Survey of roasted street-vended nuts in Sierra Leone for toxic metabolites of fungal origin

Abstract

Consumption of mycotoxin contaminated foodstuffs is common in regions where foods are not adequately controlled and routinely monitored, and this could have adverse effects on the health of consumers. In this study, 100 samples of roasted nuts (50 cashew nuts and 50 peanuts) vended within two cities of Sierra Leone were analysed for mycotoxins and other microbial metabolites by a LC-MS/MS method. The peanut samples contained detectable levels of 17 microbial metabolites, including aflatoxins B₁, B₂, G₁ and G₂ and alternariol, while none of these metabolites were found in the cashew samples. Aflatoxins (max: 5,729 μg/kg; mean: 487.8 μg/kg) and alternariol (3 μg/kg) were found in 24% and 2% of the peanut samples, respectively. One-third of the aflatoxin-contaminated peanut samples contained aflatoxins at levels exceeding the total aflatoxin limit of 4 μg/kg set by the European Union. Aflatoxin contamination of Sierra Leonean peanuts is high and requires urgent intervention to reduce consequent exposure.

Keywords: Aflatoxin; cashew; food safety; fungal metabolites; nuts; peanut.