Sensory properties and aroma compounds of sweet Fiano wine

The aroma of sweet Fiano wine, the most representative non-aromatic white wine variety in southern Italy, was evaluated by sensory and instrumental analysis to determine the influence of grape overripeness, drying and Botrytis cinerea infection. Sensory descriptive analysis was used to evaluate the sensory properties of wines. Gas chromatography/mass spectrometry (GC/MS), gas chromatography (GC) and gas chromatography/olfactometry (GC/O) techniques were used to identify and to determine the content of free and bound volatile compounds and their odour impact. A sensory descriptive analysis had revealed that the sensory descriptors such as citrus jam, dried apricot, dried figs, prune, honey and coconut, occur in sweet Fiano wine more than in base Fiano wine. Thirty five free volatile compounds had higher levels in sweet Fiano wine than in base Fiano wine, these components were mostly terpenes, β-damascenone, lactones, aldehydes and ketones. Moreover higher levels of terpenes, β-damascenone, benzyl alcohol and 2-phenylethanol were found in the bound volatile fraction of sweet Fiano wine. The main odour impact compounds in sweet Fiano wine were nerol, geraniol and linalool (orange flowers), vitispirane (camphor), lactones such as γ-nonalactone (coconut), δ-decalactone and γ-decalactone (apricot) and 1-octen-3-ol (mushroom). These differences appear to be due to the fact that grape overripeness and the drying process allows concentration of varietal aromatic compounds and an easier transfer of them from skins to must during vinification.