Acidic Content of Tea
Phenols and polyphenols are compounds found naturally in plants. A group of natural phenols called the flavonoids are of popular interest because researchers have found them to have the potential to contribute to better health.[1][2][3][4][5]
Tea has one of the highest contents of flavonoids among common food and beverage products.[6] Catechins are the largest type of flavonoids in growing tea leaves.[7] Contents [hide] * 1 Catechins * 2 Theaflavins * 3 Tannins * 4 Metabolism * 5 See also * 6 References |
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[edit]Catechins
Catechins in tea include epigallocatechin-3-gallate (EGCG), epicatechin (EC), epicatechin-3-gallate (ECg), epigallocatechin (EGC), catechin, and gallocatechin (GC).[citation needed]
Catechins constitute about 25% of the dry weight of fresh tea leaf,[8] although total catechin content varies widely depending on species, clonal variation, growing location, season, light variation, and altitude. They are present in nearly all teas made from Camellia sinensis, including white tea, green tea, black tea and oolong tea.
According to a report released by USDA, in a 200-ml cup of tea, the mean total content of flavonoids is 266.68 mg for green tea, and 233.12 mg for black tea.[6]
Of all the catechins in tea, EGCG is the main subject of scientific study with regard to its potential health effects.[1][2][4][5]
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[edit]Theaflavins
Darjeeling black tea infusion: Finer black tea has a more orange tone than red as a result of higher theaflavins content.
Catechin monomer structures are metabolized into dimers theaflavins and oligomers thearubigins with increasing degrees of oxidation of tea leaves.[7]. Theaflavins directly contribute to the bitterness and astringency of steeped black tea.[citation needed] The mean amount of theaflavins in a cup of black tea (200 ml) is 12.18 mg.[6]
Three main types of theaflavins are found in black tea,
Tea has one of the highest contents of flavonoids among common food and beverage products.[6] Catechins are the largest type of flavonoids in growing tea leaves.[7] Contents [hide] * 1 Catechins * 2 Theaflavins * 3 Tannins * 4 Metabolism * 5 See also * 6 References |
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[edit]Catechins
Catechins in tea include epigallocatechin-3-gallate (EGCG), epicatechin (EC), epicatechin-3-gallate (ECg), epigallocatechin (EGC), catechin, and gallocatechin (GC).[citation needed]
Catechins constitute about 25% of the dry weight of fresh tea leaf,[8] although total catechin content varies widely depending on species, clonal variation, growing location, season, light variation, and altitude. They are present in nearly all teas made from Camellia sinensis, including white tea, green tea, black tea and oolong tea.
According to a report released by USDA, in a 200-ml cup of tea, the mean total content of flavonoids is 266.68 mg for green tea, and 233.12 mg for black tea.[6]
Of all the catechins in tea, EGCG is the main subject of scientific study with regard to its potential health effects.[1][2][4][5]
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[edit]Theaflavins
Darjeeling black tea infusion: Finer black tea has a more orange tone than red as a result of higher theaflavins content.
Catechin monomer structures are metabolized into dimers theaflavins and oligomers thearubigins with increasing degrees of oxidation of tea leaves.[7]. Theaflavins directly contribute to the bitterness and astringency of steeped black tea.[citation needed] The mean amount of theaflavins in a cup of black tea (200 ml) is 12.18 mg.[6]
Three main types of theaflavins are found in black tea,