title: Thermo-oxidation of cholesterol: effect of the unsaturation degree of the lipid matrix.
abstract: The influence of the unsaturation degree of different triacylglycerols (tristearin, triolein, trilinolein and trilinolenin) on cholesterol oxidation at 180 °C, was evaluated. Cholesterol degraded faster when heated alone than in the presence of triacylglycerols; moreover, the more unsaturated the matrix, the slower the degradation of cholesterol. Both cholesterol and triacylglycerols degradation fit a first order kinetic model (R(2)>0.9), except for the tristearin sample. Cholesterol oxidation products (COPs) and peroxides were formed during the heating treatment. The presence of any type of lipid matrix postponed and decreased the maximum concentration of both oxidation parameters. Maximum total COPs concentrations were achieved at 20 min in neat cholesterol, 120 min in tristearin and triolein and 180 min in polyunsaturated matrix samples. 7-Ketocholesterol was the main COP in most cases during the whole heating treatment. Both the presence of triacylglycerols and their unsaturation degree inhibited cholesterol thermooxidation at 180 °C.
authors.affiliation: Departamento de Ciencias de la Alimentación y Fisiología, Facultad de Farmacia, Universidad de Navarra, C/Irunlarrea s/n, 31008 Pamplona, Spain. dansorena@unav.es
authors.forename: Diana
authors.initials: D
authors.lastname: Ansorena
authors.forename: Blanca
authors.initials: B
authors.lastname: Barriuso
authors.forename: Vladimiro
authors.initials: V
authors.lastname: Cardenia
authors.forename: Iciar
authors.initials: I
authors.lastname: Astiasarán
authors.forename: Giovanni
authors.initials: G
authors.lastname: Lercker
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Rodriguez-Estrada
mesh_terms: D002784:Cholesterol / Q000737:chemistry*; D006358:Hot Temperature; D007700:Kinetics; D015394:Molecular Structure; D010084:Oxidation-Reduction; D014280:Triglycerides / Q000737:chemistry*
chemical_list: D014280:Triglycerides; D002784:Cholesterol
keywords: Cholesterol; Peroxides; Thermoxidation; Triacylglycerols; Unsaturation degree