Tef protein: Solubility characterization, in-vitro digestibility and its suitability as a gluten free ingredient

In this study, SDS-PAGE characterization of total protein and Osborne fractionation, in-vitro digestibility and immunogenicity of tef protein of seven different varieties were investigated. The contribution of globulin fraction alone ranged from 51 to 61% making it as the major storage protein in tef flour. The Osborne fractionation method resulted in a very low total storage protein recovery of tef, prompting a need for further optimization of the method. The major protein bands of SDS-PAGE of all the tef varieties were observed between 14.4 and 66.2 kDa. Major bands of SDS-PAGE of albumin, globulin, prolamin and glutelin proteins appeared between molecular weights markers of 14.4-97.4, 14.4-66.2, 14.4-45 and 14.4-66.2 kDa, respectively. In-vitro protein digestibility of the flour and injera ranged from 71 to 72% and 73-75%, respectively. The gluten content of the tef varieties ranged from 7.4 to 14.5 mg/kg, allowing to classify tef as a gluten free cereal grain.