Monitoring alkylphenols in commercial pasteurized and sterilized milk: Packaging type, storage duration and fat content effects along with kinetic studies, and consumer health risks

This study investigated the concentration levels of alkylphenols (APs), including 4-nonylphenol (4-NP) and 4-tert-octylphenol (4-t-OP), in 120 commercial milk samples analysed via gas chromatography-mass spectrometry (GC-MS). The effects of key parameters including microbial control processes (pasteurization and sterilization), packaging type (plastic pouches, PET bottles, and aseptic cartons), fat content (reduced-fat and whole-fat) and storage duration on APs levels in milk were evaluated. The non-carcinogenic health risks from exposure to alkylphenols (APs) via packaged milk consumption were determined, along with their estrogenic equivalent concentrations (EEQ). Both 4-NP and 4-t-OP were detected in all samples. Results demonstrated that storage duration significantly affected APs concentrations, with longer storage correlating with higher levels. Fat content also played a significant role, as whole-fat milk exhibited higher APs levels due to the lipophilicity of these compounds. The level of APs varied by packaging type. Plastic pouches exhibited a statistically significant higher mean concentration compared to both PET bottles and aseptic cartons, while no statistically significant difference was found between PET bottles and aseptic packages. Kinetic analysis indicated that APs migration followed first-order kinetics. Our results showed no health risk and estrogenic potential from APs in packaged milks. However, since there are multiple pathways through which APs can enter the human body via packaged food, further research is warranted to comprehensively evaluate all potential routes of exposure and associated health risks.