Tea, the magical "oriental leaves". Its magic lies in the rich and unique endoplasm, and there are hundreds of fresh leaf components that have been isolated and identified; in the post-processing process, more ingredients are generated through chemical reactions.
The reason why tea is so magical and highly sought after is that there are "three treasures" in tea: tea polyphenols, caffeine, and theanine. These three types of substances are also known as the characteristic components of tea, what are the characteristic components? That is to say, these ingredients are unique to tea or have a high specific content, and there are none or very few in other plants; they must be easily soluble in water and can be obtained by tea drinkers; they have clear pharmacological health value, and can obviously act on the human body; and are positively related to the quality of tea, the higher the content, the better the quality of tea.
Let's take a look at the three important substances to be talked about today: tea polyphenols, catechins, and tea pigments, and see their role and relationship.
Tea polyphenols: also known as tea tannic acid, tea tannins. It is a general term for polyphenols present in tea, accounting for about 15% to 40% of the total dry matter.
Catechins: a kind of tea polyphenols, accounting for about 50 to 70% of the total amount of tea polyphenols, it plays an important role in the formation of tea color, aroma and taste quality, and is also the primary component of tea health care functions, with antioxidant, anti-cancer, anti-mutation and other activities. Its antioxidant activity is at least more than 100 times that of vitamin C and 25 times that of vitamin E, so catechins are also called "body preservatives".
Tea pigment: see here, it seems that there is no tea pigment in the fresh leaves, not to mention the list of the three treasures, not even mentioned, but obviously heard that tea pigment has a very high medical and health value, which theaflavin is also known as the "soft gold" in tea, is the first to find from tea has a definite pharmacological effect and no side effects of the compound. What's going on here?
This has to start with the tea making process. Tea polyphenols (catechins) in fresh leaves will undergo enzymatic oxidation during the production process, tea pigment is catechin after oxidation polymerization, divided into: theaflavins, thearubicin, theaflamin, water-soluble pigments, very stable in the air, and greatly active in water, will change with temperature and time changes. Tea pigment has the highest stock in black tea, is a characteristic component of black tea, and its molecular structure still maintains the maternal nucleus characteristics of catechins, so the pharmacology of the two is the same, but the medicinal and health value tea pigment is higher, safer, more balanced and stable.
Take Keemun black tea as an example, let's take a look at the changes in the "three treasures in tea". Qi Hong will continue to undergo complex chemical changes in the processing process: tea polyphenols (catechins) are greatly reduced, tea pigments such as theaflavins and thearubicins are continuously generated and increased; the total amount of dozens of amino acids and theanine is slightly reduced; caffeine is increased; and most of the reduced phenols and amino acids are converted into other flavor substances and aromatic substances. It is these changes that have created the unique high quality of Keemun black tea, which is famous for its remarkable characteristics of "soup color, mellow taste, high aroma and beautiful shape", and the health care effect is also obvious.
It turns out that the tea pigment is not the original component of the fresh leaf itself, but the substance produced by the chemical changes in the later stage, so it is normal to say that the "three treasures in tea" in the fresh leaf are not mentioned.
Differences between tea pigments and tea polyphenols:
1, the PH value of tea pigment is 8.0-10.0, which belongs to weak alkalinity, while the PH value of tea polyphenols is 4.0-6.0, which is weakly acidic.
2, tea polyphenol taste astringent, cold, astringent irritation, drink more easy to hurt the stomach; tea pigment taste smooth, warm, irritating weak, can nourish the stomach.
3. Tea polyphenols are easily oxidized and denatured in the air, and tea pigments are stable in the air and relatively easy to preserve.
4. The medicinal principles of the two are the same, but the stability, safety and balance of tea pigments are stronger.
Taking green tea and black tea as an example, green tea is rich in tea polyphenols and catechins, very few tea pigments, a large number of tea polyphenols (catechins) in black tea are converted into tea pigments, and the content of tea polyphenols (catechins) is small. The result is that green tea is relatively bitter in taste, while black tea tastes smooth; green tea is cold, irritating, easy to hurt the stomach when drinking more, and black tea is warm and can also nourish the stomach. Black tea is easier to preserve and has a longer shelf life. From the perspective of the health and pharmacological effects that everyone is most concerned about, the two are roughly the same, and after the tea polyphenols are converted into tea pigments, they will become stronger in terms of safety, stability and efficient balance.