đź“’Contents
1、What is green tea
2、How to make green tea
3、The production process of green tea
4、Cautions for drinking green tea
5、Quality identification of green tea
6、How to preserve green tea
7、Efficacy and effects of green tea
8、Can pregnant women drink green tea?
9、The benefits and disadvantages of drinking green tea
What is green tea
Green tea is a product made from the new leaves or buds of tea trees, unfermented, by the typical process of killing, or shaping, drying and so on. The color of its finished product, the tea soup after brewing preserves more of the green main tone of the fresh tea leaves. Regular consumption of green tea can prevent cancer, lower blood lipids and weight loss. Smokers can reduce nicotine damage.
Green tea is unfermented tea, so it retains more of the natural substances of the fresh leaves and contains more nutrients such as polyphenols, catechins, chlorophyll, caffeine, amino acids and vitamins. These natural nutrients in green tea have special effects on anti-aging, cancer prevention, anti-cancer, sterilization, anti-inflammatory, etc., which are not available in other teas. Green tea is a tea made from the new tops of suitable tea trees, through the typical process of killing, kneading and drying. Its dry tea color and brewed tea soup and leaf base are green in tone, hence the name green tea. Green tea is made by killing the fresh picked leaves at high temperature to kill all kinds of oxidizing enzymes and keep the green color of tea leaves, and then it is made by kneading and drying.
Green tea brewing method
The correct way to brew green tea for drinking can make it taste better and more healthy to drink. There are certain instructions for brewing tea, especially the water temperature.
General green tea brewing methods and precautions：
- When brewing green tea, the water temperature is controlled at about 80 ℃ to 90 ℃. If you are brewing green tea powder, you can brew it with lukewarm water at 40℃~60℃. The serving size is 2 grams of green tea powder with 450 ml of plain water.
- Don't drink the first brew of tea, just shake it after brewing hot water and pour it away.
- Green tea powder should not be brewed too strong, otherwise it will affect the secretion of gastric juice, and it is best not to drink on an empty stomach.
The production process of green tea
1. Killing
Killing plays a decisive role in the quality of green tea. Through high temperature, it destroys the characteristics of enzymes in the fresh leaves and stops the oxidation of polyphenols to prevent the leaves from turning red; at the same time, it evaporates part of the water inside the leaves to make the leaves soft and create conditions for kneading and shaping. With the evaporation of water, the low boiling point aromatic substances in the fresh leaves with green grass smell evaporate and disappear, thus improving the aroma of tea leaves.
2. Kneading
Kneading is the process of shaping the shape of green tea. By using external force, the leaves are broken and lightened, rolled into strips, reduced in volume, and easy to brew. At the same time, some of the tea juice is squeezed and attached to the surface of the leaves, which also plays an important role in improving the flavor concentration of tea. The kneading process of green tea is divided into cold kneading and hot kneading. The so-called cold kneading is to knead the green leaves after cooling; hot kneading is to knead the green leaves while they are hot without cooling. Young leaves should be cold kneaded to maintain the bright yellow-green color of the soup on the bottom of the young green leaves, while old leaves should be hot kneaded to facilitate the tightening of the ropes and reduce the shreds.
3. Drying
The purpose of drying is to evaporate the water, and to tidy up the shape and give full play to the aroma of tea. There are three drying methods, namely drying, frying and sun-drying. The drying process of green tea is generally done by drying first and then by frying. Because the tea leaves after kneading, the water content is still very high, if directly fried, will soon form a lump in the pot of the frying dryer, the tea juice is easy to bond the pot wall. Therefore, the tea leaves are dried first, so that the water content is reduced to meet the requirements of the wok frying.
Precautions for drinking green tea
In green tea, it is mainly a substance called tea polyphenol that plays a role in skin care and beauty. This substance has an antioxidant effect, and together with vitamins B and E, it can play a role in hydrating and firming the skin. However, it should be noted that tea polyphenols, as a general term for phenolic substances or their derivatives, are easily volatilized in the air and lose their antioxidant effect, so such skin care products, especially face masks, to the best new tea products for the year.
Green tea contains a certain amount of caffeine, and when coexisting with tea polyphenols, it can stop the effect of caffeine in the stomach and avoid stimulating the secretion of gastric acid, so that the disadvantages of caffeine do not play in the body, but promote the function of the central nervous system, heart and liver. The aromatic compounds in green tea can also dissolve fat and prevent fat accumulation in the body, caffeine can also promote gastric secretion, help digestion and fat elimination, but women in the period is best not to drink more. Because green tea contains more tannic acid, will combine with the iron molecules in food, forming a large number of precipitates, preventing the absorption of iron molecules in the intestinal mucosa. The stronger the green tea, the greater the impediment to the absorption of iron, especially after meals, drinking tea is more obvious. Therefore, women and people suffering from anemia, even in normal times, it is best to drink less strong tea.
