Cracking Open Egg Innovation

Eggs are nutritional powerhouses, prized not only for their protein but also for their unique functional properties in foods. Yet allergies, volatile supply chains, and the environmental toll of large-scale poultry farming are prompting scientists to explore creating egg proteins using precision fermentation at a commercial scale.

Researchers from the Technical University of Munich realized that in the field of recombinant proteins, which are made using genetic engineering, there wasn’t much research available on egg protein production using precision fermentation.

“Egg is really underrepresented in this field, and we didn’t get why, to be honest, because the functionality of the protein is so important,” says Marius Henkel, a professor of cellular agriculture at the TUM School of Life Sciences, Technical University of Munich. Henkel coauthored a recent review paper published in BMC Biotechnology that fills in some of those blanks.

The food industry relies on egg proteins for nutritional content but also as foaming agents, binding agents, and emulsifiers. That’s why they’re found in everything from pasta to cakes and sauces to breads. But there are no large-scale commercially available engineered egg proteins. “For me, this is the food with the least convincing alternatives,” says Henkel.

One of the reasons for that, the researchers surmised, is the fact that creating a recombinant egg protein requires specific changes to the protein sequence so that it replicates the functionalities of natural proteins from hen eggs. “This makes things a lot more complicated,” says Henkel. “This is maybe why it’s underrepresented.”

The protein is not only dictated by its DNA sequence but also by post-translational modifications (PTMs), which are changes to the protein’s chemicals. What’s new in the field, says Henkel, is using PTMs to create proteins identical to those found in natural eggs. That’s important for two reasons: one is that then these proteins provide exactly the same functions, and the second is for regulatory reasons. “I think it’s easier in terms of legal issues if it’s completely indistinguishable from the natural product,” says Henkel.

Promising Proteins

The review paper identified two proteins as most promising for recombinant production. The first is ovalbumin, a protein found in egg whites that creates foam. That is a relatively straightforward protein to create, says Henkel. The second is phosvitin, a protein found in egg yolks that is high in phosphate and helps with emulsification. Phosvitin is very complicated and difficult to make, he says, but it’s a very powerful protein. Henkel sees a solid market opportunity for any company that succeeds in producing commercial amounts of phosvitin in a pure form. “You would only need very, very small amounts to achieve the desired effect in your final product,” he says.

PTMs represent another challenge because they can trigger deterioration. There is also no system—protocol or methodology—for using PTMs to create egg proteins, says Henkel.

Although eggs contain more than 100 proteins, not all are worth replicating. The opportunity, Henkel says, lies in producing individual proteins that offer a specific functionality, giving product developers the option to source the ones that best meet their product formulation needs.

“If we take the protein that does foaming the best, the protein that does the creaminess the best, then we can limit it to just a few proteins,” says Henkel. “I think these will be the first products we see on the market.”

The business-to-business market will likely be the first to adopt these proteins. They could be used to make vegan products, for example, and also act as a hedge against egg shortages and price fluctuations. They could also be used to extend product portfolios to make foods that are not otherwise possible to produce without hen eggs and identical protein substitutes. While there are a handful of companies with patents for recombinant egg proteins, none have yet become established in either the commercial or consumer markets, according to the researchers.

Henkel says this research has attracted interest from the convenience product and bakery product industries; his research team already has companies that are trialing their recombinant proteins. But to enable broader adoption, researchers and industry need to develop an efficient process at the right price point.

“We need to have the best yield possible to transfer the process eventually and then the product can be cheap in the way it needs to be,” says Henkel.ft