Table 5.
Antioxidant properties of the EOs measured by two different methods.
| Essential Oils/Reference Compounds | DPPH Free Radical Scavenging Assay | β-Carotene Bleaching Test | ||
|---|---|---|---|---|
| IC50 ( v/v) | AAI | Strength of Antioxidant Activity | IC50 ( v/v) | |
| Eucalyptus citriodora | 0.51 ± 0.10 a | 6.62 ± 1.04 a | Very strong | 3.23 ± 0.05 e |
| Eucalyptus smithii | 24.10 ± 0.05 e | 0.19 ± 0.01 a | Poor | 5.20 ± 0.10 g |
| Eucalyptus staigeriana | 0.52 ± 0.11 a | 10.45 ± 2.19 a | Very strong | 1.94 ± 0.04 b |
| Lavandula angustifolia (Croatia) | 3.39 ± 0.35 b | 0.82 ± 0.09 a | Moderate | 3.27 ± 0.04 ef |
| Lavandula officinalis (Croatia) | 2.51 ± 0.32 c | 1.65 ± 0.06 a | Strong | 3.39 ± 0.09 f |
| Lavandula angustifolia (France) | 1.70 ± 0.04 d | 2.62 ± 0.10 a | Very strong | 2.95 ± 0.03 de |
| Lavandula angustifolia (High altitude, France) | 1.33 ± 0.07 d | 4.04 ± 1.15 a | Very strong | 2.79 ± 0.06 d |
| Rosmarinus officinalis | 2.82 ± 0.02 bc | 1.21 ± 0.36 a | Strong | 3.20 ± 0.13 e |
| Cymbopogon citratus | 0.03 ± 0.01 a | 183.37 ± 22.00 b | Very strong | 2.27 ± 0.04 c |
| Juniperus communis | 1.18 ± 0.09 d | 4.43 ± 1.10 a | Very strong | 1.48 ± 0.03 a |
| Gallic acid | 0.22 ± 0.01 | 22.77 ± 0.25 | Very strong | - |
| BHT | - | - | - | 3.58 ± 0.02 |
IC50—Concentration providing 50% of inhibition; AAI—Antioxidant activity index; BHT—Butylated hydroxytoluene; DPPH—2,2-diphenyl-1-picrylhydrazyl. Data expressed as means ± standard deviation (SD) of triplicate assays; Mean values in a column with different letters are significantly different (p < 0.05).