Purine alkaloids: including caffeine, theanine, theobromine, etc. , accounting for about 4% of black tea. These three alkaloids have similar effects, but caffeine is the most effective to stimulate the central nervous system to refresh, and theanine has stronger cardiotonic, diuretic, vasodilator and smooth muscle effects than caffeine. (In the following introduction, caffeine will be collectively referred to as the three. )

Aromatic substances: Although the aromatic substances in black tea only account for 100-300 ppm, there are as many as 325 kinds. They can not only remove the malodor in the mouth, but also have antibacterial, anti-inflammatory, sedative and analgesic effects.

Amino acids: Glutamate helps to reduce blood ammonia and treat hepatic coma; Methionine can regulate fat metabolism.

Other elements: fluorine contained in black tea is a great weapon to prevent dental caries and osteoporosis; Bait helps to lower blood pressure; Acetic acid polysaccharide has been paid attention to in radiation protection research.