The prevalence and concentration of aflatoxin M1 among different types of cheeses: A global systematic review, meta-analysis, and meta-regression

Abstract Aflatoxin M1 (AFM1) is a hepatocarcinogen found in the milk of lactating animals that have ingested feed contaminated with aflatoxin B1 (AFB1). In this study, a systematic review was conducted to collect and evaluate the quantitative data regarding the prevalence and concentration of AFM1 in several types of cheeses produced with milk from cows and goats in different world areas. According to the findings, the rank order of AFM1 concentration was cow’s cheeses (13,000.00 ng/kg) > mixed cow-goat-sheep cheeses (7,214.71 ng/kg) > goat’s-milk cheeses (178.30 ng/kg). The rank order of AFM1 contamination based on the cheese texture was hard (14,000.00 ng/kg) > semi-hard (2,175.03 ng/kg) > soft (533.71 ng/kg) > semi-soft (70.30 ng/kg). While the higher prevalence of AFM1 was reported for soft (53%) and mixed cow-goat-sheep (51%) cheeses while compared with other types of cheeses. Importantly, the AFM1 concentrations in all types of cheese except semi-soft cheese and goat's milk cheese were exceeded the recommended level. Thus, stringent control regarding animal feed, milk production, and cheese processing as well as storage conditions should be carried out, aiming at reducing the AFM1 in cheeses, particularly in regions with higher consumption of this dairy product.