Introduction of Green Tea:green tea leaves and its uses.
✵The article gives records of the herb Green Tea, its English name, Latin name, common names, property and flavor, its botanical source one plant species, ①.Camellia sinensis(L.,)Kuntze., with a detailed introduction to the botanical features of this plant species, the growth characteristics, and ecological environment of this plant species, the features of the herb Green Tea, its pharmacological actions, medicinal efficacy, and administration guide.
Green Tea(Green tea leaves).
English Name: Tea, Green.
Latin Name: Camellia sinensis(L.)Kuntze.
Common Names: Tea, Green Tea, West-lake Longjing Tea, Biluochun Tea, etc.
Property and flavor: cool, tastes bitter and sweet.
Brief introduction: Green tea is a drink made from the new leaves or buds of the tea tree, unfermented, and processed by fixing, rolling, shaping, drying, and other processes. It is one of the main tea types in China. Green tea retains the natural substances of fresh leaves and contains tea polyphenols, catechins, chlorophyll, and other nutrients.
The famous varieties include Biluochun and West-Lake Longjing. Its green color and tea soup preserve the green flavor of fresh tea leaves. Green tea is non-fermented tea, because of its characteristics, it reserves more of the natural substances in the fresh leaves. Among them, tea polyphenols and caffeine retain over 85% of fresh leaves, and chlorophyll retains about 50%, the loss of vitamins is less too, forming the characteristics of green tea as "clear soup with green leaves, strong astringency in taste".
Botanical source: Common herbal classics defined the herb green tea as the processed leaves of the species (1). Camellia sinensis(L.,)Kuntze. It is a plant species of the Camellia genus, the Theaceae family (Ternstroemiaceae, tea family). The harvested very young downy leaves are processed. This commonly used species is introduced:
(1).Camellia sinensis(L.,)Kuntze.
Botanical description: Camellia sinensis is an evergreen heavily branched shrub or small tree, twigs are glabrous. Leaves are leathery, 4~12 cm long, 2~5 cm wide, leaves are glossy dark green, alternate, short-petiolate, coreacious, oblong or elliptic, and roughly serrate, the apex is obtuse or sharp, the base is cuneate, shiny at the upper part, glabrous or initially pilose at the lower part, lateral veins 5~7 pairs, the margin is serrated, petioles are 3~8 mm long, glabrous. The young leaves appear silver because of the covering of downy hairs on the surface.
Flowers are 1~3 axillary, white, the peduncle is 4~6 mm long, sometimes slightly longer, grow short-pedicled and singly or in clusters of a few flowers in the leaf axils, flowers are white or pale pink and have a diameter of 3 to 5 cm; bracts 2, caducous; sepals 5, broadly ovate to round, 3~4 mm long, glabrous, persistent; petals 5~6, broadly ovate, 1~1.6 cm long, slightly conjoined at the base, glabrous on the back, sometimes pubescent; stamens are 8~13 mm long, 1~2 mm long at the base; ovary has densely white hairs, the ovary has 3 chambers; style is glabrous, the apex is 3-lobed, lobes are 2~4 mm long.
Capsularfruit is greenish-brown, 3-spherical or 1~2 spherical, 1.1~1.5 cm high, each with 1~3 smooth brown seeds. The flowering period is from October to February of the following year.
Ecological environment: Wild species of Camellia sinensis are widely found in the mountainous areas of the provinces south of the Yangtze River in China. They are small trees with large leaves, often more than 10 cm long. For a long time, after extensive cultivation, the coat and leaf shape varies greatly. Green tea tree has been introduced from China to other areas of the world for cultivation.
