Tapping Into the Protein Power of Pulses

With mounting consumer interest in plant-based eating, alternative proteins are playing a growing role in food formulation. A group of researchers at the University of Alberta is working to make faba beans a more viable option for product developers seeking new protein sources for meat substitutes.

Pulses like faba beans hold promise because they are naturally high in protein as well as environmentally friendly and cost-effective to grow. Meat contains about 23% protein while faba beans can hit 30%.

“Faba beans have a much higher protein content than animal protein, so faba beans are definitely promising,” says Thava Vasanthan, professor of grain processing science and technology and former division director of food science and bioresource technology at the University of Alberta. Vasanthan has been conducting faba bean research with his colleague Feral Temelli, a professor in the Department of Agricultural, Food & Nutritional Science, and former doctoral student Brasathe Jeganathan.

Tackling Texture

Faba beans, like other pulses, lack the texture of meat, however. To replicate meat’s chewy texture, faba proteins need to be purified to 65%–70%, followed by a process called high-moisture extrusion texturization, Vasanthan explains. The problem is that the technologies the food industry uses to purify and texturize beans, including faba, are expensive and use a lot of energy and water, which, Vasanthan points out, isn’t great for environmental sustainability.

The researchers realized that there was no baseline to help the food industry understand the different technologies available to isolate faba’s proteins and to assess their advantages and disadvantages. So they did a comparative study to outline the basic processes and identified a method that delivered a high level of protein as well as a high level of purity. This method has the added benefit of creating starch and dietary fiber concentrate or isolate as possible valuable coproducts.

“We have clearly established the tissue structure of faba bean in comparison to other pulses, and the advantages that the bean’s composition, which is mainly the protein content, offers to the food industry,” explains Vasanthan.

One focus of the researchers’ work was reducing water usage. Wet processing is required to get a higher concentration of proteins, says Vasanthan, and it is more expensive than dry processing. “We looked at ways we can reduce the water content and energy utilization in processing so that the overall process becomes sustainable and adaptable in the long term,” he says.

Customized Content

Currently, faba processing produces only about 16% yield with a high level of purity. Vasanthan offers the example of a comparable product, peas, to explain why that’s an issue. Peas yield only about 160 kilograms of protein isolate at 90%–95% purity per metric ton, he says, and that’s why the cost of pea protein isolates is so high, at about $5,000 per metric ton. Soy proteins, a competing and more developed market, sell for much less, at around $2,500 per metric ton.

“The soybean industry has fine-tuned everything, and they are selling all these products to get the final revenue out of the grain,” Vasanthan observes. In comparison, he says, pulses are only really valued for the fractionated protein; the other fractions don’t have a market at the moment.

The researchers are continuing their work and have developed a technology that improves processing and uses 50% less water and 39% less energy than conventional methods. It’s also been designed so that the processing parameters can be customized for protein concentrations between 50% and 86%. They’re working on patenting it.

Faba beans deserve more attention, says Vasanthan. But first, the food industry needs a better understanding of how to use them. “If you understand the challenges in the existing process differently, you can create new approaches,” he says.

TO LEARN MORE

"Isolation of clean-label faba bean (Vicia faba L.) proteins: A comparative study of mild fractionation methods against traditional technologies”

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“Potential of air-currents assisted particle separation (ACAPS) technology for hybrid fractionation of clean-label faba bean (Vicia faba L.) protein”