Eggs are a super ingredient in cooking. They foam, provide structure and texture, and contribute to both taste and appearance. In cakes, they make the texture light and fluffy; in mayonnaise, they bind oil and water, and in many ready foods they gel and give firmness. In other words, eggs are hard to do without.

But that is exactly what researchers from the Department of Food Science at Aarhus University and collaborating companies are trying to do in the project PIER – Plant-based Food Ingredients to be Egg Replacers. The goal is not necessarily to remove eggs completely, but to find plant-based alternatives that can replace some of the egg in the many foods where it currently plays a central role as functional ingredient.

“If we can simply reduce the use of eggs by 25% in these foods, it could have a major impact on the climate, on production — and ultimately on consumers,” says project leader and Professor Marianne Hammershøj from the Department of Food Science at Aarhus University.

Several reasons to find alternatives

The background for the project is environmental, economic, and geopolitical. The egg production has a relatively high CO₂ footprint compared to plant production, and with increasing focus on sustainability and animal welfare, the demand for plant-based alternatives is growing.

At the same time, the price of eggs has risen significantly in recent years — partly due to bird flu in the U.S., where many laying hens have been culled, and the war in Ukraine, which has affected the export of eggs for egg-products.

“Companies are sensing consumers’ interest in more climate-friendly products — but they still must taste good and look appealing. It’s not enough that they’re just sustainable,” says Marianne Hammershøj.

Collaboration between research and industry

PIER is a four-year project supported by the Innovation Fund Denmark and involves both research institutions — such as the Department of Food Science (AU FOOD) and the MAPP Centre, which studies consumer behavior and food marketing at the Department of Management (AU BSS) — as well as companies Palsgaard A/S and Nexus A/S, which produce and supply ingredients to the food industry.

The aim of the project is to understand how plant-based proteins behave in various cooking contexts where eggs are normally used, such as:

• When foam is built, as in a fluffy cake
• When liquid is bound, as in a gel
• When emulsions are made, as in mayonnaise

Researchers have various protein sources from plants such as soy, peas, fava beans, lentils, lupins, and chickpeas. They are studying how these proteins work in practice — both alone and in combination with eggs.

Fava beans, soy, and chickpeas instead of eggs?

One of the major discoveries so far is that in some cases, it’s not necessary to use expensive, highly processed proteins — you can get surprisingly good results with simpler solutions, such as dried and ground chickpea flour.

“In fact, there can be advantages to using the least processed products — both economically and environmentally. That’s also important if the solutions are to be widely applicable and not just for niche products,” says Marianne Hammershøj.

Results so far show variation in the functional properties of plant-based proteins:

• Soy protein is best for forming gels and binding liquids
• Fava bean protein is good for creating foam, for example in cakes
• Lupin protein works well as an emulsifier, e.g. in mayonnaise

But unlike eggs, which can “do it all,” plant proteins often need to be combined to achieve the same effect. This requires knowledge — and that’s where the researchers play a key role.

From laboratory to real life

The company Palsgaard A/S, which is part of the project, has already launched its first egg-reduced product on the market. It contains about 50% fava bean protein and is used, for example, in a classic pound cake.

But texture remains a major challenge.

“It’s easy to notice when a cake becomes too dense, dry, or doesn’t rise properly. Consumers pick it up immediately. That’s why we’re working a lot on maintaining lightness and elasticity,” explains Marianne Hammershøj.

Researchers are measuring everything from how elastic a cake is to how sticky it feels in the mouth. Sensory scientists from AU FOOD also help analyze the cakes’ taste, texture, and appearance.

What about price and climate?

The project also includes consumer studies in which participants are presented with egg and egg-reduced products to examine how taste and texture influence their perception — and to explore whether information about climate impact, price, and ethics affects how consumers view egg-reduced foods.

And the results are clear: price and climate impact matter most to respondents in the study. Appearance and taste are also important, but usually come second — as long as the product doesn’t differ too much from the familiar. Color can also play a role: a cake without eggs often gets slightly less golden and more grayish. Here, researchers are testing, for example, adding cocoa to adjust the appearance.

Another part of the project looks at how consumers are inspired on social media to use plant-based products instead of eggs. “We know that social media influencers play an important role in engaging consumers in sustainable eating habits,” says Associate Professor Susanne Pedersen from the MAPP Centre.

An analysis of more than 5,000 Instagram posts from micro- and macro-influencers in four European countries shows that macro-influencers create the most consumer engagement — regardless of whether the message is emotional or rational. The findings suggest that the size of the influencer’s following matters more than the type of message.

“These results will guide us when we test different communication strategies aimed at consumers,” explains Susanne Pedersen.

What’s next?

The project is ongoing and runs until 2028. In the coming years, researchers will:

• Examine how different plant-based protein sources can be blended for optimal effect
• Expand testing to other products such as muffins, pound cakes (with higher fat content), and mayonnaise
• Explore emulsifiers that can enhance the functionality of plant proteins
• Consider allergens and microbiological risks to ensure safe and broad application
• Study how egg-reduced products can be effectively communicated to consumers across markets

And they are eagerly awaiting feedback from the first customers who have received the initial versions of these egg-reduced solutions.

“It’s a complex puzzle, but we’re making great progress,” says Marianne Hammershøj. “The goal is not just to make a good cake without eggs — but to find solutions that industry can use and that consumers will actually buy.”

Facts about the PIER-project 

Scientific declaration & contact information