Development of Gluten-Free Baking Methods Utilizing Sorghum Flour
Increasing diagnosis and awareness of celiac disease and gluten intolerance has created a need for developing improved quality gluten-free sandwich breads. Sorghum is a naturally gluten-free grain with ideal baking qualities that is underutilized in the gluten-free baking industry. Research is needed on developing gluten-free breads utilizing sorghum flour that could be used in future research and commercial production. Three objectives were tested. Objectives evaluated feasibility of using egg white foam with leavening agents in yeast-free bread, optimum mixing time in a laboratory control bread utilizing sorghum flour, and maximizing the amount of sorghum flour that could be used in the control formulation. Four comparisons were tested for yeast-free breads and 5 were compared for yeast breads. Volume, hardness, and color were measured using 15 replications. Environmental Scanning Electron Microscopy (ESEM) was performed on selected treatments to evaluate crumb structure. Utilizing egg white foam for gluten-free breads produced acceptable volume, color, crumb structure and hardness compared to commercial gluten-free controls. Using egg white foam eliminates proofing time with increased production speed. Increasing mixing time in gluten-free yeast breads significantly (P<0.05) improved specific volume and overall loaf volume without negatively affecting crumb hardness in 10 and 15 minute mixing treatments. Crumb structure was significantly improved between 5 and 15 minute treatments. Evaluation with ESEM showed reduced clumping of ingredients in the crumb and thinner air cell walls. Specific volume and loaf volume were significantly (P<0.05) higher in 15 minute mixing (2.13 cm^3/g; 1845 cm^3) versus the commercial comparison (2.00 cm^3/g; 923 cm^3). Optimum mixing for yeast bread was 15 minutes and optimum percentage of sorghum used in the flour blend was 60 percent. Increasing the use of commodity grade gluten-free decorticated white sorghum flour will reduce cost of specialty milled ingredients. In future studies mixing for 15 minutes using the laboratory yeast bread formulation containing 60 percent sorghum should be used as the research control as it provided consistent optimum results.