Assessing Olive Oil Quality Using Different DNA-Based Methods

Olive oil is appreciated worldwide for its unique nutritional and organoleptic properties. It is rich in unsaturated fatty acids and antioxidants, which are well-known for their health benefits. The qualitative characteristics of olive oil can be adversely affected by various biotic and abiotic factors. Particularly, microbial pathogens, such as mold fungi, can cause the deterioration of the oil and, thus, be a serious risk to consumer health. In this study, the effectiveness of DNA-based methods, i.e., endpoint PCR, Real-Time PCR (RT-PCR), and loop-mediated isothermal amplification (LAMP), all based on the ITS2-28S region, were used to evaluate the fungal contamination of samples of extra virgin olive oil. All the DNA techniques were able to detect, albeit at different levels, fungal infections affecting some of the basic quality parameters of the olive oils analyzed. However, compared to endpoint PCR and/or RT-PCR, the LAMP assay greatly simplified and accelerated the identification of pathogenic mold in the oil samples. This may encourage the olive oil industry to adopt this method in order to offer the consumer an oil with specific health parameters and therefore guarantee the safety and quality of this precious food product.