Evaluation of Williopsis saturnus Inoculum Level on Fermentation and Flavor Compounds of White Wines Made from Emir (Vitis vinifera L.) Grown in Anatolia

Abstract

The effects of different W. saturnus inoculum levels together with S. cerevisiae on fermentation and production of volatile compounds were studied in Emir grape must. Monocultures of W. saturnus and S. cerevisiae were also used. Inoculum level influenced the yeast growth, chemical composition and volatile compounds. W. saturnus began to die off with an increase in ethanol levels. The amounts of ethyl acetate and isoamyl acetate increased, but concentrations of 3-methylbutanol and ethanol decreased with increasing inoculum level from 5x10(6) to 1x10(8) cells/mL of W. saturnus in mixed cultures. Mono-and mixed culture fermentations inoculated with W. saturnus and S. cerevisiae yeasts did not form undesirable levels of flavour compounds. According to chemical composition and volatile compounds the differences between obtained wines were found significant. The addition of 5x10(6) cells/mL of W. saturnus appeared to a suitable inoculum level. It could be said that W. saturnus yeast can be used in mixed starter cultures with S. cerevisiae.