Influence of Fermentation Methods on Jujube Wine Quality: A Volatile Metabolomics-Based Investigation

Co-fermentation with Saccharomyces cerevisiae and selected non-Saccharomyces yeasts is an effective approach for producing fruit wines with distinctive aromas. This study aimed to improve the aroma complexity of jujube wine by evaluating multi-strain sequential inoculation strategies. Two indigenous non-Saccharomyces strains, Hanseniaspora uvarum TD74 and Metschnikowia pulcherrima HJ79, were sequentially inoculated for fermentation in combination with S. cerevisiae. The physicochemical properties and volatile compound profiles of jujube wines produced under different inoculation conditions were analyzed using HS-SPME-GC-MS, coupled with electronic nose, electronic tongue, and chemometric analyses. Compared with single-strain fermentation, sequential inoculation with the two non-Saccharomyces yeasts produced significantly more distinct volatile profiles. In particular, the triple-strain sequential inoculation group (MHS) exhibited higher semi-quantitative levels of most ethyl esters, with a more pronounced fruity aroma in the wine, consistent with the results of sensory analysis. These findings demonstrated that the use of multiple non-Saccharomyces yeasts is an effective strategy for enhancing the aromatic diversity and overall sensory quality of jujube wine, offering a theoretical basis for the rational design of optimized starter cultures for industrial jujube wine production.