IMPACT OF METSCHNIKOWIA PULCHERRIMA DURING FERMENTATION ON AROMATIC PROFILE OF VIDAL BLANC ICEWINE
Non-Saccharomyces yeasts not only increase microbial diversity during wine fermentation, but also have a positive effect on improving wine aroma. Among these non-Saccharomyces yeast species, Metschnikowia pulcherrima is often studied and used in winemaking in recent years, but its application in icewine has been rarely reported. In this study, indigenous M. pulcherrima strains and Saccharomyces cerevisiae strains (commercial and indigenous strains) were sequentially inoculated for icewine fer-mentations; meanwhile, pure S. cerevisiae fermentations were used as the control; indigenous strains used above were screened from spontaneous fermentations of Vidal blanc icewine. The aim was to stu-dy the effect of M. pulcherrima on the aroma complexity of icewine, which is of great significance to the application of M. pulcherrima in icewine production. The results showed that M. pulcherrima was completely replaced by S. cerevisiae at the middle and later fermentative stages in mixed culture fer-mentations. Compared with the icewine fermented with pure S. cerevisiae, mixed culture fermented icewines contained lower concentrations acetic acid and ethanol, and higher concentrations glycerol and succinic acid. The inoculation of M. pulcherrima greatly impacted the levels of several important volatile compounds, and more ethyl esters (such as ethyl caprylate, ethyl hexanoate, ethyl heptanoate, eta.), 2,4-hexadienoic acid, decanal, 1-octanol, and trans-rose oxide were produced, and the pleasant fruity and flowery characteristic was intensified. Moreover, the relevance of strain-specificity within M. pulcherrima to aroma compound differences was shown.
Issue: OENO Macrowine 2023
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Metschnikowia pulcherrima, mixed culture fermentation, Vidal blanc icewine, volatile aroma compounds