Investigation on color features and oxidative stability of rosé wines

This PhD project first focused on developing a map of the tannin and color profile of Italian rosé wines, highlighting the relationship between regional grape varieties, and color features across different wine styles in Italy. This research aimed to identify the ideal balance in tannin and anthocyanin content that contributes to improved color retention and overall wine quality. Another aim was to analyze the color characteristics of rosé wines, offering valuable insights into how these wines can be better produced, marketed, and appreciated. It primarily investigates the effects of the variation in anthocyanin and tannin content on the oxidative color evolution of rosé wines. The research analyzed how these pigments degrade over time, focusing on oxidative reactions that cause color changes, including browning, which can affect the visual appeal and perceived freshness of wine. Rosé wines with a higher anthocyanin content retained their colorimetric and phenolic characteristics better. The project also assessed the role of different oenological tannins in preserving the color and phenolic parameters of rosé wine over time. It explored the formation of polymeric pigments that are less prone to oxidation and contribute to extended color stability. Chestnut tannin showed notably higher iron-chelating and oxygen-consumption abilities, making it effective in limiting oxidative reactions that can degrade wine color and phenolic stability. Additionally, the project also considered the effects of light exposure on color degradation. The effects of the photo-Fenton process on model rosé wine were examined, particularly how different colored bottles and lighting can reduce light-induced oxidation. Brown bottles are ideal for mitigating light-induced oxidative changes, while wines stored in flint bottles are more vulnerable to photooxidative damage, particularly under daylight. In addition, the UV filter demonstrated intermediate degrees of protection, suggesting a possible trade-off between allowing wine color to be seen and preserving it over time.