In food industry the solid-liquid extraction process is found in the production of a wide range of products. Besides the application in the coffee and tea industry solid-liquid extraction processes include the separation of oils and lipids from vegetable or animal materials, nuts and seeds, extraction of sugar from beet and flavour from herbs and spices
In the basic process a liquid phase is utilized to separate components contained in a solid phase, whereas the components that are transferred can be either solids or liquids. There are two techniques commonly applied immersion and percolation extraction . The focus will be brought to percolation extraction where liquid trickles through the bed of particles. Thus, mass transfer is influenced by the solid bed characteristics. The influence of the bed characteristics on the extracted components is object to this study.
The aim is the development of a predictive model regarding extract compositions incorporating the bed structure and particle morphology. Therefore governing factors will be evaluated and opportunities to influence the final composition from the same raw material at the same extraction yield will be studied. In order to develop the model the Discrete Element Method (DEM) will be used to construct the particle bed, while the Computational Fluid Dynamic (CFD) will be applied to simulate the flow of the solvent that trickles through the particle bed.
 Fellows, P. (2017): Food processing technology. Principles and practice. Fourth edition. Duxford, United Kingdom: Woodhead Publishing (Woodhead Publishing series in food science, technology and nutrition).