Table 6.
Effect of nitrate deprivation at different days before harvest (DBH) on total phenols, total flavonoids and ferric-reducing antioxidant power (FRAP) in leaves of cardoon plants (Cynara cardunculus L. var. altilis DC) harvested at different days after sowing (DAS); cardoon plants were grown in a floating system under greenhouse conditions (Experiment 2).
| Nitrate deprivation | Total phenols (mg gallic acid g-1 DW) |
Total flavonoids (mg quercitin g-1 DW) |
FRAP (μmol FeSO4 g-1 DW) |
||||||
|---|---|---|---|---|---|---|---|---|---|
| DBH | 59 DAS | 97 DAS | 124 DAS | 59 DAS | 97 DAS | 124 DAS | 59 DAS | 97 DAS | 124 DAS |
| 0 | 10.00 | 23.18 | 15.23 | 10.67 | 38.55 | 12.21 | 130.11 | 401.82 | 194.05 |
| 5 | 11.27 | 20.34 | 17.11 | 14.80 | 25.34 | 18.08 | 157.58 | 343.02 | 231.51 |
| 10 | 11.10 | 25.03 | 20.09 | 14.42 | 42.20 | 30.30 | 151.25 | 438.93 | 294.07 |
| 15 | 14.31 | 33.12 | 21.99 | 25.21 | 75.51 | 31.85 | 221.81 | 566.17 | 314.74 |
| Significance | L* | L* | L*** | L** | L* | L*** | L* | L* | L*** |
L, linear; *P < 0.05; **P < 0.01; ***P < 0.001.