Influence of drying method and 3D design on the 4D morphing of beef products

4D printing refers to the physical or chemical transformation of 3D printed structures subjected to external triggers. This study investigates drying methods (freeze-drying and combi oven drying) as stimuli to generate 4D morphing of 3D printed beef products. The effect of drying method and model design (infill density (25%, 50%, 75%), infill pattern (Grid, Honeycomb, Stars), and thickness (2 mm, 3 mm, 4 mm)) on the bending degree, porosity, textural attributes, and the microstructure is assessed through a linear regression model with two continuous (thickness and infill density) and two categorical (drying method and infill pattern) independent variables. Overall, the results showed larger 4D morphing when drying by combi-oven, using the design of 4 mm thickness, 75% infill density, and a honeycomb pattern. In addition, a paired-preference test showed that the appearance of 3D printed beef snacks with 100% infill density was preferred over a cast design, although no differences in textural preferences were found. 4D food printing processing allows the manufacturing of intricate and innovative snacking end-products. This study proposes a combination of design and drying process to generate 4D morphing, textural, and porosity changes of beef snacks upon 3D printing post-processing. In addition, the formulation used in this study can be adapted for texture-modified foods or regular textures, based on the post-processing conditions it is subjected to.