In vitro compositional and phytochemical analysis of green and black tea

Abstract

The traditional beverage that people consume more after water is a tea. The ethanolic extract of green and black tea have antioxidant and antimicrobial activity and these activities may differ in their processing methods. In this study, physiochemical analysis of green and black tea was carried out.  The physiochemical analysis showed that green tea has higher moisture content, crude fat and crude fiber except for crude protein and ash content which is found higher in black tea. The maceration process was used for extraction purposes. This extract was used to analyze the total phenolic and flavonoid content, antioxidant potential, and antimicrobial activity. A significant difference was found in the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity of green and black tea. The flavonoids and phenolic content in T1 (ethanol 100%) acquired average and significant in the extract of green and black tea. The maximum value of TPC was observed in green tea extract 152.17a ± 0.28 mg GAE/g in treatment T1, and the value of TFC in green tea was found 40.26±11.387mg QE/g and the minimum value was found in black tea at 36.85±13.68 mg QE/g of extract. Antioxidant activity of green tea extract ranged from 90.64% to 69.07%, and black tea extract ranged from 89.05% to 50.93% in each extract. The parallel determination of the inhibitory effect of gram-negative and positive bacterial strains (Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa) was found sensitivity and resistivity towards extract of tea. The positive and negative effect was found in antimicrobial activity by using antibiotics against these bacterial strains.