Wheat bran research shows fiber- and protein-rich food gels can be entirely plant-based

Millions of tons of wheat bran are left over when flour is milled, and bran often ends up as feed for chickens and other livestock despite the fact that it’s loaded with valuable dietary fiber. Research at KTH Royal Institute of Technology shows this leftover part of the grain can be transformed into soft, jelly like hydrogels—materials widely used to give structure, thickness, and texture to many foods.

“That’s in contrast to the rough and fibrous mouth-feel of wheat bran, which normally prevents us from enjoying it in healthy food products,” says Francisco Vilaplana, professor in glycoscience at KTH and director of the PLENTY research center at KTH.

Vilaplana says gels created with this technology could potentially be used to thicken, stabilize or add texture to foods, such as plant-based meat and dairy alternatives, high-fiber snacks, sauces or sports and medical nutrition products. He says early tests show the method may also work with other plant proteins, such as pea or soy.

The study marks the first time wheat gluten protein—rather than animal-based protein—has been successfully incorporated into hydrogels based on wheat bran arabinoxylan (AX), and systematically studied in this way.

The research team extracted arabinoxylan, a natural fiber found in wheat bran, and mixed it with proteins from wheat. “We developed new functional food ingredients that combine two of the most nutritious components in our diets, the protein and the fiber,” Vilaplana says.

To make the gel, the researchers used an enzyme called laccase, which links the fibre molecules (the arabinoxylan, which also contains natural antioxidants like ferulic acid) together. The result is a stable gel. When the protein is added, it simply gets trapped inside the fiber network. Vilaplana says this actually improves how the protein behaves, because it cannot form a gel as easily as the fiber molecules can.

When plant proteins try to gel independently, the result can be brittle, uneven or sensitive to salt, pH, or temperature, he says. This is a problem for food texture and for using them as reliable ingredients.

The work was carried out by postdoctoral researcher Niklas Wahlström under a funded project by Lantmännen Research Foundation.

“Now, are expanding these biotechnological approaches to valorise agrifood side streams through PLENTY at KTH,” he says. PLENTY is a Formas Swedish Research Council-funded center dedicated towards resource optimization and circular supply chains reducing food losses and waste.

“This could add new value to agricultural side streams that are already produced in huge amounts but not used in human food,” Vilaplana says.

The results were published this month in the scientific journal, Food Hydrocolloids, by KTH researchers Wahlström, Marjorie Ladd Parada, Secil Yilmaz-Turan, Pramod Sivan, Mikael S. Hedenqvist and Vilaplana.