Total flavonoid content was determined according to the method of Zhishen et al. (1999). Tomato extract (0.5 mg/ mL; 500 μL) was mixed with 5 % (w/v) sodium nitrite (30 μL) and was incubated at room temperature (26–28 °C) for 5 min. The mixture was further mixed with 10 % (w/v) aluminum chloride (30 μL) and was incubated at room temperature (26–28 °C) for 10 min. To the mixture, 200 μL of 1 M sodium hydroxide and 240 μL of distilled water were added. The mixture was incubated at room temperature (26– 28 °C) in dark for 15 min. The absorbance of the resulting mixture was measured at 517 nm using a spectrophotometer. The blank was prepared in the same manner, except that distilled water was used instead of the sample. A standard curve was prepared using tannic acid in the range of 0–60 ppm. The activity was expressed as mg tannic acid equivalents (TA)/ 100 g dry sample.