Cultivar Origin and Admixture Detection in Turkish Olive Oils by SNP-Based CAPS Assays

Abstract

The aim of this study was to establish a DNA-based identification key to ascertain the cultivar origin of Turkish monovarietal olive oils. To reach this aim, we sequenced short fragments from five olive genes for SNP (single nucleotide polymorphism) identification and developed CAPS (cleaved amplified polymorphic DNA) assays for SNPs that alter restriction enzyme recognition motifs. When applied on the oils of 17 olive cultivars, a maximum of five CAPS assays were necessary to discriminate the varietal origin of the samples. We also tested the efficiency and limit of our approach for detecting olive oil admixtures. As a result of the analysis, we were able to detect admixing down to a limit of 20%. The SNP-based CAPS assays developed in this work can be used for testing and verification of the authenticity of Turkish monovarietal olive oils, for olive tree certification, and in germplasm characterization and preservation studies.

Monovarietal extra-virgin olive oil classification: a fusion of human sensory attributes and an electronic tongue

“…Regarding monovarietal olive oil classification according to olive cultivar, other approaches have been described in the literature, reporting in some cases slightly less accurate correct classification performances (ranging from 70 to 100 %) depending on the analytical technique used (e.g., NMR, NIR, and MIR spectroscopy; PTR-MS; HS-SPME-GC/MS; SNP-based PCR-RFLP capillary electrophoresis; SNP-based CAPS assays), the number of olive cultivars under study (3,5, or 10 cultivars) and chemometric tool used (e.g., LDA PLS-DA and canonical discriminant analysis) [13,14,22,[50][51][52].…”

Recent advances in the application of capillary electromigration methods for food analysis and Foodomics

“…In consequence, CE is still the method of choice in many food applications for DNA analysis. It is interesting to note that, in the period covered by the present review, most of de published CE methods for DNA analysis have been aimed at assessing food authenticity [128][129][130][131][132][133][134] and traceability [135].…”

Recent developments in olive (Olea europaea L.) genetics and genomics: applications in taxonomy, varietal identification, traceability and breeding

“…While SSRs are usually the most frequently used DNA markers in these studies, the use of SNPs has been suggested based on the following criteria: (1) as the DNA recovered from processed food is usually highly degraded, SNPs provide the advantage of enabling genotyping with shorter DNA fragments (Uncu et al 2015); (2) SNPs are abundant in both coding and non-coding regions of a genome, allowing an easy discrimination of related genotypes. Bazakos et al (2012Bazakos et al ( , 2016, using SNPs markers residing in restriction sites, associated with PCR-RFLP capillary electrophoresis, could discriminate both olive cultivars and the corresponding monovarietal oil from Greece and from different Mediterranean countries (Tunisia and Lebanon), eventually evidencing admixtures at the limit of 10%.…”