UV-vis irradiation: An alternative to reduce SO2 in white wines?

Ultraviolet-visible irradiation was tested as an innovative technology that can help reducing the amount of sulfur dioxide used in white wine manufacturing. In addition, the effects of must freezing before processing were also investigated. Musts from Xarel·lo and Parellada varieties were vinified without any protective treatment, with a standard amount of SO2 addition or after an irradiation step. The results showed that UV-vis irradiation of must was able to prevent wine from spoilage in the same degree as SO2, without changing other quality parameters such as pH, tartaric acid and alcohol content. However, a residual addition of SO2 would be required in order to completely inhibit polyphenol oxidase activity. Moreover, the obtained changes in wine color parameters led to the conclusion that further optimization of the irradiation process is required before its implementation. Must freezing was shown to have some influence on quality parameters of Xarel·lo wines, but not in those from Parellada.

► Musts from Xarel·lo and Parellada were UV-vis-irradiated before vinification. ► Quality parameters of musts and wines were compared with SO2-added ones. ► UV-vis irradiation prevented wine from spoilage as SO2. ► pH, tartaric acid and alcohol content were not different. ► PPO was not completely inactivated, so a residual use of SO2 would be needed.