Monitoring the process to obtain red wine enriched in resveratrol and piceatannol without quality loss

Stilbene-enriched wine is considered an interesting new food product with added value as a consequence of the numerous health-promoting properties ascribed to it, mainly from its trans-resveratrol content. Postharvest grapes have been treated with ultraviolet-C light to produce stilbene-enriched grapes that were later used in a conventional winemaking process to obtain a red wine enriched in stilbenes.By measuring oenological parameters and stilbene concentration it has been possible to monitor both the quality parameters and stilbenes throughout the process. The maximum concentration in trans-resveratrol and piceatannol was obtained after pressing, but there was significant loss from grape to wine. A significant increase in both piceatannol and trans-resveratrol concentration (up to 26 times and 3.2 times higher than in control, respectively) was achieved in bottled wine. Regarding the oenological parameters, the wines obtained possessed good quality, apart from a herbaceous aroma, which could not be identified by GC–olfactometry.