Incidence of aflatoxin M1 in fresh milk from small farms

Abstract The objective of this work was to determine aflatoxin M1 in fresh milk from fifty-two small farms in the city of Concórdia - SC, Brazil. Samples from the cooling tanks of each property were collected from November 2014 to January 2015. The QuEChERS method was used for the extraction of aflatoxin M1, and quantification was performed in UHPLC-FL. 40.4% of the analyzed samples (eg, 21 samples) showed contamination levels by aflatoxin M1 above the maximum limit allowed by the Brazilian regulation, which is 0.5 μg L-1. These results suggest the importance of implementing Good Practices in obtaining feed for dairy cows, since the contamination of milk by aflatoxin M1 occurs through the biotransformation of aflatoxin B1, after the ingestion of feed or silage contaminated by the animals, posing risk to the animals themselves, as well as to consumers of milk and dairy products.摘要 本研究旨在检测巴西圣卡塔琳娜州孔科迪亚市52家小型牧场的生鲜牛乳中黄曲霉毒素M1（aflatoxin M1）的含量。于2014年11月至2015年1月期间，采集各牧场冷却储奶罐内的牛乳样本。采用QuEChERS方法完成黄曲霉毒素M1的提取，并通过超高效液相色谱-荧光检测法（UHPLC-FL）进行定量分析。检测结果显示，40.4%的样本（例如21份）中黄曲霉毒素M1的污染水平超出巴西法规规定的0.5 μg·L⁻¹最大限量标准。本研究结果凸显了在奶牛饲料采购环节落实良好操作规范（Good Practices）的重要性：牛乳中的黄曲霉毒素M1源于奶牛采食被污染的饲料或青贮饲料后，机体内黄曲霉毒素B1的生物转化过程，该污染途径不仅会对奶牛自身健康造成威胁，同时也会危及牛乳及乳制品消费者的健康安全。