Traditional fermentation of tef injera: Impact on in vitro iron and zinc dialysability

Abstract

Tef [Eragrostis tef (Zucc.) Trotter], an ancient cereal mainly produced in Ethiopia, is increasingly getting higher acceptance in the global market because it is gluten free and has high iron content. The aim of this study was to evaluate the in vitro dialysability of Fe and Zn in a backslop fermented gluten free flat bread known as injera. The traditional fermentation caused up to 49–66% reduction of phytic acid (PA). Molar ratios of PA:Fe and PA:Zn decreased from 14 to 1 and from 63 to 19, respectively, after 120h of fermentation. The total soluble fractions of Fe and Zn ranged between 11 and 38% and between 11 and 29%, respectively, after 120h of fermentation. The dialyzable Fe content of the white varieties ranged between 3 and 9% after 120h fermentation while no effect was observed for the brown varieties. The dialyzable Zn ranged between 2 and 11%, with only a clear effect of fermentation in one white variety. Consumption of tef could be a good source of Fe and Zn, but may not provide the absolute recommended daily Fe and Zn intakes.