Stress-testing sausages may give vegan products a meat-like mouthfeel

Mimicking the mouth’s mechanical properties in the lab helps explain why plant-based sausages don’t quite feel the same when you eat them as meat-based ones – while also providing tips that could help make their texture more meat-like.

Despite recent improvements, plant-based sausages are still very different from meat versions in the eyes – and the mouths – of many people. But because the ways that sausages interact with the mouth and taste buds are so complex – not to mention the molecular complexity of the sausage itself – working out how to make plant-based alternatives more meat-like is a difficult task.

Thomas Vilgis at the Max Planck Institute for Polymer Research in Germany and his colleagues measured the different physical properties of three sausages from the same manufacturer – one meat, one vegetarian with egg white and one purely plant-based – to better understand how their underlying structure affected so-called mouthfeel. They applied a number of different mechanical forces to the sausage samples to simulate the mouth environment, such as compression, stretching and friction.

“Massive proteins which are [present] in [meat] sausages behave differently on a molecular scale compared to plant-based proteins,” says Vilgis. “This is always a problem in plant-based foods because they will never resemble a meat product on a molecular scale.”

Vilgis and his team found that the meat sausages slid more easily under friction than the plant and vegetarian versions, which he suggests is because the meat has more available fat that isn’t bound up in the molecular structure. The meat sausages were also more elastic under compression because of different protein structures, says Vilgis.

These findings could lead to different ingredients being used in plant-based sausages. Solid vegetable fats – which are already added to some meat-free products – could be used more widely to mimic the friction properties of the animal fats in meat sausages, which are solid at room temperature. Sunflower proteins, meanwhile, are relatively elastic among plant proteins and could be used to mimic the elasticity of meat sausages.

“It is critical for the advancement of this area to have fundamental polymer scientists applying their techniques and knowledge to understand plant-based foods, since these are extremely complex materials, both compositionally and structurally,” says David Julian McClements at the University of Massachusetts Amherst.