Tailoring dysphagia-friendly 3D printed starch-based gels: olive oil modulation of lotus root-whey protein inks

Developing dysphagia-oriented 3D-printed foods requires balancing extrudability during printing and shape retention after deposition while maintaining macronutrient balance. This study proposes a composite ink system combining whole lotus root powder, whey protein, and an unsaturated liquid oil phase to explore lipid-mediated modulation of printability and texture. Oil incorporation reduced apparent viscosity and altered viscoelastic responses, revealing a formulation-dependent trade-off between flowability and structural integrity. Based on an integrated evaluation of printing fidelity and texture performance, a printable-and-swallowable formulation window was identified, with the formulations at solid-to-oil ratios of 10:0 and 10:1 exhibiting similarly low printing deviations and improved water-holding capacity. Multi-technique characterization indicated a predominantly amorphous matrix and a redistribution of bonding environments within aqueous domains, alongside droplet-matrix interactions that facilitated extrusion and post-printing structural evolution. The present results provide mechanistic insights and a preliminary quantitative basis for understanding how structural evolution relates to rheology, printability, and quality-related properties in dysphagia-oriented 3D-printed foods.