Characterization and Analysis of Polyphenols in Green and Black Tea Brands Available in Commercial Market of Pakistan

Abstract

In present study, the quality of commercially brands of green and black tea available in Pakistan was analyzed on the basis of phenolic contents. Total phenolic content was analyzed through spectrophotometric measurement using the Ferrous Tartrate method. Individual catechins along with gallic acid and caffeine were determined using HPLC-UV. TPC of green tea was found to be higher than black tea. Among green tea brands, Lipton Clear Green showed higher TPC than Tapal Gulbahar. Both green and black tea polyphenols showed higher solubility in the aqueous acetone (50%, v/v) compared to water. (-)-EGCG was detected as the most abundant catechins in all green and black tea samples. Theaflavin content of Lipton Yellow Label and Vital was significantly higher than Tapal Family Mixture and Tetley. Based on catechins and theaflavins content, Lipton Clear Green, Lipton Yellow Label, and Vital Tea were considered to be of higher quality than other brands.

Keywords

• catechins
• total phenolic content
• theaflavins
• thearubigins