The combination of gas chromatography-olfactometry and multidimensional gas chromatography for the characterisation of essential oils.
A research area of great interest to the flavour industry is the analysis of odour active compounds in essential oils. In this paper, a methodology is presented for the identification of character-impact odorants in essential oil samples using (a) gas chromatography-olfactometry (GC-O); (b) comprehensive two-dimensional gas chromatography (GC x GC) combined to time-of-flight mass spectrometry (TOFMS) and (c) heart-cut multidimensional gas chromatography-olfactometry (MDGC-O). The specific advantages and limitations of each technique are discussed. The advantage of combining these techniques in a strategy to identify character-impact odorants is demonstrated using examples from coriander leaf (Coriandrum sativum) and hop (Humulus lupulus) essential oils. In particular, resolution of co-eluting regions of compounds and evaluation of their individual odour activity is discussed. In coriander leaf, only E-2-dodecenal was found to contribute to a co-eluting odour region, E-2-dodecen-1-ol and 1-dodecanol being present below detection threshold. Using MDGC on a hop essential oil sample, eight significant peaks were resolved from an 18 s heart-cut where a potent odorant was perceived during GC-O.
Eyres
Graham
G
Department of Food Science, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
Marriott
Philip J
PJ
Dufour
Jean-Pierre
JP
D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods; D009812:Odorants / Q000032:analysis*; D009822:Oils, Volatile / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results
D009822:Oils, Volatile