Table 1.
Density, viscosity and basic composition of Trial 1 wines before and after RO-EP treatment, and following RO-EP treatment and alcohol re-adjustment.
| Wine A | Wine B | Wine C | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pre-RO-EP | Post-RO-EP | Post-EtOH | P | Pre-RO-EP | Post-RO-EP | Post-EtOH | P | Pre-RO-EP | Post-RO-EP | Post-EtOH | P | |||
| alcohol (% abv) | 14.1a | 12.5b | 14.1a | <0.001 | 17.1a | 14.5b | 17.1a | <0.001 | 14.9a | 14.2b | 14.9a | <0.001 | ||
| free SO2 (mg/L) | 3.8 | nd | nd | – | 6.4 | nd | nd | – | 7.7 | 1.9 | 1.9 | – | ||
| density (g/mL) | 0.995 | 0.995 | 0.993 | – | 0.993 | 0.996 | 0.993 | – | 0.993 | 0.994 | 0.993 | – | ||
| viscosity (mPa s) | 1836a | 1711c | 1796b | <0.001 | 2009a | 1829c | 1982b | <0.001 | 1858a | 1751c | 1836b | <0.001 | ||
| glycerol (g/L) | 10.2a | 10.2a | 10.0b | <0.001 | 10.9b | 11.0a | 10.7c | <0.001 | 11.9a | 11.8a | 11.6b | 0.039 | ||
| gelatin index (%) | 38c | 55a | 46 b | <0.001 | 49 | 54 | 48 | – | 44a | 44a | 41b | 0.040 | ||
| pH | 3.7 | 3.6 | 3.7 | – | 3.6 | 3.6 | 3.6 | – | 3.7 | 3.7 | 3.7 | – | ||
| TA (g/L) | 5.9 | 6.1 | 5.9 | – | 7.2 | 7.1 | 7.2 | – | 6.4 | 6.5 | 6.4 | – | ||
| VA (g/L) | 0.4 | 0.3 | 0.4 | – | 0.5 | 0.8 | 0.5 | – | 0.6 | 0.6 | 0.6 | – | ||
| citric acid (g/L) | 1.2 | 1.2 | 1.1 | – | 0.7 | 0.7 | 0.7 | – | 0.9 | 0.9 | 0.8 | – | ||
| succinic acid (g/L) | 6.2 | 6.2 | 6.1 | – | 8.2 | 8.3 | 8.3 | – | 6.5 | 6.5 | 6.4 | – | ||
| lactic acid (g/L) | 3.7 | 3.8 | 3.7 | – | 2.8 | 2.8 | 2.8 | – | 3.8 | 3.8 | 3.7 | – | ||
| wine color (au) | 10.8c | 12.6a | 12.2b | <0.001 | 19.6b | 21.0a | 18.8c | <0.001 | 17.2 | 17.3 | 17.1 | – | ||
| wine hue | 2.8c | 4.9a | 3.8b | <0.001 | 4.1b | 4.2a | 3.9c | <0.001 | 3.4b | 3.6a | 3.4b | <0.001 | ||
| L* | 67.6a | 62.7c | 64.0b | <0.001 | 49.7a | 47.5b | 49.8a | <0.001 | 52.9b | 53.1a | 52.7c | 0.003 | ||
| a* | 34.7c | 36.8a | 36.1b | <0.001 | 50.8b | 52.6a | 50.9b | <0.001 | 49.5a | 48.5b | 49.6a | <0.001 | ||
| b* | 5.0c | 5.6b | 5.9a | <0.001 | 5.3a | 5.3a | 3.3b | <0.001 | 0.6b | 3.4a | 0.5b | <0.001 | ||
| ∆E* 1 | – | 5.3 | 4.0 | – | – | 2.7 | 2.0 | – | – | 3.0 | 0.3 | – | ||
Values are means of duplicate measurements (n = 2). Standard errors were ≤10%; nd = not detected. Values followed by different letters within rows (for each wine) are statistically significantly different. 1 Total color differences (∆E*) were calculated relative to the color of each wine prior to RO-EP treatment.