Assessment of aflatoxin M1 and B1 in some dairy products with referring to the analytical performances of enzyme-linked immunosorbent assay in comparison to high-performance liquid chromatography

Background and Aim: Aflatoxin M1 (AFM1) is a major fungal metabolite found in milk coming from aflatoxin B1 (AFB1) contaminated rations and is subsequently present in milk-based products demonstrating a serious public health hazard. This study aimed to investigate the levels of AFM1 and AFB1 in milk and some dairy products consumed widely by infants and children. Materials and Methods: This study investigated the incidence of AFM1 in 105 samples of processed cheese, Ras cheese, and raw milk (35 of each) retailed in the Egyptian markets. The degree of sensitivity and accuracy was evaluated using the enzyme-linked immunosorbent assay (ELISA) method followed by the estimation of the positive samples using the high-performance liquid chromatography (HPLC) with fluorescence detection. Mold count was determined in the examined samples by investigating AFB1 content using HPLC. Results: AFM1 was found in all investigated Ras cheese, raw milk, and 82.86% of the processed cheese samples with mean values of 51.05±6.19, 40.27±3.996, and 10.77±1.39 ng/kg, respectively. Moreover, there was statistically no significant difference between AFM1 levels in the core and crust parts of the tested Ras cheese. AFM1 contaminated Ras cheese and raw milk samples were 48.57% and 25.71%, which exceeded the European and Egyptian tolerance levels. Results showed an acceptable correlation between ELISA and HPLC methods with no significant difference (p>0.05). Alternatively, none of the examined samples proved to be contaminated with AFB1 despite the presence of mold with mean counts of 3.79±3.29, 4.39±4.34, and 4.84±4.29 log CFU/g in the examined processed cheese, Ras cheese, and raw milk samples, respectively. Conclusion: Therefore, it is urgent to regularly inspect the contamination of animal feeds with AFB1 and apply special measures and novel techniques to protect the feed and food from public health hazards.