THE IMPACT OF NON-SACCHAROMYCES YEASTS ON THE WHITE WINE QUALITY
Selected strains of non-Saccharomyces yeasts showed a positive effect on sensory characteristics and aromatic complexity of wine. A sequential microbial culture of non-Saccharomyces and S. cerevisiae species is usually inoculated due to poorer fermentability of non-Saccharomyces species. The aim of the study was to investigate the role of non-Saccharomyces yeasts in the production of white wines. We evaluated how individual combinations of sequential inoculations of non-Saccharomyces and S. cerevisiae species affect the aromatic compounds (volatile thiols and esters) and sensory characteristics of the wines. Sauvignon Blanc and Istrian Malvasia musts were inoculated sequentially with different species of non-Saccharomyces yeasts (Pichia kluyveri FrootZen (Chr. Hansen Holding A/S), Kluyveromyces dobzhanskii Re19L, Pichia guilliermondii ZIM624, Starmerella orientalis 126, Torulaspora delbrueckii IVV7, Lachancea thermotolerans BLF LT7 (Laffort),) and yeasts of the Saccharomyces genus (S. cerevisiae Zymaflore X5 (Laffort), S. uvarum NO608/1, S. cerevisiae Ca39). Fermentation kinetics and reducing sugars content were monitored gravimetrically during alcoholic fermentation. After completion of alcoholic fermentation, physicochemical analyses were performed, and the content of volatile thiols and esters was determined by GC-MS and the content of hydroxycinnamates by HPLC-DAD. We also performed sensory analysis using intensity ranking test. The mixed yeast cultures showed differences in fermentation kinetics, in the ability to release thiols, and in the synthesis of esters during alcoholic fermentation. According to the sensory evaluation, the best evaluated wine was produced with the yeast K. dobzhanskii Re19L in the vinification of Sauvignon Blanc and with T. delbrueckii IVV7 in the Istrian Malvasia variety.
Issue: OENO Macrowine 2023
1University of Nova Gorica, Wine Research Centre, Glavni trg 8, 5271 Vipava, Slovenia
2University of Ljubljana, Biotechnical Faculty, Jamnikarjeva ulica 101, 1000 Ljubljana, Slovenia
3Agricultural Institute of Slovenia, Central Laboratories, Hacquetova ulica 17, 1000 Ljubljana, Sloveni
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non-Saccharomyces yeasts, volatile thiols, esters, sensory properties