The effects of enzymatic pre-treatment and type of yeast on chemical properties of white wine

- Must pre-treatment significantly affected final wine quality.
- Yeast strains altered basic parameters of white wine to greater extent than enzymatic pre-treatment of must.
- Saccharomyces cerevisiae was much more valuable yeast species than S. bayanus.
- Wines obtained with S. cerevisiae were characterized by higher polyphenol content, smaller reduction of antioxidant activity and the strongest aroma.

The study investigated 15 variants of wine differing in their must pre-treatment (maceration by enzymes: Siha Pectinase or SihazymUni) and fermentation by different yeast strains (S.cerevisiae as ICV - D-47; SIHA- Cryaroma; Challenge Aroma White; and S. bayanus as SIHA Active Yeast). The effects of experimental conditions on chemical composition (pH, acidity, sugar), content of phenolic (LC-PDA-QTOF/MS) and volatile compounds (GC-MS), antioxidant activity (ABTS and FRAP assay), color property (CIEL*a*b*), and ethanol content were measured. For all production processes, significant changes in basic parameters and in the amount of polyphenolic compounds and antioxidant activity in wine were observed as compared to must. The wines obtained with S. cerevisiae were characterized by higher polyphenol content, smaller reduction of antioxidant activity and the strongest aroma. Challenge Aroma White yeast strain particularly contributed to good quality of wine. Enzymatic pre-treatment did not significantly affect the studied parameters (expect pH and the content of phenolic acids).