Researchers Devise Novel Heating Process for Legumes, Enhancing Their Digestibility
Legumes, including beans and peas, are dietary mainstays across the globe. However, they are captive to natural substances called "antinutrients" that make digestion tricky. Now, an intriguing development by scientists at the University of Saskatchewan (USask) could transform these plant-based proteins into a breeze to digest and more eco-friendly to process.
Antinutrients, such as tannins, lectins, phytic acid, and trypsin inhibitors, work as the plants' protective shield, keeping seeds safe from predators. Heat can deactivate these compounds, yet conventional methods often come up short. Typical ovens, for example, burn the legumes' exterior before the heat penetrates the core, reducing efficiency.
USask's Department of Chemical and Biological Engineering researchers spearheaded by PhD student Tolen Moirangthem propose an innovative solution: radio frequency (RF) heating. Much like microwaves, RF waves directly heat the water within the legumes instead of warming the outer surface.
According to Moirangthem, this targeted heating method effectively deactivates antinutrients without damaging the seed's outer shell - a technique referred to as "selective heating." This method significantly hastens the cooking process to mere minutes, simultaneously preserving valuable nutrients lost in lengthy heating.
The inner water content heats up and turns to steam, generating pressure that bursts internal pores within the legumes, making them more porous and thus enhancing digestion. By employing advanced imaging tools at the Canadian Light Source, the team confirmed that RF-treated beans displayed significantly more pores and registered an 81% reduction in trypsin inhibitors, one of the hardest antinutrients to tackle.
The researchers highlight the potential benefits of this breakthrough, particularly as animal protein remains costly and scarce in numerous regions. The technology offers an eco-friendly, scalable solution for processing plant-based proteins to fulfill growing global demand for nourishing, affordable food.
(Source: University of Saskatchewan)
(First published on: 27 Jun 2025, 09:18 IST)
(Enrichment and elaboration below)
More details about RF Heating method
The quantum leap in food processing using RF heating is rooted in its selective internal heating method. As opposed to traditional methods where heat is applied to the outer layer, RF waves penetrate legumes and directly reach the water content within the seeds, ensuring core temperature rises to dismantle antinutrients without damaging the seed structure[1][3][5].
Antinutrient reduction
The RF heating process significantly reduces the levels of antinutrients, for instance, achieving an 81% reduction in trypsin inhibitors, which are traditionally resilient to heat treatment[3][4].
Nutrient preservation and increased digestibility
Rapid heating paired with targeted treatment reduces cooking time to only a few minutes while safeguarding desirable nutrients often lost during prolonged traditional heating methods[3]. The heightened porosity brought by RF heating makes legumes more digestible, enabling better nutrient accessibility[3][4].
- The novel radio frequency (RF) heating method, introduced by researchers at the University of Saskatchewan (USask), provides a solution to make legumes more digestible by selectively heating the water within the legumes, deactivating antinutrients without damaging the seed's outer shell.
- This RF heating process is marked by its ability to significantly reduce antinutrients like trypsin inhibitors, achieving an impressive 81% reduction, which are usually hard to tackle with conventional heat treatment methods.
- By rapidly heating and exposing the legumes to targeted treatment, the cooking time is reduced to mere minutes, while preserving valuable nutrients that are often lost during lengthy traditional heating.
- The heightened porosity resulting from RF heating enhances the digestibility of legumes, thus improving nutrient accessibility, which could potentially contribute to healthier diets rich in plant-based proteins.
