Effects of noble rot on must composition and aroma profile of Amarone wine produced by the traditional grape withering protocol

The effects of noble rot on the overall quality of Amarone wine, a “Passito” dry red wine, produced with traditional withering grape process is still poorly investigated. Wines obtained from healthy and selected grapes infected by noble-rot were compared. Validation of the experimental plan was carried out by determining glycerol and gluconic acid content, laccase activity and microbial analysis of the musts. The B. cinerea infection produced significant variation on esterase and β-glucosidase activity of grape must. Aroma analysis in healthy and botrytized wines, was carried out by SPE extraction followed by GC–MS quantification. A decrease of several fermentative esters was observed in botrytized wine, while the one produced from healthy grapes showed a higher fatty acid content. Molecules as 1-octen-3-ol, phenylacetaldehyde and furaneol were correlated positively to the noble-rotten grapes. Interestingly, γ-nonalactone and 4-carbethoxy-γ-butyrolactone increased, while Sherry lactones decreased in botrytized wine. The strong increase of N-(3-methylbutyl)-acetamide was related to B. cinerea grape infection.