A study on the contamination of aflatoxin M1, aflatoxicol, and sterigmatocystin in sheep, goat, and buffalo Italian cheese

Background Aflatoxin M 1 (AFM 1 ), aflatoxicol (AFX) and sterigmatocystin (STC) are mycotoxins that can contaminate dairy products and pose health risks due to their carcinogenic or potentially carcinogenic properties. Aim This study assessed the prevalence and concentration of AFM 1 , STC, and AFX cheeses made from sheep, goat, and buffalo milk. Methods Sample from 435 cheeses were collected from retail outlets across seven Italian regions. Cheeses were stratified by milk origin and texture and analysed using immunoaffinity purification and Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) determination. Results Both AFM 1 and STC were detected in approximately half of the samples (ranging from 41.3% to 63.9% depending on the cheese type), with higher contamination rates in sheep cheeses. Moreover, hard ripened cheeses were generally more contaminated than semi-hard and soft. In the various cheese categories, mean concentrations of AFM 1 and STC ranged between 5.0–15.0 ng/kg and 1.2–13.1 ng/kg, respectively, typically staying below a threshold of 15 ng/kg. Aflatoxicol was not detected in any sample. Conclusion Mycotoxin levels were lower than in previous bovine cheese studies. While current levels pose no immediate threat, formal risk assessment and expanded monitoring are required to quantify exposure for vulnerable subgroups.