Shear-induced structuring of phase-separated sodium caseinate - sodium alginate blends using extrusion-based 3D printing: Creation of anisotropic aligned micron-size fibrous structures and macroscale filament bundles

3D food printing is considered a promising method to prepare personalized foods having unique macroscopic design and composition. It is still challenging to create 3D printed foods with tailored microstructure, e.g. fibrous microstructures, to print meat-like foods. In this study we investigated the preparation of 3D printed model food gels that have macro- and microscale aligned fibrous structures using sodium caseinate - sodium alginate (SC/SA) blends with extrusion-based printing. A bath containing an agar fluid gel was used to allow precise deposition and solidification of the SC/SA blend after the printing process. Besides, the influences of nozzle type and printing speeds on texture were assessed. We succesfully created aligned micron-size fibrous structures and macroscale aligned filament bundles. Filaments extruded using tapered nozzles had finer fibrous structures compared to those extruded using straight nozzles. Both printing speed and nozzle type significantly influenced Young's moduli of 3D printed model food gels. A higher printing speed resulted in smaller Young's moduli of individual printed filaments. This study shows that anisotropic structures can be created by extrusion-based 3D printing of phase-separated sodium caseinate - sodium alginate blends. The results of this study might become relevant when striving for meat analogues made by 3D-printing.