Aflatoxin M 1 levels in cheese samples from some provinces of Turkey T. Yaroglu a , H.H. Oruc b, * , M. Tayar c a Central Commandery of Military Veterinary School, 16600 Gemlik, Bursa, Turkey b Faculty of Veterinary Medicine, Department of Pharmacology and Toxicology, Uludag University, 16059 Gorukle Kampusu, Bursa, Turkey c Faculty of Veterinary Medicine, Department of Food Hygiene and Technology, Uludag University, 16059 Gorukle Kampusu, Bursa, Turkey Received 11 May 2004; received in revised form 27 July 2004; accepted 2 August 2004 Abstract Aflatoxin M 1 (AFM 1 ) levels were determined in 600 cheese samples (200 white, 200 kashar and 200 processed cheeses). The sam- ples were collected from some provinces of Turkey and analysed between January 2001 and February 2002 in Bursa, Turkey. AFM 1 levels were determined by competitive enzyme-linked immunosorbent assay (ELISA) technique. The highest AFM 1 concentration was 800ng/kg in kashar cheese. AFM 1 was detected in 30 (5%) samples consisting of 10 white, 12 kashar and 8 processed cheese. Altogether, the AFM 1 levels in 6 of 600 (1%) exceeded the legal limits of 250ng/kg established by the Turkish Food Codex. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Aflatoxin M 1 ; Cheese; ELISA 1. Introduction Aflatoxins are a group of toxicants which belong to the group of mycotoxins. Aflatoxins are mainly pro- duced by three species of moulds, Aspergillus flavus, Aspergillus parasiticus and Aspergillus nomius which may grow on a number of crops. The formation of afla- toxins depends on the foods on which the moulds grow and the conditions of heat and humidity during the growth, harvesting and storage of the crops. Aflatoxins B 1 ,B 2 ,G 1 ,G 2 and their metabolites M 1 and M 2 are the most common, and of these B 1 and G 1 are observed most frequently in foods. AFM 1 is found in the milk and dairy products of animals that have consumed feed contaminated by aflatoxin B 1 (AFB 1 ). AFM 1 occurs as a hydroxylated metabolite of AFB 1 in liver and it is se- creted into milk from the mammary glands. Aflatoxins have toxic and carcinogenic effects on humans and ani- mals (FAO/WHO News Archive: Codex Committee on Food Additives & Contaminants, 1998; Rothschild, 1992). Therefore, there are predetermined tolerance lim- its for AFM 1 in milk, cheese and other dairy products. This limit is 250ng/kg in Turkey (Gida Mevzuati, Mik- robiyal Toksinler, 2003). AFM 1 is relatively stable in raw and processed milk products, and unaffected by pas- teurisation or processing into cheese (Barbieri, Berga- mini, Ori, & Reska, 1994; Blanco et al., 1988). At present, aflatoxin presence in feed, milk and dairy prod- ucts can be systematically controlled in Europe and other developed countries. In contrast, there is practi- cally not enough control system on the factual contam- ination of milk, dairy products and feed with AFM 1 and AFB 1 in Turkey. This study aims to investigate both the overall presence of AFM 1 in Turkish white, kashar and processed cheese samples that were brought from some provinces of Turkey, and to determine whether there is a significant difference among the AFM 1 levels of the different kind of cheese samples. 2. Materials and methods The research materials consisted of 600 cheese samples comprising 200 Turkish white cheese, 200 0956-7135/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodcont.2004.08.001 * Corresponding author. www.elsevier.com/locate/foodcont Food Control 16 (2005) 883–885