Kumsa, Delessa (PhD)Tullo, Tubaro2021-08-182023-11-102021-08-182023-11-102021-07http://etd.aau.edu.et/handle/12345678/27695Gluten free-bread is recently gaining popularity due to its suitability for people suffering from celiac disease. A study was conducted to investigate the effects of gums grown in Ethiopia on the dough rheological properties and on final quality of gluten-free bread made from maize. Gum from each Varity was used at a concentration of 3% on the flour weight basis and wheat and maize was considered as control. The dough rheological properties such as farinographic, pasting, gaseous release and dough development properties were analyzed. The control (wheat and maize) and gluten-free bread samples contain a gum were analyzed for their proximate composition, loaf and specific volumes, texture profile and sensory analysis. In addition, the pH, moisture content, viscosity, water and oil holding capacities, and functional group and gelatinization properties of the gums were determined. The results indicated that the addition of local gums into maize flour significantly reduced the water absorption capacity and degree of softening of the doughs. The addition of Gumero gum resulted in the lowest water holding capacity of the maize dough (52.95%). All the gums used in the experiment improved the stability of maize dough; however, only the dough containing Gumero gum had significantly higher dough development time (10.35 min) than the control maize dough (4.45 min). All the pasting properties except pasting temperature were considerably affected by the addition of the local gums. The dough containing Gumero gum exhibited the lowest peak viscosity (430.50 RVU). The doughs containing the Humera (65.77%) and Harar-Sidamo (65.61%) gums had significantly high gas retention capacity compared with the control dough (62.56%). The dough mixed with Harar-Sidamo gum (3.10 mm) also had significantly higher height of the dough at the end of the test than control dough (0.00 mm) and the one containing Humera (1.85 mm) and Gumero (1.65 mm) gums. The loaf volume and specific volume of the bread were affected significantly by the incorporation of the local gums. The gluten-free bread made with Harar-Sidamo gum had considerably higher values of loaf volume (314.87 cm3) and specific volume (2.03cm3/g) than the control maize bread and the one made with Humera and Gumero gums. The maize bread had the highest firmness value (1844.91 g) and the maize bread mixed with Harar-Sidamo gum had the lowest firmness (1580.00 g). The addition of gums improved the ash and fiber contents as well as the sensory attributes of the gluten-free breads. However, the crude protein, crude fat and carbohydrate contents were also reduced with addition of the local gums. In conclusion, among the three gums, HSG resulted in better dough characteristic and quality attribute of bread nearly comparable to bead wheat.en-USCeliac DiseasesGluten free breadGumMaizeRheological propertiesThesis