Gluten-free bread : characterization and development of pre- and post- baked gluten free bread

Abstract

The study was conducted to characterize the effects of xanthan gum on gluten-free bread formulations. An improved gluten-free flour blend consisting of brown rice flour, quinoa flour, and sorghum flour was used with the aim of developing a gluten-free bread formulation comparable to traditional gluten-based bread and commercial gluten-free bread mix. Rheological measurements were taken to analyze the effects of xanthan gum on pre-baked dough formulations. Higher concentrations of xanthan gum were found to decrease the loss factor thus strengthening the elastic properties of the dough, elongating the linear viscoelastic region and increasing the viscosity of the dough. Furthermore, the xanthan gum samples were not independent of frequency and the loss factor decreased as frequency increased. Porosity of samples was also analyzed using imaging technology to determine the average pore size. Pore size increased as xanthan gum concentration increased indicating the ability for xanthan gum to retain gas during the proofing stage before baking. It was concluded that xanthan gum was necessary for a loaf with nice crumb texture, loaf color, and moisture content though different than gluten-based and commercial brand gluten-free bread mix. 0.3% xanthan gum concentration provided the most desirable post-baked crumb texture, loaf volume, and moisture content