Growth characteristics: Camellia sinensis prefers a warm and humid climate, and is resistant to drought, cold, waterlogging, and salinity. The annual average temperature in the suitable cultivation area is between 15~25 °C (Celsius, or 59~77 degrees Fahrenheit), the effective accumulated temperature (above 10 °C) is above 3500 °C; the annual rainfall is 1,000~2,000 mm. The tea tree can withstand -6~8 °C (Celsius, or 21.2~46.4 degrees Fahrenheit), and it can survive the winter when the temperature reaches -30 °C (Celsius, or -22 degrees Fahrenheit) in a short time, and its growth is inhibited at about 35 °C (Celsius, or 95 degrees Fahrenheit). The absolute maximum temperature is 45 °C (Celsius, or 113 degrees Fahrenheit). Although tea trees can tolerate shade, high-quality leaves must be cultivated in full light. Yellow soil, red-yellow soil, and red soil with pH (pH scale:acidity-basicity) 4.5~5 are suitable for cultivation in mountains, hills, and flat land; it is not suitable for planting in near-neutral or alkaline soil.
Harvest of Green Tea: The leaves can be harvested after 3 years of cultivation. Spring tea and summer tea are picked from April to June. For harvesting specimens, various teas have different requirements for fresh leaves. Generally, red and green tea picking specimens are 1 bud and 1~2 leaves; crude old tea can have 1 bud and 4~5 leaves. The processing methods vary according to the type of tea and can be divided into three categories: full fermentation, semi-fermentation, and non-fermentation. Green tea, after picking fresh leaves, is made by fixing, rolling, and drying. Green tea is processed and smoked with fragrant flowers to make a scented tea.
Oxidation does not occur with green tea because the steaming process inactivates the enzymes responsible for oxidation. The antioxidant activity of Green Tea is six times greater than that of Black Tea.
Characters of herbs: The leaves are often rolled into strips or flaked or wrinkled. After the complete leaf is flattened, the leaf is needle-shaped to oblong, 1.5~4 cm long, 0.5~1.5 cm wide, the apex is sharp or obtuse, the leaf base is wedge-shaped and descends, the edge is serrated, and the tooth tip is brown-red claw-like, sometimes shedding; both upper and lower surfaces are pubescent; pinnate reticulated veins, 4~10 pairs of lateral veins, the main vein is more prominent on the lower surface, papery and thick, petioles are short, covered with white pubescence; old leaves are leathery, larger, nearly smooth; the odor is weak and fragrant, and the taste is bitter and puckery.
Green tea help to prevent certain types of cancer, the East area where green tea is a very popular drink has a lower cancer rate than many other parts of the world. A high intake of green tea was linked to a decreased risk of developing polyp-like growths in the lower colon, some of which can be pre-cancerous. Green tea is an antioxidant, it helps to control the formation of free radicals, free radicals are dangerous substances in the body that damage cells through oxidation, and some free radicals contribute to cancer cell formation. Studies found green tea consumption has been shown to prevent or lower the risk of various types of cancer, including cancers of the pancreas, small intestine, breast, and lung, and digestive tract cancers (esophagus, stomach, colon, and rectal), green tea appeared to block the smoking-induced increase in sister chromatid exchange. Studies attribute its anti-cancer actions to the presence of its polyphenols and flavonoids.
The consumption of large amounts of green tea, nine or more cups a day, decreased total cholesterol levels, but green tea do not lower triglyceride levels or raise levels of the high-density lipoprotein cholesterol.
Green tea consumption has resulted in relatively lower levels of ferritin and lipid peroxides in the blood, so it helps to prevent atherosclerosis and liver ailments.
Green tea has a central nervous system stimulant effect as it contains caffeine, its tannin substance has some astringent effect and helps control some types of diarrhea, and constricts skin tissues when used topically, its components tannins and fluoride help prevent tooth decay, but tea can also stain teeth.
Anticaries activity: green tea ethylacetate extracts are potent inhibitors of cavity-associated bacteria such as Escherichia coli, Streptococcus salivirus, and Streptococcus mutans, with weak inhibitory activity on the growth of Proteus rettgeri and Proteus mirabilis bacteria, is a weak inhibitor of salivary amylase due to tannins in the tea, green tea polyphenols inhibit the growth of Porphyromonas gingivalis and its adherence to oral epithelial cells.
