The Main Quality and Functional Chemical Composition of Tea

Tea plant (Camellia sinensis) biosynthesizes various specialized metabolites, and the main quality and functional chemical compositions of tea are critical factors that directly determine its sensory attributes and potential health benefits. This paper introduces the main quality and functional chemical composition of tea, including tea polyphenols (flavanols, flavonols and flavones, anthocyanins, and phenolic acids), amino acids, purine alkaloids (caffeine, theobromine, theophylline, and theacrine), other nonvolatile chemicals (tea polysaccharides, carotenoids, theasaponins, mineral elements), and volatile compounds. In addition, suggestions on the future study of these chemical compounds in tea have been provided.