Selenium and Aflatoxin Levels in Raw Brazil Nuts from the Amazon Basin

Abstract

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.

Brazil nuts: determination of natural elements and aflatoxin

“…In that study, the authors found also a correlation between levels of Se and aflatoxin: the higher the level of Se, the higher the aflatoxin contamination. Considering the fact that their correlation, as well as the levels obtained in our study is significantly lower than those reported by Pacheco and Scussel (2007), it may be possible to explain the non-detection of aflatoxins in our samples studied by the LOQ.…”

“…The concentration of Se in Brazil nuts seems to be influenced by the absorption capacity of the tree and may vary according to factors arising from the composition of the soil from which they originate. Levels of 8.0 to 69.7 µg g -1 in shelled Brazil nuts from different regions of the Amazon have been reported by Pacheco and Scussel (2007). In that study, the authors found also a correlation between levels of Se and aflatoxin: the higher the level of Se, the higher the aflatoxin contamination.…”

Properties of Brazil nuts: A review

“…The contents of alpha-and gamma-tocopherol in Brazil nuts are 72.55 and 74.35 mg/g of oil, respectively, and the contents of beta-sitosterol, campesterol and stigmasterol are 79.00, 4.00, and 11:33 mg/g of oil, respectively (Costa et al, 2010). Compared to other tree nuts, Brazil nuts are known as the best source of Se (Chunhieng et al, 2004;Pacheco and Scussel, 2007;Chunhieng et al, 2008;Welna et al, 2008). Furthermore, it also contains numerous vital minerals such as calcium, magnesium, phosphorus, and potassium (USDA, 2008;Yang, 2009).…”

Brazil nut allergy: A review

“…Barium (Ba) and Radio (Ra) can also be found in Brazil nuts (Martins et al, 2012). Compared to other tree nuts, Brazil nuts are known as the best source of Se (Pacheco and Scussel, 2007;Chunhieng et al, 2008;Manfio et al, 2012). Adequate intake of Se is essential for normal activity of Se-enzymes involved in the protection against oxidative stress, maintenance of the redox system, modulating the immune system, and regulation of the thyroid.…”