Abstract
Epidemiological studies assessing the health benefits of drinking black tea are equivocal. Such disparity may reflect an inability of semiquantitative assessment to consider how infusion time and addition of milk affect the bioavailability of potentially beneficial antioxidant polyphenols. Six brands of tea demonstrated similar increases in antioxidant capacity and total phenolic and catechin contents with increasing infusion time. These results were unaffected by the addition of milk. Consumption of black tea (400 mL) was associated with significant increases in plasma antioxidant capacity (10%) and concentrations of total phenols (20%), catechins (32%), and the flavonols quercetin (39%) and kaempferol (45%) (all p < 0.01) within 80 min. This was unaffected by adding milk. Infusion time may therefore be a more important determinant in the absorption of polyphenols from black tea. Observational studies assessing the health benefits of tea consumption require recording of brewing methods as well as frequency of consumption.
Original language | English |
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Pages (from-to) | 4889-4894 |
Number of pages | 6 |
Journal | Journal of Agricultural and Food Chemistry |
Volume | 55 |
Issue number | 12 |
Early online date | 10 May 2007 |
DOIs | |
Publication status | Published - 13 Jun 2007 |
Keywords
- black tea
- polyphenols
- flavonoids
- catechins
- antioxidant capacity
- infusion time
- absorption
- milk
- total antioxidant capacity
- heart-disease
- dietary flavonoids
- total phenol
- plasma
- consumption
- health
- humans
- green
- assay