title: Synergistic mixture interactions in detection of perithreshold odors by humans.
abstract: Laboratory demonstrations of synergistic mixture interactions in human odor perception have been rare. The current study examined perithreshold mixture interactions between maple lactone (ML) and selected carboxylic acids. An air-dilution olfactometer allowed precise stimulus control. Experimenters measured stimulus concentrations in vapor phase using a combination of solid-phase microextraction and gas chromatography/mass spectrometry. A probability of detection versus concentration, or a psychometric, functions was measured for pure ML. Psychometric functions were also measured for ML with the addition of fixed, subthreshold concentrations of carboxylic acids. Relative to statistical independence in detection, clear synergy occurred over a range of ML concentrations. To the best of our knowledge, the current results constitute the first clear demonstration of synergy in odor detection by humans from an experiment that combined precise stimulus control, vapor-phase calibration of stimuli, and a clear statistical definition of synergy.
authors.affiliation: Flavor System & Technology Laboratory, R&D Control Division, Ogawa & Co. Ltd, 15-7 Chidori Urayashu-shi, Chiba 279-0032, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Miyazawa
authors.forename: Michelle
authors.initials: M
authors.lastname: Gallagher
authors.forename: George
authors.initials: G
authors.lastname: Preti
authors.forename: Paul M
authors.initials: PM
authors.lastname: Wise
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry; D004357:Drug Synergism; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007783:Lactones / Q000737:chemistry; D009812:Odorants / Q000032:analysis*; D012684:Sensory Thresholds / Q000502:physiology*; D017603:Signal Detection, Psychological / Q000502:physiology*; D012903:Smell / Q000502:physiology*; D014835:Volatilization
chemical_list: D002264:Carboxylic Acids; D007783:Lactones