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 B1 (AFB1). 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 °C, 30 °C); and water activities (0.74 a w, 0.85 a w) on AFB1 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 1 month under various °C + a w regimes. AFB1 production was quantified by high performance liquid chromatography with fluorescence detector (HPLC-FLD). For A. flavus in PELA, no AFB1 was detected (100% reduction) at 25 °C for both a w tested. For A. parasiticus in PELA, no AFB1 was detected at 25 °C (0.85 a w) and 30 °C (0.74 a w). Highest concentration of AFB1 was detected in LDPE for both A. flavus (46.41 ppb) and A. parasiticus (414.42 ppb), followed by PP (A. flavus 24.29 ppb; A. parasiticus 386.73 ppb). 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 AFB1 contamination in peanuts.