Potato Protein Could Give Gluten-Free Plant-Based Meat Its Structure, but Bitterness Remains a Hurdle

Scientists in Scotland and southeast England have been testing whether the humble potato could solve a stubborn problem in meat-free food: how to make a plant-based product chewy and fibrous without wheat gluten. Their results, published in the journal Food Hydrocolloids, point to a real structural benefit and a real flavour cost.

The work comes from researchers at the University of Greenwich and Heriot-Watt University in Edinburgh. They asked whether potato protein could be paired with fava bean protein to produce the firm, fibrous texture that makes a meat substitute feel like meat.

The question matters because wheat gluten is commonly added to vegan and vegetarian meat alternatives. It is a large part of what gives those products their characteristic chewiness. But gluten rules the products out for people with coeliac disease and for those who are sensitive to it, so a gluten-free route to the same texture has obvious appeal.

The team mixed fava bean protein with either wheat gluten or potato protein, then ran the blends through high-moisture extrusion. The process uses heat, pressure and mechanical force to reshape proteins into fibrous structures similar to those found in meat. The potato mixture was 75% fava bean protein and 25% potato protein. The researchers compared it with fava bean protein on its own and with a blend containing wheat gluten. They found that potato protein formed a particularly strong network with the fava bean protein.

Dr Parag Archaya of the Bezos Centre for Sustainable Protein at the University of Greenwich said the gluten version came out softer and springier, but that the potato version still delivered the structure a meat alternative needs. He also made the case for fava beans themselves: they can be grown in cooler climates, they are high in protein, and they remain underused in a meat-free sector that leans heavily on soy, pea protein and wheat gluten. In his words, combining fava beans with potato protein could be the secret ingredient to more realistic plant-based meat.

Texture was only half the test. The researchers then looked at whether the potato and fava version tasted better, and here the news was less welcome. Professor Stephen Euston, a food scientist in Heriot-Watt's School of Engineering and Physical Sciences, said the team used an electronic taste sensing system able to detect bitterness, astringency, umami and aftertastes.

The readings showed that the potato protein version, for all its good structure, was more bitter and more astringent, and it left a stronger lingering aftertaste. Euston said food companies would need to find ways to reduce the bitterness before the ingredient could be widely used in consumer products.

That leaves the finding at an early stage. The structural case for potato protein with fava beans has been made in the lab, but the flavour problem is unresolved, and the next step is for processors to work out how to tame the bitterness.