Bread staling: Effect of gluten on physico-chemical properties and molecular mobility

Three gluten enriched breads were produced (5% and 15% gluten samples where water was adjusted with farinograph determination, and a 15% sample with the same water amount of the control). The effect of gluten on bread staling (7 days) was evaluated, focussing on texture, amylopectin retrogradation, water status and H-1 molecular mobility. The addition of gluten at higher levels (15%) resulted in breads, that retained higher softness, springiness and cohesiveness upon storage. Crumb moisture content was not affected by gluten but at a macromolecular level (DSC) 15% samples showed higher frozen water content. NMR measurements showed a significant effect of gluten on proton T-2 relaxation time distributions, revealing a larger presence of protons strongly interacting with water and a more pronounced proton exchange with increasing storage time. The results suggested that, in the presence of gluten, a larger amount of water might be available to plasticize the crumb structure, resulting in a softer product. (C) 2014 Elsevier Ltd. All rights reserved.