Fungi associated with Brazil nut and groundnut kernels sold in Fortaleza city (Brazil)

Abstract

A comprehensive study was carried out on the fungi associated with kelnels of Brazil nut and peanut normally traded in Fortaleza city (State of Ceará, Brazil). Samples were obtained from local retail outlets and distributors and before surface sterilization were divided into two portions, one shelled and another unshelled. Fungi were enumerated by direct plating on water agar. Data for percentage of infection were calculated and and fungi were identified to species level. Aspergillus, mainly A. flavus, and Penicillium were the most frequently species found on both commodities. The fungi Curvularia lunata, Emericella nidulans, Fusarium verticilloides, Gongronella butleri, Graphium putredinis, Macrophomina phaseolina, Paecilomyces variotii, Saksenae vasiformis, Syncephalis sphaerica e Syncephalastrum racemosum are reported for the first time associated with Brazil nut. Five isolates of A. flavus from shelled Brazil nut kernels were efficient B₁ and G₁ aflatoxin producers. None of the peanut A. flavus isolates was capable of producing aflatoxins. The possible occurrence of aflatoxins on these commodities and their importance to human health are discussed.