human pathogens. Green tea and black tea were collected, and extracts were obtained using different solvents. These extracts were tested for their antimicrobial activity against human test pathogens using well-diffusion and disc-diffusion methods. The extracts were then subjected to partial purification by thin layer chromatography (TLC), column chromatography, and HPLC, and screened for the presence of active phytochemical compounds. The results demonstrated that the antimicrobial and antioxidant properties of the extracts from green tea performed well in all attributes, followed by black tea. The good performance of the tea extracts was primarily the result of their high polyphenol concentrations, which are present as a series of chemicals called catechins, including gallocatechin (GC), epigallocatechin (EGC), epicatechin (EC), and epigallocatechin gallate (EGCG). In conclusion, the present work, the methanolic extracts of green tea showed greater antioxidant activity compared to black tea. These purified compounds showed broad antimicrobial and antioxidant activity against all tested human pathogens and are worthy of further study.

Keywords : Green tea, Black tea, Microbial pathogens, Antimicrobial activity, HPLC, Antioxidant activity, Phytochemical compounds.