Table 5.
Retention times, ESI-MS/MS m/z values (molecular ion (MS); product ions (MS2)), average contents and range in parentheses of nonflavonoid compounds in the skins of different grape groups.
| Compounds | Rt (min) | MS; MS2 (m/z) | Eu-grapes | As-grapes | Eu-As hybrids | Am-grapes | Eu-Am hybrids | Mu-grapes |
|---|---|---|---|---|---|---|---|---|
| Cinnamic acids (μg CAE/g DW) | ||||||||
| Chlorgenic acid | 0.56 | 191 | 0.67 (0–1.33) | 7.57 (0–10.16) | 5.83 (0–9.82) | 6.13 (0.38–8.85) | 4.86 (0.71–7.09) | 8.07 (7.89–8.26) |
| Caffeic acid | 1.19 | 179 | nd | 1.15 (0–10.36) | nd | 1.63 (0–5.55) | nd | nd |
| Caftaric acid | 1.30 | 311;179 | nd | 8.56 (0–24.16) | nd | nd | nd | nd |
| p-Coumaric acid | 2.90 | 163 | nd | 1.68 (0–11.45) | 3.28 (0–9.85) | 2.25 (0–8.99) | 7.92 (0–23.75) | 7.40 (0–14.80) |
| Ferulic acid | 3.01 | 193 | nd | 15.36 (0–58.44) | 17.81 (0–36.13) | 12.40 (0–32.58) | 5.13 (0–7.87) | nd |
| HE of caffeic acid | 5.63 | 341;179 | nd | nd | nd | nd | nd | 17.64 (0–35.29) |
| HE of p-coumaric acid | 6.11 | 325;163 | nd | 1.82 (0–16.36) | nd | nd | 3.26 (0–9.79) | 4.15 (0–8.29) |
| HE of ferulic acid | 7.47 | 355;193 | 0 (0-tr) | 16.98 (0–131.33) | 69.31 (10.26–183.29) | 13.18 (6.64–26.55) | 4.15 (1.25–8.97) | 4.17 (0–8.34) |
| Fertaric acid | 8.45 | 325;193 | nd | 58.15 (0–196.63) | 11.87 (0–25.11) | 8.50 (0–27.86) | 7.21 (0–18.15) | nd |
| Benzoic acids (μg GAE/g DW) | ||||||||
| HE of protocatechuic acid | 0.86 | 315;153 | 0.46 (0–0.91) | 6.96 (3.10–12.59) | 4.84 (tr-11.51) | 0.05 (0–0.19) | 4.38 (0–8.08) | 9.20 (7.07–11.34) |
| protocatechuic acid | 1.41 | 153 | nd | 0.17 (0–1.56) | nd | nd | nd | nd |
| p-Hydroxybenzoic acid | 1.77 | 137 | nd | 0.79 (0–3.70) | nd | nd | nd | nd |
| Ethyl gallate | 4.41 | 197;169 | nd | 1.45 (0–13.05) | nd | 0.94 (0–3.78) | 3.55 (0–6.08) | nd |
| HE of vanillic acid | 5.15 | 329;167 | 8.95 (7.73–10.17) | 3.99 (0–15.27) | 7.63 (4.39–11.17) | 6.75 (0.58–12.73) | 3.70 (tr-6.30) | 8.36 (6.96–9.75) |
| Ellagic acids (μg EAE/g DW) | ||||||||
| Ellagic acid-rha | 9.33 | 331;169,125 | nd | nd | nd | nd | nd | 16.49 (0–32.97) |
| HHDP-galloylglucose | 0.64 | 633;481,301 | nd | nd | nd | nd | nd | 140.16 (95.42–184.91) |
| HHDP-glucose | 3.81 | 481;421,301 | nd | nd | nd | nd | nd | 5.41 (0.00–10.82) |
| Ellagitannin 1 | 9.76 | 813;781,301 | nd | nd | nd | nd | nd | 92.91 (92.37–93.45) |
| Ellagitannin 2 | 14.47 | 831;813,301 | nd | nd | nd | nd | nd | 331.45 (303.32–359.59) |
| Stilbenes (μg RE/g DW) | ||||||||
| trans-Piceid | 10.19 | 389;227 | 2.50 (tr–5.01) | 0.96 (0–8.67) | 1.21 (0–3.64) | nd | nd | 28.21 (tr-56.41) |
| trans-Resveratrol | 23.67 | 227 | 94.44 (26.83–162.05) | 10.25 (0–67.09) | 9.10 (tr-27.31) | 0 (0-tr) | 0 (0-tr) | 13.71 (12.15–15.26) |
nd means not detected. tr means trace. Abbreviations: Eu, European; As, East Asian; Am, North Amrican; Mu, Muscadine; HE, hexose ester; rha, rhamnoside. The contents of the nonflavonoid compounds in the skins of each wine grape cultivars are shown in the supplementary file.