09 Apr tea可数还是不可数?_百度知道
Polyphenols in tea include flavonoids, epigallocatechin gallate (EGCG), and other catechins. The most important chemicals in tea are the tannins, or polyphenols, which are colourless, bitter-tasting substances that give the drink its astringency. When acted upon by an enzyme called polyphenol oxidase, polyphenols acquire a...