Characterization of microplastics in extra-virgin olive oils by Laser Direct InfraRed (LDIR) spectroscopy

The growing concern over microplastics (MPs) in agriculture and food resources underscore the urgent need for effective monitoring and mitigation strategies. While MPs have been identified in various food products, this study presents the first application of Laser Direct InfraRed (LDIR) Imaging, a recent spectroscopic technique offering a simultaneous characterization of MPs in extra-virgin olive oils (EVOOs), in terms of polymer composition, morphology and size. EVOO samples, collected from Tuscan olive oil mills and in the large distribution, were pre-treated through solvent dilution, vacuum filtration, and ethanol backwashing before LDIR analysis. The research demonstrates the method's sensitivity and applicability in complex lipid matrices. Results show that different kind of MPs are present in all samples. Although further studies with a larger number of samples are required to confirm these observations, the present work provides preliminary evidence that production practices and supply chain management may influence the level of microplastic contamination in EVOOs.