Stretched along a river in the heart of the Netherlands, the town of Wageningen is not postcard-pretty.
It doesn’t have Amsterdam’s historic canals or Rotterdam’s bold modern architecture. Wageningen’s only claim to fame, in fact, is its university, ranked as the world’s top agricultural research hub. Much of the institution focuses on how to feed humanity in the coming decades, and the work is badly needed: By 2050, Earth, now home to about 7.5 billion people, may have nearly 2 billion more.
At the top of research priorities in Wageningen is protein, or rather, how to find more of it — and we’ll need to look beyond meat-based diets. Obtaining 1 pound of animal protein uses about 7.5 pounds of plant proteins, which are consumed by the animal as it grows. About 80 percent of agricultural land is already used for grain that’s fed to livestock. The calculus is simple: If we don’t change the way we eat, and quickly, there won’t be enough protein for our expanding population.
The good news is that scientists in places like Wageningen are working hard to find alternatives to animal products other than soy, the current staple: plant-based steaks, duckweed, microalgae, seaweeds and edible insects — and creating poop machines, literally, to evaluate them all.
In the Netherlands, Wageningen University researchers are pioneering the future of plant-based proteins. Here, vivid green microalgae fill photobioreactor tubes at a growing facility.
The agrotechnology building is a hub for cutting-edge innovation in the field.
The greenhouselike microalgae growing facility looks out onto open fields.
Set up in the middle of an open field, the microalgae growing facility in Wageningen is eerily quiet. Snow fell yesterday, and the contrast between the white powder and the vibrant green of the photobioreactors, dozens of tubes as thick as an arm spread over an area the size of a basketball court, is otherworldly.
Production at the facility has slowed with the arrival of the cold, but Maria Barbosa, a bioprocess engineer, says the colors are even more stunning when the microalgae are actively growing. Some of the glass tubes snake horizontally on the ground, while others are arranged in vertical rows like giant green radiators. Farther out, there is a small pond, also for microalgae. By comparing seasonal growth in the different systems, the researchers are learning which method has the best balance of high productivity and low energy consumption. In a 2017 study, for example, Barbosa and her colleagues found that, in autumn, cultivating microalgae in horizontal tubes requires up to 30 percent less electricity than it does in vertical ones. An open pond, meanwhile, can be a good idea in the summer — but winter rains and lower temperatures can disrupt production.
In theory, microalgae could make for a great protein source. Some, such as spirulina, can contain up to 70 percent protein in dry weight, and have all the essential amino acids that humans need to survive. But there’s a reason why you can’t buy spirulina steaks just yet. Cultivation of these microscopic organisms is still inefficient and expensive — something that Barbosa and her colleagues in Wageningen hope to change.
Barbosa’s favorite microalgae are Nannochloropsis, a genus of several easy-to-grow marine species. Another of her top choices, intensely green Tetraselmis, is so productive that even in the cool climate of the Netherlands, you can get 30 metric tons per hectare — about 13.4 U.S. tons per acre. “That means 15 metric tons of protein per hectare,” she says. By comparison, 1 acre of land used to raise cattle can yield as little as a pound or less of beef. What’s more, microalgae could be produced in places where nothing else can be grown, such as marginal lands or even at sea.
Barbosa believes that the first large application for microalgae protein will be feed for salmon or shrimp. Microalgae protein could also be added to existing foods, such as bread — it’s already happening in bakeries around Wageningen. Barbosa has also tried microalgae ice cream and pizza cooked up with her colleagues. Although she admits the taste can be a little on the fishy side, she believes we’ll see microalgae protein added to many products over the next few years. Nannochloropsis steaks are likely further off in the future, though “in principle, you could also use the protein from microalgae to make these kind of textures,” she says.
Bioprocess engineer Maria Barbosa grows microalgae inside room-long photobioreactor tubes that are designed for high production and low energy consumption.
Varieties cultivated, such as Nannochloropsis (pictured) and Tetraselmis, may one day be cheap and sustainable protein sources, blended into foods or fed to farmed fish.
A cross-section of one of the tubes shows growing solution bubbling with microalgal life.
Ingrid van der Meer, a plant biotechnologist at Wageningen University, opens a petri dish and fishes out some duckweed with her fingers. She slides a few of the pinhead-sized plants into her mouth and starts chewing. “It has a nutty taste,” she says, then adds, smiling, “It’s such a nice plant. But it sticks to everything — when you are working with it, you end up with duckweed everywhere. It’s their way to spread around.”
Duckweed is one of the fastest-growing plants on Earth. Its biomass can double in size in as little as 16 hours — it’s so fast that in 2004, the government of Venezuela declared a state of emergency due to the spreading duckweed cover on Lake Maracaibo. A NASA photo taken that year showed the large body of water resembling an enormous green glob.
