3D printing of date paste and cornstarch-based composite gels: Rheological characterization and printability assessment

This study aims to improve the 3D printability of the date fruit paste through integration with the pregelatinized cornstarch. The cornstarch concentrations were varied (5, 10, 15, and 20% w/w) and the date paste-cornstarch gels were physiochemically evaluated, with a focus on their suitability for 3D printing applications. Starch addition increased the gel hardness, adhesiveness, and enhanced the gel structural network. The results showed that the dimensional accuracy in printed products enhanced, where the gel shape fidelity improved significantly at 15-20% starch levels. However, excessive starch addition at 20% led to reduced cohesiveness and springiness which governed fragile 3D printed structures during handling. Although the elastic modulus decreased with higher starch levels the syneresis decreased by 0.3% at 20% starch, suggesting the formation of denser, water-retentive networks by starch. Starch addition increased the endothermic peak temperatures progressively due to improved gel stability, consistent with gel microstructural observations where compact and continuous gel matrices was observed at higher starch concentrations. Overall, these results highlight the impact of starch content on gel behavior, supporting formulation strategies to optimize printability and product performance in 3D food printing.