Table 2.
Extraction yield (EY, %, db), total phenolic compounds (TPC, mg GAE/mg extract), total flavonoids (TF, mg CATE/mg extract), tannins (TAN, % w/w, db), anthocyanins (ANT, µg C3G/mg, db), and antioxidant activity (AA expressed in terms of IC50, mg/mL, db) of the peels and seeds of three pomegranate cultivars (Acco, Big Full, Wonderful) according to extraction method (conventional vs. sonication-assisted).
| Extraction Method | By-Product | Cultivar | EY | TPC | TF | TAN | ANT | AA (IC50) |
|---|---|---|---|---|---|---|---|---|
| Conventional | Peels | Acco | 49.9 ± 0.9 | 0.39 ± 0.02 | 0.029 ± 0.002 | 16.7 ± 0.6 | 0.05 ± 0.02 | 0.024 ± 0.000 |
| Big Full | 51.0 ± 0.3 | 0.73 ± 0.18 | 0.052 ± 0.003 | 25.3 ± 0.2 | 0.12 ± 0.01 | 0.180 ± 0.005 | ||
| Wonderful | 46.3 ± 4.8 | 0.32 ± 0.01 | 0.042 ± 0.005 | 18.7 ± 0.3 | 0.00 ± 0.01 | 0.022 ± 0.001 | ||
| Seeds | Acco | 59.2 ± 1.3 | 0.21 ± 0.03 | 0.008 ± 0.000 | 3.5 ± 0.5 | 0.14 ± 0.01 | 0.063 ± 0.004 | |
| Big Full | 35.7 ± 1.2 | 0.16 ± 0.03 | 0.007 ± 0.001 | 1.8 ± 0.3 | 0.22 ± 0.02 | 0.398 ± 0.017 | ||
| Wonderful | 32.0 ± 1.7 | 0.23 ± 0.00 | 0.021 ± 0.001 | 9.6 ± 1.0 | 0.08 ± 0.01 | 0.042 ± 0.003 | ||
| Sonication | Peels | Acco | 49.1 ± 0.4 | 0.37 ± 0.04 | 0.038 ± 0.004 | 16.1 ± 1.0 | 0.18 ± 0.03 | 0.024 ± 0.013 |
| Big Full | 54.9 ± 1.2 | 0.50 ± 0.05 | 0.047 ± 0.002 | 26.7 ± 1.4 | 0.29 ± 0.03 | 0.010 ± 0.000 | ||
| Wonderful | 47.8 ± 0.5 | 0.33 ± 0.00 | 0.038 ± 0.002 | 18.3 ± 0.5 | 0.06 ± 0.05 | 0.021 ± 0.001 | ||
| Seeds | Acco | 48.9 ± 1.3 | 0.14 ± 0.00 | 0.019 ± 0.002 | 3.5 ± 0.7 | 0.28 ± 0.03 | 0.067 ± 0.003 | |
| Big Full | 36.8 ± 0.4 | 0.11 ± 0.00 | 0.032 ± 0.004 | 1.3 ± 0.3 | 0.60 ± 0.13 | 0.200 ± 0.001 | ||
| Wonderful | 30.8 ± 1.0 | 0.19 ± 0.02 | 0.068 ± 0.010 | 8.5 ± 0.2 | 0.18 ± 0.08 | 0.030 ± 0.000 | ||
| p-value | Cultivar (A) | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | |
| By-product (B) | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | ||
| Extraction method (C) | 0.0778 | 0.0005 | <0.0001 | 0.3244 | <0.0001 | <0.0001 | ||
| A × B interaction | <0.0001 | <0.0001 | <0.0001 | <0.0001 | 0.0038 | <0.0001 | ||
| A × C interaction | <0.0001 | 0.0083 | 0.0009 | 0.0869 | <0.0001 | <0.0001 | ||
| B × C interaction | <0.0001 | 0.4289 | <0.0001 | 0.1395 | 0.0045 | 0.0652 | ||
| A × B × C interaction | 0.0244 | 0.0139 | <0.0001 | 0.0829 | 0.0086 | 0.0777 | ||
Results are expressed as mean values ± standard deviation of four independent extractions for EY (n = 4) and duplicates of two independent extractions for TPC, TF, TAN, ANT, and IC50 (n = 4). Three-way ANOVA (p-value < 0.05).