Table 2 Analysis of the flavanol content of Masquelier’s grape seed extract. The data were provided by the extract’s manufacturer
Compound | Analytical method | Content |
|---|---|---|
Total polyphenols | Spectrophotometric (GAE), n = 3 | 90–95% |
Folin-Ciocalteau reagent (GAE), n = 3 | ||
Flavan-3-ols | Vanillin-H2SO4 (Sun et al., [50]), n = 9 | 60–70% |
HPLC, n = 14 | ||
Monomeric flavanols | HPLC (every batch) | 25–30% |
Oligomeric flavanols (2–5 units) | HPLC (every batch) | 35–40% |
Polymeric flavanols (>6 units) | HPLC (every batch) | 1–5% |