title: Quantitation of Acyl Chain Oxidation Products Formed upon Thermo-oxidation of Phytosteryl/-stanyl Oleates and Linoleates.
abstract: A GC-based approach involving preseparation via solid-phase extraction was established for the quantitation of acyl chain oxidation products (ACOPs) formed upon thermo-oxidation (180 °C, 40 min) of oleates and linoleates of phytostanols and phytosterols. The concentrations of ACOPs resulting from initially formed 9-hydroperoxides (octanoates, 8-hydroxyoctanoates, 9-oxononanoates) were higher than those from 8-hydroperoxides (heptanoates, 7-hydroxy- and 7-oxoheptanoates, 8-oxooctanoates) in both oleates and linoleates. Significantly higher amounts of ACOPs were found in heat-treated linoleates compared to oleates. However, despite lower thermally induced losses of stanyl oleates and linoleates compared to the respective steryl esters, higher concentrations of ACOPs (approximately 9 and 10% of the ester losses, respectively) were observed in the heat-treated stanyl esters. In contrast, in the heated steryl oleates and linoleates the contribution of the ACOPs to the ester losses was lower (approximately 3 and 5%, respectively), and there was a more pronounced formation of oxidation products of the sterol moieties (approximately 26 and 18% of the ester losses, respectively).
authors.affiliation: Lehrstuhl für Allgemeine Lebensmitteltechnologie, Technische Universität München , Maximus-von-Imhof-Forum 2, D-85354 Freising, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Wocheslander
authors.affiliation: Lehrstuhl für Allgemeine Lebensmitteltechnologie, Technische Universität München , Maximus-von-Imhof-Forum 2, D-85354 Freising, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Groß
authors.affiliation: Lehrstuhl für Allgemeine Lebensmitteltechnologie, Technische Universität München , Maximus-von-Imhof-Forum 2, D-85354 Freising, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Scholz
authors.affiliation: Lehrstuhl für Allgemeine Lebensmitteltechnologie, Technische Universität München , Maximus-von-Imhof-Forum 2, D-85354 Freising, Germany.
authors.forename: Karl-Heinz
authors.identifier: http://orcid.org/0000-0001-8932-5175
authors.initials: KH
authors.lastname: Engel
mesh_terms: D006358:Hot Temperature; D019787:Linoleic Acid / Q000737:chemistry*; D015394:Molecular Structure; D019301:Oleic Acid / Q000737:chemistry*; D010084:Oxidation-Reduction; D010840:Phytosterols / Q000737:chemistry*
chemical_list: D010840:Phytosterols; D019301:Oleic Acid; D019787:Linoleic Acid
keywords: core aldehydes; lipid autoxidation; phytosteryl ester oxidation