This study aimed to verify the use of aqueous ozone as alternative technology for fungal control. Brazil nuts sterilized were inoculated with either or ?conidia?mL?1 of Aspergillus flavus (MUM 9201) to determine optimal treatment parameters and different aqueous ozone contact times. These assays showed that the effect of ozone is almost immediate against A. flavus, and the optimum ozone concentration depended on the number of initial viable spores on the shell. The remaining viable spores in the ozone solution were recorded, and the rate of inactivation for each treatment was determined by assessing the ratio between the cfu of each treatment and the control. The ozonized nuts were also cultured to recover the fungal population. Aqueous ozone was effective in reducing the conidia of A. flavus and the natural fungal population associated with Brazil nuts. Aqueous ozone presented a great potential to reduce microorganisms counts in Brazil nuts with a great potential use in packing houses for decontamination step. 1. Introduction The Brazil nut (Bertholietia excelsa) is an important nontimber forest product (NTFP) from the Amazon forest. Brazil produces approximately 24% of the total world supply of this nut. Brazil nuts exploitation is an important social and economic activity for people living in forest areas. Besides this, it is an important factor in forestry conservation and environmental sustainability [1]. Despite the positive nutrition and health-related aspects of Brazil nuts, they are susceptible to colonization by mycotoxin-producing fungi and consequently to contamination with mycotoxins. There are reports of the presence of Aspergillus flavus, and A. nomius, which are the main producers of aflatoxins (AF) [2], and more recently two other aflatoxigenic species A. bombycis and A. arachidicola [3] and a new nonaflatoxigenic species A. bertholletius [4], all of them from this same section, were isolated and identified in Brazil nut samples. EU countries and the United States have been the major importers of in-shell and shelled Brazil nuts, respectively. AF contamination constitutes not only an economic problem for Brazil nut producing countries but also a serious health risk for consumers all over the world [5]. Both industries and producers have been making considerable efforts in the past 15 years to minimize fungal growth and AF contamination of tree nuts. Particularly in the case of Brazil nuts, the climate conditions in the Amazon environment and the characteristics of the exploitation activity (collecting and primary handling) cannot be
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