WUR researchers search for viable plant proteins in bid to boost food security

28 Jul 2022 --- Wageningen University and Research (WUR) scientists have delved into research on developing cheese from microorganisms, improving the taste of pulses and boosting the nutritional value of fermented foods to demonstrate viable, nutritious food sources that can support low-income countries or other food insecure regions.

While the demand for plant-based alternatives has grown considerably, the products are still difficult to make and infuse the right flavor and texture into them.

Beyond replicated cheese
Dairy products based on plant-based proteins do not have the same taste and structure as cheese from milk. WUR researchers are analyzing whether microorganisms can serve in creating flavorful alternative cheese.

The researchers intend to use yeasts to produce casein to deliver protein with the same nutritional value and properties as cow’s milk. 

“Cow milk contains caseins. These proteins form clusters (micelles), and it’s these that create the gel-like structure of dairy products,” says Etske Bijl, food quality and design researcher. 

“The vegan cheeses currently available on the market are, for example, made from starch or compressed nuts. These may also be delicious, but they aren’t the same as cheese.” 

The plan is to build the genetic code for casein into yeasts so that they produce cow milk protein. The genetic code is created in a laboratory. Plant-based proteins often do not have the same taste as cheese from milk.

“Then we’ll look at whether the yeasts make the protein and whether they make modifications themselves. The question is whether it has to be identical with casein from a cow and whether a protein that is slightly different still has the desired properties, such as the forms of the micelles. Otherwise, you still don’t have the right structure,” Bijl underscores.

The researchers are working together with Those Vegan Cowboys, a Belgium-based company founded by the former owners of The Vegetarian Butcher. “We carry out the same kind of research in parallel. We share all the knowledge, which isn’t usual in the industry. Many start-ups are working on similar studies, but they often protect their work, for example, because they want to patent it.” 

The taste challenge
Due to the popularity of formulating meat and dairy substitutes with plant pulses, WUR researchers are studying better ways to infuse flavor into the products. However, the advantage of pulses such as peas is that it is a sustainable source of protein.   

“The taste is sometimes compared to cardboard,” notes Laurice Pouvreau, Wageningen Food & Biobased Research.

“Crops such as peas and broad beans grow well in the European climate,” says Pouvreau. “This means we don’t have to import so much soy, for example. In addition, they have a relatively high yield and fix nitrogen in the soil,” she says.

The WUR researchers are working on a project to breed pulses (e.g., by cross-pollination and genetic selection) to have better taste and other properties for use in food. 

“We know what causes the cardboard-like taste, and through breeding, we want to find existing varieties or develop new varieties that have a less unpleasant taste,” explains Pouvreau.  

The researchers are also looking at other properties, such as soil type and the climate in which a variety grows best. 

The crop must also be high yielding, as it must be financially attractive for farmers to grow pulses.

Letting the concept fermentWUR researchers looked at what fermentation does to protein quality using rice and barley. 
A third example of alternative protein sources is fermented products with bacteria or fungi, such as tempé and kimchi. Despite having been used for centuries, WUR researchers aim to put the process to better use.

Jasper Zwinkels, food microbiology, WUR, studied whether fungal fermentation can improve the nutritional value of a product using rice and barley. 

“We chose these because these crops are eaten in large quantities, also in low-income countries, and it’s precisely in these countries that people need a high-quality protein,” he says.

Proteins from fungi do have a different composition to plant proteins. “These protein sources come together in a fermented product, which means they can form an amino acid composition that fits better with our nutritional requirements.”

The researchers looked at what the process does to protein quality which has not previously been studied. 

“You take a substrate, like rice or barley, and grow the fungi on it,” adds Zwinkels. 

“We saw an increase in protein quality. There was 10% more microbial biomass after fermentation with fungi compared to the normal quantity after bacterial fermentation.” 

“Mycoproteins also have a better amino acid composition. Lysine, for example, is an essential amino acid that our body doesn’t make itself, so we have to obtain it from food. Lysine is present in high concentrations in meat, dairy and fish, but it is very little in grains. There’s a lot of lysine in mycoprotein,” explains Zwinkels. 

According to Zwinkels, this is very valuable for many low-income countries, where grains, rice and root crops form the basic diet. 

“Fermentation is a simple way to make this more nutritious. All you need is a warm, damp place. It has advantages compared to fermentation with fungi in bioreactors, which is expensive and more difficult to adapt to the location,” he says.

There was 10% more microbial biomass after fermentation with fungi compared to the normal quantity after bacterial fermentation. 

Zwinkels also shares that the study could mainly contribute to forming guidelines for good nutrition. 

Consumer perceptions of GMOs
One potential obstacle to developing the alternative cheese from microorganisms is consumer perceptions of genetically modified yeast. 

WUR is collaborating with the university’s philosophy group to understand the concept better “as it is often much more complex than simply being for or against it.”

The researchers are also in discussion with farmers regularly about these issues. Farmers could, for example, produce the proteins themselves and make their own ‘boerenkaas’ (farmer’s cheese).

WUR is looking for start-ups who can help make simple installations so that the farmers can do this themselves, a “microbrewery for proteins”.

 Further obstacles to microorganism-produced casein are that it cannot be sold in Europe at present because it is a GMO and scaling it up affordably. 

“Our knowledge will also help to change the legislation. It’s already permitted in countries like Singapore and the US. Perfect Day makes ice cream from animal-free proteins, but it’s still very expensive,” she affirms. 

By Inga de Jong