Tea is one of the three largest drinks in the world, and is known as the drink of the 21st century, which is not only because of the long history of tea culture, but also because tea is a natural drink, which has nutritional value and health care effects on the human body.
Studies have shown that tea contains a large number of bioactive ingredients, including tea polyphenols, tea pigments, tea polysaccharides, tea saponins, alkaloids, aromatic substances, vitamins, amino acids, trace elements and minerals and other components.
▲ The main chemical component in tea
Among them, the tea content is the most abundant and the most widely studied is tea polyphenols. Today Xiaobian will give you a look at the relevant knowledge points of tea polyphenols ↓↓↓
1. What are tea polyphenols?
Polyphenols are widely present in nature, and are well known as tea polyphenols, apple polyphenols, grape polyphenols, etc., because of their good antioxidant function, are widely used in cosmetics, pharmaceuticals and other fields.
Tea polyphenols, also known as "tea tannins" and "tea tannins", are a mixture of polyphenols present in the tea plant. It is one of the main components that form the color, aroma and taste of tea, and it is also one of the main components of health care functions in tea. It has high content, wide distribution and great variation, and has the most significant impact on tea quality.
Introduction to Tea Polyphenols:
Chinese Name: Tea polyphenols
Nickname: tea tannin or tea tannin
Interpretation: The general term for polyphenols in tea
Contains: flavanols, anthocyanins, flavonoids, flavonols and phenolic acids
Important content: flavanols (catechins), accounting for about 70% of the total amount of tea polyphenols
Features: It is one of the main ingredients that form the color and fragrance of tea, and it is also one of the main components of health care functions in tea
▲ Tea polyphenols
The content of polyphenols in tea fresh leaves is generally between 18-36% (dry weight), that is, a pound of dry tea contains about 100g to 200g of this substance. Tea polyphenols include catechins, anthocyanins, flavonoids, flavonols and phenolic acids, among which catechin compounds have the highest content and are the most important.
Polyphenols are extremely active in nature, easy to occur a series of chemical reactions under external conditions, the formation of some new chemicals, affecting the quality of various types of tea, so the degree of oxidation of tea polyphenols, is one of the important basis for the classification of six major teas.
▲ Schematic diagram of the degree of oxidation of polyphenols in different teas
Polyphenols are the main part of the water-soluble pigment in tea, which is the main body of tea soup color, and also participates in the composition of dry tea color; at the same time, the main component causing astringency in tea is polyphenol compounds and their oxidation products, among which catechins play a particularly important role in the presentation of astringency.
Second, what are the benefits of tea polyphenols?
Tea polyphenols are the main active ingredient of tea leaves. In the past ten years, the preventive and health care effects of tea polyphenols have been a research hotspot in the medical community. Modern pharmacological research results and epidemiological survey results show that tea polyphenols have obvious anti-aging, antioxidant, antilipidemia, bacteriostatic sterilization, anti-allergy, prevention of atherosclerosis, anti-ejection and other physiological activities. These results show that drinking tea is beneficial for health.
1. Antioxidant effect. Tea polyphenols help to eliminate too many free radicals in the human body, act as a free radical scavenger in the human body, and help prevent aging.
2. Has a good impact on cardiovascular diseases. Tea polyphenols help regulate the metabolism of human blood lipids, prevent cardiovascular and cerebrovascular diseases, and help prevent diseases such as three highs, cerebral stroke, liver and coronary atherosclerosis.
3. It helps to resist allergic reactions and regulate immune function, soothe gastrointestinal tension, anti-inflammatory, anti-diarrhea, diuretic, etc., help enhance the body's immune function, and improve disease resistance.
▲ The beneficial effects of tea drinking
4. Helps prevent cancer and fight cancer. It mainly works through antioxidant, regulation of human gene expression, inhibition of tumor transformation, proliferation pathways.
5. Has antibacterial, antiviral and bactericidal effects, often drink tea can help prevent caries, remove bad breath; can be used for food preservation and preservative, non-toxic side effects, edible safety.
6. It has anti-inflammatory, detoxifying and anti-allergic effects, and helps to inhibit skin inflammation, edema, allergic reactions, etc.
Third, radiation buster - tea polyphenols
In modern life, in addition to natural such as solar visible light and ultraviolet radiation, various man-made radiation injuries also exist in all aspects of work and life, such as mobile phones, computers and other equipment, high-frequency electromagnetic waves of some household appliances, microwaves and radioactive substances of home decoration materials, radioactive substances for diagnosis and treatment, and so on.
Modern medical research shows that excessive radiation may lead to damage to the human hematopoietic system, immune system, reproductive system, digestive system, nervous system, etc., and even irreversible lesions and cancerous changes. Tea polyphenols are known as "radiation busters" by the modern health and medical community, which can effectively reduce the damage of radiation to the human body.
A large number of epidemiological and physical, internal and external experimental studies have confirmed that tea polyphenols have anti-radiation pharmacological effects. Existing research results show that tea polyphenols mainly achieve anti-radiation function by scavenging free radicals and regulating gene expression and protein synthesis.
In 1945, an atomic bomb killed more than 100,000 people in Hiroshima, Japan, and hundreds of thousands of people who suffered radiation damage fell ill with leukemia and various cancers several years later, and died one after another. There are three kinds of people who survive: tea farmers, tea merchants and tea lovers. In fact, there is only one kind of person, that is, tea lovers. It can be said that it is blessed by tea, and the world calls it the "Hiroshima phenomenon".
In 2011, a major earthquake occurred in Japan, triggering a series of explosions at the Fukushima Daiichi Nuclear Power Plant due to earthquakes and tsunamis. The Japanese have offered assistance to countries around the world, hoping that the world's major tea-producing countries (China, Kenya, India) will provide them with more tea assistance. The Department of Tea Science of Zhejiang University has donated 28 boxes of self-developed tea polyphenol products to all the staff of the Chinese Embassy in Japan, and received deep thanks from the Chinese Embassy in Japan and the Japanese.
▲ In 2011, the Department of Tea Science of Zhejiang University donated homemade tea polyphenol products to Japan
In 1998, the second international symposium on tea and human health held in Washington, D.C., on the anti-radiation report of tea pointed out that green tea and black tea have the effect of preventing skin cancer caused by p-rays, and pilots can drink tea drinks for 8 consecutive years to prevent a variety of radiation hazards in space.
In addition, according to biochemical and molecular biology scientists, polysaccharides in tea also have anti-radiation, anti-coagulation, anti-mutation and other physiological pharmacological effects, which is a good helper against radiation; at the same time, the purine alkaloids in vc and tea become effective free radical scavengers through appropriate transformation.
Tea polyphenols have so many functional effects that are beneficial to human health, why not develop the habit of drinking tea? Enjoy this fragrance in the hustle and bustle of life, relax your mood, and then meet the next challenge; second, it is also a long-term, potential protection of your body, so that you can better enjoy life.
Healthy living starts with a cup of tea.
Key References:
1. WAN Xiaochun. Tea Biochemistry (3rd Edition).Beijing:China Agriculture Press,2003,8-11.]
2.katiyar s, elmets c a, katiyar s k. green tea and skin cancer: photoimmunology, angiogenesis and dna repair. [j]. journal of nutritional biochemistry, 2007, 18(5):287-296.
3. Wei Zhiwen, Li Daxiang, Wan Xiaochun. A review of methods for the separation and preparation of catechin monomers. Food and Fermentation Industry,2008,34(1):141-146.]