The increase of people that follow a gluten-free diet due to a gluten-related problem such as celiac disease, non-celiac gluten sensitivity, wheat allergy or because they perceive gluten-free diet as healthier, is causing an important rise of gluten-free products market. Besides, since gluten gives unique viscoelastic properties to wheat dough, gluten-free products, and specially bread, usually have poorer quality compared to their gluten-containing counterparts. For these reasons, continuous development of gluten-free bread formulations to improve their organoleptic and nutritional characteristics and shelf-life is needed. The influence of different ingredients (tiger nut derived products, chickpea flour, shortening, emulsifier and chestnut flour) and technologies (sourdough and final baking technologies) in gluten-free bread quality has been evaluated. In the first study, the use of tiger nut milk, tiger nut milk by-product and tiger nut flour was assessed in order to replace soya flour. Tiger nut milk improved gluten-free bread characteristics (batter rheology, specific volume, texture and consumers’ preference), tiger nut flour rendered breads that were similar to soya flour breads, and tiger nut milk by-product impaired gluten-free bread quality, giving a harder and darker crumb. In the second study, chickpea flour and/or tiger nut flour were added into gluten-free bread in order to partially or totally replace emulsifier and/or shortening. The combination of both flours maintained bread characteristics (bake loss, specific volume, crust and crumb color, and crumb hardness) even when shortening and/or emulsifier were reduced or eliminated. To evaluate the effect of spontaneously fermented chestnut flour sourdough in gluten-free bread, a third study was performed. Chestnut flour sourdough improved gluten-free bread specific volume and crumb texture and structure. However, it had no effect on yeasts and moulds growth and decreased consumers’ preference, as sourdough breads were less sweet. Finally, in the fourth study the influence of three final baking technologies (convection oven, microwave oven and microwave oven with susceptor packaging material) in partially baked frozen gluten-free bread was evaluated. Final baking in microwave oven did not induce crust browning and increased crumb hardness. In contrast, microwave oven using susceptor packaging material changed crust color and rendered breads similar to those that were finally baked in convection oven.
|Date of Award||30 Jan 2015|
|Supervisor||Elena Albanell Trullàs (Director) & Marta Capellas Puig (Director)|