Phenolic content in tea
The phenolic content in tea refers to the phenols and polyphenols, natural plant compounds which are found in tea. These chemical compounds affect the flavor and mouthfeel and are speculated to provide potential health benefits. Polyphenols in tea include catechins, theaflavins, tannins, and flavonoids.
Catechins constitute about 25% of the dry weight of fresh tea leaf. They are present in nearly all teas made from Camellia sinensis, including white tea, green tea, black tea and oolong tea.
Theaflavins directly contribute to the bitterness and astringency of steeped black tea.
Tannins are astringent, bitter polyphenolic compounds that bind to and precipitate organic compounds.
A group of natural phenols called the flavonoids are of popular interest because researchers have found them to have the potential to contribute to better health. Tea has one of the highest contents of flavonoids among common food and beverage products. Catechins are the largest type of flavonoids in growing tea leaves.