After analysis and identification, there are about 500 compounds in green tea. Some of these compounds are essential ingredients for human body, which are called nutritional ingredients. Such as vitamins, protein, amino acids, lipids, sugars, mineral elements, etc., have high nutritional value for human body. There are also some compounds that have health care and medicinal effects on human body, which are called medicinal components. Such as tea polyphenols, caffeine and lipopolysaccharide.

The nutritional value of green tea is mainly reflected in:

1. Green tea can supplement various vitamins needed by human body.

Green tea contains many vitamins. Among them, water-soluble vitamins (including vitamin C and B vitamins) can be directly absorbed and utilized by the human body by drinking tea. Therefore, drinking green tea regularly is a good way to supplement water-soluble vitamins, which can supplement the body's needs for various vitamins, especially vitamin C.

Vitamin C, also known as ascorbic acid, can improve human resistance and immunity. The content of vitamin C in green tea is very high. Generally, the content of vitamin C per 100g of green tea can be as high as 10 mg ~ 250 mg, which is higher than that in lemon, citrus and other fruits. During the fermentation of black tea and oolong tea, the content of vitamin C decreased due to oxidative damage. Only a few tens of milligrams are left per100g of tea, especially black tea, with a lower content. Therefore, the higher the grade of green tea, the higher its nutritional value. Everyone can meet the daily requirement of vitamin C by drinking 10g of high-grade green tea every day.

2. Green tea can supplement protein and amino acids needed by human body.

The content of water-soluble protein in green tea which can be absorbed directly by drinking tea is about 2%. Green tea contains more than 25 kinds of amino acids, among which isoleucine, leucine, lysine, phenylalanine, threonine and valine are six of the eight essential amino acids. There is also histidine needed for the growth and development of babies. Although the content of these amino acids in green tea is not high, it can be used as a supplement to the lack of daily needs of human body.

3. Green tea can supplement the mineral elements needed by human body.

Green tea contains many elements and trace elements needed by human body. The main elements are phosphorus, calcium, potassium, sodium, magnesium and sulfur. Trace elements are mainly iron, manganese, zinc, selenium, copper, fluorine and iodine. For example, the zinc content in green tea is high, the average zinc content per gram of green strips is 73 micrograms, and the high zinc content is 252 micrograms; The average zinc content per gram of black tea is only 32 micrograms. The average content of iron in green tea is 123 micrograms per gram of dry bar. These elements play an important role in the physiological function of human body. Drinking green tea regularly is one of the important channels to obtain these mineral elements.

The health care function of green tea has been studied more extensively and professionally all over the world.

American researchers point out that blood vessels will harden after eating a high-fat diet. If you drink green tea at the same time or after meals, you can soften blood vessels and improve blood flow. Theanine and catechin contained in green tea can improve blood flow and prevent obesity, stroke and heart disease. The dissolution rate of theanine in green tea is closely related to water temperature and time. The experimental results show that theanine can be dissolved about 6 1% by soaking in cold boiled water at 5℃ for 30 minutes, and the effect is good. Soaking in 90℃ water for 65438 0 minutes, the dissolution rate was 39%; Soaking in cold boiled water at 5℃ for 24 hours only dissolves about 50%. Generally, the buds of green tea are rich in theanine, which is suitable for soaking in cold boiled water for about half an hour to make theanine dissolve out. Taking it regularly has a good effect on preventing obesity, stroke and heart disease. The old green tea leaves picked in the late growth stage have long Sun Long exposure time, low price and more catechins, and the dissolution rate of catechins increases with the increase of water temperature, so they are suitable for drinking with boiled water. Catechin has a strong anti-free radical effect, which is beneficial to the prevention and treatment of cancer. The research of Japan Vegetable Tea Industry Research Institute confirmed that green tea can not only prevent the formation and proliferation of cancer cells, but also inhibit the metastasis of cancer cells. Recently, Nagasaki University in Japan pointed out that when drinking green tea, adding apple slices or broken grains will produce an effective substance, which is more effective in preventing cancer and aging.