Phenolic Compounds in Tea: Phytochemical, Biological, and Therapeutic Applications

Abstract

Phenolic compounds are one of the major and most complex groups of phytochemicals found among plant kingdom. Structurally they comprise of aromatic ring along with one or more hydroxyl groups. Based on the structure they are divided into subgroups such as phenolic acids, flavonoids, tannins, coumarins, lignans, quinones, stilbenes and carotenoids. Plant polyphenols are gaining popularity as a result of their potent antioxidant properties and notable effects in the prevention of oxidative stress-related diseases. Extraction, identification and characterisation of phenolic compounds from various plant sources has become a major area of health and medical research in the recent years. The major bioactive compounds responsible for tea’s health benefits are thought to be phenolics. Catechin derivatives make up the majority of the phenolic compounds found in tea, and though flavonols and phenolic acids are also present in smaller amounts. The bioactivity of the compounds has been linked to a lower risk of serious illnesses like cancer, cardiovascular disease, and neurodegenerative disease. This chapter covers phenolic extraction, purification, analysis and quantification, as well as their antioxidant properties in different varieties of tea leaves.