Occurrence, seasonal variation and risk assessment of exposure to aflatoxin M1 in Iranian traditional cheeses

Abstract A total of 360 traditional cheeses consisted of Lighvan (n = 62), Koozeh (n = 62), Siahmazgi (n = 58), Khiki (n = 58), Talesh (n = 58) and Lactic (n = 62) collected from different parts of Iran were analyzed for aflatoxin M 1 (AFM 1 ) using an enzyme linked immunosorbent assay (ELISA). Frequency of AFM 1 and its concentration ranges of all the ELISA positive samples were determined by high-performance liquid chromatography with fluorescence detection (HPLC-FD). AFM 1 was detected in 60.3%, 75.8%, 72.4%, 43.5%, 38.7% and 35.4% of Siahmazgi, Khiki, Talesh, Lighvan, Koozeh and Lactic cheeses, respectively with concentration ranging from 50.5 to 308.7 ng/kg, respectively. HPLC analyses confirmed the ELISA results although the rates of contaminated cheese samples were lower than that of ELISA. There was significant difference in AFM 1 level between various cheese types and samples collected from summer and winter seasons ( P 1 .