Chemical Fingerprints of Honey Fermented by Conventional and Non-Conventional Yeasts

Previous studies have shown the positive effects of non-conventional <i>Metschnikowia</i> spp. yeasts in mixed cultures with <i>Saccharomyces cerevisiae</i> on the properties of fruit wines. In this study, we investigated the effects of using conventional <i>S. cerevisiae</i> and non-conventional <i>Metschnikowia pulcherrima</i> yeasts as starter cultures in controlled mixed fermentations of honey wort. Other non-conventional yeasts were also tested for comparison, including <i>Wickerhamomyces anomalus</i>, <i>Dekkera</i>/<i>Bretannomyces bruxellensis</i>, and <i>Wickerhamomyces anomalus</i>. We evaluated the tolerance of the tested yeasts to high sugar content and analyzed the metabolic profiles of both monocultures and mixed systems. The <i>M. pulcherrima</i> strain showed the highest tolerance to 30% <i>w</i>/<i>v</i> glucose. The chemical complexity of fermented honey was improved using <i>M. pulcherrima</i> in co-starters with <i>S. cerevisiae.</i> The fermented honey samples were characterized by lower ethanol content, higher glycerol level, and rich volatilomes containing higher levels of both esters (ethyl acetate, 3-methylbutyl acetate, 2-methylpropyl acetate) and aliphatic alcohols (2-methylpropan-1-ol, 3-methylbutan-1-ol, and 2-methylbutan-1-ol). Similar characteristics were obtained using mixed populations of four strains: <i>S. cerevisiae</i>, <i>M. pulcherrima</i>, <i>D. bruxellensis</i>, and <i>W. anomalus</i>.