Production of aflatoxin B and B by Aspergillus flavus in inoculated wheat using typical craft beer malting conditions.

The production of aflatoxin (AF) B and B 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. AFB and AFB were quantified in eleven samples collected during the three malting steps and in malted wheat. Both, AFB and AFB were produced at the beginning of steeping and detected in all samples. The levels of AFB ranged from 229.35 to 455.66 μg/kg, and from 5.65 to 13.05 μg/kg for AFB. The AFB increased during steeping, while no changes were observed in AFB Otherwise, AFB decreased during germination and AFB did not change. AFB and AFB 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 AFB wheat malt were lower than those detected in wheat grains during steeping; however, levels of both AFB (240.46 μg/kg) and AFB (6.36 μg/kg) in Aspergillus flavus inoculated wheat malt exceeded the limits imposed by the regulatory agencies for cereals and derived products.