Effect of Issatchenkia terricola and Pichia kudriavzevii on wine flavor and quality through simultaneous and sequential co-fermentation with Saccharomyces cerevisiae

Using co-fermentation of non-Saccharomyces yeast and Saccharomyces cerevisiae to improve wine flavor and quality has received more and more acceptance. To investigate the effect of selected Issatchenkia terricola SLY-4 and Pichia kudriavzevii F2-24 on wine flavor and quality when co-fermented with S. cerevisiae, the yeast growth kinetics, physicochemical characteristics, aroma compounds and sensory evaluation of wine samples with different inoculation strategies were analyzed. The results indicated that co-fermentation improved wine flavor and quality for its lower volatile acidity and higher aroma compound content than S. cerevisiae fermentation. Moreover, the sequential co-fermentation was more conducive to the improvement of wine flavor and quality than their simultaneous co-fermentation, due to its higher esters content and lower concentrations of C-6 compounds, benzene derivatives, higher alcohols and fatty acids. On the other hand, P. kudriavzevii F2-24/S. cerevisiae co-fermentation wine samples got higher scores in sensory evaluation than I. terricola SLY-4/S. cerevisiae co-fermentations. The sequential co-fermentation of P. kudriavzevii F2-24/S. cerevisiae was the best way to improve wine flavor and quality. These results not only highlighted the role of these two non-Saccharomyces yeast strains in improving wine flavor and quality but also provided a reference for co-fermentation of other non-Saccharomyces yeasts.