title: Development and validation of methodologies for the quantification of phytosterols and phytosterol oxidation products in cooked and baked food products.
abstract: Chromatography-mass spectrometry (GC-MS) methodologies for the analysis of the main phytosterols (PS) and phytosterol oxidation products (POPs) present in 19 different foodstuffs cooked or baked using margarines with or without added plant sterols are presented. Various methods for fat extraction were evaluated to allow the GC-MS analysis of large numbers of prepared vegetable, fish and meat products, egg and bakery items in a practically feasible manner. The optimized methods resulted in a good sensitivity and allowed the analysis of both PS and POPs in the broad selection of foods at a wide range of concentrations. Calibration curves for both PS and POPs showed correlation coefficients (R(2)) better than 0.99. Detection limits were below 0.24mgkg(-1) for PS and 0.02mgkg(-1) for POPs, respectively. Average recovery data were between 81% and 105.1% for PS and between 65.5 and 121.8% for POPs. Good results were obtained for within- and between-day repeatability, with most values being below 10%. Entire sample servings were analyzed, avoiding problems with inhomogeneity and making the method an exact representation of the typical use of the food by the consumer.
authors.affiliation: Unilever Research and Development Vlaardingen, P.O. Box 114, 3130 AC Vlaardingen, The Netherlands.
authors.forename: María
authors.initials: M
authors.lastname: Menéndez-Carreño
authors.affiliation: Unilever Research and Development Vlaardingen, P.O. Box 114, 3130 AC Vlaardingen, The Netherlands.
authors.forename: Diny
authors.initials: D
authors.lastname: Knol
authors.affiliation: Unilever Research and Development Vlaardingen, P.O. Box 114, 3130 AC Vlaardingen, The Netherlands; Analytical-Chemistry Group, van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, P.O. Box 94157, 1090 GD Amsterdam, The Netherlands. Electronic address: hans-gerd.janssen@unilever.com.
authors.forename: Hans-Gerd
authors.initials: HG
authors.lastname: Janssen
mesh_terms: D003296:Cooking; D005504:Food Analysis / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000592:standards; D057230:Limit of Detection; D008383:Margarine / Q000032:analysis*; D010084:Oxidation-Reduction; D010840:Phytosterols / Q000032:analysis*
chemical_list: D010840:Phytosterols; D008383:Margarine
keywords: Cooking and baking; Fat extraction; Phytosterol oxidation products; Phytosterols; Plant sterols