Green tea quality identification
Shape: including the thickness, length, weight, size, and tightness of the tea leaves, the whole and even, and clean, whether there are inclusions and adulteration, whether there are old and hard leaves, as well as the lower plate, the degree of dryness and wetness, and the weight of the bones. The shape of green tea varies with the type of tea, such as eyebrow tea with tight and thin ropes shaped like fish fishing is the top, the bending part of the third is appropriate, the upper tip of the lower blunt, the body bone is heavy, the lower plate is less, the ropes are uniform, clean and no inclusions and old leaves hard piece of the top. Longjing is flat and straight, the tip is not bent, the body and bones are fine and tender. Mao Feng is the top one with long and slender and slightly bent tips. Japanese yulu is as long and thin as a needle, and not bent for the top. Pearl tea is round like a pearl, and very small as the top. From the shape aspect, the origin of the tea can be identified. From the origin of the top, such as Huangshan Mao Feng, Lion Peak Longjing, Liu An Gua Piece, are extremely valuable. However, the shape alone cannot absolutely determine the correctness of the origin, but must also look at the quality of the fragrance, so as not to be wrong.
Color and luster: including the depth of the tea color, withered, fresh and dark, uniform, and whether there is an incorrect color, poor color, etc. The color of green tea also varies with the type of tea, such as eyebrow tea pearl tea Hui Bai are grayish white green as the top. Mao Feng is dark green and slightly brown for the top, Longjing Yulu Gua slices are emerald green for the top. In short, the color shall be deep and fresh, moist and uniform for the top. Dark and withered, shallow and uneven, or even have not the right color, poor color, blistered, with spots, are inferior. Particular attention should be paid to the bending part of the tea strip must also be uniform and moderate, in order to be of the highest quality. Identification of shape and color, the tea must be mixed evenly, up and down more, and make the light respectively before and after itself to compare the two plates of tea leaves, but also must always exchange its position to compare the.
Aroma: including high and low, clear and cloudy, pure and sharp and dull, and the presence or absence of grass, smoke and sour smell, etc. The aroma of green tea also varies with the place of origin and tea type, such as green tea exported with kettle fragrance, Longjing with special clear fragrance, Mao Feng with chestnut fragrance, Gua Qian with thick and pure fragrance, and Yu Lu with special overlapping fragrance. In short, green tea aroma to high and clear, pure and sharp as the top. Aroma low and turbid, blunt and mixed, or even grass smoke smell sour mold smell, are inferior. There are two kinds of aroma identification methods: dry aroma and wet aroma.
Taste: including sweetness and, strength, clarity, mellowness, astringency, bitterness, fire, and the presence of bad odors such as bad sour rot, burnt smoke and mildew. The taste of green tea is also like the aroma, which varies with the origin and tea type. Generally speaking, are sweet and clear, thick and mellow for the top. The taste is thin, and bitter and stimulating are not the best. Some green tea? Although slightly bitter and astringent? But also must be bitter and sweet side of the good, its grass smoke smell sour moldy coke taste. Or bitter heavy numb tongue stinging throat, are not the best. Identification of the taste, tea soup inlet not too much, tea soup in the mouth, must be turned from time to time, so that the circumference of the tongue up and down left and right before and after. Cover the tip of the tongue to feel sweet and spicy, the tongue lack of acidity on both sides, the root of the tongue to feel bitter, the whole tongue to feel salty, must reach the whole tongue, can be separated from all the taste of tea.
Water color: including the intensity, clarity, freshness and darkness, and the presence of free matter and sediment. Regardless of any green tea, are green and clear and distinct, and the water color is thick for the top. Yellow turbid light dark, or free matter sediment, are not good. But sometimes to meet the needs of consumers, the water color to yellow and not green, it is another story. Identification of the water color, the cup must be slightly tilted from time to time, pay attention to its free matter and so on.
Leaf base: including bright dark color, uniformity, leaf buds are rough and tender, curled or unfolded? And whether there are broken, scorched, green, black, fake, stale leaves, and bronze, purple, yellow-brown and other improper colors. In short, for any green tea, the bottom of the leaves should be turquoise, the leaf buds should be tender and even, the color should be sharp and the leaves should be unfolded. The bottom of the leaves are dark and sluggish, old and tender, broken, curled, astringent and non-fuzzy, or mixed with green and black pieces, or there is no correct color, withered and not moistened with blistering, are inferior.
Green tea preservation methods
A, lime block preservation method.
Lime block in a bag made of white fine cloth. Green tea into a white cotton paper bag, outer kraft paper bag, then the small mouth of the pottery altar washed and dried, under the pad of white paper, the green tea tea bags placed in the small mouth of the pottery altar, embedded in the middle of one or two lime bags. Seal the mouth of the altar with several layers of grass, and finally compacted with bricks or thick wooden plates to reduce the amount of air exchange. Thereafter, the preservation should be checked frequently, and the lime should be replaced in time after the dampness.
Second, carbon storage method.
The operation method is basically the same as the lime block preservation method. The materials used, however, is to use the charcoal after burning out, tea utensils can be replaced by tile cans or small mouth tin barrels. Charcoal bag and green tea tea bag capacity can be increased or decreased depending on the size of the container.
Third, green tea refrigeration method.
