Investigation of total antioxidant capacity and total poly phenols of black tea in Iranian markets

Tea is the most widely consumed and popular non-alcoholic beverage in the world. Reactive oxygen species may cause a wide range of damages to biological systems. The purpose of this study was to determine the total antioxidant capacity and total phenolic of different black tea samples in Iran. The FRAP (Ferric reducing antioxidant power) assay was used for antioxidant activity. The total phenolic content was measured based on the Folin-Ciocalteu method. The results showed that all samples had substantial antioxidant activity and total phenolic. Iranian tea samples had significantly the lowest 0.98 ± 0.15, 0.75±0.17 µmolL-1 and Kenya tea samples had significantly the highest 2.67 ± 0.61, 2.10±0.65 µmolL-1 amount of total antioxidant capacity and total phenolic, respectively. A linear positive relationship was observed between the antioxidant activity and total phenolic content of the black tea samples. These findings suggest that black tea can be considered a natural source of antioxidant and total phenolic.