Abstract: To enrich the flavor and enhance the quality of crown pear wine, Saccharomyces cerevisiae (Sc) and Torulaspora delbrueckii (Td) were selected for co-culture. Changes in the phenolic composition and antioxidant activity of crown pear wine were investigated during single and mixed yeast fermentation and the correlation between them was investigated. Besides, the organic acid and volatile compounds of the two wines were compared. The results showed that the contents of total polyphenols (TP) and total flavonoids (TF) in pear wine increased first and then decreased during fermentation, and so did the scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Compared with pure Sc, the contents of TP and TF in the co-fermented wine increased significantly by 16.5% and 15.9%, respectively. The DPPH radical scavenging capacity significantly increased by 8.3% and the total acid content decreased by 10.05%, with malic acid being the major one. The predominant phenolic compounds in pear wine were arbutin, chlorogenic acid and catechin, whose contents changed in a complex manner during the fermentation process. The phenolic profiles of the two samples were different. Pearson correlation coefficients showed that there was a strongly positive correlation between the DPPH radical scavenging capacity and the contents of TP, arbutin and epicatechin (P < 0.01). The co-fermented wine had higher concentrations of volatile compounds, especially acetate esters contributing to fruity aroma, compared with that obtained with pure Sc. Overall, mixed fermentation of Sc with Td can improve the quality and flavor intensity of crown pear wine. This study provides a support for the deep-processing of crown pear.

Key words: crown pear wine; binary yeast fermentation; phenols; antioxidant activity; flavor volatiles