Identification of character-impact odorants in coriander and wild coriander leaves using gas chromatography-olfactometry (GCO) and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOFMS)

The essential oil of coriander leaves (Coriandrum sativum) and wild coriander leaves (Eryngium foetidum) grown in Fiji was obtained by steam distillation. The aroma profiles were characterised using gas chromatography-olfactometry (GCO) and CharmAnalysis. The character-impact odorants were identified using comprehensive two-dimensional gas chromatography (GC x GC) combined with time-of-flight mass spectrometry (TOFMS). During GCO analysis, the co-elution of E-2-alkenals and E-2-alken-1-ols resulted in the perception of 'odour-clusters'. The most important odorants in C. sativum were found to be Z-2-decenal, a co-eluting odour-cluster (E-2-dodecenal, E-2-dodecen-1-ol, and 1-dodecanol), beta-ionone, eugenol, and E-2-decenal. E-2-decen-1-ol was the most abundant compound in C. sativum (26.0% TIC) but only contributed 0.39% of the total odour activity. The most abundant compound in E. foetidum was E-2-dodecenal (63.5% TIC), which also contributed the most odour activity (52.9%). Other important odorants were either eugenol or a trimethylbenzaldehyde isomer, beta-ionone, Z-4-dodecenal, dodecanal, and E-2-tetradecenal. GC x GC-TOFMS allowed the identification of 42 and 20 compounds not previously reported in the literature for C. sativum and E. foetidum, respectively. In particular, beta-ionone was determined to be an important odorant in both samples but could not be identified with GC-qMS.