J. M. L. de Souza

Incidence of Aspergillus flavus, Aspergillus parasiticus and aflatoxins in Brazil nuts in the Amazon forest environment

This work aimed to evaluate, in the Amazon Forest environment, the effect of time on contamination of Brazil nuts with Aspergillus flavus, Aspergillus parasiticus and aflatoxins after falling of the pods. Samples were collected at three different times and analysed for water activity, potentially aflatoxigenic fungi A. flavus and A. parasiticus, other fungi and aflatoxins. The mean values for the parameters tested were: water activity 0.98; A. flavus and A. parasiticus 1.3×101 colony forming units (cfu)/g; other fungi 3.2×103 cfu/g; aflatoxin B1 0.073 μg/kg, aflatoxin B2 0.009 μg/kg, aflatoxin G1 0.034 μg/kg and aflatoxin G2 0.007 μg/kg. The incidence of A. flavus and A. parasiticus was not significantly affected by the time, during which the pods were on the forest soil. Moreover, aflatoxins levels were low during the whole study period, suggesting that adverse forest conditions were not the main factor that stimulate the production of aflatoxins.