Electrical resistance oven baking as a tool to study crumb structure formation in gluten-free bread

Gradientless baking by means of ohmic heating was used for the first time in gluten-free (GF) bread making. Combination thereof with in-line measurements of batter height, viscosity and carbon dioxide (CO₂) release proved to be powerful for studying structure formation in GF breads. GF breads studied here were based on (i) a mixture of potato and cassava starches and egg white powder (C/P-S+EW), (ii) rice flour (RF) or (iii) a mixture of RF and egg white powder (RF+EW). The work revealed that bread volume and crumb structure rely heavily on the balance between the moment of CO₂ release from batter during baking and that of crumb setting. At the moment of CO₂ release, C/P-S+EW bread crumb had already (partly) set, while this was not the case for RF bread crumb, resulting in a collapse and thus low volume of the latter. When a part of RF was replaced by egg white powder, the moment of CO₂ release was postponed and the batter collapse was less pronounced, leading to a higher volume and a finer crumb. The presence of egg white proteins in C/P-S+EW or RF+EW batters improved gas cell stabilization. Thus, increasing batter stability or altering the moment of crumb setting results in GF breads with higher volume and a finer crumb structure.