A survey of aflatoxin M1 of raw cow milk in China during the four seasons from 2013 to 2015

- AFM1 was detected in 334 of 1550 raw cow milk samples in China from 2013 to 2015.
- No samples were found to have AFM1 levels above 0.5 μg/L, the legal limit in China, US and CAC.
- AFM1 contamination in milk in China have gradually decreased between 2013 and 2015.
- AFM1 levels were higher in autumn than in the other seasons during the study period.
- AFM1 levels were higher in Southern China than in those from other regions.

In the present study, a total of 1550 raw cow milk samples were collected from Southern, Northern, Northeast, and Western regions of China during the four seasons from 2013 to 2015. Samples were analyzed for aflatoxin M1 (AFM1) using high performance liquid chromatography (HPLC). In 2013, AFM1 was detected in 21% of 366 raw cow milk samples with levels ranging between 0.01 and 0.24 μg/L. In 11.7% of samples, AFM1 levels were >0.05 μg/L, which is the legal limit in the European Union. The mean and median of positive samples were 0.069 ± 0.052 μg/L and 0.056 μg/L, respectively. In 2014, AFM1 was detected in 28.5% of 624 raw cow milk samples, with levels ranging from 0.01 to 0.25 μg/L. Of these samples, 7.7% had AFM1 levels exceeding 0.05 μg/L, with a mean of 0.042 ± 0.039 μg/L and median of 0.028 μg/L. AFMI was detected in 14.1% of 560 raw cow milk samples in 2015, with levels ranging from 0.01 to 0.144 μg/L. In 1.8% of these samples, AFM1 levels were above 0.05 μg/L, with a mean of 0.026 ± 0.024 μg/L and median of 0.017 μg/L. Our results demonstrate that AFM1 levels of the samples did not exceed the legal limit of 0.5 μg/L in China, the United States, and Codex Alimentarius Commission. Geographically, AFM1 contamination was more predominant in raw cow milk samples from Southern China than in those from other regions, with a higher number of samples containing AFM1 levels above 0.05 μg/L in 2013, 2014, and 2015. AFM1 levels were higher in autumn than in the other seasons during the entire study period. According to our survey, AFM1 contamination has been well-controlled in China during recent years; however, some samples still exceeded the European Union (EU) legal limit. Better prevention and management of aflatoxins in both feed and milk should be considered especially in Southern regions of China and in autumn.