Isolation of mycotoxigenic moulds contaminating maize and groundnuts in selected districts of Kenya

Abstract

Moulds damage foods, feeds and other agricultural commodities in the field and storage, leading to postharvest losses. In addition, moulds produce mycotoxins that cause illness or even death to consumers. This study evaluated maize and groundnuts from selected districts in Kenya for mycotoxigenic moulds. Both good and mouldy maize and groundnuts were obtained from randomly selected rural households and markets in Trans Nzoia, Kakamega Central and Kuria West districts in Kenya and analysed for moulds using the direct plating method. All the samples were positive for moulds and contained at least one genera of mycotoxigenic fungi; Fusarium, Aspergillus and Penicillium. The major moulds isolated in order of frequency were Aspergillus (91.3%), Penicillium (86.2%) and Fusarium (79.3%). Fifteen species of Aspergillus, eighteen of Fusarium and fifteen of Penicillium were isolated. Most of the samples (86.2%) contained more than two types of moulds. Some of the samples categorized as 'good' based on visual observation were highly contaminated by more species of moulds than samples categorized as mouldy. The highest occurring mould species were A. flavus (56.9%), A. niger (27.6%), A. parasiticus (25.9%), A. ochraceus (24.1%), F. subglutinans (29.3%), F. oxysporum (19%), F. graminearum (17.2%), P. rubrum (41.3%), P. cyclopium (34.5%) and P. rugulosum (22.4%). Seventy five percent of the moulds isolated in this study are known to be mycotoxigenic or produce other harmful compounds. The high occurrence of mycotoxigenic moulds in maize and groundnuts points to the great danger posed to human and animal health from consumption of contaminated grains and their associated mycotoxins. © 2014 Academic Journals Inc.