Zewdu, Ashagrie (PhD)Makiso, Markos2019-05-212023-11-082019-05-212023-11-082017-06-03http://etd.aau.edu.et/handle/123456789/18279The oilseed sector is one of the fastest growing sectors in Ethiopia, both in terms of its foreign exchange earnings and as source of income for millions of Ethiopians. Oilseed crops are recognized to be potentially suitable substrates for the production of aflatoxins by aflatoxigenic fungi. This study aimed to evaluate Knowledge attitude and practice (KAP) of sesame exporters about aflatoxin contamination, analyze thousand seed weight, moisture, crude fat and peroxide value of white and red sesame collected from Humera and Wollega varieties. Determining the level of aflatoxins of white and red Ethiopian sesame seeds. Compare the level of aflatoxins between white and red Humera and Wollega varieties. Isolate and identify aflatoxigenic fungi from sesame seeds. A total of 27 sesame samples were collected from Ethiopian Agricultural commodities warehouse service enterprise, located in Addis Ababa. Semi-structured questionnaires used for knowledge, attitude and practice survey of sesame exporters and Thousand seed weight, moisture, crude fat and peroxide value of sesame seeds have been done according to American oil chemists society (AOCS) method. Analysis of aflatoxins was done by using HPLC with solid phase extraction clean up method. Isolation and identification of aflatoxigenic fungi has been done by culturing sesame samples on Potato dextrose agar (PDA) media. Sixty percent of exporters doesn't have any idea about aflatoxins and all of them cannot make aflatoxins test for sesame seed before export. Thousand seed weight, moisture, crude fat and peroxide value were ranged 2.89-3.22g/1000 seed, 3.33-4.99 %, 46.75-57.75% and 2-8.2 meq/kg, respectively. Aflatoxins detected from 93 % of samples in the range of (0.44 - 48.28 ng/g). Average content of AFB1, AFB2, AFG1, AFG2 and total aflatoxins are 0.83 ng/g, 6.82 ng/g, 17.25 ng/g, 1.17 ng/g and 26.07 ng/g, respectively. AFB1 and AFG2 detected below European union (EU) maximum limit for individual aflatoxin (2 ng/g). AFB2, AFG1 and total aflatoxins content is above the permissible limit set by EU for both individual and total aflatoxins (15 ng/g). Red sesame variety indicates relatively higher level of aflatoxins contamination as compared with white Humera and white Wollega sesame. Aspergillus flavus, A. parasiticus and A. niger isolates identified. Based on the finding, the contamination level may affect national economy.enSesameAflatoxinsHPLCSolid Phase ExtractionOilseedThesis