title: Barcode DNA length polymorphisms vs fatty acid profiling for adulteration detection in olive oil.
abstract: The aim of this study was to compare the performance of a DNA-barcode assay with fatty acid profile analysis to authenticate the botanical origin of olive oil. To achieve this aim, we performed a PCR-capillary electrophoresis (PCR-CE) approach on olive oil: seed oil blends using the plastid trnL (UAA) intron barcode. In parallel to genomic analysis, we subjected the samples to gas chromatography analysis of fatty acid composition. While the PCR-CE assay proved equally efficient as gas chromatography analysis in detecting adulteration with soybean, palm, rapeseed, sunflower, sesame, cottonseed and peanut oils, it was superior to the widely utilized analytical chemistry approach in revealing the adulterant species and detecting small quantities of corn and safflower oils in olive oil. Moreover, the DNA-based test correctly identified all tested olive oil: hazelnut oil blends whereas it was not feasible to detect hazelnut oil adulteration through fatty acid profile analysis. Thus, the present research has shown the feasibility of a PCR-CE barcode assay to detect adulteration in olive oil.
authors.affiliation: Izmir Institute of Technology, Department of Molecular Biology & Genetics, Urla, Izmir 35430, Turkey. Electronic address: atuncu@konya.edu.tr.
authors.forename: Ali Tevfik
authors.initials: AT
authors.lastname: Uncu
authors.affiliation: Izmir Institute of Technology, Department of Molecular Biology & Genetics, Urla, Izmir 35430, Turkey. Electronic address: ozgurayseuncu@gmail.com.
authors.forename: Ayse Ozgur
authors.initials: AO
authors.lastname: Uncu
authors.affiliation: Izmir Institute of Technology, Department of Molecular Biology & Genetics, Urla, Izmir 35430, Turkey. Electronic address: annefrary@iyte.edu.tr.
authors.forename: Anne
authors.initials: A
authors.lastname: Frary
authors.affiliation: Izmir Institute of Technology, Department of Molecular Biology & Genetics, Urla, Izmir 35430, Turkey. Electronic address: samidoganlar@iyte.edu.tr.
authors.forename: Sami
authors.initials: S
authors.lastname: Doganlar
mesh_terms: D002849:Chromatography, Gas / Q000379:methods; D058893:DNA Barcoding, Taxonomic / Q000379:methods*; D018744:DNA, Plant / Q000032:analysis* / Q000235:genetics; D019075:Electrophoresis, Capillary / Q000379:methods; D005227:Fatty Acids / Q000032:analysis* / Q000235:genetics; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D000069463:Olive Oil / Q000032:analysis* / Q000592:standards; D010938:Plant Oils / Q000032:analysis / Q000592:standards; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic / Q000235:genetics
chemical_list: D018744:DNA, Plant; D005227:Fatty Acids; D000069463:Olive Oil; D010938:Plant Oils
keywords: Capillary electrophoresis; Food authenticity; Food genomics; Traceability