Occurrence of aflatoxin M1 in raw, pasteurized and UHT milk commercialized in Esfahan and Shahr-e Kord, Iran

Abstract

Between September 2006 and September 2007, 236 samples of raw (n = 140), pasteurized (n = 48) and UHT (n = 48) milk were collected from supermarkets and from bulk milk tanks of eight dairy plants in the cities of Esfahan and Shahr-e Kord, Iran. All samples were analyzed for aflatoxin M1 (AFM1) contamination by ELISA and 213 (90.3%) were positive with mean concentrations 65 ng.l−1. These concentrations are lower than the standards of Codex Alimentarius and FDA (500 ng.l−1), but 119 samples (55.9%) had higher concentrations than the maximum tolerance accepted by some European countries (50 ng.l−1). Mean concentrations of AFM1 in raw, pasteurized and UHT milk were 68, 56, and 65 ng.l−1, respectively. Mean concentrations of AFM1 in autumn and winter samples were significantly higher (P < 0.05) than those of spring and summer but differences between AFM1 concentrations of spring and summer samples were not significantly different. Concentrations of AFM1 in milk from Shahr-e Kord were significantly lower (P ≤ 0.05) than those from Esfahan.