Characterization of flavor metabolites of cocultured fermented high acidity fruit wines, and the correlation between organic acids and esters

Abstract

High acidity is a major challenge in producing high-quality fruit wines, particularly those derived from Prunus mume (greengage). This study investigated the physicochemical properties, organic acids, and flavor profiles of high-acidity greengage wines fermented by four Saccharomyces yeasts, followed by coculture fermentation with Torulaspora delbrueckii to evaluate flavor modification. Among the single cultures, ScBV818 exhibited the strongest fermentation capacity, achieving an alcohol content of 13.27%, total acidity of 54.55 g L⁻¹, and significantly enhanced levels of esters, aldehydes, and ketones. Its OAVs of ethyl hexanoate, ethyl octanoate, ethyl benzoate, methyl salicylate, and isoamyl acetate were the highest, contributing to rich fruity and floral aromas. Coculture fermentation further improved flavor complexity, with simultaneous inoculation of ScBV818 and T. delbrueckii increasing acetate and ethyl ester contents by 1124.09% and 29.06%, respectively, while enhancing OAVs of ethyl hexanoate, ethyl octanoate, eugenol, linalool, and α-terpineol. Mantel and RDA analyses revealed that high levels of organic acids, such as citric acid and L-malic acid, negatively correlated with acetate and ethyl ester synthesis, while positively influencing ketones, eugenol, and terpenes. These findings highlight the potential of tailored fermentation strategies, such as sequential or simultaneous inoculation, to optimize flavor profiles and sensory quality in high-acidity fruit wines.