Wood-resident yeasts: A tool for healthier and more sustainable winemaking

The use of non-Saccharomyces yeasts in wine production has gained attention not only for their impact on wine quality and complexity but also for their potential health benefits. Therefore, it is essential to explore unusual ecological niches to isolate yeast species with peculiar metabolic and physiological properties. In this study, the yeasts inhabiting the interior surface of the wine barrels were studied. In particular, the yeasts were tested for some healthy properties including the production of γ-aminobutyric acid (GABA) and antioxidant activity. The species detected were Zygosaccharomyces bisporus, Zygosaccharomyces bailii, Millerozyma farinosa, Starmerella lactis-condensi, Wickeramiella versatilis, and Zygosaccharomyces rouxii. The highest GABA production was detected for S. lactis-condensi, Z. bisporus and Z. rouxii. A certain intra-species and inter-species variability was detected for the anti-oxidant activity. The Z. bailii, S. lactis-condensi, and Z. rouxii strains showed the highest DPPH and ABTS radical-scavenging activity. The lowest activity was shown by the W. versatilis strains. The use of the yeasts selected in this study with health-promoting properties in winemaking aligns with sustainability goals by enhancing both the nutritional value of wine and the efficiency of the production process. In particular, the high-GABA-producing strains detected as well as the strains with excellent anti-oxidant activity could be proposed as healthful microorganisms for the production of functional beverages or natural antioxidant supplements in the wine industry. Moreover, the strains with anti-oxidant activity might enhance the protection of wines from oxidation, thus potentially assuming an important role in the sensorial quality. By integrating these beneficial yeasts into winemaking, the industry can produce wines that are both healthier for consumers and more environmentally responsible.