Comprehensive study on the effect of fermentation time, baking temperature and baking time on the physicochemical and nutritional properties of injera teff (Eragrostis teff)

Abstract

Injera is an Ethiopian fermented flatbread made from teff grain flour (Eragrostis teff [Zucc.) Trotter). The fermentation time and baking temperature-time combination can affect the quality attributes of the injera during baking. As a result, the goal of this study was to determine the effects of three factors on the physicochemical quality (pH, color, and moisture content), proximate composition, mineral content (Zn, Fe, and Ca), antinutritional factor (tannin and phytic acid), and sensory acceptability of baked teff injera. The injera baking process variables studied were fermentation time (24, 48, and 72 h), baking temperature (160, 180, and 200 ℃), and baking time (2, 3, and 4 min), comprising 17 experimental runs with 5 center points, and were analyzed using the BoxBehnken Response Surface Methodology (RSM). An increase in fermentation time decreased the pH (3.63) and antinutritional factor concentration (0.24 mg/100 g tannin, 192.2 mg/100 g at 72 h fermentation time) of the injera. The moisture content of the injera was shown to be significantly affected by baking temperature and time. The overall acceptability was optimized, and the optimized results (6.54) clearly showed that the overall acceptability of the injera teff was strongly dependent on the baking time and temperature. Even though injera baked at the lower and upper points had positive effects on proximate and antinutritional factors, the injera baked at the center point (180 ℃, 3 min, 48 h) at the baking temperature, baking time and fermentation time, respectively, had better injera quality in terms of sensory acceptability.