Since the legendary “Shennong tasted a hundred herbs and encountered seventy-two poisons, which were cured by tea” 4,700 years ago, the magical effects of tea have been admired and puzzled over by generations. The Herbal Supplement marvels: “All medicines are specific for certain diseases, but tea is a medicine for all ailments.”
Why does tea have such miraculous value? What mysterious substances does it contain?
Modern high technology has finally deciphered this age-old mystery: scientists have discovered that the main components of tea are catechins and tea pigments. Among these, tea pigments are the jewel in the crown, the crystallization of tea culture, the dream of tea medicine, and the pinnacle of tea science.
1. What Are Tea Pigments?
Tea pigments (Teapigments) refer to water-soluble pigment mixtures generated through the oxidation and polymerization of polyphenols, primarily catechins, during tea processing. They mainly include theaflavins (TFs), thearubigins (TRs), and theabrownins (TBs).
The molecular structure of tea pigments still retains the basic characteristics of catechins, but they are more valuable, safer, and more stable than catechins. Theabrownins in tea pigments are the most stable and have the largest molecular weight.
Tea pigments are weakly alkaline, and their weak alkalinity is one of the reasons they can exert therapeutic effects. They are stable in air and can regulate trace elements to maintain bodily balance.
The Special Issue on Clinical Research Papers on Chinese Tea Pigments presents these findings, providing scientific evidence for the general public.
2. The Important Active Substance in Dark Tea —— Tea Pigments
In the piling and drying processes of dark tea, the conversion and accumulation of colored oxidized polyphenols occur rapidly. The overall trend is a significant decrease in TFs and TRs and a large accumulation of TBs. Luo Longxin et al. measured (TF + TR)/TB = 1.52 in black tea, while in dark tea, (TF + TR)/TB = 0.33. Although dark tea and black tea have similar HPLC profiles in terms of raw materials and both involve enzymatic action and moist heat during processing, no characteristic peaks of TFs and TRs similar to those in black tea were found in the HPLC profile of dark tea. However, MS was able to detect small amounts of theaflavins and theaflavins in dark tea, indicating significant differences in the composition and structure of polyphenolic oxidized products between dark tea and black tea.
TBs are the characteristic components of dark tea, as they originate from further oxidation and polymerization of polyphenols, TFs, and TRs. It can be inferred that the molecular weight of TBs should far exceed the molecular weight range of TRs (700–40,000 Da). Current research suggests that TBs are polyphenolic polymers containing multiple benzene rings, combined with protein residues, polysaccharides, methyl groups, and acid substances (including carboxylic acids and phenolic hydroxyl groups), with lower contents of caffeine and catechins.
The carboxylic acid (1.975 mmol/g) and phenolic hydroxyl (5.805 mmol/g) groups in TBs were successfully quantified using BaCl2 and Ca(CH3COO)2 precipitation methods, indicating that phenolic hydroxyl groups are the dominant acidic functional groups in TBs. Yang Dapeng used dilute hydrochloric acid to acid-hydrolyze TBs; after separation and purification of the product, a compound C3H8Na2O9P2, suspected to be formed by dehydration and condensation of glycerol and phosphate salts, was obtained.
3. The Value and Status of Tea Pigments
The emergence of tea pigments has received significant attention and affirmation, being successively listed as key projects under the State Science and Technology Commission's Seventh Five-Year Torch Plan, Eighth Five-Year High-Tech Product Development and Promotion Program, and the Ninth Five-Year Medicine and Technology Innovation Drug Project, the top priority of the “1035” project plan.
In 1997, it was also selected as a project under the Chinese Medical Association's “Key Promotion Project.” This is a major breakthrough in China's traditional medicine industry, marking a shift in the understanding of tea's functions from a medicinal and health-oriented herbal product to a drug with multiple biological activities. It is also a great innovation in the history of Chinese medicine.
All the above information comes from the Special Issue on Clinical Research Papers on Chinese Tea Pigments and Chinese Tea Medicine. The Special Issue on Clinical Research Papers on Chinese Tea Pigments is published by “China Medical Science and Technology Press,” and Chinese Tea Medicine is published by “Tianjin Science and Technology Press.”
Tea pigments are food-grade medicinal products. Generally, drugs are only used for treatment; according to traditional Chinese medicine, “one-third is for treatment, and seven-tenths is for nurturing.” Treatment alone accounts for only one-third of the body's needs, whereas tea pigments not only have a one-third treatment effect but also a seven-tenths nurturing effect, combining treatment and nurturing for a total effect of ten-tenths.