The role of corn starch, amaranth flour, pea isolate, and Psyllium flour on the rheological properties and the ultrastructure of gluten-free doughs

The removal of gluten from bakery products, in order to produce foods (mainly based on gluten-free cereal flours and starch) for people with celiac disease, impairs dough's capacity to properly develop during leavening and baking. The main aim of this research was to produce and evaluate some experimental gluten-free (GF) doughs containing different levels of corn starch, amaranth flour (to enhance the nutritional benefits), pea isolate (to increase the protein content) and Psyllium fiber (as thickening agent and fiber source) in order to study the influence of the different ingredients on the theological properties and on the ultrastructure of the doughs. Psyllium fiber generally enhanced the physical properties of the Boughs, due to the film-like structure that it was able to form, and the most complex among the experimental formulations looked promising in terms of final bread technological and nutritional quality even when compared to two different commercial GF mixtures. (C) 2009 Elsevier Ltd. All rights reserved.