Influence of milk and sugar on antioxidant potential of black tea

Black tea is often consumed with milk and sugar. It is still unknown with certainty whether addition of milk and (or) sugar affects its antioxidant activity. The present study is aimed to investigate the effect on antioxidant and radical scavenging activities of black tea on addition of milk and sugar. Four types of black tea brew samples are prepared, viz., plain black tea (B), black tea with sugar (BS), black tea with milk (BM) and black tea with milk and sugar (BMS). The freeze-dried solids of all the brew samples are evaluated for their biological activities. The radical scavenging and antioxidant activities are estimated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and β-carotene-linoleic acid model systems, respectively. It is observed that radical scavenging activity of B was highest followed by BS and BMS. BM shows lowest activity. The antioxidant activity of black tea enhances and stabilizes with milk or sugar. The total polyphenol content is also determined and found to be higher in black tea sample compared to other samples. Both activities are compared with that of butylated hydroxy anisole (BHA) as a standard antioxidant and found to be less in all cases.