Impact of mixed non-Saccharomyces yeast during fermentation on volatile aroma compounds of Vidal blanc icewine

Candida zemplinina , Candida californica , Hanseniaspora uvarum , and Hanseniaspora osmophila were screened from spontaneous fermentations of Vidal blanc icewine. These non- Saccharomyces yeasts and commercial Saccharomyces cerevisiae were used in mixed inoculated fermentations, and pure S. cerevisiae fermentation was used as the control. The aim is to investigate the effects of these non- Saccharomyces yeasts on the aroma complexity of icewine, which is of great significance for the application of these non- Saccharomyces yeasts in icewine production. Compared with the icewine fermented with pure S. cerevisiae , the icewines fermented using mixed C. zemplinina contained higher glycerol, ethyl esters and β-damascenone contents, while icewines fermented using mixed C. californica had more acetate esters and terpenes. Icewines fermented using mixed H. uvarum contained higher ethanol and ethyl acetate contents, and icewines fermented using mixed H. osmophila had lower ethanol and higher phenethyl acetate contents, than icewine fermented with pure S. cerevisiae . Therefore, mixed fermentations of different non- Saccharomyces yeasts contributed different aroma characteristics to icewines. To the best of our knowledge, this study is the first to investigate the application of C. californica and volatile aroma compounds in icewines.