A gluten-free biscuit for celiac children based on composite rice-chickpea flour was developed. Xanthan gum was used to overcome the handling difficulties associated with the absence of gluten in the rice-chickpea flour. The effect of different levels of xanthan gum incorporation (0.5, 1, and 1.5% of flour) on the texture and rheological properties of the dough and on the texture, dimensions, moisture, water activity (aw), and sensory acceptability of the biscuit was studied. The incorporation of xanthan gum into rice-chickpea flour significantly affected the textural and linear viscoelastic properties of the dough, as well as the texture, weight, moisture, aw, and dimensions of the biscuits. Increasing the xanthan gum level increases the hardness and elasticity of the dough, and decreases its springiness, cohesiveness, and adhesiveness. The addition of xanthan gum resulted in a significant improvement in the thickness and specific volume of biscuits. Xanthan gum water holding capacity increases the moisture content and the aw of the baked biscuits and reduces biscuit hardness. In terms of sensory acceptability, xanthan gum slightly reduces rice-chickpea flour biscuit acceptability, but the differences were not significant. Consequently, using xanthan gum to achieve the proper technological properties of dough required for the industrial production of gluten-free rice-chickpea flour biscuits is a viable alternative.
Keywords: Celiac children; biscuit; rheology; texture; xanthan.