The remarkable effects of the non-volatile matrix of wine on the release of volatile compounds evaluated by analysing their release to the headspaces

Six Spanish wines with different wine-making styles were completely dearomatised and later reconstituted to their original volume with a standard volatile solution containing 15 wine aroma compounds with broad differences in physicochemical characteristics. The headspace composition of the reconstituted wines was evaluated using an automated dynamic headspace (DHS) method combined with thermal desorption (TD) and gas chromatography-mass spectrometry (GC-MS). This method provides a snapshot of the volatile profiles transferred to the headspace in non-equilibrium conditions. The results showed that the non-volatile matrix of the wine significantly affected the transference to the headspace of the 15 aroma compounds. Differences between wines for butanoic and hexanoic acids, DMS and vanillin are above factors 5, 4 or 3, respectively, while for ethyl acetate, ethyl decanoate, 3-methylbutan-1-ol, 2-phenylethan-1-ol or 4-ethylphenol are close to a factor 2. Only ethyl butanoate was uniformly transferred. The release of DMS was related to copper levels, while pH explained part of the release of fatty acids. However, most effects of volatility are difficult to explain. Results strongly indicate that a sample-specific correction for volatility is required to interpret the sensory effects of aroma volatiles.