title: GC-based analysis of plant stanyl fatty acid esters in enriched foods.
abstract: Approaches for the capillary gas chromatographic (GC) based analysis of intact plant stanyl esters in enriched foods were developed. Reference compounds were synthesized by enzyme-catalyzed transesterifications. Their identities were confirmed by means of mass spectrometry. Using a medium polar trifluoropropylmethyl polysiloxane stationary phase, long-chain plant stanyl esters could be separated according to their stanol moieties and their fatty acid chains. Thermal degradation during GC analysis was compensated by determining response factors; calibrations were performed for ten individual plant stanyl esters. For the analysis of low-fat products (skimmed milk drinking yogurts), the GC separation was combined with a "fast extraction" under acidic conditions. For fat-based foods (margarines), online coupled LC-GC offered an elegant and efficient way to avoid time-consuming sample preparation steps. The robust and rapid methods allow conclusions on both, the stanol profiles and the fatty acid moieties, and thus provide a basis for the authentication of this type of functional food ingredients.
authors.affiliation: Lehrstuhl für Allgemeine Lebensmitteltechnologie, Technische Universität München, Freising-Weihenstephan, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Barnsteiner
authors.forename: Tim
authors.initials: T
authors.lastname: Lubinus
authors.forename: Angelica
authors.initials: A
authors.lastname: di Gianvito
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schmid
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Engel
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D004951:Esterification; D005227:Fatty Acids / Q000032:analysis*; D005527:Food, Fortified / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D008041:Linoleic Acids / Q000032:analysis; D010168:Palmitates / Q000032:analysis; D010840:Phytosterols / Q000032:analysis; D010944:Plants / Q000737:chemistry*; D015014:Yogurt / Q000032:analysis
chemical_list: D005227:Fatty Acids; D008041:Linoleic Acids; D010168:Palmitates; D010840:Phytosterols