sábado, 20 de setembro de 2014

Determination of aflatoxins in wheat and wheat by-products intended for human consumption, marketed in Rio de Janeiro, Brazil


The  consumption  of  wheat  bran,  whole-wheat  grains  and  other  whole-wheat  products  has grown  in recent years in Brazil. These foods are considered more nutritious than the refined ones and have  been associated with  a  reduced risk of  some  major chronic diseases. On the other hand, other research,  carried out in  Brazil, has found  different  groups  of  fungi  toxins,  called mycotoxins, contaminating  these  wheat  products.  Among  these mycotoxins, are the aflatoxins, a group of genotoxic and carcinogenic compounds produced by Aspergillus spp. This study aimed to determine the levels of aflatoxins B1, B2, G1 and G2 in samples of whole-wheat grains and derivatives, intended  for  human consumption, marketed in the metropolitan region of Rio de Janeiro,  Brazil. One hundred and eight samples of whole-wheat grains (n=35), wheat bran (n=32), whole-wheat flour (n=26) and refined wheat flour (n=15) marketed in hypermarkets, supermarkets and health food stores were analyzed by High Performance Liquid Chromatography with fluorescence detection (HPLC-FL). Thirty-three samples (30.6%)  were positive for at least one aflatoxin and the B1 form had the highest prevalence in the samples. The overall average was 0.69 µg/kg and the contamination was the highest in the grain samples, followed by bran, whole-flour and refined flour. Just one sample showed total aflatoxins levels (B1+B2+G1+G2) higher than the limit established by Brazilian legislation (5 µg/kg). The levels found in this study indicated that the presence of aflatoxins in wheat and wheat products consumed in Rio de Janeiro, Brazil, are not a hazard for public health.

Available at: Journal of Food and Nutrition Research
http://pubs.sciepub.com/jfnr/2/10/3/index.html
Keywords: mycotoxins, AFB1, wheat bran, whole-wheat products, HPLC Journal of Food