Comparison of isolation methods for the determination of buckwheat volatile compounds

Five different isolation techniques were combined with gas chromatographic–mass spectrometric determination of aroma compounds from buckwheat: dynamic headspace (DHS) with cryotrapping or sorbent trapping, solid-phase microextraction (SPME), headspace sorptive extraction (HSSE), solvent extraction (SE) and simultaneous distillation–extraction (SDE). Optimisation of each technique is presented, as well as comparison of the chemical profiles obtained by them. Solvent extraction with methanol resulted in the isolation of rather polar and less volatile compounds and was deemed least suitable for the odour-active compounds. Only SPME with DVB/CAR/PDMS fibre was suitable for the isolation of highly volatile compounds in a wider polarity range. DHS extracted the smallest number of compounds, but with the comparable chemical profile as obtained by SDE, which was chosen as the most suitable technique to obtain the aroma compounds of cooked buckwheat. The applied isolation techniques are complementary in their ability to extract a representative aroma profile of buckwheat.