A Focus on Quality and Safety Traits of Saccharomyces cerevisiae Isolated from Uva di Troia Grape Variety

The aim of this work was to study Saccharomyces cerevisiae strains isolated from vineyards of the autochthonous grape variety Uva di Troia located in different geographical areas of Apulian region (Southern Italy). Four hundred isolates were studied in relation to H2S production, -glucosidase activity, and pigments adsorption from grape skin. Thus, 81 isolates were selected, identified through the amplification of the interdelta region, and grouped in 19 biotypes (from I to XIX). The enological performances were assessed to determine the content of residual sugars, ethanol, glycerol, and volatile acidity, after a microfermentation in Uva di Troia must for each isolate. The ability to remove ochratoxin A (OTA) was studied as an additional tool to select promising strains. A geographical-dependent technological variability was found for glycerol and volatile acidity, suggesting that the different indigenous yeasts can have a peculiar impact on the final characteristics of the corresponding wine (Nero di Troia). Only 2 biotypes (VI and XVII) were able to remove OTA throughout fermentation, with the highest reduction achieved by the biotype XVII (ca. 30%). Practical Application The improvement of autochthonous grape varieties should be based on the selection of wild starter strains. This paper proposes a selection approach on yeasts to improve Uva di Troia grape variety.