Aflatoxin M1 in Spanish infant formulae: occurrence and dietary intake regarding type, protein-base and physical state.

The incidence of aflatoxin M1 (AFM1) in 69 different infant formulae marketed in Spain between 2007 and 2008 was studied and dietary intake estimated. Samples were analysed using an HPLC method coupled with fluorescence detection after immunoaffinity column clean-up. The toxin was detected in 26 formulae (37.7%) at levels below the permissible limit set by EC legislation, giving a range of 0.6-11.6 ng kg(-1) with a mean value of 3.1 ng kg(-1). Increasing occurrence was found in those formulae produced by the less complex manufacturing processes affecting casein/whey protein ratio: pre-term, 14.3%; starter, 35.3%; follow-up, 42.1%; toddler 87.6%; while hypoallergenic and lactose-free were totally exempt. Additionally, the influence of main protein source and physical state (powdered and ready-to-use formula) on AFM1 occurrence was evaluated leading to similar conclusions. Dietary AFM1 weekly intake was observed to be stable around 1 ng kg(-1) bw for standard formula and 0.1 ng kg(-1) bw for pre-term feeding.