Assessment of Aflatoxin M1 Contamination in Egyptian Milk and Cheese تقييم تلوث اللبن والجبن في السوق المصري بالأفلاتوکسين M1

Abstract

A screening survey of the presence of aflatoxin M1 (AFM1) was carried out on 170 samples of Egyptian dairy products. Selected samples included raw buffalo or cow milk, pasteurized milk, UHT milk, fermented milk, soft cheese, hard cheese, and processed cheese were analyzed by competitive ELISA technique. Out of 60 liquid milk and fermented milk samples analyzed, 12 samples (20%) were found to be contaminated with AFM1, at levels ranging from 10.12 to 86.54 ng/kg. Eight from the positive samples (66.6%) failed to reach the acceptable level of the European Commission Regulation (50 ng/kg). Buffalo’s milk is safe regarding AFM1 contamination since all the buffalo milk samples were consistently negative. AFM1 was found in 22 samples (36.67%) of out 60 cheese samples at concentrations between 25.12 to 253.04 ng/kg. The highest mean value of AFM1, 231.39 ng/kg, was found in Ras cheese (hard type) samples followed by the processed cheeses with 114.76 ng/kg. Kariesh cheeses displayed the lowest levels, 53.32 ng/kg. Cheeses made from cow’s milk showed higher AFM1 positive samples, while cheeses made from buffalo’s milk tested were consistently negative. Regarding the cheese ripening age, out of 50 cow milk cheese samples, 26 were found to be positive to AFM1. The highest positive incidence was noted in long-term ripened hard cheeses (70%), while the lowest in fresh unripened cheeses (40%). It is highly recommended from the results that milk and cheese products have to be controlled periodically for AFM1 contamination.