Aflatoxins and aflatoxigenic fungi in export standard white and red sesame seeds (Sesamum indicum L.) from Ethiopia

The oil seed sectors one of the fastest growing sectors in Ethiopia, both in terms of its foreign exchange earnings and as a source of income for millions of Ethiopians. Oilseed crops are recognized to be potentially suitable substrate for the production of aflatoxins by aflatoxigenic fungi. This study intended to evaluate knowledge, attitude and practice of sesame exporters about aflatoxins contamination, to characterize the seed and to determine the level of aflatoxins, from export standard white and red Humera and Wollega sesame seeds. Twenty seven ready to export sesame samples were collected from Ethiopian Commodity Exchange (ECX) warehouse. Thousand seed weight, moisture, crude fat and peroxide value were determined according to AOAC. Aflatoxin B1, B2, G1, G2 and total aflatoxins were determined at ng/g level by SupelTM Tox Aflazea cartridge clean up and reversed-phase liquid chromatography. Thousand seed weight determined in the range of 2.89-3.22 g/1000 seeds, moisture is 3.33-4.99%, crude fat is 46.75-57.75% and peroxide value is 2-8.2 meq/Kg. Aflatoxin B1, B2, G1, G2 and total aflatoxins detected in the range of 1.32 - 2.12 ng/g, 1.52-31.98 ng/g, 16.2-48.28 ng/g, 0.56-9.04 ng/g and 0.44-64.96 ng/g, respectively. The aflatoxins contamination of sesame seeds could ruin the oilseed export and thus decrease the revenues of the state.