Withering aptitude of Italian autochthonous Erbaluce wine grape variety: withering kinetics, grape composition and wine aroma evaluation.

Erbaluce white grape cultivar is an autochthonous variety found in the north Piedmont region (northwest Italy). This work reports some results of different research experiences finalized to evaluate the withering aptitude of Erbaluce grapes and the related grape and wine composition, with particular attention to the aroma profile. A preliminary study on how the withering kinetics are influenced by initial grapes' mechanical parameters was carried out on berries selected by their sugar content, evidencing a faster withering for the berries presenting a lower berry skin break force. At the end of a natural dehydration process, withered berries were separated according to their external color and then analyzed: Botrytis cinerea influence was evidenced only in blue berries according to grape chemical composition and aroma analysis, while a profile of the other groups (green and gold berry color) didn’t show the chemical markers of this fungus at the stage of noble rot. Finally, a large number of commercial Caluso Passito wines, made with withered Erbaluce grapes, were characterized by their chemical composition and aroma profile, with for the latter more than 100 aroma compounds found.