by Emirhan Turan, 24 June, 2020
Camellia sinensis – Tea plant is a species of evergreen shrubs belonging to the flowering plant family Theaceae which leaf buds and leaves are used to produce tea.
White tea, yellow tea, green tea, oolong, dark tea, and black tea are all harvested from the same tea plant but are processed differently (varying levels of oxidation). Kukicha is also harvested from the tea plant, but harvested twigs and stems rather than leaves. Premium tea is the segment of high-quality tea, which is carefully cultivated and usually handpicked, in the end, this affects the quality.
Tea plants are native to East Asia and probably originated in the region of north Burma and southwest China.
‘’According to Chinese legend, the history of tea began in 2737 B.C.E. when the Emperor Shen Nong, a skilled ruler, and scientist, accidentally discovered tea. While boiling water in the garden, a leaf from an overhanging wild tea tree drifted into his pot. The Emperor enjoyed drinking the infused water so much that he was compelled to research the plant further. Legend has it that the Emperor discovered tea’s medicinal properties during his research in western China.’’
Nowadays, there are almost 1500 different varieties of tea hybridized from Chinese (Chinese small leaf tea) and Assam teas. Chinese small leaf tea is estimated to have diverged from Assam tea around 22,000 years ago, while Chinese Assam tea and Indian Assam tea diverged 2,800 years ago.
The tea plant is mainly grown in tropical and sub-tropical areas with at least 127 cm of rainfall a year. Tea plant prefers wet zones and from full to partial sun. As the tea plant grow more slowly and acquire more flavor, many high-quality teas are grown mainly at high elevations (hills and mountains).
‘’In Japan, ducks are put in the tea field to eat the weeds and pests. They also act as a natural source of fertilizer for soil production.’’
Tea is one of the most important non-alcoholic beverage drinks worldwide and gaining further popularity as an important ‘health drink’. It is served as morning drink for 2/3rd of the world population daily.
Chemical composition of Tea
The tea plant is reported to include more than 4000 bioactive compounds. Black tea has many more components than green tea, partly because of the oxidation processes that occur during fermentation. Further reactions take place when the dried finished tea leaves are extracted into the water, increasing the complexity of the chemical mix in a cup of tea. Also, further chemical changes occur when a cup of tea is left to stand. Tea plants are rich in the polyphenolic compounds based on the isoflavane structure (the simplest compounds in this class are the catechins); these make up some 30% of the dry weight of buds, immature leaves, and black tea leaf. The larger molecules include theaflavins and thearubigins, which are oxidation and polymerization products of isoflavonoids.
Theaflavins, found predominantly in black tea, contains tropolone. They combine with caffeine to form a substance known as ‘‘cream,’’ by that modulating the bitterness and sensation of the individual compounds and giving the tea its flavor. Leaf tea also contains small amounts of flavonols, such as quercetin, kaempferol, and myricetin.
Recent studies showed theaflavins are playing a role in anti‐SARS‐CoV‐2.
Health Benefits of Tea
The tea plant has shown to have a wide range of beneficial physiological and pharmacological effects. The most known effects include activation of leukocytes, antioxidant and antimutagenic activities, lowering of plasma cholesterol levels, and protection from the effects of radiation. Moreover, slowing the catabolism of catecholamines, strengthening capillaries, exerting an anti-inflammatory effect by enhancing the effectiveness of ascorbic acid, acting as an antioxidant, inhibiting the angiotensin-converting enzyme, having a hypo-cholesterolemic action, and inhibiting the growth of implanted malignant cells, anti-microbial effect.
Systematic researches found that extracts of tea inhibited and killed Staphylococcus aureus, Staphylococcus epidermidis, Salmonella typhi, Salmonella typhimurium, Salmonella enteritidis, Shigella flexneri, Shigella dysenteriae, and Vibrio spp., pathogenic protozoa, cariogenic streptococci, Clostridium spp. and phytopathogens such as Erwinia spp. and Pseudomonas spp., Mycoplasma pneumoniae, and Mycoplasma orale.
Medicinal Properties of Green tea plant extract:
Anti-Aging activity
Anti-Alzheimer activity
Anti-Parkinson activity
Anti-stroke activity
Protection against cardiovascular diseases
Anti-cancer activity
Antidiabetic activity
Anticaries activity
Obesity and Weight Loss
Skin Disorders
While black tea is made from Camellia sinensis plant as all other teas, the oxidation and processing are distinguishing black tea from the rest. Premium black teas are withered, rolled, oxidized, and fired in an oven to create a warm and toasty flavor. The lengthier oxidation process causes the tea leaves to develop into darker colors such as brown and black. The flavors can range from malty or smokey to fruity and sweet. Black teas range from mellow teas from China to full-bodied teas from Assam, India.
