The aroma of Grenache red wine: hierarchy and nature of its main odorants

Abstract

A young Grenache red wine from 1995 harvest was continuously extracted with Freon-11 and the extract cleaned up with aqueous NaHCO3 in order to remove fatty acids. An Aroma Extract Dilution Analysis was carried out with that extract in a Carbowax 20M capillary column with simultaneous MS and olfactometric detections. The AEDA analysis showed that there are 43 flavour active regions in the chromatogram whose aromatic intensities ranged from less than 16 to more than 1000 arbitrary flavour dilution coefficients. To isolate the odorants, the extract was further washed with propylglycol, concentrated, and then fractionated by normal phase HPLC with UV detection at 220 nm in order to obtain 29 fractions. All the fractions were concentrated and analysed in the same HRGC-MS-olfactometric system in which the AEDA experiment was performed. The strategy allowed to isolate most of the odorants, and 30 of them, among which were the most important, could be clearly identified. Some others could not be identified but their mass spectra are given. Among the most important odorants there are some well known fermentation esters but, surprisingly, the role played by some minor esters, such as the ethyl esters of isobutyric, isovaleric and 2-methylbutyric acids, seems to be very important. Equally important could be the role played by some volatile phenols, terpenols, lactones and some nor-isoprenoids. © 1998 SCI.