Rheological analysis of swelling food soils for optimized cleaning in plant-based food production

Abstract The ongoing shift towards replacing traditional animal-based foods with plant-based alternatives presents several technical challenges. In particular, there is a change in swelling properties of soils and cleaning behavior of production lines. Increased quantities of water, chemicals, and heat are often used to ensure food safety. A comparison of changes in mechanical properties of different food soils combined with cleaning liquids enables cleaning to be tailored to specific products while saving resources. Consequently, a rheological methodology for analysis of swelling soil layers immerged in cleaning liquids was improved with regard to efficiency of measurements, the adjustment of moisture content in the soil layer, and the insight into the time dependence of swelling. With the CP method, the measuring period on the rheometer could be reduced to approx. one tenth. Drying soil layers in a climate chamber allows for reproducible soil layers and moisture content adjustment, enabling analysis of soil layers with different drying degrees. Due to compression-related effects, the time dependency of the swelling can only be understood to a limited extent through measurements in the immersed state after different swelling times. Nevertheless, the improved method offers the potential to select suitable cleaning liquids and cleaning cycle.