Ohmic baking of wheat bread – effect of process parameters on physico-chemical quality attributes

The potential of ohmic baking as an energy-efficient alternative to conventional baking was investigated in wheat bread production, with a particular focus on bread quality parameters. The effects of specific power input (1–5 kW/kg) and various parallel plate treatment chamber configurations were evaluated regarding resulting physico-chemical parameters. Ohmic baking at high power inputs (5 kW/kg) reduced baking times by 98 % compared to conventional baking. Concerning product quality, however, lower power input levels ($\le$ 3 kW/kg) revealed specific benefits in terms of a more uniform crumb structure and higher degrees of starch cooking. Treatment chambers with thick electrodes ($\ge$ 5 mm) and decreased product surface area were associated with treatment inhomogeneities that resulted in higher product losses and lower bread volume. The results underline the importance of power input and treatment chamber design as control tools for tailored ohmic baking concepts to attain specific product properties. The necessity for a subsequent holding time after the heating phase was ascertained to achieve product quality comparable to conventionally baked breads.