Recent aflatoxin levels in maize, feed mixtures, milk and cheese in Serbia

Abstract

Aflatoxins are the most widespread mycotoxins primar?ly produced by fungi of the genus Aspergillus such as A. flavus and A. parasiticus, infecting grains during storage, spices, nuts, milk and animal feed. Even in low concentrations, they are highly toxic. Major forms of aflatoxins include B1, B2, G1, G2, and M1. Mammals that ingest AFB1 contaminated food eliminate amounts of the main hepatic metabolite known as milk toxin or aflatoxin M1 (AFM1) via milk. The incidence of contamination of aflatoxin in maize, feed mixtures, milk and cheese samples collected from Serbian producers was investigated by using the competitive enzyme linked immunosorbent assay (ELISA) technique. In this study, a total of 22 samples of maize, 25 samples of feed mixtures, 284 samples of raw, pasteurised and UHT milk and 20 samples of cheese were examined in 2021. Aflatoxin B1 (AFB1) was quantified in 3 samples (13.6%) of maize, at levels ranging from 2.45?g/kg to 48.31?g/kg and 12 samples (48%) of feed mixtures at levels ranging from 2.04 ?g/kg to 21.48 ?g/kg. On the other hand, AFM1 was quantified in 51 samples (17.90%) of milk at levels ranging 0.02 ?g/kg to 0.26 ?g/kg and 15 samples (75%) of cheese at levels ranging from 0.15 ?g/kg to 0.46 ?g/kg. In the Republic of Serbia, maximum limit of AFB1 in maize used for livestock is 30 ?g/kg and for feed mixtures for dairy cows is 5 ?g/kg. On the other hand, maximum limit of AFM1 in milk is 0.25 ?g/kg. Maximum limit of AFM1 in cheese is not set. These results suggest the obvious presence of AFB1 in maize and the fact that number of feed mixture, milk and cheese samples contaminated with aflatoxins is not negligible. The occurence of aflatoxins in raw milk and comercially available milk is one of the most serious problems, as milk is a key source of nutrients for infants and young children. There?fore, continuous monitoring over milk is necessary as well as further research and risk analysis on AFM1 presence in cheese.