Assessment of aflatoxin M1 contamination in pasteurized and UHT milk marketed in central part of Iran

This study was conducted as a screening survey to determine the occurrence of aflatoxin M1 (AFM1) in 225 commercial liquid milk samples composed of pasteurized milk (116 samples) and UHT milk (109 samples) obtained from popular markets in central part of Iran. The competitive enzyme-linked immunosorbent assay method was employed to determine level of the toxin in the samples. Aflatoxin M1 was detected in 151 (67.1%) samples, consisted of 83 (71.5%) pasteurized milk samples (mean: 52.8 ng/l; range: 5.8–528.5 ng/l) and 68 (62.3%) UHT milk samples (mean: 46.4 ng/l; range: 5.6–515.9 ng/l). Considering the US FDA and Iranian national standard limits for AFM1 in milk (500 ng/l), 2 samples (1.7%) of pasteurized and 3 samples (2.7%) of UHT milk had levels above the maximum tolerance limit. However, according to European Commission limit (50 ng/l), this figure increased to 31 (26.7%) and 19 (17.4%) samples for pasteurized and UHT milk, respectively. The results indicated that the contamination of the samples with AFM1 in such a level could be a serious public health problem at the moment. This paper represents the data of the first survey on the occurrence of AFM1 in commercial liquid milk marketed in central part of Iran.