Tea, Tea bush, or Chinese Camellia (lat. Caméllia sinénsis) – a plant; a species of the genus Camellia of the Tea family (Theaceae).
Place of occurrence – tropical and subtropical mountain forests of Southeast Asia (Indochina). In the wild, a tea bush was discovered in Upper Assam and on Hainan Island.
Tea bush was first cultivated in China, from where it came to Japan. In 1824, the Dutch began to cultivate tea on the island of Java, and in 1834 the British – in the Himalayas. Currently, the main tea cultures are concentrated in China, India, Japan, Indonesia, Sri Lanka (in Ceylon), Africa (in Kenya and Natal), and in South America. In Europe, it grows under the open sky in Russia (Krasnodar Territory), in the Caucasus (Georgia, Azerbaijan), in southern England, Portugal, Sicily, western France.
Chinese camellia is an evergreen shrub or small tree up to 10 m or more tall (in the case of seed trees) with spaced branches.
The leaves are leathery alternating, oval or elongated-oval, narrowed to the apex, short-tailed to the apex, dark to the top, light green below, 5-7 long, 3.5-4 cm wide, in the young state slightly silver-pubescent. The edge of the leaf is serrated. In the pulp of the leaves there are branched supporting scleroids.
The flowers are fragrant, solitary or sit 2-4 in the axils of the leaves. Bracts and color beds are arranged in a spiral. Calyx has a leaf-leaf of five to seven sepals, almost round, remaining with the fruit; a corolla 2.5–3 cm across, falling after flowering, of five to nine white petals with a yellowish-pink hue, fused at the base of each other and a cup. Stamens in two circles: the outer ones grow together with stamens and grow to the petals, the inner ones are free; anthers are small, ovoid. Gynoecium cenocarpous, with columns fused to the middle.
The fruit is a flattened 3-5-fold ligneous capsule. Seeds are rounded, dark brown, 10-13 mm long, 1 mm thick.
It blooms from August to late autumn. Fruits in October – December.
Leaves contain 9–36% tannins, among them up to 26% soluble and up to 10% insoluble, resins, nucleoproteins containing iron and manganese. The composition of soluble tannins includes gallocatechin gallate, L-epiatechin gallate, L-epigallocatechin, L-gallocatechin gallate and L-epicatechin, free gallic acid and other substances. Alkaloids were also found in the leaves — caffeine (1.5–3.5%), theophylline, theobromine, xanthine, adenine, hypoxanthine, paraxanthin, methylxanthine, isatin, and other organic bases. Flavonoids were found – kempferol, 3-ramnoglycoside kempferol, quercetin, quercetrin, isocvercitrin, rutin, etc.
Stems, roots and seeds contain steroidal saponins.
The seeds contain 22-25% fatty oil, 30% hysteric starch – stigmasterol and β, γ-sitosterol, up to 8.5% protein. The leaves also contain coumarins, vitamins – ascorbic acid (more than 0.230%), thiamine, riboflavin, pyridoxine, phylloquinone, nicotinic and pantothenic acids, essential oil.
The composition of essential oil from fresh unfermented leaves (yield 0.007-0.014%) includes hexene-Z-ol-1 (66%), methyl alcohol, hexene-2-al-1, isobutyric and isovalerian aldehydes, acetic, propionic, butyric, n-caproic and palmitic acids, salicylic acid methyl ester.
Fermented green leaf oil (yield 0.003-0.006%) consists of β, γ-hexenol (25%), n-hexanol, methyl alcohol, n-octyl alcohol, geraniol, linalool, citranellol, benzyl, phenylethyl alcohol, secondary alcohols, butyl isobutyl and isovalerian aldehydes, hexene-2-ala-1, benzaldehyde, acetophenol, n-hydroxybenzalacetone, cresol, phenol, acetic, butyric, caproic, salicylic and phenylacetic acids and methyl salicylate.
Ingredients of black tea oil: citronallol, geraniol, linalool, secondary terpene alcohol, benzyl, phenylethyl, butyl, isobutyl, isoamyl, hexyl, octyl and 3-methylbutyl alcohols, aldehydes (caproic, isovalerianovyl, propanediol, benzalide, benzalide and palmitic acid, esters of these acids, cresols, quinoline, methyl mercaptan, methanesulfonic acid, 2-acetylpyrrole, methyl-, dimethyl-, trimethylamines, ethylamine, 1-propylamine, 2-propylamine, etc.
A significant part of the leaves and branches of tea cut off when caring for tea bush plantations (during molding), as well as tea dust generated in tea-packing factories, are used as raw materials for the factory production of caffeine and theophylline alkaloids. Caffeine is an important drug. It acts excitingly and tonic on the central nervous system, improves mental and physical activity, is a diuretic and a remedy for migraines. Theophylline is used as a means of improving coronary circulation, as a diuretic for circulatory disorders of cardiac and renal origin. Tea alkaloids are included in a number of drugs (aminophylline, diuretin, etc.) used for coronary insufficiency, hypertension, bronchial asthma, angina pectoris, edema of cardiac origin, etc. Currently, caffeine is obtained mainly synthetically.
In addition, a complex of catechins with P-vitamin activity is obtained from old tea leaves and tea dust, used for disorders of permeability and increased fragility of blood vessels, hemorrhagic diathesis, retinal hemorrhages, radiation therapy, hypertension, etc. Due to the presence of caffeine and tannins Tea drink and secreted alkaloid caffeine are used as an antidote for poisoning by poisons, narcotic substances and alcohol.