The Tea leaf is composed by a number of different elements and components, which are responsible for the beneficial effects of Tea, and can be extracted since they are water soluble. The three most important chemical substances in the fresh Tea leaf are caffeine (which we discussed before), essential oils and polyphenols. Polyphenols can also be divided between natural polyphenols and oxidized polyphenols (those resulting from the oxidation process). The polyphenol level vary depending on how the Tea was harvested, handled, processed and brewed. Polyphenols include flavonoids and tannins, two of the most important substances found in Tea.
Tannins is what give Tea the bitter aftertaste. The length of the brewing process determines the amount of Tannin in your Tea cup. Tannins are also said to have an antibacterial effect.
Flavonoids are responsible for the antioxidant power of Tea while also boosting immune system, preventing inflammations, strengthen blood vessels among other beneficial health. The mean flavonoid content in a 150 ml cup of green Tea is approximately 200 mg, while it is 42 mg in the same volume of red wine and around 22 mg in an apple. That means one cup of green tea has the same flavonoid content of almost 5 glasses of red wine or 9 apples.
Happy Tea Break.