Filamentous fungi, bacteria and yeasts associated with cashew kernels in Brazil

Abstract

During the past ten years a study has been conducted on the occurrence of fungi, bacteria and yeasts associated with cashew kernels in Brazil. Over a 1,000 samples from farmers and retailers have been examined. This paper aims to list the microorganisms so far isolated. A total of 79 fungal, 18 bacterial and 1 yeast species have been confirmed. Members of Aspergillus and Penicillium are dominant. Species potentially toxigenic such as Alternaria alternata, Aspergillus clavatus, A. flavus, A. parasiticus, A. ochraceus, A. ustus, Penicillium citrinum and P. oxalicum were frequently isolated. Among the bacteria those of the genus Bacillus were dominant. Escherichia coli, Staphylococcus aureus and Salmonella sp. were identified in some small processing plants. Pichia guillermondii was the only yeast confirmed. Measures aiming to reduce microbial contamination of kernels during processing and to improve hygienic conditions in big plant as well as in small processing units are discussed.