At present, a total of 26 amino acids have been found in tea extracts, including 20 protein amino acids and 6 non-protein amino acids. Theanine is one of the non-protein amino acids.
Theanine that exists in nature is left-handed, which is called L-theanine. The content of L-theanine in tea leaves is higher in young leaves than in old leaves. L-theanine has a caramel aroma and umami similar to monosodium glutamate, which can reduce the bitterness and astringency caused by caffeine and catechin, and enhance the sweetness.
In addition, because L-theanine can alleviate the bitter and spicy taste of other foods and effectively improve the flavor of food, it has been used in the field of food additives. Studies in recent years have also shown that L-theanine has physiological effects such as lowering blood pressure, improving memory, and calming the nerves.
It is worth noting that in the medical field, L-theanine is being put into anti-tumor research.