Electric shocks might be the secret to better gluten-free bread

WITH THE RISING popularity of gluten-free bread, there is more demand for it lately. The catch? It takes longer to make. But scientists from the Institute of Food Technology of the University of Natural Resources and Life Sciences (BOKU) in Vienna, Austria, may have come up with an energy-saving fix: using electric shocks to cook it from the inside out. They believe a concept called ohmic heating could save energy and time during the manufacturing process, according to a paper published in the journal Food and Bioprocess Technology.

Ohmic heating passes an electric current through food to generate heat and cook it. This is possible through what’s known as Ohm’s law, where electrical energy is dissipated into heat.

‘The heat is generated instantaneously within the complete dough,’ professor of food technology at BOKU and paper co-author Henry Jäger, PhD, said in a press statement in October 2019. ‘This is the main advantage of the Ohmic heating technology. Conventional baking in the oven requires more time, since the heat needs to penetrate from the outside towards the centre of the dough.’

Gluten-free bread in general requires around twice as much water as wheatbased bread during preparation. But more water can make the dough thinner and give it a lower viscosity. Less viscous dough often takes longer to bake, a time suck that can make gluten-free bread more expensive.

Ohmic heating also provides uniform heating to a loaf of bread. That uniformity, along with the quick-acting nature of ohmic heating, could solve several problems related to gluten-free bread.

‘In order to really benefit from these advantages and obtain the best results, the optimal process and product characteristics had to be identified,’ says Jäger. ‘Achieving such convincing results and improving the efficiency of the process at the same time was also surprising for us.’

The ohmic bread seemed superior in a cook-off against traditional gluten-free bread – it had 10 to 30 per cent more volume, the team reports. The texture was also better. Crumbs were ‘softer and more elastic’, and the pores ‘were smaller and more evenly distributed’.

And, as the scientists theorised, ohmic heating saved serious time and energy – as much as a two-thirds reduction on both counts.

‘At the end, the subsequent application of three different process intensities with different holding times proved to be the most suitable option,’ Jäger says. ‘An initial baking step at two to six kilowatts for 15 seconds followed by one kilowatt for 10 seconds and a final baking at 0.3 kilowatts for five minutes is the recipe for the successful production of gluten-free bread using ohmic heating.’