RESUMO
The production of aflatoxin (AF) B1 and B2 was determined during malting of wheat grains artificially contaminated with a toxigenic A. flavus strain (CCDCA 11553) isolated from craft beer raw material. Malting was performed in three steps (steeping, germination and kilning) following standard Central European Commission for Brewing Analysis procedures. AFB1 and AFB2 were quantified in eleven samples collected during the three malting steps and in malted wheat. Both, AFB1 and AFB2 were produced at the beginning of steeping and detected in all samples. The levels of AFB1 ranged from 229.35 to 455.66 µg/kg, and from 5.65 to 13.05 µg/kg for AFB2. The AFB2 increased during steeping, while no changes were observed in AFB1. Otherwise, AFB1 decreased during germination and AFB2 did not change. AFB1 and AFB2 increased after 16 h of kilning at 50 °C and decreased at the end of kilning, when the temperature reached 80 °C. The levels of AFB1 wheat malt were lower than those detected in wheat grains during steeping; however, levels of both AFB1 (240.46 µg/kg) and AFB2 (6.36 µg/kg) in Aspergillus flavus inoculated wheat malt exceeded the limits imposed by the regulatory agencies for cereals and derived products.
