Table 1.
Product composition of the flavonoid-rich black tea extract and of beetroot juice
| Compounds | Flavonoid-rich black tea extract | Beetroot juice Beet-It |
|---|---|---|
| Protein (g) | 0.01 | 2.5 |
| Carbohydrates (g) | 0.03 | 16 |
| Fat (g) | ND | <0.1 |
| Fibre (g) | ND | <0.5 |
| Sodium (mg) | ND | <100 |
| Nitrate (mg) | ND | 300 |
| Total Polyphenol (Folin Ciocalteu) (mg) | 228.1 | 68.4 |
| consisting of: (-)-Epicatechin (mg) | 2.3 | |
| (-)-Epigallocatechin (mg) | 1.1 | |
| (-)-Epigallocatechin gallate (mg) | 6.2 | |
| (-)-Epicatechin gallate (mg) | 5.0 | |
| Theaflavins (mg) | 2.3 | |
| Gallic acid (mg) | 3.9 | |
| Flavonol-glycosides (mg) | 2.3 | |
| Thearubiginsa (mg) | 161.9 | |
| Caffeine (mg) | 37.1 | ND |
Product composition is provided per serving, i.e. 442 mg black tea solids and 70 ml beetroot juice, respectively. The composition of Beet-it beetroot juice was provided by James White Drinks Ltd. (Ipswich, UK). Total polyphenol content of tea was determined by Folin Ciocalteu and the content of specific flavonoids by reversed phase HPLC with a Luna Phenyl hexyl column (4.6x250 mm, 5 μm) and a Phenyl propyl guard column (Phenomenex)
aThearubigins were assumed to represent the total polyphenol fraction substracted by catechins, theaflavins, flavonol-glycosides and organic acids (i.e. gallic acid, theogallin and chlorogenic acid)
ND, not determined