Extrusion-Based 3D Food Printing: Printability Assessment and Improvement Techniques

The food industry is seriously considering 3D printing technology as demand for personalized and customized food is rising. Printability is one of the critical parameters to judge the success of an extrusion-based 3D printing process. The printability evaluation includes an assessment of extrudability, dimensional accuracy, and stability of 3D printed objects using computational fluid dynamics (CFD) modeling and qualitative or quantitative methods. For better printability, food ink should have appropriate rheological properties. Thus, food ink is either added with food additives or subjected to pre- and post-processing treatments to facilitate easier extrusion and better shape stability. Hence, the present paper aims to provide a comprehensive overview of printability assessment methods in extrusion-based 3D printing. The paper also elaborates on the desirable rheological properties and 3D printing parameters for better printability and methods to improve the printability of food ink. Therefore, this review can guide future research targeting improved printability of 3D printed foods.