Occurrence and seasonal variation of aflatoxin M1 in raw cow milk in the Czech Republic, Central Europe

The presence of aflatoxin M1 (AFM1) in milk is a global public health problem with serious socioeconomic consequences. In this study, the presence and concentration of AFM1 in bulk milk (n = 172) were evaluated in April, July, September, and December 2022 across 47 Czech dairy farms. The AFM1 concentration was analysed via an immunochromatographic method (Charm MRL AFM1 Quantitative Test). AFM1 was detected in 23 examined samples (13.4%) from 17 dairy farms, of which the AFM1 concentrations in only two samples (at one farm) exceeded the maximum residue limit in the European Union (0.050 μg/l). The average AFM1 concentration was 0.0037 μg/l. The effect of season was not statistically significant, but AFM1 was detected more frequently in September (autumn; 18.6%) and less frequently in July (summer; 11.1%). Except for total solids (p = 0.0447), no statistically significant differences in the monitored milk parameters (fat, protein, casein, lactose contents, somatic cell count, and freezing point depression) were observed. •The presence of AFM1 in raw cow milk was evaluated at 47 Czech farms.•AFM1 was detected in 13.4% samples.•The maximum EU limit was exceeded only in two samples from one farm.•The most AFM1-positive samples were found in September.•The effect of the presence of AFM1 on milk parameters was not proven.