Table 1.
Total polar phenolic (TPP) content, antioxidant activity (DPPH) and main individual phenolic families’ contents * in walnut (‘Lara’ cv.) and pistachio (‘Sirora’ cv.) nut kernels and their corresponding lyophilized phenolic-rich extracts (n = 3).
| Walnut | (‘Lara’ cv) | Pistachio | (‘Sirora’ cv.) | |
|---|---|---|---|---|
| Kernel | Extract | Kernel | Extract | |
| TPP (g/kg gallic acid) | 11 ± 1 b | 274 ± 4 d | 7 ± 1 a | 51 ± 3 c |
| DPPH (mol/kg Trolox) | 0.11 ± 0.02 b | 255 ± 3 d | 0.020 ± 0.01 a | 13 ± 1 c |
| Flavanols (g/kg) | 0.9 ± 0.1 a | 84 ± 1 d | 2.3 ± 0.3 b | 12.7 ± 0.3 c |
|
0.8 ± 0.1 a | 66 ± 1 c | 1.1 ± 0.1 a | 6.3 ± 0.3 b |
|
0.2 ± 0.1 a | 18 ± 1 d | 0.7 ± 0.1 b | 4.1 ± 0.2 c |
|
nd | nd | 0.6 ± 0.1 a | 2.4 ± 0.2 b |
| Flavonols (g/kg) | 0.9 ± 0.1 c | 84 ± 1 d | 0.1 ± 0.0 a | 0.3 ± 0.0 b |
| Flavanones (g/kg) | nd | nd | nd | 0.1 ± 0.0 |
| Anthocyanins (g/kg) | nd | nd | 0.1 ± 0.0 a | 0.9 ± 0.0 b |
| Hydrolysable Tannins (g/kg) | 2.1 ± 0.4 a | 92 ± 1 b | nd | nd |
| Ellagic acid deriv. (g/kg) | 0.1 ± 0.0 a | 13 ± 1 b | nd | nd |
* determined by an HPLC-DADESI-MS/MS. a–d, a different superscript letter means a statistically significant difference (at 95%) between data in rows within the same variable (i.e., TPP, DPPH, flavanols, …). nd, not determined.