Tasty meat and dairy substitutes: how precision fermentation is changing our food

What will our food supply look like if we no longer need cows or chickens for milk and meat? Julia Keppler, researcher at Wageningen University & Research (WUR), is looking into exactly that question. She is investigating how alternative proteins — from plants or micro-organisms — can contribute to full-fledged and tasty meat and dairy substitutes.

Julia Keppler investigates how proteins from plants, fungi, insects and micro-organisms can replace animal meat and dairy products. In her research, she does not limit herself to one protein source or technology, but looks at a wide range of proteins, and investigates in particular how you can process them in such a way that they can be used in real food. Surprisingly enough, her career started in a completely different field: architecture. “Back then I designed buildings, now I also design, but then on a micro scale,” she says with a laugh. “Proteins are surprisingly suitable for this — they literally form the building blocks of our food.”

 Anyone who’s ever tried vegan cheese knows that it rarely melts like real cheese—let alone tastes the same. Keppler explains that this is because plant proteins are fundamentally different from animal proteins. Animal milk, for example, contains casein micelles: complex protein structures that, together with calcium and fat, form a strong network. “That network provides the structure, the meltability, the flavor development… everything that makes cheese cheese.”

Precision fermentation

Enter precision fermentation, a technology that’s gaining traction as a promising source of protein. Where traditional fermentation, like beer or yogurt, uses microorganisms to produce flavor or alcohol, precision fermentation modifies a microbe’s DNA so that it produces exactly the protein you need—a milk protein, for example. “You introduce a piece of genetic code into a yeast cell,” Keppler says, “and then that cell grows into a whole colony that produces that specific protein.”

The result is a protein that is nearly indistinguishable from the animal original, but produced without the animal. “And the beauty of it,” she says, “is that the microbe itself doesn’t end up in the final product. You just filter out the protein.” But there are challenges: the fermentation process also produces other substances, such as polysaccharides, that affect the behavior of the protein. “We have to learn to deal with those ‘byproducts’, without removing them all – because in many cases they are healthy. And less processing is ultimately more sustainable.”

Hybrid products

In addition to precision fermentation, Keppler is also investigating whether we can eat microorganisms directly — for example, as a meat substitute. Some yeasts or bacteria contain up to 80 percent protein, and with a little technological processing you can transform them into something that closely resembles meat. “The idea is to use the biomass as purely as possible, without excessive processing. That is more sustainable, and sometimes yields surprisingly good results.”

Keppler talks about a promising direction, in which plant, microbial and animal proteins are combined: hybrid products. “This way you can use the best properties of both worlds,” she says. Still, Keppler does not expect animal proteins to disappear completely. “We may discover completely new products, with such fine properties that people will automatically prefer them over animal alternatives.”

Frog tongues

The future of our food doesn’t have to be a carbon copy of the past. Instead of imitating existing animal products, Keppler believes the real challenge lies in discovering something new — inspired by nature. “In nature, you see clever protein structures everywhere: adhesive strength, color, texture. Think of a frog’s tongue. It consists of very specific protein structures that make flies stick to it. If we look at that carefully, we can learn to control proteins to do exactly what we want. That’s what makes this work so special to me.”