Investigation of the presence of aflatoxin M1 in commercially sold yoghurts

Aflatoxins (AF) are toxic secondary metabolites produced by Aspergillus species and can be found in various foodstuffs. AFM1, one of the important AF types, is the hydroxylated metabolite of AFB1 and can be found in milk and dairy products obtained from animals fed with AFB1 contaminated feeds. Since milk and dairy products are important foods, presence of AFM1, which shows carcinogenic and hepatotoxic effects, poses a health hazard. According to the Turkish Food Codex (TFC) and the European Union (EU), the highest AFM1 concentration that can be found in milk and dairy products is 50 ng/kg. In this study, 35 natural, 19 organic, 15 fruity and 15 strained, sold in the markets in Istanbul were examined by ELISA method for the detection of presence and level of AFM1. It was determined that all of the yoghurt samples contained an average of 23.99±14.67 ng/kg AFM1 in the range of 5.08-77.48 ng/kg. Twenty-four of the samples were found to be contaminated with AFM1 below 15 ng/kg, 41 were between 15.01-30 ng/kg, and 14 were between 30.01-50 ng/kg. It was determined that five of the examined yoghurt samples contained AFM1 above the limit value determined according to the TFC and EU criteria. AFM1 concentrations of these samples, all of which were organic yoghurts, were 54.78; 59.30; 69.98; 77.09 and 77.48 ng/kg. It was thought that the contamination of all samples with AFM1 constitutes a public health problem, and it is important to take the necessary precautions and make controls to prevent this.