title: Effect of domestic cooking methods on egg yolk xanthophylls.
abstract: Xanthophylls are a class of bioactive compounds known to play an important role in preventing age-related macular degeneration. Egg yolk is a rich source of highly bioavailable xanthophylls including lutein and zeaxanthin. The effects of domestic cooking methods (boiling, frying, microwaving) on egg yolk xanthophyll content were investigated. A LC-(APCI)-MS/MS method was used to identify and quantify all-E- and Z-isomers of lutein, zeaxanthin, canthaxanthin, and β-apo-8'-carotenoic acid ethyl ester in fresh and cooked egg yolks. Both fresh and cooked yolks showed similar xanthophyll profiles but with higher contents of Z-isomers in cooked samples. All-E-lutein was the most affected, with 22.5%, 16.7%, and 19.3% reductions in boiled, microwaved, and fried yolk extracts, respectively. Total xanthophyll losses ranged from 6% to 18%. The results presented here could be useful in calculating the dietary intake of xanthophylls and also in assessing the xanthophyll profiles and contents of egg-containing products.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
authors.forename: Chamila
authors.initials: C
authors.lastname: Nimalaratne
authors.forename: Daise
authors.initials: D
authors.lastname: Lopes-Lutz
authors.forename: Andreas
authors.initials: A
authors.lastname: Schieber
authors.forename: Jianping
authors.initials: J
authors.lastname: Wu
mesh_terms: D016644:Canthaxanthin / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D003296:Cooking / Q000379:methods*; D004530:Egg Yolk / Q000737:chemistry*; D006358:Hot Temperature; D014975:Lutein / Q000032:analysis; D008872:Microwaves; D053719:Tandem Mass Spectrometry; D024341:Xanthophylls / Q000032:analysis*; D065146:Zeaxanthins
chemical_list: D024341:Xanthophylls; D065146:Zeaxanthins; D016644:Canthaxanthin; D014975:Lutein