Application of high resolution melting combined with DNA-based markers for quantitative analysis of olive oil authenticity and adulteration

Food Chem X. 2020 Feb 24:6:100082. doi: 10.1016/j.fochx.2020.100082. eCollection 2020 Jun 30.

Abstract

A plethora of biotechnological methodologies is used to authenticate quality olive oils. Among the DNA-based approaches, SNPs and SSRs combined with high resolution melting (HRM) provide certain advantages such as speed, simplicity and reliability. SNP-HRM and SSR-HRM were used for the authentication of monovarietal olive oils as well as the quantification of varietal composition in olive oil DNA admixtures and olive oil blends of two different cultivars. The SSR-HRM was more efficient in distinguishing monovarietal olive oils while the SNP-HRM assay was more reliable in discriminating olive oil blends. HRM was also used for the detection of adulteration of olive oil with oils of different plant origin by using plastid trnL indels and SNPs. The trnL-indels-HRM showed higher discrimination power than the trnL-SNP-HRM in determining adulteration in olive oil. These results indicate that traceability of adulteration might be more reliable than authentication of the varietal origin in olive oil blends.

Keywords: Adulteration; High resolution melting; Maize oil; Molecular markers; Olive oil; Quantitative authentication; SNPs; SSRs; Sunflower oil.