Table 5.
Total phenolic content (TPC) and free radical scavenging activities (ABTS, DPPH, and ORAC) of Monastrell grapes under non-irrigation (rainfed) and regulated deficit irrigation (RDI) regime.
| TPC (mg GAE/mL) |
ABTS 1 (mmol TE/mL) |
DPPH (mmol TE/mL) |
ORAC (μmol TE/mL) |
|
|---|---|---|---|---|
| Rainfed | 1.5 ± 0.2 b | 3.7 ± 0.1 a | 5.6 ± 0.5 | 43.6 ± 6.9 b |
| RDI | 1.2 ± 0.1 a | 3.9 ± 0.1 a | 5.3 ± 0.1 | 23.4 ± 3.1 a |
| p-value 2 | ** | * | 0.265 | ** |
1 ABTS: 2,2′-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), DPPH: 2,2-diphenyl-1-picryl-hydrazyl-hydrate, ORAC: 2,2′-Azobis(2-amidinopropane) dihydrochloride (AAPH) radical test-Oxygen radical absorbance capacity (ORAC), GAE: galic acid equivalent, TE: Trolox equivalent. All parameters are given as average values ± the standard deviations (n = 4). Different letters (a and b) indicate significant differences between grapes under non-irrigation (rainfed) and regulated deficit irrigation (RDI) regime (p < 0.05). 2 Statistical significance: * p ≤ 0.05, ** p ≤ 0.01. When there is no difference between treatments (p > 0.05), no significance letters are shown.