Characterization of 3D Printing Using Protein Reinforced Food Ink

This study investigates the development and optimization of food inks for 3D printing using protein-starch composites and hydro-oleocolloid (HOC) systems. The research investigates mashed potato (MP), pea protein (PP), and their combinations, as well as HOC formulations comprising whey protein solution (WPS) and oleogels (OG). By analyzing their mechanical and structural properties, the study identifies optimal formulations for achieving print fidelity, dimensional accuracy, and overhang stability in intricate designs. The findings reveal that mashed potato with a 1:4 mashed potato-to-water ratio (MP_1:4) and pea protein with a 1:3 protein-to-water ratio (PP_1:3) offer superior printability compared to other tested ratios in their specific food ink category, exhibiting less shape distortion. While formulations with higher water content showed excessive spreading and poor structural retention and with those of lower water content resulted in inconsistent extrusion, the optimal formulations achieved balanced moisture content and viscosity characteristics, enabling a smooth extrusion and structural (overhang) stability. A combination of MP (1:4) and PP (1:3) in a 1:1 weight ratio demonstrates improved overhang stability compared to single-component inks, resulting in enhanced structural integrity and geometric precision particularly in the overhang structures. Additionally, for the hydro-oleocolloid (HOC) systems, extended storage at 5°C for 24 hours significantly improves protein-lipid network crystallization compared to 1-hour room temperature conditioning. The formulation containing 40% whey protein isolate and 27% oleogel (40:27 WPS:OG ratio) emerges as optimal, displaying superior dimensional accuracy and overhang stability compared to other tested ratios. This composition achieves better print precision through enhanced network formation during cold storage, maintaining shape fidelity particularly in complex geometrical features. This research highlights the critical interplay between ingredient composition, processing conditions, and 3D printing performance, paving the way for personalized nutrition and sustainable food production. Future work will focus on rapid conditioning protocols, alternative structuring agents, and smart material integration to expand the scope of 3D food printing applications.