Infants have a more restricted diet and they generally consume more food on a body weight basis than adults. Therefore, the significance and potential health risk of any contaminant in foods consumed by infants is increased and diligent attention must be paid to this particular area. The present study aims to determine the occurrence of aflatoxin M-1 (AFM(1)), aflatoxin B-1 (AFB(1)) and ochratoxin A (OTA) in processed cereal-based foods (flours) and infant formulae (milk powder) available in the Portuguese market, both sold as conventional and organic origin. Mycotoxin determination was carried out using a method previously applied to duplicate diet samples. This method employed chloroform extraction, liquid-liquid extraction, immunoaffinity column (IAC) cleanup and HPLC analysis with fluorescence detection after post-column derivatisation. Quantification limits were 0.014, 0.004 and 0.028 mu g kg(-1) for AFM(1), AFB(1) and OTA, respectively. These toxins could only be quantified in 12 of 27 analysed samples (15 positive results): two samples with AFM(1), two samples with AFM(1) and OTA, one sample with AFB(1) and OTA and seven samples with OTA. Positive results concerned four for AFM(1) (26%), one for AFB(1) (7%) and ten for OTA (67%). For these samples, contents ranged between 0.017-0.041 mu g AFM(1) kg(-1), 0.034-0.212 mu g OTA kg(-1), and one sample had a value of 0.009 mu g AFB(1) kg(-1). Considering the presented results, we could provisionally conclude that the presence of these mycotoxins in baby foods does not constitute a public health problem. These are the first results concerning the occurrence of mycotoxins in marketed baby foods in Portugal and this is the first study using the HPLC method, proposed for duplicate diets, in baby food sample analysis.
