Assessment for fungal, mycotoxin and insect spoilage in maize stored for human consumption in Zambia.
BACKGROUND: Maize constitutes the main staple food and most important crop grown in Zambia. However, maize incurs considerable losses both in field and storage due to pathogens and insects. Some of the pathogens and resultant mycotoxins reduce the nutritional quality of the product. Mycotoxins are toxigenic fungal compounds that can cause cancer and suppress growth. In spite of this health hazard, there has been very little research to document their occurrence. Maize grains stored for human consumption were sampled from different agro-ecosystems (forest, valley and plateau areas) of three agroecological zones (high, mid and low altitude). RESULTS: Several fungal genera were recovered among which Aspergillus flavus, A. niger, Fusarium verticillioides, F. solani, Rhizopus stolonifer and Penicillium spp. were prevalent. The weevil Sitophilus zeamais and the larger grain borer Prostephanus truncatus were the most damaging. Enzyme-linked immunosorbent assay (ELISA) tests yielded fumonisins and aflatoxins ranging between 0.02 and 21.44 ppm, and 0.7 and 108.39 ppb in 96.4% and 21.4% of samples, respectively. Fumonisin was more pronounced in villages in forest areas whereas aflatoxin was highest in valley and forest areas in Zone II. CONCLUSION: Strategic interventions to curtail fungal, mycotoxin and insect contamination should be directed towards improved agronomic and post-harvest practices of maize from fields to consumers.