Aflatoxigenic and ochratoxigenic fungi and their mycotoxins in spices marketed in Brazil

Abstract

During their processing, spices usually remain close to the ground for drying, a fact that disposes to fungal contamination, as well as moisture transferred from the tropical environment can allow their multiplication and synthesis of mycotoxins. The objective of this study was to evaluate the presence of potentially toxigenic fungi and mycotoxins in spices marketed in Brazil. The fungal contamination was evaluated by direct plating for samples of clove, black and white peppers. Spread plate was used for the samples of rosemary, cinnamon, fennel, pepperoni pepper and oregano. Analyses were performed in triplicate in DG18 media with incubation at 25°C for 7days. The isolation and identification of fungi followed specific recommendations of culture media and incubation period for each genus. The presence of mycotoxins in spices was verified by high-performance liquid chromatography (HPLC) coupled to fluorescence. The frequency of species potentially toxigenic was high in white and black peppers with presence of both aflatoxigenic and ochratoxigenic fungi. Only rosemary and fennel showed contamination with aflatoxin B1 and there was a positive correlation (ρ<0.01) between the rosemary contamination with the presence of AFB1 and A. flavus. Even in the presence of ochratoxigenic fungi, ochratoxin A was not detected in the samples. The presence of natural components with antimicrobial activity could justify the low presence of mycotoxins, even in the presence of known toxigenic fungi in the samples. Mycotoxins were not detected in spices covered by Brazilian regulation of mycotoxins. On the other hand, these contaminants were present in other spices consumed by population and not mentioned in the regulation, which could be considered a cause to concern.