ProTEXtrusion

For ecological, ethical and health reasons, there has been an increased demand in recent years for alternative products based on plant proteins to replace products of animal origin. Products that imitate meat or sausage products are particularly popular. To replicate the typical meat-like texture, textured vegetable proteins (TVP) are required, which are usually produced by thermoplastic extrusion.

However, a major challenge in extrusion is that the complex correlations between a large number of independent parameters have not yet fully understood. As a result, it is not possible to predict or specifically influence final product properties such as texture, color, flavor and fibrousness. Replacing one raw material with another is also not possible without an enormous investment in terms of trials, time and cost.

In order to overcome this and to be able to test the "extrudability" and "texturability" before starting the trials, this project aims to develop a method for offline characterization of plant proteins. Initially, rheological measurements under extrusion-relevant conditions (high protein concentration, high temperatures, high shear rates) will be performed using a Closed Cavity Rheometer (CCR). These methods will provide information on the viscosity and elasticity of the plant proteins. In a second step, the selected plant proteins are textured by thermoplastic extrusion and analyzed for relevant product parameters such as textural and rehydration properties. The rheological data are then correlated with the results of the extrusion parameters to determine which rheological properties correlate with stable extrusion conditions and high product quality. The data and results will then be used to develop a standardized offline rheological measurement method.