Shelled whole and whole in-shell Brazil nuts were
imported from a Peruvian Brazil nut processor and 50 nuts of each type were randomly chosen,
then surface treated by immersion in 0.4% sodium hypochlorite solution for 2 min
. Using alcohol-flamed forceps, 25 groups each consisting of two SW nuts and 25 groups
each consisting of WIS nuts were transferred onto the surface of deepPetri dishes
pre-poured with A. flavus and A. parasiticus agar. Following
incubation , the dishes were examined for fungal growth. A yellow/orange colour on
the reverse of the colony was used to indicate presumptive A. flavus/parasiticus
. Presumptive cultures were subsequently purified and cultivated on both Czapek
and malt agar at 28 1C until extensive formation of conidia was observed.
The isolates were then compared to known A. flavus and A. parasiticus strains grown on the same
media. Aspergillus flavus strains were tentatively identified and several were confirmed by the
National Fungal Identification Laboratory, Agriculture and Agri-Food Canada.
Cultures were maintained on AFPA slants at 5 1C following growth at 25 1C for 5 d.