The effects of different packaging materials, temperatures and water activities to control aflatoxin B1 production by Aspergillus flavus and A. parasiticus in stored peanuts

Aflatoxins (AFs) are secondary metabolites produced by aflatoxigenic strains of Aspergillus flavus and A. parasiticus, the most toxic being aflatoxin B-1 (AFB(1)). The purpose of the present work was to investigate the effects of industrial-grade packaging materials (low-density polyethylene, polypropylene, polyethylene-laminated aluminium); temperatures (25 degrees C, 30 degrees C); and water activities (0.74 a(w), 0.85 a(w)) on AFB(1) production by A. flavus and A. parasiticus in stored peanut kernels. Commercially-obtained samples were segregated into packaging materials, separately inoculated with the aflatoxigenic Aspergillus spp., and stored for 1month under various degrees C+a(w) regimes. AFB(1) production was quantified by high performance liquid chromatography with fluorescence detector (HPLC-FLD). For A. flavus in PELA, no AFB(1) was detected (100% reduction) at 25 degrees C for both a(w) tested. For A. parasiticus in PELA, no AFB(1) was detected at 25 degrees C (0.85 a(w)) and 30 degrees C (0.74 a(w)). Highest concentration of AFB(1) was detected in LDPE for both A. flavus (46.41ppb) and A. parasiticus (414.42ppb), followed by PP (A. flavus 24.29ppb; A. parasiticus 386.73ppb). In conclusion, storing peanut kernels in PELA in a dry place at room temperature has been demonstrated as an adequate and inexpensive method in inhibiting growth of Aspergillus spp. and lowering AFB(1) contamination in peanuts.