Characterization of citrus and kiwi flavors and their degradation processes by combination of GC/FTIR and GC/MS

Flavor samples are complex mixtures with components of sometimes very similar chemical behavior (e.g. isomeres). As an approach towards their characterization an integrated analytical method on the basis of capillary gas-chromatography (HRGC) was applied consisting of two molecular specific techniques for component-identification in unknown samples: GC-FTIRS (GC-Fourier transform infrared spectrometry) and GC-MS (GC-mass spectrometry).In addition GC-retention indices-from simultaneous GC on two columns (nonpolar/polar) —were stored in a database for routine retrieval and quantitative monitoring. To correlate this information with sensory perception sniffing chromatograms were generated with the human nose as a high performance detector.Because of the high information contents of GC-FTIR spectra in this field a small but specific vapor-phase-FTIR flavor library was accumulated, which dramatically improved the fast identification power of GC-FTIRS alone.