Occurrence and seasonality of aflatoxin M1 in milk in two different climate zones

Aflatoxin M1 (AFM1) is a mycotoxin found in milk as a result of the ingestion of aflatoxin B1 (AFB1) by dairy cattle. Because of its carcinogenic properties, the control of its occurrence in dairy products is of great importance. We evaluated the occurrence and seasonality of AFM1 in milk from farms with subtropical and temperate climates, where significant milk production occurs. Forty samples of raw milk were collected from bulk tansk milk during the summer (five samples from a subtropical climate and 14 from a temperate climate) and winter (six samples from a subtropical climate and 15 from a temperate climate) months of 2017 and conducted an analysis using an enzyme-linked immunosorbent assay (ELISA) (detection limit 5 ng L^-1 ). Data from eight random samples were compared with respect to liquid chromatography with mass spectrometry detection and ELISA. A significant correlation was observed.

The presence of AFM1 was detected in 87.50% (n = 35) of the samples analyzed (a mean of 16.66 ng L^-1 and a median of 12.42 ng L^-1 in positive samples); however, its concentration in all samples was below the maximum limit allowed by European (50 ng L^-1 ) and Brazilian (500 ng L^-1 ) legislations. There were no significant differences in the levels of AFM1 between the properties located in the two climate zones, in both summer and winter. The estimated daily intake of AFM1 based on the milk analyzed was 0.0107 ng kg^-1 day^-1 for adolescents, 0.0072 ng kg^-1 day^-1 for adults and 0.0098 ng kg^-1 day^-1 for the elderly.

The present work demonstrated a low exposure to AFM1. © 2018 Society of Chemical Industry.