ABSTRACT
Natural contamination of sorghum grains by aflatoxin B1 and total fumonisin and their producing toxigenic fungi has been studied. A total of 90 sorghum grain samples were collected from small-scale farmers’ threshing floors and 5–6 months later from underground pits during 2013 harvest from three districts of East Hararghe, Ethiopia. Mycotoxin analysis was done using enzyme-linked immunosorbent assay (ELISA). The limits of detection were in the range 0.01–0.03 μg kg–1. The results revealed that all sorghum grain samples were contaminated with both Aspergillus and Fusarium species. Aflatoxin B1 was detected at levels ranging from <LOD to 33.10 µg kg−1 grain. There were marked variations in aflatoxin B1 concentrations between fresh and stored samples, with much higher levels in the latter. Total fumonisin levels varied between 907 and 2041 µg kg−1 grain across the samples. Lowest total fumonisin was recorded in freshly harvested sorghum grain samples. Sorghum is a main staple cereal in the studied districts and its consumption per day per person is high. Daily intake of low doses of mycotoxin-contaminated food stuff over a period of time could lead to chronic mycotoxicosis.
Acknowledgements
We acknowledge the financial support of the Ethiopian Ministry of Education and German Academic Exchange Service (DAAD). We also thank all staff members of the Haramaya University Plant Pathology Laboratory for their unreserved support during the laboratory work. Mr Melkamu Ayalew will take credit for his support of the enzyme-linked immune-sorbent assay (ELISA) kits. Appreciation also goes to all the farmers in the study areas who willingly provided samples.
Disclosure statement
No potential conflict of interest was reported by the authors.