Investigating the Effects of Teff–Sorghum–Fenugreek Flour Blending Ratios on Quality Attributes of Injera

Injera is Ethiopian fermented and leavened flat bread mainly made from teff flour. For improving the protein content and sensory quality of injera, the flours are enriched with fenugreek. Injera made from sorghum flour alone or its blend, however, has noted shortcomings in qualities when compared to teff injera qualities. Therefore this study was carried out to investigate the effects of teff-sorghum - fenugreek flour blending ratios on quality attributes of injera and to optimize the blending ratios of teff, sorghum, and fenugreek flours that give better quality attributes of injera made from these flour formulations. The effects of blending flour ratios on injera quality were investigated using mixture design methodology with a D-optimal design. Fourteen formulations of injera were produced from constrained blends of sorghum (0–50%), teff (50–100%), and fenugreek (0–5%), while a teff flour alone (100% teff flour) injera was served as control. Analyses of response parameters were made using the AACC and AOAC standard methods. Response variables considered in this study were staling rate, proximate, mineral, antinutritional factors and sensory attributes. Proximate compositions (g/100 g) ranged from 56.16 to 69.92 (moisture), 2.64 to 3.91 (ash), 11.36 to 17.19 (protein), 2.258 to 10.838 (fat), 4.179 to 6.988 (fiber) and 59.54 to 77.74 (carbohydrate), and energy, 348.1-385.62 (kcal/100g). Minerals (mg/100 g) varied from Fe: 12.83 to 21.23, Zn: 1.19–2.36, and Ca: 75.26 to 151.13. Antinutritional factors (mg/100 g) varied from 4.106 to0.449 (condensed tannin), 72.83 to 174.84 (phytic acid). Sensory scores for sourness, sweetness, bitterness, softness, stickness, rollability, odour, flavor, eye distribution, color and overall acceptability were 5.00-6.37, 5.14-6.36, 5.24-6.29, 5.14-6.57, 5.14-6.43, 5.93-6.57, 5.57-6.57, 5.43-6.71, 5.49-6.43, 4.87-6.29 and 5.60-6.23, respectively.3.670 to 4.105(pH) and staling rate (%) varies from 8.95 to 33.43, 9.52 to 34.58, and 12.32 to 52.31 after 24,48 and 72hours, respectively. Alkaline water retention capacity, AWRC (%) varies from 49.42 to 84.01(at zero time), 32.92 to76.49 (after 24 hr), 32.64 to76.01 (after 48 hr), 23.57 to 73.66 (after 72 hr), respectively. Results showed that quality attributes were mainly affected by ingredients and it is possible to prepare better quality attribute injera with a significant fenugreek enrichment without compromising its acceptability by adding in appropriate flour blending ratios. The best blending ratio of injera in terms of overall quality attributes was found 64.1% teff, 32% sorghum and 3.80% fenugreek