Identification of saffron aroma compound β-isophorone (3,5,5-trimethyl-3-cyclohexen-1-one) in some V. vinifera grape varieties.

Carotenoid-derived aroma compounds play an important role in the composition of aroma and grapes, and consequently of wine. The volatile composition of forty-five grape varieties harvested in 2011 and 2012 was investigated by solid phase extraction of samples and gas chromatography-mass spectrometry (GC-MS) analysis. In grape extracts of cultivars Barbera, Refosco dal Peducolo Rosso, Ribolla gialla and Rossese, the C9-norisoprenoid compound β-isophorone (3,5,5-trimethyl-3-cyclohexen-1-one) was found and quantified. This carotenoid-derived compound is characterised by a saffron aroma and is here reported in grape for the first time.