Occurrence and regulatory compliance of aflatoxin M1 in milk and dairy products on the Serbian market

Abstract

Contamination of milk and dairy products with aflatoxin M1 (AFM1), a toxic metabolite of aflatoxin B1 from animal feed, continues to pose a persistent food safety concern. Monitoring the prevalence and concentration of AFM1 in dairy products is critical for public health protection, regulatory compliance, and consumer safety. This study aimed to assess the occurrence and concentration of AFM1 in milk and selected dairy products available on the Serbian market in 2024. A total of 96 samples, including milk, yoghurt, sour milk, kefir, sour cream, cheeses, milk-based spreads, goat milk products, and imported dairy products, were collected and analysed using an ELISA method. AFM1 was detected across all analysed product categories, with prevalence ranging from 50 % in cheeses and milk-based spread products to 100 % in milk, yoghurt, kefir, whey, and goat milk products. Mean concentrations ranged from 0.058 µg/kg in milk to 0.226 µg/kg in cheese and milk-based spreads, with the highest individual value (0.573 µg/kg) detected in a cheese spread. Although all milk samples complied with the Serbian limit (0.25 µg/kg), 63 % exceeded the stricter European Union reference value of 0.05 µg/kg. Concentrations above 0.05 µg/kg were also frequently observed in fermented products, particularly sour cream (78 %), yoghurt (62 %), and kefir (50 %), whereas imported products showed generally lower concentrations. Two-way ANOVA of log₁₀-transformed data showed a significant effect of product origin (p<0.001), with lower AFM1 levels in imported compared to domestic products. These findings confirm that AFM1 contamination persists as a food safety concern in Serbia and highlight the need for continuous monitoring and improved control of aflatoxin contamination in animal feed, especially under conditions of increasing climatic variability.