First, the main functions of green tea
1, anti-aging
Antioxidants contained in green tea help to fight aging. Because the metabolic process of human body, if oxidized, will produce a large number of free radicals, easy to aging, resulting in cell damage. SOD (Superoxide Dismutase) is a kind of free radical scavenger, which can effectively remove excess free radicals and prevent the harm of free radicals to human body. Catechins in green tea can significantly improve SOD activity and scavenge free radicals.
2, antibacterial
Studies have shown that catechins in green tea can inhibit some bacteria that cause human diseases without harming the proliferation of beneficial bacteria in the intestine, so green tea has the function of whole intestine.
3. Reduce blood lipids
Scientists' animal experiments show that catechins in tea can reduce total cholesterol, free cholesterol, low-density lipoprotein cholesterol and triglyceride in plasma, and at the same time increase high-density lipoprotein cholesterol. Human experiments show that it can inhibit platelet aggregation and reduce the incidence of arteriosclerosis. Green tea contains flavonol, which has antioxidant effect, prevents thrombosis and platelet aggregation, and reduces cardiovascular diseases.
Step 4 lose weight and fat
Green tea contains theophylline and caffeine, which can activate protein kinase and triglyceride lipolytic enzyme through multiple functions, reduce the accumulation of fat cells, and thus achieve the effect of losing weight.
5. Prevent dental caries
Green tea for removing bad breath contains fluorine, in which catechins can inhibit the action of cariogenic bacteria and reduce the occurrence of dental plaque and periodontitis. Tannic acid contained in tea has bactericidal effect, which can prevent food residues from breeding bacteria, so it can effectively prevent bad breath.
6. Cancer prevention
Green tea can inhibit some cancers, but its principle is limited to the inference stage. Drinking more tea is bound to have a positive encouraging effect on preventing cancer.
7, whitening and anti-ultraviolet function
Experts found in animal experiments that catechins in green tea can resist skin cancer caused by UV-B.
8, can improve indigestion.
Recent research reports show that green tea helps to improve indigestion, such as acute diarrhea caused by bacteria, which can be alleviated by drinking a little green tea.
Second, the types of green tea
Fried green tea
Stir-fried green tea: Due to the different mechanical or manual forces in the drying process, the finished tea forms different shapes such as long strip, round bead, flat fan, needle and spiral, so it is divided into long stir-fried, round stir-fried and flat stir-fried. Long-fried but refined, it is called eyebrow tea. The finished products have different colors, such as Zhenmei, Gong, Yucha, Needle Mei, Xiumei, etc., each with different quality characteristics. Ruzhenmei: The rope is tight and straight or looks like a lady's girl. The color is blue and cream, the aroma is high and fresh, the taste is strong and refreshing, and the soup color and leaf bottom are slightly yellow and bright; Gong Xi: This is a kind of round tea in long-fried green tea, which is called Gong Xi after refining. The shape particles are similar to bamboo tea, and the bottom of round leaves is tender and even; Rain tea: originally a long tea separated from pearl tea, now rain tea is mostly obtained from eyebrow tea, with short and tight shape, even green color, pure aroma, rich taste, yellow-green soup color and tender and even leaf bottom; Round fried green: Round and compact in appearance. Due to different producing areas and processing methods, it can be divided into flat fried green, Quangang Bai Hui and Yongxi Huo Qing. Flat fried green: produced in Shengxian, Xinchang, Shangyu and other counties in Zhejiang. Historically, coarse tea was refined in Pingshui Town, Shaoxing, and the finished tea was round and firm as pearls, so it was called "Pingshuizhu Tea" or "Pingshui Tea", while coarse Chaze was called Pingchao Tea. Fried green: due to different origin and preparation methods, it is mainly divided into Longjing, Qiqiang and Dafang. Longjing: produced in Xihu District, Hangzhou, also known as West Lake Longjing. Picking fresh leaves is exquisite, and the buds and leaves are required to bloom evenly. Senior Longjing is particularly fine in workmanship, with "green color and fragrant smell". Sweet taste and beautiful shape. Flag gun: produced in the surrounding area of Longjing tea area in Hangzhou and adjacent counties such as Yuhang, Fuyang and Xiaoshan. Dafang: produced in Shexian County, Anhui Province and adjacent areas of Lin 'an and Chun 'an, Zhejiang Province, with Laozhu Dafang being the most famous.
Hongqing green tea
Baking green tea: drying in a baking cage. Most of the roasted green tea, after reprocessing and refining, is used as the tea blank for smoking scented tea. The aroma is generally not as high as that of fried green tea, and a few fried green teas have excellent quality. According to its shape, it can also be divided into strip tea, pointed tea, slice tea and needle tea. Bar baking is produced in the main tea-producing areas in China; Pointed tea and flake tea are mainly produced in Anhui, Zhejiang and other provinces and cities. Among them, the characteristic green baking mainly includes Huangshan Mao Feng, Taiping Monkey Kui, Luan Guapian, Jingting Green Snow, Tianshan Green Tea and ancient Zhuzi bamboo shoots. Jiangshan Green Peony, Emei Mao Feng, Jinshui Cuifeng, Zhouxiabi Peak, Nannuo Bai Hao and so on. Such as Huangshan Mao Feng: produced in Nennen County, Huangshan, Anhui Province. The appearance is tender, smooth and slightly curly, the buds are fat and even, and the edges are sharp. Shaped like a "sparrow tongue", it is golden and shiny, commonly known as ivory. The aroma is fresh and long, the soup color is clear, the taste is mellow and fresh, and the leaves at the bottom of the leaves are blooming, rich and bright.
