Effects of Mixed Fermentation of Torulaspora delbrueckii and Saccharomyces cerevisiae on the Aroma of Yellow Peach Wine

This study explored the potential of Torulaspora delbrueckii in peach wine fermentation and its impact on peach wine aroma. The aroma compounds of yellow peach wines (cv. ‘Jinxiu’) obtained by mixed fermentations of T. delbrueckii PL09 and Saccharomyces cerevisiae K1 or DV10 were determined by headspace-solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) and were analyzed by odor activity value, principal component analysis and sensory evaluation. The results showed that mixed fermentation with T. delbrueckii and S. cerevisiae significantly reduced the total acid and volatile acid contents in yellow peach wine. Additionally, the types and contents of aroma components in the wine fermented with mixed cultures were higher than those in the wine fermented with S. cerevisiae alone, and mixed fermentation promoted the production of esters and alcohols. Among the three wines, the one co-fermented with PL09 and K1 had the highest content of aroma compounds and showed significantly increased levels of ethyl esters (e.g., ethyl acetate, ethyl hexanoate and ethyl laurate) and terpenoids (e.g., phenethyl alcohol and linalool) and enhanced floral and fruity aromas than did the two other wines. Sensory analysis revealed that the PL09 + K1 fermented wine exhibited the most intense sweet and floral notes, with moderate fruity and wine-like aromas, and scored highest for overall aroma. In conclusion, PL09 + K1 co-fermentation increases the aroma complexity of yellow peach wine, providing a theoretical reference for the flavor improvement of yellow peach wine and the industrial application of mixed fermentation.