Investigating local residence time and thermomechanical stress profile in twin-screw extrusion of plant proteins by using the moving particle semi-implicit simulation method

Temperature, mechanical stress, and the residence time are important process variables that must be monitored during the production of food by twin-screw extrusion. In production, these variables are mainly considered as integral variables over the entire process. However, local deviations, for example in temperature, can lead to uncontrolled product changes. In this work, the moving particle semi-implicit simulation method was used to simulate local sections of a partially filled twin-screw extruder. The influence of screw configurations with kneading blocks with different offset angles on the degree of filling, the residence time, and mechanical stress was investigated. Further, the temperature profile was determined for a screw configuration with neutral kneading blocks. To evaluate the physical reliability of the simulation results, dead-stop experiments were performed, and a good agreement was found between the filling degrees obtained from the simulation and the experiments. •The flow of a plant protein isolate during extrusion was simulated using MPS.•Important local process variables could be obtained from the simulation results.•A temperature profile of the material along the screws was obtained.•The physical reliability of the simulations was tested using experimental data.