Interfacial engineering of starch-based ternary gels under nutritional constraints: Linking structure, rheology, and 3D printability

Achieving nutritional adequacy and desirable printing performance in starch-based 3D-printed foods remains challenging. A nutrition-constrained design strategy was developed for starch-based gel systems by limiting the formulation space within the Acceptable Macronutrient Distribution Range (AMDR), accompanied by an AMDR-based scoring method to evaluate energy supply rationality. Starch-based ternary gel networks were constructed by incorporating soy protein and lipid components through different interfacial engineering strategies, including direct blending, pre-emulsification, Pickering emulsification, and high-pressure homogenization. CLSM and droplet size analysis demonstrated that interfacial engineering modulated lipid dispersion within the starch-based matrix, with oil droplet size decreasing from 26.92 to 0.20 μm. Multi-scale characterization showed that the Pickering-treated starch-based gel (CSOEP) exhibited the best printability, achieving a printing accuracy of 89.7%, which remained above 89% after five printing cycles, along with a structural recovery rate of 92.0%. Although the high-pressure homogenized gel (CSOEH) possessed the smallest oil droplets, excessive interfacial refinement disrupted effective starch-based network reconstruction after high-shear deformation, reducing printing accuracy to 55.6%. This study reveals a multi-scale relationship of component incorporation and lipid interfacial regulation → starch-based network reconstruction → rheological behavior → printing performance, providing a basis for designing nutritionally balanced starch-based 3D-printable foods for dysphagia applications.