Julia Keppler appointed personal professor

Demand for more sustainable food production is growing, along with interest in alternatives to animal-based proteins. However, animal proteins cannot be replaced easily by plant-based or other alternatives. Many alternative proteins behave differently in food: some dissolve poorly in water, others fail to form stable structures or give products an undesirable texture. This makes them difficult to use in applications such as plant-based dairy products or meat alternatives.

A second challenge is that the protein transition currently relies heavily on a limited number of crops, such as soy. This is unfavourable for biodiversity and makes the food system more vulnerable. Yet, as Keppler points out, there are many more potential sources of sustainable proteins. In her research, she works with proteins from microalgae, yeasts, fungi and bacteria in addition to plant proteins. She also studies animal proteins produced through precision fermentation. In this approach, scientists modify animal cells or micro-organisms in the laboratory so that they produce animal proteins, without the use of animals. Chemically, the resulting protein is almost identical to that from a living animal, but it is produced in a fermentation tank.

Within her research, food processing plays a key role. This includes treatments such as heating, applying pressure and changing the pH value. Food technologists use these processes to extract protein ingredients or make products safer. “But that is not all”, says Keppler. “These processes also affect the ingredients on a very small scale: they change the structure of the protein.” That structure determines how a protein behaves; whether it foams, forms a gel, or keeps fat and water together. Keppler studies how these processes affect proteins across different length scales, from the level of molecular bonds to the resulting macroscopic structures. By understanding what happens with protein ingredients during processing, food technologists can better control and adjust the food processes. “We can apply this knowledge to tailor the protein functionality towards a desired performance”, Keppler explains.

Keppler leads several large collaborative projects with universities and industry partners. Within these consortia, new protein ingredients are developed and tested, such as animal-free milk protein ingredients produced from precision fermentation or ingredients obtained from microbial biomass. In the most recent projects the researchers explore tools such as automated experiments and artificial intelligence. The aim is to understand more quickly which protein ingredient or ingredient mixture, under which conditions, is suitable for a specific food product. With these approaches, Keppler hopes to accelerate the development of sustainable proteins.

Julia Keppler studied food sciences in Germany and obtained her PhD on the use of natural milk proteins as nanotransporters. After research positions in Kiel and France, she joined Wageningen University & Research in 2019, where she works within the Food Process Engineering chair group. With her appointment as personal professor, she continues her research at the intersection of fundamental protein science and the practical question of how to produce sustainable, affordable and high-quality food in the future.