Comparison of melamine and inorganic contaminant levels in animal-derived milk and plant-based milk alternatives according to processing, flavoring, and packaging

This study aimed to evaluate the levels of inorganic contaminants —lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As)—as well as melamine in animal-derived milk (ADM) and plant-based milk alternatives (PBMAs) available on the Turkish market. A total of 54 milk samples, representing 12 brands, were collected from four supermarkets in Ankara in June 2023. Contaminant levels were quantified using inductively coupled plasma mass spectrometry (ICP-MS). Melamine was detected in the majority of samples, with only two PBMAs—coconut-based and soy-based—exceeding 50 μg/kg. All PBMA and ADM samples were below the European Union (EU) limit for Pb (20 μg/kg), although one cow milk sample surpassed 10 μg/kg. Cd concentrations above 10 μg/kg were found in 10.3 % of cow milk samples, particularly in ultra-high-temperature (UHT) processed products. Hg was undetectable in four samples and remained below 5 μg/kg in all others. As levels were consistently below 10 μg/kg. Hg and As levels varied significantly by processing method, while Pb and As levels differed depending on the type of packaging. No significant correlation was observed between protein or fat content and contaminant concentrations. Health risk assessments conducted for 6-year-old children indicated that both daily dietary intake (DDI) and hazard quotient (HQ) values for all toxic elements and melamine were below the threshold of 1, suggesting no significant non-carcinogenic risk. Overall, the findings indicate that both milks are chemically safe for young children. However, continued monitoring is recommended, particularly for melamine and arsenic, due to their potential for cumulative toxicity.