IDENTIFICATION OF VOLATILE CONSTITUENTS IN WINES FROM VITIS-VINIFERA VAR VIDADILLO AND SENSORY CONTRIBUTION OF THE DIFFERENT WINE FLAVOR FRACTIONS

A wine made with vidadillo, a very old Spanish variety, has been continuously extracted and the extract further fractionated in a silica gel column with successive portions of hexane/dichloromethane/ether mixtures following an elutropic order. Ten fractions showing different odours were isolated and analysed by HRGC-MS and their olfactory and flavour threshold determined via triangular tests. More than 200 compounds belonging to different biosynthetic pathways have been identified. It is important to note the large number of gamma- and delta-lactones and of compounds derived from the phenylpropanoid metabolism present. From a sensory point of view, all the fractions showed aroma values below 100, meaning that there are no clear impact compounds. Three fractions scored aroma values higher than 10, and therefore play an important role in the perception of the different flavour and aroma nuances of the wine. Compounds that may play an outstanding role are fusel alcohol acetates in the fruity notes, gamma- and delta-lactones in the peach notes, and some unidentified compounds in the liquorice notes. The silica gel prefractionation method leads to a class separation, and compounds showing similar aromatic notes are eluted together, allowing an easy interpretation of the role of the different groups of flavours.