Response surface methodology (RSM) was used to analyze effects of hydroxypropylmethylcellulose
(HPMC), yeast b-glucan, and whey protein isolate (WPI) on physical properties of gluten-free bread
baked from formulas based on rice starch. A BoxeBehnken design with three independent variables
(HPMC, yeast b-glucan, and WPI) and three levels was used to develop models for the different responses
(physical properties). Individual contour plots of the different responses produced from the models were
compared to the corresponding reference wheat bread data and were superimposed to locate gluten-free
bread formulations that met the wheat bread standards for spread ratio, specific volume, hardness,
cohesiveness, chewiness, and crumb color L* value. The optimal formulation, determined from the data,
contained 4.35 g/100 g HPMC, 1 g/100 g b-glucan, and 0.37 g/100 g WPI, rice starch basis. Predicted
values of the optimized bread were experimentally tested and compared with the experimental wheat
bread data. A good agreement among these data was observed. Moreover, the optimized rice starch
bread was found to be acceptable according to the results of sensory analysis.