- Gluten-free bread is crucial for those with certain allergies and conditions like Celiac disease. However, it’s time-consuming to produce.
- Scientists have successfully made gluten-free bread using a technique called Ohmic heating, in which the bread itself is a conductor for electricity.
- The test bread had more volume and more uniformity, and was made with less time and energy than traditional methods.
Cooking is a science as old as time, but scientists are still figuring out cool ways to improve it. Scientists from the Institute of Food Technology of the University of Natural Resources and Life Sciences (BOKU) in Vienna have used electric shocks to heat gluten-free varieties from the inside. They believe a concept called Ohmic heating could save energy and time during the manufacturing process.
Ohmic heating, also known as joule heating, is when electric currents pass through a conductor and the passage itself generates heat. This is possible through what’s known as Ohm’s Law, developed by German physicist George Ohm in 1827. Ohm was able to prove that a current moving through a conductor from Point A to Point B is directly proportional to the voltage.
Ohm’s Law is crucial to the modern world in field like electronics, where it keeps wires from heating. The same technique can be used during cooking.
“The heat is generated instantaneously within the complete dough,” explains study author Henry Jäger in a press statement. “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 toward the center of the dough.”
Gluten-free bread in general requires around twice as much water as wheat-based bread during preparation. That often makes heating more of a time suck, which can make gluten-free bread more expensive. More water can give the bread a lower viscosity, making it thinner and more watery. Bread, in general, should not be watery.
Ohmic heating provides uniform heating to all parts of the conductor, in this case a loaf or piece 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 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.”
There was only one way to compare Ohmic gluten-free bread to gluten-free bread made the traditional way: a cook-off. Across the board, the Ohmic bread seemed to present a superior option.
The Ohmic bread had 10 to 30 percent more volume, the team reports. Crumbs were “softer and more elastic,” and the pores “were smaller and more evenly distributed.” There was some concern about a crucial sticking point for bread—digestibility—but none of the fears came to pass.
And, as the scientists theorized, 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.”