Table 1.
Antioxidant activity of hydroxytyrosol (HT) or tyrosol (TY) quantified as Radical Scavenging Activity (RSA) by (a) DPPH assay (% RSA at 50 min) and (b) ABTS assay (% RSA at 30 min); (c) Antioxidant activity quantified as Trolox Equivalent (TE) by ORACFL assay. Trolox™ (TR) and α-tocopherol (TOC) were used as antioxidant references.
| (a) | |||
|---|---|---|---|
| mole AH/ mole DPPH | HT | TY | TOC |
| n.d.: not determined. | |||
| 0 | 3.96 | 3.64 | 3.63 |
| 0.06 | 36.24 | n.d. | 23.21 |
| 0.13 | 71.47 | 5.20 | 48.16 |
| 0.25 | 96.40 | 4.25 | 75.85 |
| 0.5 | 97.80 | 3.02 | 90.17 |
| 1 | 98.07 | 2.59 | 95.98 |
| 2.5 | n.d. | 2.34 | n.d. |
| 5 | n.d. | 3.44 | n.d. |
| 10 | n.d. | 3.37 | n.d. |
| (b) | |||
|---|---|---|---|
| µM | HT | TY | TR |
| n.d.: not determined. | |||
| 6 | 5.07 | 10.31 | n.d. |
| 12.5 | 5.45 | 14.32 | n.d. |
| 25 | 8.42 | 20.14 | n.d. |
| 50 | 18.09 | 31.81 | 16.21 |
| 100 | 36.63 | 44.55 | 29.39 |
| 200 | 69.53 | 58.25 | 50.07 |
| 400 | 96.30 | 73.82 | 88.03 |
| 800 | 99.47 | 85.04 | 99.48 |
| (c) | ||
|---|---|---|
| TE (µM) | HT (µM) | TY (µM) |
| 3.12 | 14.82 | 1.64 |
| 6.25 | 30.97 | 8.30 |
| 12.5 | 50.37 | 20.84 |
| 25 | 92.24 | 58.35 |
| 50 | 150.43 | 106.76 |
| 100 | 262.76 | 205.57 |