Table 4.
Analytical precision (RSD, n = 5) for free and bound VPs in three grape cultivars.
| VPs | Free VPs | Bound VPs | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Shiraz | Chardonnay | Pinot | Shiraz | Chardonnay | Pinot | |||||||
| Mean | RSD | Mean | RSD | Mean | RSD | Mean | RSD | Mean | RSD | Mean | RSD | |
| (ng/g) | (%) | (ng/g) | (%) | (ng/g) | (%) | (ng/g) | (%) | (ng/g) | (%) | (ng/g) | (%) | |
| Guaiacol | 6.4 | 7.8 | 4.4 | 13.6 | 7.8 | 4.1 | 143.4 | 5.1 | 50.7 | 2.9 | 41.8 | 4.1 |
| 4-methylguaiacol | 1.9 | 6.8 | 1.3 | 17.3 | 2.4 | 10.2 | 37.2 | 7.9 | 23.3 | 7.2 | 13.2 | 3.6 |
| Syringol | 59.3 | 8.6 | 47.7 | 12.9 | 40.9 | 7.2 | 988.7 | 11.3 | 540.7 | 5.7 | 394.9 | 2.2 |
| 4-methylsyringol | 544.9 | 11.3 | 200.7 | 5.4 | 147.5 | 9.0 | ||||||
| o-cresol | 1.0 | 11.6 | 2.6 | 3.9 | 13.1 | 5.9 | 11.5 | 5.2 | 7.7 | 9.2 | ||
| p-cresol | 1.8 | 7.4 | 1.2 | 10.7 | 2.8 | 3.9 | 16.3 | 6.4 | 16.9 | 3.2 | 14.1 | 4.6 |
| m-cresol | 1.2 | 13.7 | 1.3 | 8.1 | 2.9 | 7.7 | 17.2 | 4.0 | 14.5 | 7.7 | 10.8 | 4.5 |
| Phenol | 12.4 | 5.0 | 11.9 | 6.1 | 17.4 | 3.7 | 79.4 | 4.5 | 72.4 | 3.0 | 61.2 | 2.0 |
| 4-ethylguaiacol | 4.3 | 8.7 | 4.6 | 10.3 | 3.1 | 8.7 | ||||||
| Eugenol | 4.0 | 6.7 | 5.7 | 8.9 | 4.1 | 21.3 | ||||||
| 2,4-dimethylphenol | 5.9 | 5.6 | 6.2 | 7.8 | 3.8 | 10.8 | ||||||
| 4-ethylphenol | 1.4 | 7.7 | 1.4 | 9.8 | 1.7 | 9.3 | 16.7 | 11.0 | 10.5 | 11.2 | 10.6 | 10.2 |
| Vanillin | 242.4 | 10.5 | 206.1 | 7.8 | 200.9 | 3.2 | 188.0 | 4.2 | 120.3 | 6.7 | 133.7 | 2.69 |
| Acetovanillone | 9.6 | 10.5 | 7.4 | 8.2 | 12.9 | 12.8 | 74.3 | 4.7 | 55.7 | 3.6 | 83.6 | 3.4 |
Hydrolysis was conducted with 1.25 N H2SO4 for bound VP determination.