Determination of Aflatoxin M1 in pasteurized Kashk distributed in Tehran Metropolitan

Aflatoxin M1 and M2 (AFM1 and AFM2) are secondary toxic metabolite of molds excreted into livestock milk and dairy products when animal consume feedstuffs contaminated with AFB1 and AFB2. Considering the importance of taking dairy products in human diet, the present study was carried out to determine AFM1 of pasteurized Kashk (industrial liquid) in Tehran Metropolitan. Totally, 32 industrial liquid Kashk samples (eight brands with four different dates of production) were purchased from supermarkets of Tehran and were analyzed using High Performance Liquid chromatography (HPLC) and immunoaffinity columns. In this study, 90.62% of samples (mean: 60.17 ± 75.48 ppt) were contaminated with AFM1. The concentration of AFM1 in 20.68% of samples were higher than Iranian national standard limits (100 ppt). Comparison of different brands showed that brand B with the mean 99.09 ± 158.47 ppt and brand G with the mean 21.27 ± 16.91 ppt had the highest and lowest level of contamination respectively, however, the difference was not statistically significant (P > 0.05). Considering contamination of more than half of the samples with AFM1 and the point that even low level of aflatoxin can be a serious problem for human health, therefore, continuous control of dairy products and preventive proceedings such as avoidance of using moldy feedstuffs for livestock is suggested.