Check of four generations of Saccharomyces cerevisiae for adsorption activity during winemaking

The different adsorption aptitude determines significant differences in wines produced with different selected yeasts [1]. The polygenic basis and the inheritability of the oenological traits “wine colour adsorption” [2] and “ochratoxin A adsorption” [3] in yeasts have been demonstrated. This work aimed to study the inheritability and the segregation during four generations of the main oenological traits related to the adsorption activity: colour intensity, phenolic content, and antioxidant activity. The traits were studied in 65 wine yeasts of the species Saccharomyces cerevisiae - 3 wild types, 24 single-spore descendants, 4 hybrids obtained by crossing the descendants and 34 single-spore descendant derived from the hybrids - both on yeast biomass, using the chromogenic medium Grape-Skin Agar, and by micro-winemaking trials. A computer-assisted assessment of the biomass colour of the yeasts grown on Grape-Skin Agar was performed. Wines were analysed for: pH, ethanol content, absorbance at 420, 520, and 620 nm, colour intensity and tint, Folin-Ciocalteu index, % of DPPH inactivation, and total ascorbic acid equivalents (TAA) expressed as mg/mL.Data have confirmed the possibility to improve wine yeast as regards the traits related to the adsorption activity. The relevant related literature and the present results are discussed considering, above all, the oenological consequences for wine starter selection.[1] Caridi A., Cufari A., Lovino R., Palumbo R., Tedesco I. - Influence of yeast on polyphenol composition of wine. Food Technology and Biotechnology, 42(1), 37-40, 2004.[2] Caridi A., Sidari R., Solieri L., Cufari A., Giudici P. - Wine colour adsorption phenotype: an inheritable quantitative trait loci of yeasts. Journal of Applied Microbiology, 103(3), 735-742, 2007.[3] Caridi A., Sidari R., Pulvirenti A., Meca G., Ritieni A. - Ochratoxin A adsorption phenotype: An inheritable yeast trait. The Journal of General and Applied Microbiology, 58(3), 225-233, 2012.