Flavor modification of dry red wine from Chinese spine grape by mixed fermentation with Pichia fermentans and S. cerevisiae

Mixed fermentation of Pichia fermentans and Saccharomyces cerevisiae was designed to circumvent the problem of weak aroma in Chinese spine grape wines. Spine grape, "Xiang Pearl", was used for wine production by red wine making processes. Physicochemical indices were measured using titratable and spectroscopic methodologies. Volatiles were quantified by SPME-GC-MS, and aroma attributes were analyzed by trained panelists. Results showed mixed fermentation benefited color properties by improving total anthocyanin, polymeric anthocyanin, and total tannin contents. The content of varietal compounds, except those of thiols, were reduced, whereas fermentative compounds contents, especially those of higher alcohols, esters, and phenylethyls, were increased by mixed fermentation. Sensory analysis showed mixed fermentation enhanced fruity and floral traits in wine; this was confirmed by mathematical regression showing elevated levels of fermentative volatiles dominated the contribution to pleasant aroma, whereas reduced content of varietal compounds, with the exception of thiols, correlated negatively with favorable characteristics.