Abuye, Cherinet (PhD)Baye, Kaleab (PhD)Ambaw, Ashenafi2021-01-252023-11-092021-01-252023-11-092013-06-06http://10.90.10.223:4000/handle/123456789/24812Background-Iron deficiency is prevalent in Ethiopia despite high dietary iron intake. The contribution of iron from extrinsic sources from soil contamination during threshing is likely to be high. However, the extent of contamination and bioavailability of the contaminant iron remains unknown. Objective-To evaluate whether there is difference in iron fractions of field and laboratories threshed teff and investigate how fermentation affects the mobility of the different iron fractions and mineral absorption inhibitors. Methods-Teff variety grown under the same conditions but threshed differently (Laboratory and field threshed) was collected and characterized for their proximate composition and mineral absorption inhibitors. Total iron analysis and iron fractionation into five fractions using sequential extraction scheme were performed. The effect of fermentation and baking on the mobility of iron fractions was also evaluated. Results-Field threshed teff had ~37% more iron content than that of laboratory threshed teff. Threshing significantly contributed to the exchangeable, reducible and residual fractions. Fermentation plays a great role in mobilizing iron fractions of both laboratory and field threshed teff. In both lab and field threshed teff samples, fermentation significantly increased the exchangeable and decreased the residual fraction. Furthermore, fermentation lead to significant decreases in phytate, iron-binding polyphenols and tannin (P<0.05.) in both laboratory and field threshed teff-injera. No significant differences in proximate composition between lab and field threshed teff, except for higher ash content in the field threshed teff, was observed. Conclusion- Contaminant iron, mainly due to threshing, adds up to the total iron content of field threshed teff. Fermentation degraded mineral absorption inhibitors and mobilized iron fractions into more mobile and bioavailable fraction i.e. exchangeable fraction. Contaminant iron is likely to contribute to the intake of bioavailable iron.enSequential ExtractionThreshingFermentationSoilContaminationFractionationBioavailabilityThesis