Meat has got competition: Plant-based sausage alternatives made from soy, peas or lupins have conquered supermarket shelves. However, there are differences: For example, plant-based sausages lack the right crunch when you bite into them. Researchers at the Max Planck Institute for Polymer Research in Mainz have now found a way to improve the mouthfeel so that vegetarian and vegan sausages resemble the animal original even more.

Proteins determine mouthfeel

The study initially focused on the question of how the properties of vegetable proteins influence the mouthfeel of vegetarian and vegan sausages. For this purpose, the proteins of the ingredients and the sequence of amino acids were examined. The results showed that it is a network of proteins in which veggie sausage and meat sausage differ fundamentally. According to the researchers, muscle proteins, fats and oils emulsify completely differently in animal tissue than plant proteins.

"Imitating the mouthfeel of meat-based foods is a complex matter," explains Thomas Vilgis, group leader at the Max Planck Institute for Polymer Research. "There are many different physical processes at play here - from the first bite to the breakdown into a chewy mass. That's what makes it so difficult for vegetarian and vegan alternatives to get at the animal product."

Texture adjustment model developed

Until now, manufacturers of plant-based sausage alternatives have had to use trial and error to change the texture and thus the mouthfeel. The Mainz research team now provides a model that can be used to make predictions about sausage behavior, for example during chewing. To do this, they simulated the chewing process and then determined the forces with which the different sausage masses can be deformed. These measurements made it possible to determine how the sausages behave both when chewed and when worked on with the tongue.

Manufacturer optimizes crunch in veggie sausage

With this model, the researchers provide a tool that can be used to change the texture of vegetarian and vegan sausages. The model has already proven itself in practice: one sausage manufacturer used it to adjust its recipe and optimize the crunch. "Ultimately, however, we can only ever approximate vegan and vegetarian alternatives to the mouthfeel of meat sausages - because plant proteins have a completely different structure than proteins in meat," explains Vilgis.

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