Comparison of proximate composition and antioxidant activity of black and green tea available in Bangladesh

Abstract

The present study was carried out to compare the black and green tea available in Bangladesh with respect to nutritive composition and antioxidant activity. Eight brands of black tea and two brands of green tea were bought from local super market. The variance between every proximate content (moisture, protein, fat, ash, and carbohydrate) of black and green tea was found statistically insignificant (p > 0.05). The total antioxidant activity was determined by phospho-molybdenum assay method and green tea performed significantly higher activity (792.87 AAE) than black tea (330.72 AAE). The variance of ferrous chelating activity between black and green was found statistically significant ( p 0.05) at concentration of 10 ppm, 100 ppm, 200 ppm, 400 ppm, and 600 ppm. Black tea showed maximum inhibition, 50.33% at 600 ppm & lowest 1.93% at 10 ppm. The highest percent inhibition for green was found 32.14 at 600 ppm & lowest 1.25 at 10 ppm. IC50 values were found 5.50 ppm and 4.50 ppmfor black and green teas respectively.