A seasonal study for determination of aflatoxin M1 level in dairy products in Iranshahr, Iran

BACKGROUND AND PURPOSE : Aflatoxin M1, in milk and dairy products, is classified by the International Agency for Research on Cancer as human carcinogens (class 2B). The aim of this study was to evaluate aflatoxin M1 contamination level in dairy products from Iranshahr city, Iran, using ELISA technique. MATERIALS AND METHODS: In our study, 87 samples of milk, white cheese, yoghurt, and butter were collected in different seasons and after preparation, were analyzed by ELISA technique. RESULTS: The contamination level of aflatoxin M1 in pasteurized milk (n=40) yoghurt (n=15), white cheese (n=6), and butter (n=10) samples were determined to be 81.6%, 83.3%, 60%, and 100%, respectively. However, in 8.1% of the pasteurized milk samples, aflatoxin M1 concentration was above the legal accepted limit (>50 ng). The level of aflatoxin M1 was significantly higher in winter compared to summer (P<0.05). In addition, the concentration of aflatoxin M1 was higher in urban regions than rural ones (P<0.05). CONCLUSION: The results of this study emphasized the importance of seasonal and regional effects on aflatoxin M1 contamination of dairy products.