title: Thermal oxidation of 9'-cis-neoxanthin in a model system containing peroxyacetic acid leads to the potent odorant beta-damascenone.
abstract: The potent odorant beta-damascenone was formed directly from 9'-cis-neoxanthin in a model system by peroxyacetic acid oxidation and two-phase thermal degradation without the involvement of enzymatic activity. Beta-damascenone formation was heavily dependent on pH (optimum at 5.0) and temperature, occurring over the two sequential phases. The first was incubation with peroxyacetic acid at 60 degrees C for 90 min, and the second was at above 90 degrees C for 20 min. Only traces of beta-damascenone were formed on application of only one of the two phases. Formate and citrate solutions produced a much better environment for beta-damascenone formation than acetate and phosphate. About 7 microg/L beta-damascenone was formed from 5.8 mg/L 9'-cis-neoxanthin under optimal experimental condition. The detailed pathway by which beta-damascenone is formed remains to be elucidated.
authors.affiliation: Institute of Biochemistry, Food Science and Nutrition, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, PO Box 12, Rehovot 76-100, Israel.
authors.forename: Yair
authors.initials: Y
authors.lastname: Bezman
authors.forename: Itzhak
authors.initials: I
authors.lastname: Bilkis
authors.forename: Peter
authors.initials: P
authors.lastname: Winterhalter
authors.forename: Peter
authors.initials: P
authors.lastname: Fleischmann
authors.forename: Russell L
authors.initials: RL
authors.lastname: Rouseff
authors.forename: Susanne
authors.initials: S
authors.lastname: Baldermann
authors.forename: Michael
authors.initials: M
authors.lastname: Naim
mesh_terms: D002021:Buffers; D002851:Chromatography, High Pressure Liquid; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D045792:Norisoprenoids / Q000737:chemistry*; D009812:Odorants; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010463:Peracetic Acid / Q000737:chemistry*; D013997:Time Factors; D024341:Xanthophylls / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D002021:Buffers; D045792:Norisoprenoids; D024341:Xanthophylls; D010463:Peracetic Acid; C011947:neoxanthin; D010100:Oxygen; C075388:beta-damascenone