Identifying key non-volatile compounds in ready-to-drink green tea and their impact on taste profile

Abstract

Thirty-nine non-volatile compounds in seven ready-to-drink (RTD) green tea samples were analysed and quantified using liquid chromatography. Taste reconstruction experiments using thirteen selected compounds were conducted to identify the key non-volatile tastants. Taste profiles of the reconstructed samples did not differ significantly from the RTD tea samples. To investigate the taste contribution and significance of individual compounds, omission experiments were carried out by removing individual or a group of compounds. Sensory evaluation revealed that the astringent- and bitter-tasting (-)-epigallocatechin gallate, bitter-tasting caffeine, and the umami-tasting l-glutamic acid were the main contributors to the taste of RTD green tea. Subsequently, the taste profile of the reduced recombinant, comprising of a combination of these three compounds and l-theanine, was found to not differ significantly from the sample recombinant and RTD tea sample. Lastly, regression models were developed to objectively predict and assess the intensities of bitterness and astringency in RTD green teas.

Keywords: Green tea; Half tongue test; Mathematical modelling; Sensory evaluation; Taste omission; Taste reconstruction.