Enrichment of Tef [Eragrostis tef (ZUCC)] Trotter Flour with Soy Protein Concentrates for Injera Making

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Date

2011-05

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Addis Ababa University

Abstract

In the continuous search for solution to the problem of malnutrition in its various forms, mainly among the people of the developing countries, views have been expressed of the need to improve the nutritive quality of staple local foods through better processing and enrichment. Consequently, this study was initiated with the aim of enriching tef (Eragrostis teff (ZUCc.) Trotter) flour (used to make injera: widely used staple food in Ethiopia) with soy protein concentrate (SPC) and thereby enhance its protein content and to analyse the effect on other nutritional component and organoleptic properties ofinjera. Very white tef (Quncho variety) and defatted Soy flour (Glycine max) were collected from Debre Zeit Agricultural Research Center and Ethiopian Spice Factory, respectively. Then, SPC was prepared using ethanol/water (3 :1 ratio) as a solvent. The prepared soy protein concentrate (with known proximate composition) was blended with tef flour in 5%, 10%, 15% and 20% ratios. The result divulges that the protein content of the injera increased from 1 1.31%for the contrDI and 14.30%, l7. 30%, 20.76 % and 25.06% for 5%, 10%, 15% and 20% SPC blended injera, respective/yo Increase in protein content at 5% blend of SPC was not statistically significant from that of control injera. Other proximate compositions (moisture, ash and crude jibel~ of the injera were also increased. However, fat, carbohydrate and gross energy content of injera were decreased. The mineral contents of enriched flour injera were found to show increment for all Fe, Zn and Ca content. Moreover, although increments in phytate and tannin content are observed in blended injera, the ANOVA performed on phytate content implies that the changes are not statistically significant (p < 0.05) with that of the control injera (100% teffloiirfui1til 20% blend. The sensory analysis conducted was resulted in acceptance of injera by the panelist until 15% SPC blend. Mixture Design Expert software used to optimize the exact combination of targeted protein value (20.76%) and ranged overall acceptability (5.7-7. 75) has demonstrated the optimum region blendfor tefand SPC with the linear models wasfound to be 87.35% and 12.65%, respectively. Thus, thi s study has revealed that it is possible to minimize the protein deficiency in developing countries through enriching various staple cereals with SPC.

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Enrichment of Tef

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