Use of Response Surface Methodology to Optimize the Formulation of Rice based Gluten Free Bread and Its Characterization

Abstract

The formulation for gluten free bread was optimized on the basis of specific volume, crumb firmness and overall acceptability of the bread. A rotatable central composite design (CCRD) was applied on three control variables viz. xanthan gum, extruded rice flour and corn starch varying within the range (-α to +α) of 0.5–1.5%, 15–35% and 15–35% w/w, respectively. All three responses were significantly (p<0.05) affected by the combinations of independent variable. The quadratic polynomial models for the measured responses could be successfully used for their prediction during baking. The numerical optimization suggested a proportion (% w/w) of xanthan gum: rice flour: corn starch = 0.94:24.91:25.11 with high overall acceptability, comparable specific volume and crumb firmness values with respect to wheat bread. Shelf life analysis of the optimized formulation over six days revealed that, as crumb firmness increased, crust firmness and crumb moisture decreased.

Keywords: Rice flour, Corn starch, Xanthan gum, Gluten free bread, Optimization, Response surface methodology