Presence of Aflatoxin M1 in Pasteurized and UHT Milk Commercialized in Shiraz, Khuzestan and Yazd, Iran

Abstract

Aflatoxin M1 (AFM1) is a hydroxylated metabolite of the carcinogen aflatoxin B1 (AFB1), and 
may be found in the milk of lactating animals that have ingested feedstuffs contaminated with AFB1 
Between Jun 2010 and March 2011, 149 samples of pasteurized (n=90) and UHT (n=59) milk were 
collected from supermarkets in the cities of Shiraz, Khuzestan and Yazed, Iran. All samples were analyzed 
for AFM1 contamination by ELISA and 142 (95.3%) were positive with mean concentrations 41 ng.l
-1
. 
These concentrations are lower than the standads of Codex Alimentarius and FDA (500 ng.l
-1
), but 33
samples (22.1%) had higher concentrations than the maximum tolerance accepted by some European
countries (50 ng.l
-1
). Mean concentrations of AFM1 in pasteurized and UHT milk were 39 and 46 ng.l
-1
, 
respectively. Mean concentrations of AFM1 in fall and winter samples were significantly higher (P<0.05) 
than those of summer but differences between AFM1 concentrations of fall and winter samples were not 
significantly different. No significant differences in Concentrations of AFM1 in milk samples between 
Shiraz, Khuzestan and Yazd. Considering the results, this survey revealed a high frequency of AFM1 
contamination in milk samples from central part of Iran.