The development of blueberry wine provides an alternative method for maintaining the nutritional value and extending the shelf life of blueberries. However, anthocyanin loss and off-flavor compound generation during fermentation impair blueberry wine color and quality. Hydroxycinnamate decarboxylase from yeast can catalyze the conversion of hydroxycinnamic acids to vinylphenols, which later may condense with anthocyanins to form more stable vinylphenolic pyranoanthocyanins. In this study, 10 non-Saccharomyces yeasts from Daqu that showed hydroxycinnamate decarboxylase activity were screened. Among the 10 strains, Wickerhamomyces anomalus Y5 showed the highest consumption (34.59%) of the total tested phenolic acids and almost no H₂S production. Furthermore, Y5 seemed to produce four vinylphenol pyranoanthocyanins (cyanidin-3-O-galactoside/glucoside-4-vinylcatechol, cyanidin-3-O-galactoside/glucoside-4-vinylsyringol, malvidin-4-vinylguaiacol, and malvidin-4-vinylcatechol) during blueberry wine fermentation, which may improve the color stability of blueberry wine. These findings provide new insights for improving the quality of blueberry wine using non-Saccharomyces yeasts.

During the fruit wine production, phenolic acid decarboxylase (PAD) converts free hydroxycinnamic acid into 4-vinyl derivatives that can then react spontaneously with anthocyanins, generating more stable pyranoanthocyanins that are responsible for the color stability of fruit wine. Nevertheless, the low PAD activity in yeast under the winemaking conditions has largely limited the generation of 4-vinyl derivatives. To bridge this gap, we expressed PAD from Bacillus amyloliquefaciens in Pichia pastoris and surface-displayed it on Saccharomyces cerevisiae. As a result, S. cerevisiae surface-displayed PAD (SDPAD) exhibited an enhanced thermal stability and tolerance to acidic conditions. Fermentation experiments showed that SDPAD can significantly increase the content of vinylphenolic pyranoanthocyanins and thus maintain the color stability of blueberry wine. Our study demonstrated the feasibility of surface display technology for color stability enhancement during the production of blueberry wine, providing a new and effective solution to increase the content of vinylphenolic pyranoanthocyanins in the fruit-based wines.

The flavor characteristics and sensory attributes of northern Sauce-flavored rounded-Baijiu (NR) and southern Sauce-flavored rounded-Baijiu (SR) were systematically studied. A total of 56 major flavor compounds were quantitatively detected through Gas chromatography-flame ionization detection (GC-FID). Besides, 20 kinds of key aroma compounds and 7 significant differential compounds were identified by calculating the odor activity values (OAVs) and orthogonal partial least squares discriminant analysis (OPLS-DA) of flavor compounds in NR and SR. And then, the relationship between sensory attributes and key aroma compounds were investigated by network analysis. Furthermore, A group of combined-Baijiu (the ratios of the first to the fifth round of Sauce-flavored Baijiu in the north (NR1–5) were 5 % NR1, 35 % NR2, 30 % NR3, 20 % NR4, 10 % NR5) was closer to the style known for blending different proportions of SR into the combined-Baijiu. This study provided a guiding significance for the standardized production of sauce-flavored Baijiu.