A Methodological Approach to the Selection of Saccharomyces cerevisiae Wine Strains
Patrizia Romano, Erminio Monteleone, Margherita Paraggio, Rossella Marchese, Gabriella Caporale, Angela Cartacei
Dipartimento di Biologia, Difesa, Biotecnologie Agro-Forestali, Universita della Basilicata, Via Anzio 10, 85110-Potenza, Italy
Received September 9, 1997
Accepted December 15, 1997
strain selection, wine characteristics, metabolic profile, wine
Yeast strains, producing different amounts of secondary compounds, exert a definite influence on the flavour and aroma of the wines and impart their characteristics. This suggests that the use of a single strain for different types of wines is not appropriate, due to a potential uniformity of aromatic characteristics in the. final products. In order to typify each product for the varietal and geographic characteristics, it becomes necessary to isolate natural autochtonous strains, which, in addition to the desirable technological characteristics, exhibit a metabolic profile corresponding to each wine. Thirty strains of Saccharomyces cerevisiae, isolated from different Aglianico grape cultivars, were tested for fermentation power, SO2-resistance, Cu-resistance and the production of secondary compounds. The results for each strain were transformed into individual functions of desirability (di), i.e. dimensionless values between 0 and 1, and then combined to obtain a response of total desirability (Dtot). The form of the transformation was subjectively selected according to the level of knowledge of the desired optimal response. The strains were tested in Aglianico fermentations and only three showed a Dioi value higher than 0.7. By comparing Dtoi values of selected strains with Dtot values of experimental wines, an evident correspondence was found. This demonstrates the value of the selection method utilised.
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