Phytochemical comparison of different tea (Camellia sinensis) cultivars and its association with sensory quality of finished tea

Abstract

Selection of appropriate tea (Camellia sinensis) cultivars, represents an essential prerequisite for tea manufacture. A detailed phytochemical comparison of different cultivars, and its influence on flavor quality of finished tea, remain to be explored. Herein, different Chinese tea cultivars which are suited for only green or black tea processing (GT, BT cultivars), or compatible for both tea types processing (BT> cultivars), were pre-selected and carefully collected. A nontargeted metabolomics using liquid chromatography coupled to mass spectrometry (LC-MS) was performed, combined with comprehensive pathway mapping. Meanwhile, all cultivars were subjected to parallel processing for sensory evaluation of finished black tea. BT cultivars showed most prominent differences, with significantly higher levels of catechins, condensed products and phenolic acids including gallotannins, whereas lower contents of flavone C-glycosides, free sugars and amino acids were found. Particularly, unique glycosylation patterns of flavonol glycosides were identified for the first time. O-rutinosylation and O-glucosylation were predominant in BT cultivars, whereas O-glucosyl/galactosyl-rutinosylation were predominant in GT and BT> cultivars. The flavor attributes of differential compounds could be well associated with corresponding processing suitability of studied cultivars. This study provides an in-depth elucidation of metabolic features associated with processing suitability of different tea cultivars.