Study of the interaction between inulin and water to optimize gluten-free dough and bread properties

Abstract

The Gluten-Free Breads (GFB) often contain numerous quality defects, including reduced volume, a dry, crumbly, grainy texture, a cracked crust, poor mouthfell and flavor, and goes stale quickly. In addition to the poor technological and sensory quality, GFB frequently present poor nutritional composition and high glycemic response, because they are made by using refined flours and starches. Hence, new approaches are needed to improve technological, sensory and nutritional quality of GFB; also considering clinical aspects related to celiac disease, like the association with diabetes mellitus and osteopenia/osteoporosis. Therefore, the Inulin-Type Fructans (ITF) are attractive ingredients for the preparation of gluten-free products. ITF are soluble dietary fiber and prebiotic ingredients, which may contribute to the increase of calcium absorption and attenuation of the glycemic response. Thus, this project aims to use inulin gel to simultaneously improve the technological, nutritional and functional quality of GFB. Initially, a central composite design with thirteen experimental formulations will be used, enabling to assess the interaction between inulin and water levels on the gluten-free dough and bread properties. Also, the inulin stability during the breadmaking process will be assessed. The response surface methodology will be used for the simultaneous optimization of the physical properties and the acceptability of GFB. The relation between dough´s rheological properties and consistency with GFB physical properties and acceptability will be investigated. A shelf-life study and a glycemic index trial will be performed for the optimized inulin-contain GFB formulation, which will be compared to a control GFB and wheat bread formulation. It is expected that the interaction between inulin and water increases the viscosity and gas holding capacity of the dough, and improves the volume, the softness and the acceptability of GFB. It is also expected that the addition of inulin results in GFB enriched with relevant dietary fiber content and reduced of glycemic response. Inulin addition can also contribute to improve moisture retention and softness, which delays staling rate of GFB. (AU)