Food Research International, cilt.225, 2026 (SCI-Expanded, Scopus)
This study aims to effectively isolate and identify microplastics (MPs), a potential risk factor for food safety and human health, from white cheese, a complex food matrix rich in fat and protein. In this context, ten different chemical digestion protocols were comparatively evaluated. Although strong acid (HNO3, H2SO4) and alkaline (KOH, NaOH) solutions partially removed the organic matrix, they were deemed inadequate due to their risk of damaging polymer integrity and incompatibility with filtration systems. In contrast, a mild oxidative treatment with 35 % H2O2 at 55 ± 2 °C for seven days enabled efficient degradation of the organic structure, improved solution clarity, and allowed smooth sieving and vacuum filtration. MPs isolated from three commercial white cheese samples (C1, C2, C3) treated with Protocol 10 were successfully analyzed using micro-Raman spectroscopy. A total of 50, 48, and 40 MP particles per 100 g were detected in samples C1, C2, and C3, respectively. Polymer identification revealed a total of 11 distinct MP types across all samples (ranging from 3 to 7 per cheese type), with polyethylene, ethylene ethyl acrylate copolymer, polyester, and poly(acrylamide-acrylic acid) being the most prevalent. The findings suggest that packaging materials and environmental factors play a significant role in MP contamination. These results highlight potential consumer exposure to MPs through dairy consumption and emphasize the importance of establishing standardized analytical methods for monitoring microplastic contamination in foods.