Tea quality assessment by analyzing key polyphenolic functional groups using flow injection analysis coupled with a dual electrochemical detector

Abstract

Tea, one of the most consumed beverages in the world, has several health benefits which include antioxidant and reducing the risk of diabetes, heart-attack and cancer etc. Polyphenols such as catechin, epicatechin, epicatechin gallate, epigallocatachin and epigallocatechin gallate (EGCG), which generally contain combination of 1,2-dihydroxy benzene (1,2-DHB), 1,3-dihydroxy benzene (1,2-DHB) and 1,2,4-trihydroxy benzene (1,2,3-THB) functional groups are rich in green tea. Among the various polyphenols, EGCG (1,2,3-trihydroxybenzene functional group), is viewed as the most active component for the health benefits and hence it has been assayed in the tea quality assessment. Here in, we report a simple, rapid and separation-less electro-analytical technique based on a flow injection analysis coupled dual electrochemical detector system, in which graphitized mesoporous/Chitosan modified glassy carbon electrodes (GCE/Chit@GMC) set at two different applied potentials (Eapp), 0.1 (case-I) and 0.7V vs Ag/AgCl (case-II), controlled by a bipotentiostat, with pH 7.0 phosphate buffer as a carrier solution has been reported for the selective and simultaneous detection of 1,2,3-THB and {1,2,3-THB +1,2-DHB+1,3-DHB} contents in tea samples.