Improving the Sensory Quality of Xinhui Citrus Wine by Mixed Yeasts Fermentation of Saccharomyces cerevisiae and Non-Saccharomyces

Abstract

Xinhui Chenpi, a China National Geographical Indication Product, faces unexploited pulp resources, resulting in resource waste and potential environmental pollution. This study employed Xinhui citrus pulp as a raw material to produce Xinhui citrus wine (XCW), focusing on enhancing the aroma of XCW by utilizing a multi-strains fermentation involving Saccharomyces cerevisiae and Lachancea thermotolerans. The effect of S. cerevisiae Red and/or L. thermotolerans L19 on the enological parameters, physicochemical characteristics and volatile compounds of XCWs were evaluated. The mixed strains fermentation demonstrated a significant increase in esters content, including 2,3-butanediol dinitrate, diethyl succinate, ethyl benzoate, ethyl lactate, and ethyl glycolate compared to those of mono fermentation (p < 0.05), thereby enhancing the fruity and floral aromas of the XCW. The key aroma compounds of relative odor activity value (rOAV) > 1, which are specific to mixed fermentation, were ethyl 2-methylbutyrate, ethyl benzoate, ethyl isovalerate, ethyl propionate, 1-penten-3-ol, and phenylethyl alcohol. These compounds could strengthen the fruity, flowery, and sweet scents of XCW. The findings align with sensory evaluations, suggesting that the mixed fermentation of S. cerevisiae Red and L. thermotolerans L19 to produce XCW might resolve the resource waste of Xinhui citrus pulp.