Doc:Tea
From Metabolomics.JP
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| − | | Per capita mean consumption of tea in the world is 120 mL/day <ref name="McKay">McKay DL, Blumberg JB (2002) "The role of tea in human health: An update" J Am Coll Nutr 21:1-13</ref>, the second most consumed beverage in the world (next to water). Black tea is principally consumed in Western countries, | + | | Per capita mean consumption of tea in the world is 120 mL/day <ref name="McKay">McKay DL, Blumberg JB (2002) "The role of tea in human health: An update" J Am Coll Nutr 21:1-13</ref>, the second most consumed beverage in the world (next to water). Black tea is principally consumed in Western countries, green tea is popular in Asia, and oolong tea in China and Taiwan<ref name="Wu">Wu CD, Wei GX (2002) "Tea as a functional food for oral health" Nutrition 18(5):443-444</ref>. |
| − | | 世界における茶の一人当たり消費量は 120 ml/日 <ref name="McKay"/> | + | | 世界における茶の一人当たり消費量は 120 ml/日 <ref name="McKay"/>で、世界で飲まれる飲料ナンバー２です。紅茶は主に西洋で飲まれ、緑茶はアジア、ウーロン茶は中国と台湾で飲まれます<ref name="Wu"/>。 |
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Revision as of 14:58, 22 December 2009
Classification 分類
- green tea
- It is non-fermented, i.e., produced by drying an steaming the fresh leaves of Camellia sinensis var. sinensis to inactivate polyphenol oxidases.
- oolong tea
- It is produced by partial fermentation before drying.
- black tea
- It is fully fermented by oxidation.
- red (pu-erh) tea
- It is fully fermented by microorganisms including Aspergillus spp. and Penicillium spp.
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Per capita mean consumption of tea in the world is 120 mL/day [1], the second most consumed beverage in the world (next to water). Black tea is principally consumed in Western countries, green tea is popular in Asia, and oolong tea in China and Taiwan[2]. | 世界における茶の一人当たり消費量は 120 ml/日 [1]で、世界で飲まれる飲料ナンバー２です。紅茶は主に西洋で飲まれ、緑茶はアジア、ウーロン茶は中国と台湾で飲まれます[2]。 |
Composition
| The major phenolics in green tea include catechins (flavan 3-ols). They are (-)-epigallocatechin-3-gallate (EGCG; 59% of total catechins), (-)-epigallocatechin (EGC; 19%), (-)-epicatechin-3-gallate (ECG; 13.6%), and (-)-epicatechin (EC; 6.4%) [1]. Catechins are converted to theaflavins and thearubigins in black tea [3]. A cup of tea may contain 90 mg of EGCG [2], but in human, EGCG is less bioavailable (i.e. absorbed) than other green tea catechins. The bioavailability is different between species and genotypes [4][5]. After drinking tea, the plasma level of catechins reach their peaks (between 1-10 µmol/L) in 2 - 4 h [6]. After 24 h, plasma levels of EGCG and EGC return to baseline, but that of ECG remains elevated in methylated forms[7]. |
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Human Health
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- ↑ 1.0 1.1 1.2 McKay DL, Blumberg JB (2002) "The role of tea in human health: An update" J Am Coll Nutr 21:1-13
- ↑ 2.0 2.1 2.2 Wu CD, Wei GX (2002) "Tea as a functional food for oral health" Nutrition 18(5):443-444
- ↑ USDA Database for the Flavonoid Contents of Selected Foods, Beltsville 2003
- ↑ Kim S, Lee MJ, Hong J (2000) "Plasma and tissue levels of tea catechins in rats and mice during chronic consumption of green tea polyphenols" Nutr Cancer 37:41-48
- ↑ Loktionov A, Bingham S et al. (1998) "Apolipoprotein E genotype modulates the effect of black tea drinking on blood lipids and blood coagulation factors: A pilot study" Br J Nutr 79:133-139
- ↑ Yang CS, Chen L et al. (1998) "Blood and urine levels of tea catechins after ingestion of different amounts of green tea by human volunteers" Cancer Epidemiol Biomarkers Prev 7:351-354
- ↑ Higdon JV, Frei B (2003) "Tea catechins and polyphenols: health effects, metabolism, and antioxidant functions" Crit Rev Food Sci Nutr 43:89-143
- ↑ Belitz DH, Grosch W (1997) "Quimica de los Alimentos" Zaragoza Acribia
