Effects of Simultaneous Co-Fermentation of Five Indigenous Non-Saccharomyces Strains with S. cerevisiae on Vidal Icewine Aroma Quality

Abstract

In this study, Vidal grape must was fermented using commercial <i>Saccharomyces cerevisiae</i> F33 in pure culture as a control and in mixed culture with five indigenous non-<i>Saccharomyces</i> yeast strains (<i>Hanseniaspora uvarum</i> QTX22, <i>Saccharomycopsis crataegensis</i> YC30, <i>Pichia kluyveri</i> HSP14, <i>Metschnikowia pulcherrima</i> YC12, and <i>Rhodosporidiobolus lusitaniae</i> QTX15) through simultaneous fermentation in a 1:1 ratio. Simultaneous fermentation inhibited the growth of <i>S. cerevisiae</i> F33 and delayed the time to reach the maximum biomass. Compared with pure fermentation, the contents of polyphenols, acetic esters, ethyl esters, other esters, and terpenes were increased by <i>R. lusitaniae</i> QTX15, <i>S. crataegensis</i> YC30, and <i>P. kluyveri</i> HSP14 through simultaneous fermentation. <i>S. crataegensis</i> YC30 produced the highest total aroma activity and the most abundant aroma substances of all the wine samples. The odor activity values of 1 C13-norisoprenoid, 3 terpenes, 6 acetic esters, and 10 ethyl esters improved significantly, and three lactones (δ-decalactone, γ-nonalactone, and γ-decalactone) related to coconut and creamy flavor were only found in this wine. Moreover, this sample showed obvious "floral" and "fruity" note odor due to having the highest amount of ethyl ester aromatic substances and cinnamene, linalool, citronellol, β-damascenone, isoamyl ethanoate, benzylcarbinyl acetate, isobutyl acetate, etc. We suggest that simultaneous fermentation of <i>S. crataegensis</i> YC30 with <i>S. cerevisiae</i> might represent a novel strategy for the future production of Vidal icewine.