Résumé
Aroma characterization of alcoholic beverages with sensor array electronic noses is a difficult challenge due to the masking effect of ethanol. Back-flush gas chromatography is proposed as a novel tool for the pretreatment of vapour samples before analysis in the electronic nose. The dehydration and desalcoholization step can be conducted in parallel with electronic nose detection, reducing significantly the analysis overall duration. As demonstration application, five molecules responsible for off-flavours in wines have been detected with a FOX 4000 system, after total dehydration and desalcoholization. Principal component analysis showed that discrimination between the control wine and off-flavour doped-wines became easy, even at concentrations corresponding to the human expert perception threshold. Back-flush gas chromatography is proposed as a novel tool for the pretreatment of vapour samples before analysis in the electronic nose. The dehydration and desalcoholization step can be conducted in parallel with electronic nose detection, reducing significantly the analysis overall duration. As demonstration application, five molecules responsible for off-flavours in wines have been detected with a FOX 4000 system, after total dehydration and desalcoholization. Principal component analysis showed that discrimination between the control wine and off-flavour doped-wines became easy, even at concentrations corresponding to the human expert perception threshold.