Assessment of aflatoxin M(1) and B(1) 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 M(1) (AFM(1)) is a major fungal metabolite found in milk coming from aflatoxin B(1) (AFB(1)) contaminated rations and is subsequently present in milk-based products demonstrating a serious public health hazard. This study aimed to investigate the levels of AFM(1) and AFB(1) in milk and some dairy products consumed widely by infants and children. MATERIALS AND METHODS: This study investigated the incidence of AFM(1) 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 AFB(1) content using HPLC. RESULTS: AFM(1) 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 AFM(1) levels in the core and crust parts of the tested Ras cheese. AFM(1) 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 AFB(1) 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 AFB(1) and apply special measures and novel techniques to protect the feed and food from public health hazards.