Aglianico and Fiano wines obtained with an autochthonous non-Saccharomyces yeast

Non-Saccharomyces yeasts are microorganisms that play a prominent role in the fermentation dynamics, composition and flavour of wine. The principal aromatic compounds responsible for varietal aroma in wine are terpenes; of these, the monoterpenes represent the oenologically most important group in terms of volatility and odour, if they are present in a free form. The glycosidically bound forms can be converted into compounds with free odours by hydrolysis with the glycosidases produced by yeasts. We performed a screening of non-Saccharomyces yeasts present in the grapes and must of Aglianico and Fiano cultivars typical of South Italy (Irpinia), which have a high extra-cellular glycosidase activity. Among the species analysed was a strain belonging to Rhodotorula spp. that showed the highest glycosidase activity, an increased free terpene fraction and, simultaneously, little modification of the bouquet. The isolated yeast was subsequently utilized for experimental winemaking processes of Aglianico and Fiano wines. The results demonstrated that the obtained wines had a more intense floral aroma and some sweet and ripened fruit notes.