ADVANCED ANALYTICAL TECHNIQUES IN CHARACTERISATION OF VARIOUS ASIAN TEAS

Abstract

Tea is a beverage with a long historical background and has been cultivated in many countries of Asia. Based on their processing parameters and characteristics, tea can be broadly classified as white, green, yellow, oolong, black and dark teas. There is great interest to characterise each type of tea for a better understanding of its unique chemical and sensory aspects but such attempts often face challenges due to the complexity of tea flavour. To address this issue, various advanced analytical techniques were explored in this study for untargeted and targeted characterisation of various Asian teas. This is achieved by understanding the process of sample extraction, chromatographic separation (multi-dimensional and enantiomers separations), high-resolution mass spectrometry detection (providing additional separation criteria), and design of experiments. The applications of the methods developed in this thesis onto green, oolong and black tea provide insights on how different parameters affect flavour development in tea.