Distribution and toxigenicity of Aspergillus section flavi in spices marketed in Morocco
Résumé
Aflatoxin B1 is a carcinogenic mycotoxin that may contaminate spices. Indeed, these ingredients are usually produced in areas where the climatic conditions are favorable to growth of Aspergillus of the Flavi section and the synthesis of mycotoxins. This study aimed to characterize the fungal flora of 80 paprika, cumin and pepper marketed in Morocco with a special focus on Aspergillus section Flavi isolates. After identification to the species level, their toxigenic potential was determined and the related contamination of spice samples was also investigated. We observed a widespread contamination of spices with Aspergilli section Flavi. Among them, 57% were found to be toxigenic. The most frequent chemotypes correspond to isolates able to produce both aflatoxin B and cyclopiazonic acid followed by B aflatoxins only producers. These chemotypes represented 25% and 16% of the isolates respectively. Eight percent of toxigenic isolates (3/36), that produced sclerotia in culture, were found able to synthesis aflatoxin G1. A molecular identification revealed that these isolates belonged to Aspergillus minisclerotigenes species. That is the first report of the presence of such species in spices. The analysis of the contamination of spice samples with AFB1 revealed that paprika is frequently contaminated since 95% were contaminated with that mycotoxin and 40% of samples exceeded European regulation for that contaminant. Therefore, this spice that is widely used for cooking in Morocco, may represent a direct source of exposure to that carcinogenic compound.