Occurrence of aflatoxins in brazil nuts commercialized in the northeast of Brazil

Abstract

The objective of this study was to detect the presence and levels of aflatoxins in Brazil nuts. The results showed that of a total of 84 Brazil nut samples (25 kg), 11 (13.1%) were found to be positive for aflatoxin using thin layer chromatographic analyses. Of the aflatoxins found, aflatoxin B1 was the most commonly found mycotoxin (n = 6, 7.2%) at the collection points evaluated. With respect to the samples evaluated by the enzyme linked immunosorbent assay, 35 (41.7%) were shown to be positive. The average level of contamination of the Brazil nuts by total aflatoxins was 6.24 µg/kg ± 5.29, the lowest value being 0.7 µg/kg and the highest 28 µg/kg, and three samples were shown to be above the limit permitted by Brazilian and European legislation. Regarding the influence of the variables of temperature and air humidity on the production of aflatoxins according to the seasonal variations of the dry and rainy periods, no statistically significant correlation could be found. The results obtained indicated the need to monitor the contamination of nuts by aflatoxins and develop strategies to guarantee the adoption of good handling practices as a contribution to assuring the quality and safety of these foods.