Complexity of the effects of pre-fermentation oxygenation, skin contact and use of pectolytic enzymes in white winemaking as revealed by comprehensive proteomics and volatilomics analysis.

Ion exchange chromatography and SDS-PAGE followed by identification by MALDI-TOF/TOF, and two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC-TOF-MS) were used for comprehensive proteomics and volatilomics evaluation of the effects of pre-fermentative oxygenation, skin contact and use of pectolytic enzymes in production of Malvazija istarska white wine, respectively. Many protein species and an unprecedented number of volatiles have been identified and (semi)quantified, revealing high complexity of the observed effects. Compared to a standard control wine, oxygenation treatment modulated the protein composition and resulted with a volatilome characterized by decreased levels of several important volatiles.

The profile of organic acids and polyphenols in apple wines fermented with different yeast strains.

Influence of two apple cultivars (cvs. Cripps Pink and Idared) and two commercial strains of (Lalvin EC1118, Fermol Blanc) on the chemical composition and sensory characteristics of apple wines was tested. Chemical parameters (alcohol, sugar-free extract, reducing sugars, titratable and volatile acidity) of the analyzed wines were strongly affected by apple variety.