title: Determination of the threshold odor concentration of main odorants in essential oils using gas chromatography-olfactometry incremental dilution technique.
abstract: An essential oil, obtained by steam distillation of Clinopodium tomentosum (Kunth) Govaerts (Lamiaceae), collected in Ecuador, was analyzed by gas chromatography-olfactometry (GC-O) and GC-MS techniques. To our knowledge, the composition of this essential oil is described here for the first time, both from the chemical and olfactometric viewpoints. A preliminary analysis by GC-MS and using Kovats' retention indexes, lead to characterize and quantify the oil constituents, while GC-O was then applied for the identification of the main odorants. By the incremental dilution method (AEDA, CHARM Analysis), applied to the GC-O technique, the flavor dilution (FD) chromatogram was obtained. In order to calculate the TOC values of the main odorants, the relationship between the odorant concentration at the sniffing port and that one in the injected solution was established. This relationship was calculated by comparing the injected amount with the TOC value of a reference compound (limonene), obtained by dynamic dilution olfactometry. A good agreement was found between calculated and measured TOC values of few odorants.
authors.affiliation: OSMOTECH s.r.l., Dipartimento di Chimica Farmaceutica, Via Taramelli 12, 27100 Pavia, Italy. osmotech@tin.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: Benzo
authors.forename: Gianluca
authors.initials: G
authors.lastname: Gilardoni
authors.forename: Carlo
authors.initials: C
authors.lastname: Gandini
authors.forename: Gabriele
authors.initials: G
authors.lastname: Caccialanza
authors.forename: Paola
authors.initials: P
authors.lastname: Vita Finzi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vidari
authors.forename: Susana
authors.initials: S
authors.lastname: Abdo
authors.forename: Patricia
authors.initials: P
authors.lastname: Layedra
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D007201:Indicator Dilution Techniques; D019686:Lamiaceae / Q000737:chemistry*; D009812:Odorants / Q000032:analysis*; D009822:Oils, Volatile / Q000032:analysis* / Q000737:chemistry; D010938:Plant Oils / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results
chemical_list: D009822:Oils, Volatile; D010938:Plant Oils