Black tea origins and brewery
Black tea origins
Tippy Teas: teas that includes a greater portion of tips (leaf buds). Tippy teas tend to be higher in caffeine, have a more delicate flavor and aroma, and be more expensive than typical teas. Some black tippy teas include Yunnan gold (China) and Golden monkey (China).
Plain Black Teas: teas made from a greater portion of large, mature leaves, lesser flavor, and aroma than tippy teas. Some plain black teas include Congous (China), Keemuns (China), and Lapsangs (China).
Indian Teas: teas varying from soft taste to strong taste depending on the location and cultivation. Some Indian teas include Darjeelings (golden amber color, light flowery flavor), First Flush, Second Flush, Tippy, Basic, or CTC.
Turkish Tea: tea that has been brought from Japan and cultivated from seeds. Red-colored, strongly aromatic, mildly sweet aroma, finely ground tea. Turkish tea includes Rize tea.
Sri Lanka (Ceylon) Teas: tea has a crisp aroma reminiscent of citrus and is used both unmixed and in blends. Ceylon teas include Special Low Grown, Middle Grown, High Grown, Dimbula, Nuwara Ellya, UVA.
Nepal Tea: tea that is like Darjeeling tea in its appearance, aroma, and fruity taste.
Iran Tea: tea that has a strong taste and nice aroma, becoming dark red color when brewed. Iran tea includes Lahijan.
Korean Tea: golden tea, light in color, and sweet taste. Korean tea includes Jaekseol.
Black Tea Brewing
Preheat your teapot with boiling water, raising the temperature of the teapot to at least 180° (All tea blends are giving better taste in different degrees).
Discard the water. Add 1 teaspoon of loose tea for each cup of tea you are brewing.
Pour fresh boiling water over the tea or tea bag. This super-saturates the tea, allowing the perfect extraction of the flavor.
Let the tea steep for at least 4-5 minutes.
Pour the tea through a strainer into the cups.
Turkish Black Tea Brewing
Fill half of the smaller (upper part) teapot with water. Add in tea leaves (2 tablespoons for 3 people) and cover with its lid.
Fill the large teapot with water (you can fill as much as you can but better more than half as it will be used for serving later). Put them together (small one above the larger) on the stove over medium-high heat. Leave it to boil.
Reduce the heat and let it sit for about 4-5 minutes so that the heat reaches the tea leaves in the small teapot.
The tea should be brewed until all tea leaves will be wet and sink by the end of this time. Then you can either leave teapot set on the stove over the lowest heat so that the tea keeps hot or remove from heat, serve, and reheat when needed.
Serve the tea in a traditional Turkish teacup with filling approximately half by half from each pot (this ratio you can adjust according to your taste, the more from the smaller pot the more the tea will be stronger).
‘’If you’re looking for a stronger cup of tea, it’s best to increase the number of tea leaves used instead of increasing the brewing time.’’
References
Hamilton-Miller, J. M. T. (2001). Anti-cariogenic properties of tea (Camellia sinensis). Journal of medical microbiology, 50(4), 299-302.
Lung, J., Lin, Y. S., Yang, Y. H., Chou, Y. L., Shu, L. H., Cheng, Y. C., … & Wu, C. Y. (2020). The potential chemical structure of anti‐SARS‐CoV‐2 RNA‐dependent RNA polymerase. Journal of Medical Virology, 92(6), 693-697.
Mondal, T. K., Bhattacharya, A., Laxmikumaran, M., & Ahuja, P. S. (2004). Recent advances of tea (Camellia sinensis) biotechnology. Plant Cell, Tissue and Organ Culture, 76(3), 195-254.
Namita, P., Mukesh, R., & Vijay, K. J. (2012). Camellia sinensis (green tea): A review. Global journal of pharmacology, 6(2), 52-59.
Perva-Uzunalić, A., Škerget, M., Knez, Ž., Weinreich, B., Otto, F., & Grüner, S. (2006). Extraction of active ingredients from green tea (Camellia sinensis): Extraction efficiency of major catechins and caffeine. Food chemistry, 96(4), 597-605.
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