Although duckweed can be a nightmare for environmentalists, it may also be one of the best shots at an environmentally friendly future food. The plant is packed with protein. “We’ve calculated that you can produce 10 times more protein per hectare per year with duckweed compared to soybean,” van der Meer says. As for the name, though, she and her colleagues prefer to call the plant “water lentils” (from the Old Dutch waterlinsen). “It’s a much better name,” she says, her mind on potential future consumers.
In her Wageningen lab, van der Meer researches how to harvest duckweed in the most efficient and safest ways — but she is also investigating how good it really is as a protein source for humans. Her team has recently finished a clinical trial comparing protein from duckweed with that of soybeans, inviting volunteers into their lab for a taste of boiled duckweed, which could be mistaken for a bowl of spinach. The scientists collected blood samples from the volunteers before and after the meal to check their amino acid levels, which would provide an insight into how well duckweed protein is digested. Although the results haven’t been published yet, van der Meer believes duckweed is good for us: “It really contains a lot of vitamins. Its B5 is very high, and B1 is very high, too, and it has a lot carotenoids. So I do not only see it as a nice source of protein — it could also be just a good vegetable.”
Wageningen University is already collaborating with several companies in the Netherlands to introduce duckweed to consumers. Products planned include ready-to-eat mixes of mashed potatoes and duckweed (based on a Dutch staple, stamppot) and soy-based “meats” with added water lentil protein.
The insect culture lab at Wageningen University is hot, humid and all abuzz. Here, entomologist Marcel Dicke studies methods of rearing insects for human consumption and animal feed. The small room where his team raises black soldier flies smells of the insects’ preferred habitat and food source, decaying plant matter. The crickets’ home, nearby, is easier on the nose: The bugs live inside empty egg cartons stacked high one atop another, and feed on fresh grain and carrots. Dicke and his colleagues are now testing how varying the insects’ diets can influence the bioavailability of nutrients such as iron and zinc for the humans that will eventually consume the invertebrates.
From a global perspective, dining on insects is nothing new. They’re part of the diet of about 2 billion people worldwide, with grasshoppers and termites the most commonly eaten, followed by caterpillars. It makes perfect nutritional sense. Some species of grasshoppers are as much as 77 percent protein in dry weight, although, according to a 2017 study done in Wageningen, protein content numbers for some other critters may be inflated. The scientists found, for example, that darkling beetle larvae, commonly reported to be 58 to 65 percent protein, are only 49 percent. But that’s still a great nutritional value. And producing insects for consumption is far more environmentally friendly than, say, cattle farming. Measured pound for pound, raising grasshoppers, for instance, produces a third of the carbon dioxide that results from raising beef cattle, and no methane whatsoever.
Since he began research on edible insects more than 20 years ago, Dicke has seen significant change in how people in the West perceive them. In the Netherlands in particular, he says, people have gotten used to the idea of snacking on bugs. Dicke believes that Westerners have a responsibility to eat insects — although, in theory, we don’t need any more protein since most of us already eat about twice as much as we require. In developing countries, people often give up their traditional bug-based dishes for Western-style foods, which they perceive as more modern. “We’re exporting a McDonald’s diet. ... That’s something that needs to be stopped,” he says. Instead, Dicke believes, we should focus on exporting more sustainable eating habits.
In Wageningen, one restaurant already offers bagels baked with crickets, mealworms and grasshoppers, and Dicke himself often cooks insects at home. He admits, though, that the best bugs he ever ate were in China: “Dragonfly larvae, with some peppermint leaves, deep-fried.”
The protein content of seaweed may not be as high as that of duckweed or insects, but Jelle van Leeuwen, a process engineer at Wageningen University, believes they still carry great feed-the-world potential.
Van Leeuwen says a biorefinery approach — similar to the way oil refineries create multiple products out of a single raw material — would allow us to “get the most products out” of seaweed. First, fuels such as biogas or ethanol would be extracted. Then, health care products and plastics would be made. And, almost as a byproduct, there would be protein. The Dutch government is already exploring whether it makes financial sense to grow that raw material around near-shore wind farms, where existing infrastructure would make the farms much cheaper to set up and run than starting from scratch farther off shore. “There are a lot of seaweed farmers at the moment who are thinking about installing their farms near these windmills,” says Adrie van der Werf, van Leeuwen’s colleague.
In his lab, van Leeuwen opens a cooler and pulls out a large sheet of frozen, brownish seaweed. In his hand, the leaves soon thaw, and become soft and stretchy. “That’s sugar kelp — this is the one we work on the most. It is a very easy species to cultivate in the North Sea. So we are now focusing on extracting all kinds of components out of it,” he says.
Humans eat quite a lot of seaweed already. According to the United Nations’ Food and Agriculture Organization, we consume about 9 million tons of seaweed a year in recognizable form, such as the nori that wraps around your California roll. That amount is even higher if you include seaweed used as food thickeners and gelling agents. Van Leeuwen imagines that protein could be extracted out of seaweed and used in its pure form, similar to the way soy is used now. “I think that might be a few years away still,” he says. “But it’s possible — it’s technically possible.”