Sundried green tea
Sun-dried green tea: It is sun-dried. Mainly distributed in Hunan and Hubei. Guangdong. Guangxi, Sichuan, Yunnan and Guizhou provinces have a small amount of production. The quality of sun-cured green tea is the best in Yunnan, which is called "Dianqing". Others, such as Qing Chuan, Qian Qing, Guiqing and Eqing, have their own merits, but they are not as good as Yunnan.
Steamed green tea
Steamed green tea: Steam fixation is an ancient fixation method in China. During the Tang Dynasty, it spread to Japan until now. But in China, it changed to frying from the Ming Dynasty. Steamed green is the use of steam to destroy the enzyme activity in fresh leaves, forming the quality characteristics of' three green' with dark green color, light green tea soup and green tea bottom, but the aroma is stuffy green and the astringency is heavy, which is not as fresh and refreshing as pot-fried green tea. Due to the need of foreign trade, China has also produced a small amount of steamed green tea since the mid-1980s. The main varieties are Enshi Yulu, produced in Enshi, Hubei; China fried tea, produced in Zhejiang. Fujian and Anhui provinces.
Third, the best time to drink green tea.
Green tea contains catechins, β-carotene, vitamin C, vitamin E and so on. Many experiments have proved that green tea can scavenge free radicals, delay aging and prevent cancer. Drinking green tea regularly can prevent cell gene mutation, inhibit the growth of malignant tumors, lower blood lipid and blood pressure, prevent cardiovascular diseases, prevent colds and dental caries, and eliminate bad breath.
1, from the season, it is better to drink green tea in spring and summer. The hot weather in summer makes people consume a lot and sweat a lot, which easily leads to the increase of blood viscosity, fatigue and dizziness. High blood viscosity brings great load to the heart. Green tea is astringent and rich in amino acids, which can relieve summer heat and cool down. Chinese medicine believes that in summer, all qi and blood are transferred to the surface of the body, while the inside is empty. Not to mention tonic ointment, even if you eat more mutton, you can't absorb it. It's very easy to have diarrhea in summer. In fact, this is not only the relationship between eating more vegetables and fruits in summer and bacteria and viruses, but also the reason why the yang is rising and the inside is the weakest. That is to say, "the most virtual place must be the place where the disease is caused." Green tea is rich in catechins, which can sterilize and diminish inflammation and improve human immunity.
Considering the time of day, drinking tea one hour after a meal and two hours before going to bed can help digestion and replenish water. Don't drink tea before and after meals, because drinking tea immediately after meals can combine tannic acid in tea with iron in food to form insoluble iron salt, which reduces the absorption of iron. It is easy to induce anemia after a long time. One hour after a meal, the iron in the food has been basically absorbed, and drinking tea will not affect the absorption of iron. Don't drink tea before going to bed, it will affect sleep.
3, don't drink green tea on an empty stomach, drinking tea on an empty stomach will harm the body, especially for people who don't drink tea often, it will inhibit the secretion of gastric juice, hinder digestion, and seriously cause palpitations, headaches and other "tea drunk" phenomena. When drinking tea at night, put less tea and don't make the tea too strong.
Fourth, buy green tea.
The quality of green tea varies greatly, which can be identified according to its appearance, tea soup and leaf bottom.
1. Fresh green tea and old green tea
Fresh green tea looks bright green and shiny, and smells rich tea fragrance; Tea soup is green in color, with fragrance, orchid fragrance and ripe chestnut fragrance. The taste is sweet and refreshing, and the leaves are light green.
Old green tea has a dark yellow appearance and low aroma. For example, hot air blows on tea leaves, and the leaves are yellow and the smell is cold in wet places; Tea soup is dark yellow in color, mellow but not refreshing, and its leaves are yellow but not bright.
2. Spring tea, summer tea and autumn tea
The appearance of spring tea buds is thick and full, dark green and moist, and the strings are tight and heavy; The tea soup is rich in fragrance, mellow and refreshing, with rich aroma and soft and bright leaves.
Summer tea is thick and loose in shape, with mixed colors and distinct leaves and buds; Tea soup tastes astringent, leaves are hard, veins are exposed, and leaves are copper green.
The shape of autumn tea is tight, thin, silky, light and green; The brewed tea soup is elegant in color, mild in taste, slightly sweet, elegant in aroma, soft in leaf bottom and single in copper color.
3. Alpine green tea and flat green tea
Alpine green tea is thick green and shiny; The brewed tea soup has green color, lasting aroma, rich taste, bright bottom and soft leaves.
Flat green tea is thin, light, light and yellow-green; Tea soup is light in color, light in fragrance, mellow in taste, hard in leaves and dewy in veins.