Table 1.
Effect of, and interaction among, production system (organic (ORG) vs. conventional (CONV)), variety, and year for the yield, dry matter content (DM), sugar content (SC) of pulp/juice, total phenolic content (TPC), total antioxidant activity (TAA) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) or Trolox Equivalent Antioxidant Capacity (TEAC (assays and total anthocyanin content (TAC) (expressed as cyanidin-3-O-glucoside (cyan) and malvidin-3-O-glucoside (mal) equivalents) in table grapes of the Cretan local varieties Kotsifali, Villana, and Vidiano (three-factor ANOVA). TE, Trolox equivalent.
| Factors | Yield (t/ha) |
DM (%) |
SC Pulp (°Brix) |
SC Juice (°Brix) |
TPC (mg GAE·kg−1) |
TAA (DPPH) (µmol TE·g−1) |
TAA (TEAC) (µmol TE·g−1) |
TAC (mg cyan·kg−1) |
TAC (mg mal·kg−1) |
|---|---|---|---|---|---|---|---|---|---|
| Year (Yr) | |||||||||
| 2014 (n = 22) | 14.6 ± 1.1 | 23.0 ± 0.6 | 21.5 ± 0.7 | 21.5 ± 0.5 | 2037 ± 150 | 84 ± 6 | 14.3 ± 1.1 | 432 ± 47 | 456 ± 50 |
| 2015 (n = 26) | 14.2 ± 1.1 | 21.3 ± 0.5 | 18.5 ± 0.4 | 19.1 ± 0.5 | 1423 ± 94 | 75 ± 5 | 7.3 ± 0.6 | 296 ± 23 | 313 ± 25 |
|
Production
System (PS) |
|||||||||
| ORG (n = 24) | 14.0 ± 1.3 | 21.6 ± 0.6 | 19.2 ± 0.5 | 19.7 ± 0.6 | 1770 ± 139 | 79 ± 6 | 11.3 ± 1.2 | 341 ± 48 | 360 ± 51 |
| CONV (n = 24) | 14.8 ± 0.9 | 22.5 ± 0.6 | 20.5 ± 0.7 | 20.7 ± 0.5 | 1638 ± 133 | 79 ± 6 | 9.7 ± 1.0 | 372 ± 34 | 392 ± 36 |
| Variety (Va) | |||||||||
| Kotsifali (n = 18) | 14.6 ± 1.3 | 23.5 ± 0.5 | 20.7 ± 0.6 | 21.6 ± 0.6 | 1906 ± 131 a | 114 ± 2 a | 12.9 ± 1.2 a | 356 ± 29 a | 376 ± 31 a |
| Villana (n = 16) | 15.7 ± 7.0 | 21.1 ± 0.7 | 19.3 ± 0.8 | 19.2 ± 0.7 | 1222 ± 113 b | 57 ± 1 b | 6.7 ± 0.8 b | 9 ± 2 b | 10 ± 2 b |
| Vidiano (n = 14) | 12.5 ± 1.0 | 21.3 ± 0.6 | 19.4 ± 0.8 | 19.6 ± 0.6 | 1996 ± 192 a | 59 ± 1 b | 11.7 ± 1.6 a | 21 ± 4 b | 23 ± 4 b |
| ANOVA results | |||||||||
| (p-values) | |||||||||
| Main effects | |||||||||
| Yr | NS | 0.0201 | 0.0028 | 0.0078 | 0.0022 | <0.0001 | <0.0001 | T | T |
| PS | NS | NS | T | NS | NS | NS | 0.0456 | NS | NS |
| Va | NS | T | NS | T | 0.0014 | <0.0001 | 0.0001 | <0.0001 | <0.0001 |
| Interactions | |||||||||
| Yr × PS | NS | NS | NS | NS | NS | NS | NS | NS | NS |
| Yr × Va | NS | NS | NS | NS | NS | 0.0067 2 | NS | 0.0275 2 | 0.0275 2 |
| PS × Va | NS | NS | NS | NS | NS | NS | 0.0160 1 | NS | NS |
| Yr × PS × Va | NS | NS | NS | NS | NS | NS | NS | NS | NS |
GAE, gallic acid equivalents; The values presented are means ± standard error (SE); means with the same letter within the same column are not significantly different according to Tukey’s honestly significant difference test (p < 0.05); NS, not significant; ND, not determined: T, trend (0.1 > p > 0.05); 1 see Table 2 for interaction means (±SE); 2 see Table S2 (Supplementary Materials) for interaction means (±SE).