Production and Polyphenolic Composition of Tea

Tea (Camellia sinensis) is the second most commonly consumed beverage in the world, and its consumption has been associated with several important health benefits due in part to its high concentration of polyphenolic compounds. Tea varieties, including white, green, oolong, pu-erh, and black tea, are all produced from the same plant but differ in postharvest processing. The level of oxidative processing from white to black tea (low to high) drives changes in polyphenol profiles from monomeric polyphenols (catechins) to oxidative products (theaflavins and thearubigins) that convert the subtle yellow color of green tea to the distinctive red/copper color of oolong and black tea. Polyphenol compounds from green teas have been well studied; however, oxidative products are more difficult to characterize and may require a combination of analytical techniques for identification and quantification. This technical summary introduces the major polyphenols in tea and discusses the main steps of tea processing and instrumentation used for polyphenol analysis.