Role of void fraction and electrical conductivity in governing microstructural changes and final properties of wheat bread during ohmic baking

• Electrical conductivity was crucial for process control and temperature regulation. • Dough void fraction strongly influenced final bread structure and texture. • Void expansion during ohmic baking minimized initial dough property differences. • Pore structure fixation occurred near a critical temperature of ∼68°C. • Void fractions >65 % promoted pore expansion but hindered structural stabilization. Ohmic baking is a volumetric heating process that exploits the electrical resistance of dough to generate heat, providing a faster and more energy-efficient alternative to conventional baking. To fully harness its potential, a detailed understanding is required of how dough properties affect structural evolution and final bread properties. This study investigated model wheat doughs varying in void fraction (16–69 %) and electrical conductivity (0.4–2.4 mS/cm) to elucidate their influence on process-structure interactions and bread characteristics, including texture, volume, and pore microstructure (via X-ray micro-tomography). Electrical conductivity exerted minimal direct influence on the final bread properties. Nevertheless, higher conductivity levels (> 1.0 mS/cm) improved process stability during ohmic baking in the used generator setup by promoting greater current intensity and refined temperature control. Furthermore, void expansion during baking compensated for initial variations in dough conductivity and void fraction, revealing the moderating effects of thermo-electrical interactions on microstructural evolution. Void fraction strongly correlated with final bread characteristics like volume, texture and porosity. Void fractions above 65 % caused excessive pore growth during heating which promoted larger pores and softer crumb, but impaired structure stabilization. Structural fixation occurred near 68°C, marking the transition between pore expansion and stabilization. The results provide mechanistic insight into the coupled effects of dough properties and electrical behaviour, supporting precise control and tailored application of ohmic baking to produce breads with desired attributes.