Biomass suppression of Hanseniaspora uvarum by killer Saccharomyces cerevisiae highly increased fruity esters in mixed culture fermentation

Abstract

Hanseniaspora uvarum strain Yun268 was inoculated with Saccharomyces cerevisiae strains of different antagonistic abilities (RV002 and RV171) to evaluate fruity ester production in mixed fermentation. Co-inoculation (CI) and sequential inoculation (SI) of two yeast species were performed in synthetic must and in Granoir winemaking. Fermentation kinetics, the formation of yeast biomass and fruity esters were monitored during fermentation, and the aroma attributes of the final wines were quantified by trained panelists. Results showed that killer S. cerevisiae suppressed biomass of Yun268 more than common S. cerevisiae, especially in CI treatment. Higher concentration of medium chain fatty acids was associated with the higher biomass suppression of H. uvarum in CI with killer S. cerevisiae, which resulted in the increased formation of fruity esters, but effectively restricted the production of ethyl acetate. However, more biomass and longer survival time of H. uvarum in SI considerably increased volatile acidity (3-fold higher than that in single fermentation), which delayed the reproduction of S. cerevisiae temporarily, and elevated the levels of ethyl acetate. Winemaking confirmed that the co-culture of H. uvarum and killer S. cerevisiae highly improved fruity aromas, which was due to the increase in ester production, especially medium chain fatty acid ethyl esters.