Detection and Characterization of Small-Sized Microplastics (≥ 4 µm) in Milk Products

Abstract Microplastics (MPs) have gained a high degree of public interest since they are associated with the global release of plastics into the environment. As a result, MPs have also been detected along the food chain. However, information on the ingestion of MPs via the consumption of many commonly consumed foods like dairy products are scarce due to the lack of studies investigating the “contamination” of this food group by MPs. This lack of occurrence data is mainly due to the absence of robust analytical methods capable of reliably quantifying MPs with size < 20 µm in foods. In this work, we have developed a new methodology to accurately determine and characterize MPs in milk-based products using μRaman technology, entailing combined enzymatic and chemical digestion steps. We demonstrate for the first time the presence of relatively low amounts of small-sized MP (≥ 4 µm) in raw milk collected at farm just after the milking machine and in some processed commercial liquid and powdered cow’s milk products.