Detection and quantification of microplastics in commercially bottled edible oil

Abstract

The presence of microplastics in the food system has raised increasing public attention due to their potential risk to human health. However, knowledge regarding the presence and quantity of microplastics in daily consumed food products is very limited. The objective of this study is to quantify microplastics in polyethylene terephthalate (PET) bottled edible oil and determine the impact of oil on microplastics released from plastic packages in an accelerated storage experiment. For microplastic recovery, hexane was used to dilute the oil and facilitate the filtration process, and 62.73–118.00% of microplastics were recovered using standard polystyrene microplastics. Microplastics present in the oil were identified based on their Raman characteristics. The most frequent polymers identified were Poly(Ethylacrylate:St:Acrylamide) and Poly(Ethylene:Propylene) The result shows particles ranging from 1.34 × 105 to 5.80 × 105 per liter of oil were detected in 4 commercial edible oil (olive oil, canola oil, sunflower oil, and coconut oil). Over 80% of detected plastics were smaller than 10 µm. The accelerated experiment (40 °C, 10 days) did not lead to an increased number of particles (p > 0.05) nor the identification of any PET particles, suggesting that no PET microplastics were released from the bottles during the storage. Our results fill in the knowledge gap regarding the microplastics in edible oil and facilitate exposure analysis of microplastics through food.