ABSTRACT
Tea is one of the world's most popular beverages, with several health benefits. Polyphenols are the predominant constituents to account for its health benefits. Despite the well-known benefits of tea on health, the uniqueness of its aroma, taste, and features is an added value that contribute to the increased popularity of this beverage worldwide, and they are associated with the alterations in the metabolites during tea processing and cultivation. The manufacturing of tea consists of several stages with various processes as withering, fixing, rolling, fermentation and drying. The classification into tea types is according to such processing. The high-quality production of the various tea classes also depends on agricultural conditions, such as shading, plucking, climate, and soil composition. Metabolomics is well recognized as an effective tool for evaluating the quality of tea products. Applications in controlling the quality of tea products and adulterant detection are discussed in this review.