title: Levels of phytosterol oxides in enriched and nonenriched spreads: application of a thin-layer chromatography-gas chromatography methodology.
abstract: The content of phytosterol oxidation products (POPs) in enriched and nonenriched commercial spreads was evaluated by thin-layer chromatography-gas chromatography (TLC-GC). Oxides of beta-sitosterol, campesterol, and stigmasterol were produced by thermo-oxidation (7-hydroxy, 7-keto, and epoxy derivatives) and chemical synthesis (triol derivatives), which were then separated and identified by TLC-GC. Their identification was further confirmed by GC-mass spectrometry (GC-MS). The total amounts of phytosterols found were 6.07 and 0.33 g/100 g of sample in phytosterol-enriched and nonenriched spread, respectively, whereas the total POPs contents were 45.60 and 13.31 mg/kg of sample in the enriched and nonenriched products. The main POPs found were the 7-keto derivatives of all phytosterols analyzed; 7-ketositosterol was the most abundant one (14.96 and 5.93 mg/kg of sample in phytosterol-enriched and nonenriched spread). No beta-epoxy and triol derivatives were detected in both types of samples. The enriched spread presented a lower phytosterol oxidation rate (0.07%) than the nonenriched one (0.41%).
authors.affiliation: Departamento de Bromatología, Tecnología de Alimentos y Toxicología, Facultad de Farmacia, University of Navarra, C/Irunlarrea s/n, E-31080 Pamplona, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Conchillo
authors.forename: Luisito
authors.initials: L
authors.lastname: Cercaci
authors.forename: Diana
authors.initials: D
authors.lastname: Ansorena
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Rodriguez-Estrada
authors.forename: Giovanni
authors.initials: G
authors.lastname: Lercker
authors.forename: Iciar
authors.initials: I
authors.lastname: Astiasarán
mesh_terms: D002784:Cholesterol / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D005504:Food Analysis; D005527:Food, Fortified / Q000032:analysis; D008383:Margarine / Q000032:analysis; D010084:Oxidation-Reduction; D010087:Oxides / Q000032:analysis; D010840:Phytosterols / Q000032:analysis* / Q000737:chemistry; D012855:Sitosterols / Q000032:analysis / Q000737:chemistry; D013265:Stigmasterol / Q000032:analysis / Q000737:chemistry
chemical_list: D010087:Oxides; D010840:Phytosterols; D012855:Sitosterols; C021273:campesterol; C025473:gamma-sitosterol; D008383:Margarine; D002784:Cholesterol; D013265:Stigmasterol