Ozone in gaseous and aqueous phases as a sanitizing agent for grapes used in winemaking and its impact on the implantation of Lachancea thermotolerans

Abstract

Ozonation is an effective and sustainable method for grape sanitation, facilitating the implementation of non-Saccharomyces yeasts such as Lachancea thermotolerans. This study evaluated gaseous (28 g h⁻¹ for 30 min) and aqueous ozone (0.5 g h⁻¹ for 30 min) treatments on L. thermotolerans implantation in Red Globe grapes. Fermentations with L. thermotolerans and Saccharomyces cerevisiae were conducted at different inoculation rates, assessing must acidification, sugar consumption and volatile compounds. Ozone treatments increased lactic acid production, lowered pH and enhanced L. thermotolerans metabolic activity. Volatile analysis revealed a higher production of 2-phenyl ethanol, a characteristic compound of L. thermotolerans. These findings suggest ozonation as a potential alternative to sulfitation, improving yeast implantation and modulating wine acidity and aroma.