The tea leaves will be dried water vapor, water content between 3-5%, not more than 6%. Green tea tea into aluminum-plated composite bags, heat sealing, with breathing extractor to extract the air in the bag, while flushing nitrogen, plus sealing on the sealing paste, placed in the tea box, and then sent to the low-temperature refrigerated storage. This method is the best tea preservation method under the current technological level. Preservation quantity is large and long.
Green Tea Efficacy and Effects
1. Anti-aging
Help delay aging, tea polyphenols have a strong antioxidant and physiological activity, is the human body free radical scavenger. Studies have shown that 1 mg of tea polyphenols to remove excess free radicals harmful to human muscles equivalent to 9 micrograms of superoxide dismutase, much higher than other similar substances. Tea polyphenols have blocked lipid peroxidation reaction, scavenging the role of active enzymes. According to the results of the Japanese Takuyasu Okuda test, confirmed that the anti-aging effect of tea polyphenols is 18 times stronger than vitamin E.
2. Inhibit disease
Help inhibit cardiovascular disease tea polyphenols on human fat metabolism has an important role. Human cholesterol, triglycerides and other high levels, fatty deposits in the inner walls of blood vessels, vascular smooth muscle cell proliferation after the formation of atherosclerotic plaques and other cardiovascular diseases. Tea polyphenols, especially tea polyphenols in the catechin ECG and EGC and its oxidation products such as theaflavin, helps to make this plaque proliferation is inhibited, so that the formation of blood clotting viscosity enhanced fibrinogen is reduced, clotting becomes clear, thereby inhibiting atherosclerosis.
3. Anti-carcinogenic
Helps prevent and fight against cancer Tea polyphenols can block the synthesis of many carcinogenic substances in the body, such as ammonium nitrite, and has the effect of directly killing cancer cells and improve the immune system. According to relevant information, tea polyphenols in tea are beneficial to the prevention and adjuvant treatment of stomach cancer, intestinal cancer and many other cancers.
4. Radiation protection
Help prevent and treat radiation damage tea polyphenols and their oxidation products have the ability to absorb radioactive substances strontium 90 and cobalt 60 poisoning. According to the relevant medical departments clinical trials have confirmed that the tumor patients in the course of radiation therapy caused by mild radiation sickness, treatment with tea extract, the efficiency of up to 90% or more; for hemocytopenia, the efficiency of tea extract treatment reached 81.7%; for radiation caused by the treatment of leukopenia better.
5. Beauty and skin care
Helps in beauty and skin care Tea polyphenols are water-soluble substances, washing the face with it can remove facial grease, astringent pores, disinfection, sterilization, anti-skin aging, reduce the sun's ultraviolet radiation damage to the skin and other effects.
6. wake up the brain and refreshing
The caffeine in tea can stimulate the central nervous system and enhance the excitement process of the cerebral cortex, which can help to refresh the mind and clear the heart. It is also effective in relieving migraine headaches.
7. Diuretic relief
The caffeine in tea can stimulate the kidneys, prompt the rapid discharge of urine, increase the filtration rate of the kidneys and reduce the retention time of harmful substances in the kidneys. Caffeine can also eliminate excessive lactic acid in urine, which helps the body eliminate fatigue as soon as possible.
Can pregnant women drink green tea
Pregnancy Risk specifically reminds that pregnant women should try to avoid excessive consumption of green tea during pregnancy, and any tea drink during pregnancy should be consumed in moderation, otherwise it is likely to increase the risk of pregnancy. This is because green tea contains large amounts of caffeine, catechins and tannins, all of which can threaten the health and growth of the pregnant woman and her fetus. Researchers have found that excessive intake of green tea can cause neural tube defects in babies, so it is best for pregnant women to drink less green tea and other varieties of tea during pregnancy.
Benefits and Disadvantages of Drinking Green Tea
The benefits of drinking green tea
It also contains more nutrients such as tea polyphenols, catechins, chlorophyll, caffeine, amino acids, and vitamins. These natural nutrients in green tea have special effects on anti-aging, cancer prevention, anti-cancer, sterilization, anti-inflammatory, etc., which are not as good as other teas.
Drinking green tea side effects
1, caffeine green tea will have side effects, mostly because of the caffeine contained in the composition, this ingredient is very detrimental to human health. After a lot of research found that each cup of green tea contains nearly 40 mg of caffeine, so if a large number of continuous drinking will lead to nervous excitement. In the role of caffeine green tea can play a very good refreshing effect, but if you do not pay attention to control then it will seriously damage the nerve health, but also may lead to sleep instability and insomnia at night.
2, anemia many times, leading to anemia there is another reason, that is, excessive consumption of green tea, I believe this is difficult for many people to imagine. Experts remind, in ordinary life should be moderate to drink less green tea, otherwise it is likely to affect the body's absorption and utilization of iron, and therefore lead to the symptoms of iron deficiency anemia. Iron is a very important raw material for hematopoiesis, and it is also the main substance to promote the production of red blood cells, if the body is deficient in iron, it will lead to a shortage of red blood cells, and therefore lead to anemia.
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