Occurrence of Aflatoxin M1 in Raw and Pasteurized Milk Produced in Rafsanjan, Iran

Introduction: Aflatoxins, known as causative factors of hepatic and extra-hepatic carcinogenesis within humans, are extremely teratogenic, mutagenic, toxic, and carcinogenic compounds. Materials & Methods: This study was undertaken to determine the occurrence of aflatoxin M1 (AFM1) in 40 raw milk and 47 pasteurized milk samples collected during spring and winter. In order to analyze the samples, the Enzyme-linked Immunosorbent Assay (ELISA) procedure was used. The statistical methods used in this study were based on normal confidence intervals and analysis of variance (ANOVA). Results: Aflatoxin M1 was detected in 97.5% of the raw milk ranging from 6.52 to 68.17 ng/l and 95.7% of the pasteurized milk, ranging from 0.8 to 58.13 ng/l. Toxin levels in 10% of the raw milk and 2.1% of the pasteurized milk samples exceeded the Iranian national standard limit i.e. 50 ng/l.  Due to seasonal variations, mean concentration of AFM1 in the samples collected in winter was significantly (P < 0.03) higher than those collected in the summer. Conclusion: Large amount of AFM1 in milk samples might be a potential hazard for the public health. Reducing the levels of AFB1 in animal feedstuffs can be regarded as the initial step to control the transfer of AFM1 to humans.