title: Total trans fatty acid analysis in spreadable cheese by capillary zone electrophoresis.
abstract: An alternative method for determination of total trans fatty acids expressed as elaidic acid by capillary zone electrophoresis (CZE) under indirect UV detection at 224 nm within an analysis time of 7.5 min was developed. The optimized running electrolyte includes 15.0 mmol L(-1) KH(2)PO(4)/Na(2)HPO(4) buffer (pH approximately 7.0), 4.0 mmol L(-1) SDBS, 8.0 mmol L(-1) Brij35, 45%v/v ACN, 8% methanol, and 1.5% v/v n-octanol. Baseline separation of the critical pair C18-9cis/C18:1-9t with a resolution higher than 1.5 was achieved using C15:0 as the internal standard. The optimum capillary electrophoresis (CE) conditions for the background electrolyte were established with the aid of Raman spectroscopy and experiments of a 3(2) factorial design. After response factor (R(F)) calculations, the CE method was applied to total trans fatty acid (TTFA) analysis in a hydrogenated vegetable fat (HVF) sample, and compared with the American Oil Chemists' Society (AOCS) official method by gas chromatography (GC). The methods were compared with an independent sample t test, and no significant difference was found between CE and GC methods within the 95% confidence interval for six genuine replicates of TTFA analysis (p-value > 0.05). The CE method was applied to TTFA analysis in a spreadable cheese sample. Satisfactory results were obtained, indicating that the optimized methodology can be used for trans fatty acid determination for these samples.
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Juiz de Fora, Cidade Universitaria CEP 36036-330, Juiz de Fora, Minas Gerais, Brazil.
authors.forename: Patrícia Mendonça
authors.initials: PM
authors.lastname: De Castro
authors.forename: Marcelo Macedo
authors.initials: MM
authors.lastname: Barra
authors.forename: Mauro Carlos
authors.initials: MC
authors.lastname: Costa Ribeiro
authors.forename: Sabria
authors.initials: S
authors.lastname: Aued-Pimentel
authors.forename: Simone Alves
authors.initials: SA
authors.lastname: Da Silva
authors.forename: Marcone Augusto Leal
authors.initials: MA
authors.lastname: De Oliveira
mesh_terms: D002611:Cheese / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D044242:Trans Fatty Acids / Q000032:analysis*
chemical_list: D044242:Trans Fatty Acids