occurrence of aflatoxin m1 in pasteurized and traditional cheese marketed in southern khorasan, iran

background: aflatoxin m1 (afm1) is a toxic and carcinogenic mycotoxin which after presence in milk and dairy products such as cheese and butter could make them as contaminated food. the main objective of this study was to evaluate the concentration of afm1 in pasteurized and traditional cheese marketed in southern khorasan, from december 2011 to january 2012. methods: a total of 102 cheese samples (including 43 non-pasteurized traditional and 59 pasteurized cheese) were analyzed for detection of afm1. the samples were collected ran-domly from three major cities of southern khorasan province, iran. a rapid and sensitive indirect competitive enzyme linked immuno sorbent assay (elisa) method using monoclonal antibody was used to measure afm1 concentration in the samples. results: according to the results of this study, afm1 was detected in 14 (32.55%) traditional and 21 (35.59%) pasteurized cheese samples. in total, 25.42% of pasteurized and 27.90% of traditional cheese samples were contaminated at above level of the iranian standard limits (50 ng/kg). conclusion: considering high contamination level of both pasteurized and traditional cheese products in southern khorasan, it is recommended to establish continuous monitoring program of afm1 by food safety agencies in order to control the incidence of mycotoxin contamination.