The influence of Wickerhamomyces anomalus killer yeast on the fermentation and chemical composition of apple wines.

The aim of this study was to determine the influence of two different Wickerhamomyces anomalus strains, CBS 1982 and CBS 5759, on the chemical composition and sensory characteristics of Gloster apple wines. They were inoculated into unpasteurized as well as pasteurized apple musts together with a S. cerevisiae strain as a mixed culture. Fermentation kinetics, basic enological parameters, antioxidant properties as well as selected polyphenol, volatile compound, and organic acid contents were analyzed during the experiments. Apple wines obtained after spontaneous fermentation were characterized by high volatile acidity, increased concentrations of acetaldehyde, and volatile esters, as well as the lowest amounts of ethyl alcohol and higher alcohols compared with other samples. Addition of 0.05 g L(-1) W. anomalus killer strains to the unpasteurized must significantly changed the fermentation kinetics and chemical composition of apple wines. The value of volatile acidity was highly decreased, while the amount of higher alcohols and titratable acidity increased. Pasteurization of must improved the fermentation efficiency. Higher amounts of polyphenol compounds and lower amounts of malic acid were also detected. Application of W. anomalus strains together with S. cerevisiae yeast as a mixed culture positively influenced the chemical composition and sensory features of produced apple wines.