Aflatoxin M1 Transfer Rate from Milk into Cheese and Whey During the Production of Hard Cheese

The aim of this study was to investigate aflatoxin M1 (AFM1) transfer from naturally contaminated raw milk into cheese and whey, during the production of Livanjski cheese (hard cheese type). Raw milk samples were collected from 4 farms in Serbia. The samples were then tested for AFM1 content and were later used for hard cheese production. Four cheese samples were produced, and the matching whey samples were also collected. The milk samples included two samples containing AFM1 above the EU maximum level (0.077±0.009 and 0.118±0.008 µg/kg) and the other two samples below the maximum level of 0.05 µg/kg (0.021±0.002 and 0.034±0.004 µg/kg). Regarding AFM1 transfer into cheese from the milk samples containing AFM1 above the EU maximum level, the rate was approximately 4-fold (383% and 410%). On the other hand, in the cheese samples made from milk containing AFM1 below the EU maximum level, almost 10-fold levels of AFM1 content in milk were found (transfer rates of 934% and 961%). As for the whey samples, AFM1 levels were below the levels found in the milk samples (transfer rates of 78%, 74%, 68% and 57%). The difference in the transfer rates for the cheese made from the milk samples contaminated at different levels may indicate the possibility that the AFM1 transfer rate from milk into cheese depends on the content of this toxin in milk.