At a Glance
- Traditional oven heating is inefficient for removing digestive-inhibiting antinutrients from legumes, often burning the outside while leaving the inside underprocessed and still difficult for humans to digest.
- Researchers at the University of Saskatchewan have developed a more effective processing method using radio frequency waves, which operates on the same principle of dielectric heating as microwaves.
- This new process rapidly vaporizes internal moisture, causing microexplosions that generate a network of new pores and expand existing ones throughout the legume’s structure.
- Advanced 3D X-ray imaging confirmed that the radio frequency treatment created a significantly more porous internal structure, which was validated by detailed computer simulations of the heating mechanism.
- The innovative treatment successfully reduced a key antinutrient by 81 percent, offering a faster and more efficient way to make plant-based proteins more digestible for consumers.
Legumes, such as peas and pinto beans, are a global food staple, but they also come with a natural defense mechanism: compounds known as anti-nutrients. These substances, which include tannins and trypsin inhibitors, can make legumes difficult for humans to digest. Food processors traditionally use large convection ovens to heat the beans and break down these compounds. However, this method is often inefficient, resulting in a burnt exterior while the inside remains underheated. This uneven heating fails to deactivate the anti-nutrients entirely and can damage the beans’ valuable proteins and vitamins.
Researchers at the University of Saskatchewan have developed a more effective method using radio frequency (RF) heating that could revolutionize how these foods are processed. Detailed in a recent paper in the journal Innovative Food Science & Emerging Technologies, the technique operates on a principle called dielectric heating. This is the same basic process used by a microwave oven, where energy selectively targets and heats water molecules within an object rather than the entire object itself. The team hypothesized that by rapidly heating the moisture inside a pea or bean, the water would turn to steam and create tiny “micro explosions,” generating a network of new pores and expanding existing ones.
To test their theory, the scientists used an advanced imaging technique at Canadian Light Source. By using powerful X-rays to create detailed three-dimensional scans of the legumes, they could peer inside and analyze their internal structure before and after treatment. The 3D images confirmed their hypothesis, revealing that RF-treated beans and peas had significantly greater porosity—the amount of space or pores within them. Computer simulations further validated that the RF waves selectively heated water trapped in the pores, leading to vaporization and expansion that created the new porous structure.
The results show that this new method has significant potential for the food industry. The increased porosity created by RF heating not only makes the legumes easier for the body to break down but also proved highly effective, reducing a key antinutrient by 81% in just a few minutes of treatment. This rapid and efficient process could help make plant-based proteins more accessible and affordable on a global scale. By making an already sustainable food source easier to process and digest, this technology could play a vital role in feeding a growing world population.
References
- Funk, E. & Canadian Light Source. (2025, June 24). Better heating method makes legumes easier to digest. Phys.Org; Canadian Light Source. https://phys.org/news/2025-06-method-legumes-easier-digest.html
- Moirangthem, T. T., Oke, A. B., Stobbs, J., Nickerson, M., & Baik, O.-D. (2025). Experimental and computational study of synchrotron X-ray micro-computed tomography imaging in peas and pinto beans after radiofrequency heating. Innovative Food Science & Emerging Technologies, 102, 104033. https://doi.org/10.1016/j.ifset.2025.104033
