Enhancement of sol-gel coatings for photoprotection of rosé wines

Exposure to short-wavelength light, including UV-A and blue light, can degrade high-value products like rosé wine, which are usually packaged in colourless bottles. This study investigates the optimisation of sol¿gel coatings enhanced with UV-absorbing additives (Tinuvin 479 and semaSORB 20109) to provide photoprotection for rosé wines. Coatings with varying additive concentrations (0.5%, 0.75%, 1%, and 1.5%) were applied to glass substrates via spin coating and cured with UV light. Then, optical and mechanical characterisation was performed. The 1.5% concentration semaSORB 20109 bilayer coating demonstrated improved photoprotective properties without compromising colour properties, leading to successful application on glass bottles by spray coating. Accelerated degradation tests confirmed that the optimised coating effectively protected against photodegradation, as indicated by the stability of polyphenol levels and colour parameters in rosé wines. The results suggest that these coatings could be a suitable option for commercial-scale applications, enhancing the light resistance of colourless-bottled products.