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Whereas selenium (Se) is an important antioxidant in human metabolism to prevent cancer, aflatoxins are highly carcinogenic. Brazil nuts from Eastern and Western Amazon regions were evaluated to find any relationship between Se and aflatoxins levels. A total of 80 (in-shell and shelled) nuts samples were collected directly from different forest sites and analyzed for Se by atomic emission spectrometry and aflatoxins by liquid chromatography tandem mass spectrometry. The limit of quantitation (LOQ) for Se was 2.0 mg/kg, and LOQ for total aflatoxins was 0.390 microg/kg. Nut Se levels from the Eastern region were higher than the Western, in addition to the aflatoxins. The moisture content (mc) and water activity (aw) of the raw nuts from the two regions did not present a significant difference, for either in-shell or shelled. The mc was 24.5% (minimum of 20.1% and maximum of 30.4%) and 22.1% (minimum of 14.6% and maximum of 28.9%) and a w of 0.85 for both regions. Further studies need to be carried out to discover the role of Se on fungi growth stress and aflatoxin production mechanisms.

Summary Antifungal and antimycotoxin properties of zinc (Zn) compounds were evaluated against toxigenic strains of Fusarium graminearum, Penicillium citrinum and Aspergillus flavus. In addition, was verified the activity of these Zn‐compounds on conidia production, hyphae morphological alterations, mortality and reactive oxygen species (ROS) production. The Zn‐compounds treatments utilised were zinc oxide nanoparticles (ZnO‐NPs), zinc oxide (ZnO), zinc sulphate (ZnSO4) and zinc perchlorate (Zn(ClO4)2). The Zn‐compounds effect on growth diameter of fungal colony was concentration dependent. Two treatments (ZnSO4 and Zn(ClO4)2) completely inhibited the fungal growth and their ability to produce mycotoxins. The conidia production of all fungi also was reduced after the treatment with Zn‐compounds. Morphological alterations occurred in the treated fungi showing hyphae damage. The treatments led to cell death and ROS production observed in the fungi hyphae. ZnSO4 and Zn(ClO4)2 were the compounds that showed better results as antifungal, presenting antimycotoxin activity and caused alterations in the fungi cell structure.