Texture modulation of starch-based closed-cell foams using 3D printing: Deformation behavior beyond the elastic...

3-dimensional printing is a novel processing method used for the design and manipulation of food textures. The systematic characterization and modulation of 3D printed food textures is imperative for the future design of sensory profiles using additive manufacturing. For 3D printed closed-cell food foams, the clarification of the deformation behavior in relation to design parameters is of interest for the processing of customized food textures. For this reason, we studied the deformation behavior of 3D printed and thermally stabilized closed-cell starch-based foams beyond the elastic regime. Periodic spherical bubble configurations at different porosity levels were used to modulate the deformation behavior of the printed foams. From a processing perspective, the integration of in-line thermal stabilization was used to eliminate post-processing and to control the moisture content of the starch-based system. Compression analysis combined with FEM simulations were performed to characterize the strain rate dependency of textural properties, the stress relaxation, and the foam's stress-strain behavior with respect to the design porosity and bubble distribution. Results showed that the stress relaxation is solely dependent on cell wall properties while different stress-strain regimes showed distinct dependencies on design parameters such as bubble size and distribution. Consequently, the precise control of the large deformation behavior of foods using 3D printing is challenging due to the superposition of structural and geometrical dependencies. Finally, through the presented approach, the structure-deformation relations of 3D printed closed-cell food structures are adequately described.