title: Fatty acid determination in chicken egg yolk: a comparison of different methods.
abstract: Four different methods (direct-methylation, saponification, chloroform-methanol extraction, and postextraction saponification) were compared to determine the fatty acids in egg yolk. About 50 mg of pooled egg yolk samples, with C23:0 as an internal standard, was used for all assays. No difference (P > 0.05) was observed among the four methods for C17:0, C18:0, C18:1, C20:1, C18:2n-6, and C22:6n-3 content of egg yolk. Direct saponification resulted in a lower (P < 0.05) content of C14:0, C16:1, C18:3n-3, and C20:4n-6. Fatty acids at less than 0.5%, such as C15:0 and C14:1, were not detectable in the direct saponification method. The total saturated, monounsaturated, or polyunsaturated fatty acids did not differ (P > 0.05) among the four methods. Direct methylation of egg yolk resulted in lower variability than other methods and is fast and economic for determining egg fatty acid composition.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Sunwoo
authors.forename: G
authors.initials: G
authors.lastname: Cherian
authors.forename: J S
authors.initials: JS
authors.lastname: Sim
mesh_terms: D000818:Animals; D002645:Chickens; D002725:Chloroform; D002849:Chromatography, Gas / Q000379:methods*; D004530:Egg Yolk / Q000737:chemistry*; D005227:Fatty Acids / Q000032:analysis*; D000432:Methanol; D008745:Methylation; D012503:Saponins
chemical_list: D005227:Fatty Acids; D012503:Saponins; D002725:Chloroform; D000432:Methanol