Effect of pure and mixed culture fermentation of Metschnikowia pulcherrima yeast on aroma and thiol compounds in white wine production

In this study, white wine was produced by using pure and mixed cultures (Mp+Sc) of Metschnikowia pulcherrima (Mp) and Saccharomyces cerevisiae (Sc) yeasts from Sauvignon Blanc grape in Güney county of Denizli, the volatile thiol and aroma compounds of these wines were determined and also, the effects of the yeasts on the quality of the wines were investigated. The analysis of volatile thiol compounds of wines was carried out by LC-MS/MS technique and external standard method using 4,4′-dithiodipyridine (DTDP) derivatizing agent. The extraction of aroma substances of the wines was carried out by the solid phase extraction (SPE) method, and the amount was identified and determined with the GC-MS-FID technique. It was determined that S. cerevisiae formed 4 MMP compounds (17.8 ng/L), and mixed culture fermentation formed 3MH and 3MHA compounds (1111.2 ng/L and 344.1 ng/L, respectively) in higher amounts than the others. 39 aroma compounds were identified in Mp, Sc and Mp+Sc wines, and their amounts were determined as 173 mg/L, 176 mg/L, and 184 mg/L, respectively. Pure M. pulcherrima produced higher alcohol compounds, while mixed culture fermentation produced ester and volatile acid compounds in higher amounts than the others. It was concluded that the mixed culture fermentation of M. pulcherrima and S. cerevisiae increased the volatile thiol and aroma concentration compared to the other two pure culture fermentations and was applicable in wine production.