American company Microzap in Lubbock, Texas, says the treatment in a sophisticated microwave array could significantly reduce the amount of wasted bread and can also be used with a variety of foods, including fresh turkey and many fruits and vegetables.
In normal conditions, bread will go moldy in around 10 days from the presence of Rhizopus stolonifer, the fungus that leads to mold.
Based on a metallic microwave device originally designed to kill bacteria such as MRSA and salmonella, the Microzap unit can kill the mold spores in bread in around 10 seconds, company Chief Executive Don Stull told the BBC.
"We treated a slice of bread in the device; we then checked the mold that was in that bread over time against a control, " he said. "And at 60 days it had the same mold content as it had when it came out of the oven."
Although the unit is similar to a home microwave oven, there are some important improvements, Stull said.
"We introduce the microwave frequencies in different ways, through a slotted radiator. We get a basically homogeneous signal density in our chamber -- in other words, we don't get the hot and cold spots you get in your home microwave."
The company said its device has attracted interest from bread manufacturers, although it acknowledges consumers might have trouble taking to bread that lasts that long.
"We'll have to get some consumer acceptance of that," Stull said. "Most people do it by feel and if you still have that quality feel they probably will accept it."