Table 2.
Descriptive statistical analysis of polyphenol content and antioxidant activity in conventional and organic BW samples.
| Parameter | All Samples | Conventional Group | Organic Group | ANOVA | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Range | RSD (%) | Mean ± SD | Median | Range of Quantified Values |
Interquartile | Mean ± SD | Median | Range of Quantified Values |
Interquartile | F | p | |
| TPI | 33.1–89.5 | 0.01–0.83 | 55.9 ± 14.0 | 56.2 | 33.1–75.2 | 47.8–68.0 | 69.3 ± 14.1 | 73.0 | 44.4–89.5 | 59.3–78.0 | 3.3849 | 0.0887 |
| TPH (mg/L) | 868–2581 | 0.02–9.26 | 1772 ± 469 | 1965 | 868–2202 | 1455–2075 | 2136 ± 466 | 2206 | 1280–2581 | 1838–2541 | 2.2599 | 0.1567 |
| Total tannins (mg/L) | 197–1158 | – 1 | 538 ± 325 | 491 | 202–1128 | 307–804 | 583 ± 300 | 534 | 197–1158 | 362–756 | 0.0779 | 0.7845 |
| Nontannins (mg/L) | 666–2117 | 0.05-5.70 | 1234 ± 307 | 1271 | 666–1568 | 1074–1474 | 1404 ± 347 | 1437 | 666–2117 | 1348–1751 | 3.4938 | 0.0843 |
| Total flavonoids (mg/L) | 161–774 | – 1 | 405 ± 247 | 287 | 161–774 | 187–699 | 491 ± 114 | 497 | 307–685 | 412–563 | 0.7745 | 0.3948 |
| Nonflavonoids (mg/L) | 681–2037 | 0.05–5.27 | 1367 ± 387 | 1452 | 681–1804 | 1168–1804 | 1645 ± 415 | 1696 | 842–2037 | 1450–2008 | 1.7871 | 0.2042 |
| ACY (mg/L) | 5.07–217 | 0.41–5.46 | 76.2 ± 87.4 | 24.2 | 5.34–217 | 7.11–168 | 53.5 ± 29.5 | 49.7 | 5.07–97.9 | 33.6–79.6 | 0.4825 | 0.4995 |
| Gallic acid (mg/L) | 23.7–118 | 0.10–4.84 | 59.7 ± 40.7 | 31.4 | 23.7–116 | 26.5–101.2 | 77.9 ± 26.5 | 72.4 | 49.9–118 | 52.2–104 | 1.0816 | 0.3173 |
| Chlorogenic acid (mg/L) | 1.23–8.32 | 0.34–2.93 | 3.46 ± 1.31 | 3.14 | 1.67–5.15 | 2.23–4.96 | 3.59 ± 2.09 | 3.21 | 1.23-8.32 | 2.47–3.93 | 0.0209 | 0.8872 |
| Caffeic acid (mg/L) | 1.25–5.05 | 0.07–3.63 | 2.21 ± 0.84 | 2.05 | 1.25–3.33 | 1.47–3.08 | 3.73 ± 1.22 | 4.09 | 1.40–5.05 | 2.84–4.75 | 7.6597 | 0.0159 |
| p-Coumaric acid (mg/L) | 0.331–4.06 | 0.22–4.41 | 0.814 ± 0.426 | 0.660 | 0.331–1.21 | 0.361–1.21 | 2.40 ± 1.23 | 2.39 | 0.881–4.06 | 1.25–3.41 | 10.3478 | 0.0067 |
| trans-Resveratrol (mg/L) | 0.415–4.00 | 0.24–4.93 | 1.30 ± 0.75 | 1.32 | 0.415–2.55 | 0.666–1.82 | 1.73 ± 1.10 | 1.51 | 0.722–4.00 | 0.859–2.28 | 0.7566 | 0.4002 |
| Cinnamic acid | <LOD (0.046 mg/L) | |||||||||||
| Antioxidant activity | ||||||||||||
| DPPH (mg/L) | 4.39–6.69 | 0.19–8.67 | 5.43 ± 0.65 | 5.62 | 4.53–6.27 | 4.57–5.84 | 5.20 ± 0.80 | 4.91 | 4.39–6.69 | 4.67–5.92 | 0.3713 | 0.5528 |
| ABTS (mg/L) | 1.23–7.77 | 0.45–7.98 | 4.95 ± 1.60 | 5.38 | 2.81–7.00 | 2.82–5.95 | 4.05 ± 2.15 | 4.20 | 1.23–7.77 | 2.19–5.46 | 0.8224 | 0.3809 |
| RPA 2 | 0.44–1.36 | 0.02–5.69 | 0.61 ± 0.33 | 0.46 | 0.45–1.36 | 0.44–0.56 | 0.51 ± 0.45 | 0.51 | 0.44–0.57 | 0.46–0.54 | 0.7961 | 0.3885 |
| MoT (mg/L) | 2.99–9.87 | 0.03–7.44 | 5.95 ± 2.13 | 5.60 | 3.79–9.87 | 3.80–7.10 | 5.25 ± 2.37 | 4.71 | 2.99–9.39 | 3.10–7.09 | 0.3637 | 0.5569 |
Cinnamic acid was below the LOD value. No significant differences were found between the triplicates for all determinations. LOD—limit of detection; TPI—total polyphenol index; TPH—total polyphenolic compounds; ACY—total monomeric anthocyanins; DPPH—IC50% values for DPPH method; ABTS—IC50% values for ABTS method; RPA—Reducing power assay; MoT—Molybdenum test; 1 The values were calculated from Equation: Total tannins = TPH—Nontannins; Total flavonoids = TPH—Nonflavonoid. 2 RPA of the samples was evaluated at a concentration of total polyphenols (40 mg/L).