Anti-inflammatory effect: green tea extract epigallocatechin gallate significantly inhibited neutrophil adhesion to and migration through endothelial cell monolayers in a dose-dependent manner. Neutrophils play an important part in the inflammatory process. By adhering to the vascular endothelium and migrating into the tissue, invading microorganisms such as bacteria are eliminated.
Antioxidant effects: Green tea polyphenols and the specific catechins in Green tea polyphenols, catechin, and epicatechin inhibit LDL oxidation (Low Density Lipoprotein oxidation). This activity may help to prevent the development of cardiovascular pathologies, such as atherosclerosis. Epigallocatechin-3-gallate (EGCG) was effective at inhibiting ultraviolet B exposure and preventing ultraviolet-induced skin damage that correlated with reduced lipid peroxidation.
Hepatoprotective effects: different fractions of green tea had relatively strong effects on D-Galactosamine-induced liver injury.
Inhibition of Xanthine Oxidase: green tea polyphenols showed levels of inhibition of the enzyme xanthine oxidase.
Trials of green tea have been down mainly for its antioxidant activity, cancer treatment and prevention, colitis, dental caries prevention, type 2 diabetes, genital warts, heart disease, hypercholesterolemia, obesity, and skin protection.
Medicinal efficacy: Green tea is a popular beverage in Asia and other parts of the world, most people drink it as a mild stimulant, and contemporary herbalists paid attention to green tea's antioxidant and anti-cancer properties, and its function to promote weight loss, prevent tooth decay, lower cholesterol levels, and high blood pressure, green tea extract is used to promote heart function and relieve peptic ulcer pain. In folk medicine, green tea is used for stomach disorders, migraine, symptoms of fatigue, vomiting and diarrhea when taken as a beverage, it is likely to be useful as a cancer preventive and as a preventive for dental caries.
TCM works recorded the herb's functions to clear the head and eyes, eliminate polydipsia, aid digestion, reduce phlegm, prompt diuresis, and detoxification. Indicated for headache, blurred vision, hot eyes, much sleep and easy to asleep, cold, vexation and thirst, dyspepsia and indigestion, halitosis or bad breath, asthma due to excessive phlegm, Epilepsia, dysuria or difficulty in micturition, diarrhea and dysentery, larynx swelling, sore and ulcer, furuncle, scald due to hot liquid or fire, etc.
Administration of Green Tea (Green tea leaves):
Reference:
Administration Guide of Green Tea (Green tea leaves)
Herbal classic books and TCM Books:
Dosage: A common daily dosage of green tea polyphenols is 50~100 mg. A cup of brewed tea contains approximately 20~30 mg of polyphenols. To prepare a tea, boiling water is poured over a heaped teaspoon of leaf tea, a level teaspoon of crushed leaves, or a tea bag and left to steep for 3 to 10 minutes are required. The caffeine is almost completely drawn after approximately 3 minutes, the tannin-containing substance (and with it the antidiarrheal action) increases when the tea is left to brew. TCM works recommended green tea internally as water decoction, 3~10 grams, or prepare to pill, powder, etc. Externally proper amount, ground to powder and apply a coating, or mashed the fresh leaves and apply a coating. Green tea should be stored tightly sealed and dried, store separately from other chemicals and aromatic substances.
Contraindications, Precautions and Adverse Reactions: People around the world drink green tea every day has no apparent ill effect. But excessive doses or those individuals who are very sensitive to caffeine may experience unwanted effects such as anxiety, restlessness, tremors, irritability, elevated reflex excitability, and trouble sleeping. The first signs of poisoning are vomiting and abdominal spasms, fatal poisonings are not possible with tea beverages. Steeping the leaves for relatively short periods of time can lower these unwanted effects. Individuals who suffer from insomnia should avoid using the herb.
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1.Introduction of Green Tea:green tea leaves and its uses.