Volatile composition and sensory profile of wines obtained from partially defoliated vines: the case of Nero di Troia wine

The effects of defoliation treatments performed in the bunch-zone on volatile composition and sensory attributes of the corresponding wines were evaluated. Nero di Troia grapes were subjected to four different treatments: no leaf removal (N); leaf removal in the fruit-zone along the east side (at complete veraison) (E); leaf removal in the fruit-zone along the east and west side (at complete veraison) (E/W); almost complete leaf removal along the west side (at complete veraison) and at pre-harvest also along the east side (F). For each defoliation thesis, half of the wine was treated with oak chips in order to verify whether the treatments with oak chips can mask the effects of defoliation. Defoliation partially affected the volatile profiles. Data concerning the volatile profiles show that the highest concentrations of total acids were detected in N and E wines, while those of the total ethyl esters were detected in F wines, and the lowest terpenes concentrations were found in E wines. The oak-treated wines show the highest contents of 1-heptanol, 1-octanol, many ethyl esters, and total hydrocarbons. They were the only in which the whisky lactone was detected. From a sensory point of view, the wines from almost completely defoliated grapes exhibited the lowest scores of gustatory-olfactory intensity, persistence, and quality. The wines that were not treated with chips exhibited sensory profiles characterized by floral and fruity notes, while those treated with oak chips showed sensory profiles characterized by spicy and fruity notes.