Ohmic heating – cooking by passing an electrical current through a material – might be used to produce gluten-free bread quicker and more cheaply than traditional baking, according to new research.

Fully expanded gluten-free bread can be produced in ‘only a few minutes’ using ohmic heating, according to a study published in the journal Food and Bioprocess Technology.

Scientists said their research showed ohmic heating was a “suitable and promising” technology for producing gluten-free crustless bread. They looked at how parameters such as power input and  holding time impacted traits including specific volume, crumb firmness, relative elasticity and digestibility.

“Compared with conventional baking, ohmic heating has shown many advantages in terms of improved bread quality and reduced baking time,” stated the paper, Ohmic Heating—a Novel Approach for Gluten-Free Bread Baking.

“Starch digestibility of the breads baked with ohmic heating was slightly reduced compared with conventional baking, resulting in breads with higher resistant starch content, which has been associated to several health-related benefits.”

Researchers also claimed ohmic heating might reduce processing costs, as baking uses around 40% of the energy during bread making. And they pointed out that water evaporation during conventional baking (14%) was at least three times that during ohmic heating (2–4.3%).

They found the ohmic heating process could be improved by applying electrical energy in three descending power steps, and that gluten-free breads made with uniform rapid heating during processing had superior functional properties. Ohmic heating produced gluten-free bread with specific volume of 2.86–3.44 cm3/g and relative elasticity of 45–56.8% compared with conventional oven-baked gluten-free bread with specific volume of 2.60 cm3/g and relative elasticity of 44.2%.

“Overall, this process is still in need of optimisation and further fundamental research should be carried out in order to understand the behaviour of the batter and its components during ohmic heating and to further optimise the process variables for a tailored and targeted processing,” concluded the researchers.

Ohmic Heating—a Novel Approach for Gluten-Free Bread Baking
Bender, D., Gratz, M., Vogt, S. et al. Food Bioprocess Technol (2019) 12: 1603. https://doi.org/10.1007/s11947-019-02324-9