High-Pressure Homogenization to Modify Yeast Performance for Sparkling Wine Production According to Traditional Methods

Higt pressure homogenization (HPH) was applied at 90 MPa to different yeasts prior to use or prior to their use in the preparation of tirage solutions for sparkling wines. The effects on yeast cell variability, fermentation, and death kinetics during secondary fermentation and aging were determinede. Saccharimyces bayanus L951 and Saccharomyces cerevisiae ML692 and commercial strains S.bayanus Lalvin CH14, S bayanus IOC 18-2007, S.byanus Lalvin EC118 and S.bayanus IT 1818 were used as starters. Chemical characteristics and volatile compound prifiles of the final sparkling wines produced with either HPH-treated or HPH-nontreated yeast were assessed. Results showed that sensitivity to HPH tretment was strain dependent and after 40 days of secondary fermentation all semples reached pressure level of at last 0.60795 MPa, independent of the HPH treatment, with the exceptionoh those inoculated with strain ML692. Scanning electron microscope microphotogaphs of the samplesaged 40 days inoculated for all strains an acceleration of autolysis due to HPH treatment