White tea

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White Bai Hao Yinzhen tea leaves.

White tea (Chinese: 白茶; pinyin: báichá) is a lightly oxidized tea grown and harvested primarily in China, mostly in the Fujian province.[1] More recently it is grown in Taiwan, Northern Thailand and Eastern Nepal.

White tea comes from the buds and leaves of the Chinese Camellia sinensis plant. The leaves and buds are allowed to wither in natural sunlight before they are lightly processed to prevent oxidation or further tea processing.

The name "white tea" derives from the fine silvery-white hairs on the unopened buds of the tea plant, which gives the plant a whitish appearance.[2] The beverage itself is not white or colourless but pale yellow.

History

Scholars and tea merchants generally disagree as to when the first production of white tea (as it is understood in China today) began. What is today known as white tea may have come into creation in the last two centuries. White tea may have first appeared in English publication in 1876, where it is categorized as a black tea because it is not initially cooked like a green tea, to deactivate internal enzymes and external microbes.[3]

White tea is often being sold as Silvery Tip Pekoe, a form of its traditional name, and now also under the simple designations China White and Fujian White.[1]

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Contents

Because white tea is derived from the Camellia sinensis plant, it contains polyphenols, a phytonutrient that is thought to be responsible for the tea’s health benefits.[4]

Catechins

White tea contains high levels of catechins, some of which reduce the occurrence of atherosclerotic plaques[5] and the severity of strokes[6] and prevent cancer[7] in non-human studies.

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Manufacturing

The base process for manufacturing white tea is as follows:

Fresh tea leaf → Withering → Drying (air drying, solar drying or mechanical drying) → White tea[8]

White tea belongs to the group of tea that does not require panning, rolling or shaking. However, the selection of raw material in white tea manufacture is extremely stringent; only the plucking of young tea leaves with much fine hair can produce good-quality white tea with lots of pekoe.[8]

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Health

Main article: Health effects of tea
The visible white hairs are a unique characteristic of the Bai Hao Yinzhen tea

Like black and green tea, white tea is also derived from Camellia sinensis. Thus, white tea shares many of the same chemical properties and health effects of tea. However, white tea contains the most antioxidants. The particular amount and ratio of the polyphenol compounds found in tea varies widely from one type of white tea to another, frequently overlapping with chemical compositions found in green tea. This is due both to the variation between strain of Camellia sinensis, as well as the preparation process itself.[9] These compounds have been shown to protect against certain types of cancer both in vitro and in vivo.[10]

Improved cardiovascular function

Catechins, a group of polyphenol antioxidants found in white tea, have been found to reduce cholesterol, decrease blood pressure, and improve the function of blood vessels, thereby decreasing the risk of cardiovascular disease.[11]

Antibacterial and antiviral action

White tea has been shown to protect animals from certain pathogenic bacteria, such as Salmonella tryphimurium.[12]

Studies

A 2004 study at Pace University [13] revealed that white tea extract may help slow viruses and bacterial growth, thus reducing the incidence of staphylococcus and streptococcus infections, pneumonia, fungus growth, and even dental plaque.

Findings from another study[specify] conducted at the Skin Study Center at University Hospitals of Cleveland and Case Western Reserve University reveal indicators that white tea helps skin cells by boosting immune systems when exposed to harmful ultra-violet radiation.

An article published in the Carcinogenesis journal by scientists from the Linus Pauling Institute at Oregon State University[specify] found that consumption of moderate amounts of white or green tea may hedge against colon tumors consistent with the prescription drug, sulindac. When used in combination with the drug, the results were more effective.

A study at Kingston University in 2009 showed that white tea has high anti-inflammatory, antioxidant, anti-collagenase, and anti-elastase properties which could potentially reduce the risks of developing rheumatoid arthritis, some cancers, heart disease and slow the enzymatic break-down of elastin and collagen, traits which accompany aging.[14][15]

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See also

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Notes

  1. ^ a b Chow 1990, p. 142
  2. ^ Rau 2004, p. 129
  3. ^ Hanson 1878, p. 46
  4. ^ Dulloo, A. G.; Seydoux, J.; Girardier, L.; Chantre, P.; Vandermander, J. (2000). "Green tea and thermogenesis: Interactions between catechin-polyphenols, caffeine and sympathetic activity". International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity 24 (2): 252–258. PMID 10702779.  edit
  5. ^ Miura, Y.; Chiba, T.; Tomita, I.; Koizumi, H.; Miura, S.; Umegaki, K.; Hara, Y.; Ikeda, M. et al. (2001). "Tea catechins prevent the development of atherosclerosis in apoprotein E-deficient mice". The Journal of nutrition 131 (1): 27–32. PMID 11208934.   edit
  6. ^ Arab, L.; Liebeskind, D. S. (2010). "Tea, flavonoids and stroke in man and mouse". Archives of Biochemistry and Biophysics 501 (1): 31–36. doi:10.1016/j.abb.2010.03.015. PMID 20361928.  edit
  7. ^ Hsu, C. P.; Shih, Y. T.; Lin, B. R.; Chiu, C. F.; Lin, C. C. (2012). "Inhibitory Effect and Mechanisms of an Anthocyanins- and Anthocyanidins-rich Extract from Purple-shoot Tea on Colorectal Carcinoma Cell Proliferation". Journal of Agricultural and Food Chemistry 60 (14): 120311103931001. doi:10.1021/jf204619n. PMID 22404116.  edit
  8. ^ a b Hui 2004, p. 961
  9. ^ Kennelly, E. J., Unachukwu, U. J.; Ahmed, S., Kavalier, A., Lyles, J. T. (2010). "White and green teas (Camellia sinensis var. sinensis): variation in phenolic, methylxanthine, and antioxidant profiles.". Journal of Food Science 75: C541–C548. PMID 20722909. 
  10. ^ Serio, K. J., Mao, J. T.; Nie, W. X., Tsu, I. H., Jin Y. S., Rao, J. Y., Lu, Q. Y., Zhang, Z. F., Go, V. L. (2010). "White tea extract induces apoptosis in non-small cell lung cancer cells: the role of peroxisome proliferator-activated receptor-{gamma} and 15-lipoxygenases.". Cancer Prevention Research 3: 1132–1140. PMID 20668019. 
  11. ^ Huff, M. W., Mulvihill, E. E. (2010). "Antiatherogenic properties of flavonoids: implications for cardiovascular health..". Canadian Journal of Cardiology 26: 17A–21A. PMID 20386755. 
  12. ^ Dastidar, S. G., Bandyopadhyay, D.; Chatterjee, T. K., Dasgupta, A., Lourduraja, J. (2005). "In vitro and in vivo antimicrobial action of tea: the commonest beverage of Asia.". Biological & Pharmaceutical Bulletin 28: 2125–2127. PMID 16272702. 
  13. ^ Pace University. "New Study Shows That White Tea Has an Inhibitory Effect on Various Pathogenic Bacteria, Fungi and Bacterial Virus". Retrieved 23 July 2012. 
  14. ^ Science Daily. "White Tea Could Keep You Healthy and Lookin Young". Retrieved 12 June 2011. 
  15. ^ Thring, Tamsyn SA; Pauline Hili, Declan P. Naughton (2009). "Anti-collagenase, anti-elastase and anti-oxidant activities of extracts from 21 plants.". BMC Complementary and Alternative Medicine 9. doi:10.1186/1472-6882-9-27. 
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References

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Last modified on 27 April 2013, at 22:23