Antibiotic residues and aflatoxin M1 contamination in milk powder used in Tehran dairy factories, Iran

Abstract

BACKGROUND: The presence of aflatoxin M1 (AFM1) and<br />antibiotic residues in milk and milk products is a public health<br />concern. Milk and milk powder have the potential for<br />introducing AFM1 and antibiotic into human diet. In recent<br />years, milk powder has been used on a large scale in dairy<br />factories. Consequently, antibiotic residues and aflatoxin<br />contamination control in these products has gained importance.<br />OBJECTIVES: The aim of this survey was to determine the level<br />of β-lactam and tetracycline antibiotic residues and also AFM1<br />contamination of milk powder used in Tehran dairy factories.<br />METHODS: During 12 months (September 2011 to September<br />2012), 240 samples of milk powder were collected from ten<br />Tehran dairy factories. All samples were analyzed for the<br />presence of AFM1 using ELISA technique. In addition,<br />antibiotic residues were determined by BetaStar Combo test, a<br />rapid assay for both β-lactam and tetracycline antibiotics.<br />RESULTS: The samples depicted positive results i.e. 30% and<br />17.5% for β-lactam and tetracycline antibiotics, respectively.<br />Also, AFM1 was found in 155 cases (64.6%) with an average<br />concentration of 29.85 ± 18.99 ng/ L. CONCLUSIONS:The results<br />showed the milk powder used by dairy factories is safe in respect<br />of AFM1 contamination and antibiotic residues in Tehran.