Back in November 2015, big news came out of Wageningen — a group of local scientists led by a food engineer, Atze Jan van der Goot, created a 15-pound steak made entirely from plants. Although burgers consisting of minced soy “beef” and cubes of bird-free “chicken” have been widely available for years, before 2015, no one had produced a piece of mock meat so large that it could actually be sliced and carved.
Couette Cell, the machine that van der Goot and his team invented, uses shear-cell technology to make “meat” out of protein powders, water and gluten. It resembles something between a spaceship and a meat grinder, with one cylinder nested inside another. The inner drum rotates, causing strands of heated soy and gluten to wrap around each other and create fibrous structures. “It is basically just heating while deforming,” van der Goot says. “You could compare it a little bit with dough kneading.”
Plant meats that are currently on the market, such as the Impossible Burger and the Beyond Burger, use an older technology called high-moisture extrusion. In comparison, the Couette Cell could not only make bigger cuts with more meatlike textures, but it could also make them much cheaper.
For now, van der Goot uses mostly soy for his steaks, but he also researches other potential protein sources, such as peas, beans and rapeseed. “It’s a great challenge,” he admits. Peas, for example, would be ideal, since they are a “very sustainable source,” but they produce a softer structure than soy does. Duckweed, too, is difficult to process, so we shouldn’t expect water lentil steaks in any near future.
Van der Goot hopes soy steaks, though, could hit the market by 2021. He’s currently collaborating with several Dutch companies, including some in the meat industry, to achieve this goal.
The Dutch Weed Burger
When you put the words Dutch and weed into one sentence, most people do not think of seaweed. The Dutch Weed Burger may change that. The company, founded in 2012, already sells its products in more than 200 restaurants across the Netherlands and neighboring regions. Co-founder Mark Kulsdom dreams big, though. He wants to be in 700 joints soon.
I decided to see for myself what the future of protein might look like. I picked a corner table at Bagels & Beans cafe on Wageningen’s main shopping street and placed an order for what was advertised on the menu as a “juicy patty” made with “Royal Kombu, a tasty and healthy winter weed, sustainably cultivated in the Dutch region of Zeeland.” In other words: a type of seaweed that grows in winter off the coast of the Netherlands, just south of Rotterdam. The bun was enriched with chlorella, a microalga, and the sauce laced with sea lettuce, another common algae.
When my order arrived, I couldn’t help but eye the burger with suspicion. I expected something far more green and seaweedy, I guess. Instead, the patty seemed unremarkable, brown and beeflike. Once I took a bite, my suspicion deepened. It tasted good, if a bit dry. Very meaty. Too meaty. A panicked thought crossed my vegetarian mind: Was it really seaweed, or maybe just regular beef with some algae added to it? The more I ate, the more I became convinced that I was, indeed, eating meat. I asked the waiter to bring the detailed ingredient sheet for the product. Together, we confirmed: The burger was vegan. The future fooled me, that’s for sure.
What Goes In Must Come Out
To an outsider, the smell in the lab where SHIME sits is almost unbearable. That’s hardly a surprise. The machine, whose full name is the Simulator of Human Intestinal Microbial Ecosystem, consists of five jarlike containers called reactors. Through controlled temperature, moisture and acidity, each reactor replicates a different part of the human gastrointestinal tract, including the colon. Also inside the reactors: human feces, donated regularly by one of the researchers, which provides the microbial populations naturally found in the human gut to digest whatever protein is loaded into the device. The Dutch media have nicknamed it the “poop machine.”
Yet the smell does not seem to bother Harry Wichers, a biochemist who spends hours in the SHIME lab, studying the digestibility of various proteins. He feeds different types of protein — insect, fungi or plant — into the reactors and observes how well they’re broken down into amino acids. “Not everything you eat is equally digested,” Wichers says. In November, his team began conducting human trials on two novel proteins, collecting blood, fecal and urine samples from participants to measure their amino acid profiles before and after consumption.
Wichers’ ultimate goal is not necessarily to come up with the ultimate protein to replace meat and dairy in the average diet, but instead to develop a broader understanding, a “toolbox” of plant-based proteins appropriate for different applications, such as ensuring optimum amino acid consumption, or even breeding more nutritious crops.
Like Wichers, the other scientists working in Wageningen aren’t hunting for a single perfect meat replacement. It won’t be just duckweed. Or just microalgae. Or just insects. What they hope for is a future in which all of these protein sources help us significantly reduce our dependence on meat, dairy and eggs.
“I don’t see duckweed or seaweed as a competition to microalgae. I think there is a place for all of these different protein sources, just like we now have beef and pork and chicken. It would be very boring to have just one source of novel protein,” Barbosa says, the green tubes of the microalgae photobioreactors glittering in the snow behind her.
Marta Zaraska, a science writer in France, is the author of Meathooked: The History and Science of Our 2.5-Million-Year Obsession With Meat. This story originally appeared in print as "Raising the Steaks."