Impact of the enzymatic activity of autochthonous non-Saccharomyces yeasts on wine volatile profiles

Abstract

Yeasts significantly influence wine aroma through various mechanisms, particularly by producing volatile aroma compounds. Yeasts contain genes that encode enzymes that play multiple roles during alcoholic fermentation (Romano et al., 2019). Non-Saccharomyces yeasts produce and release various enzymes, such as esterases, glycosidases, lipases, β-glucosidases, and proteases, into the periplasmic space and surrounding medium (Styger et al., 2011). These enzymes can interact with grape precursor compounds to generate aroma-active compounds, thereby significantly influencing the wine’s aroma and flavour profile. Asignificant concentration of the aromatic compounds that shape the wine’s aroma is produced by yeasts during fermentation (Carpena et al., 2021).

This research investigates the enzymatic activity of indigenous non-Saccharomyces yeasts and their influence on the volatile aroma profile of Maraština white wine. Selected indigenous yeast strains isolated from 11 vineyards across Dalmatia wine region were evaluated for their enzymatic potential and their impact on wine volatile composition during fermentation. In vitro enzymatic screening revealed significant variability among strains, with Hypopichia pseudoburtonii N- 11, Metschnikowia sinensis/shanxiensis P-7, and Hanseniaspora pseudoguilliermondii V-13 showing enhanced esterase activity. Strong proteolytic activity was observed within Hanseniaspora species, particularly leucine and valine arylamidase activity associated with aromatic amino acid metabolism and aroma precursor transformation. β-glucosidase activity, linked to terpene release, was also detected in several Hanseniaspora strains. Cluster analysis suggested that enzymatic profiles were more strongly influenced by yeast genus than species. Fermentation trials demonstrated that non- Saccharomyces yeasts significantly modified the volatile profile of Maraština wines. Metschnikowia pulcherrima K-6 and Hanseniaspora guilliermondii N-29 promoted the formation of terpenes and C13-norisoprenoids, contributing to enhanced floral and fruity aroma characteristics. Pichia kluyveri Z-3 and Starmerella apicola VP-8 showed increased ester production. Emerging strains such as M. chrysoperlae K-11 and M. sinensis/shanxiensis P-7 reduced the concentration of volatile phenols associated with undesirable “Brett” aromas. The results highlight the oenological potential of indigenous non-Saccharomyces yeasts as multifunctional starter cultures capable of improving aroma complexity and typicity of Maraština wines through specific enzymatic activities and modulation of volatile compounds.

References

Romano, P., Ciani, M., Fleet, G.H. (2019) Yeasts in the Production of Wine, 1st ed, Springer, Berlin/Heidelberg, Germany, pp. 45-54.

Styger, G., Prior, B., Bauer, F.F. (2011) Wine flavor and aroma. J. Ind. Microbiol. Biotechnol., 38, 1145-1159.

Carpena, M., Fraga-Corral, M., Otero, P., Nogueira, R.A., Garcia-Oliveira, P., Prieto, M.A, SimalGandara, J. (2020) Secondary Aroma: Influence of Wine Microorganisms in Their Aroma Profile. Foods, 10, 51.

Acknowledgements

This study was supported by the Croatian Science Foundation under the Research project IP-2020-02-1872 Impact of native non-Saccharomyces wine yeast on wine aromas (WINE AROMAS) and Young Researchers’ Career Development Project–Training New Doctoral Students (DOK2021-02-2070).