Ultrasound-assisted 3D printing of pork emulsions: A hybrid strategy for structural fidelity and industrial scalability

This study investigated ultrasound-assisted structural modulation of pork emulsions for 3D printing. Ultrasound treatments (200–600 W, 10–30 min) were screened, and UHP20 was identified as optimal. At this setting, emulsions showed smaller particle size, more negative zeta potential, and uniform fat–protein distribution. These structural changes were linked to partial protein unfolding, exposure of hydrophobic residues, and enhanced intermolecular interactions. Rheological analysis demonstrated improved shear-thinning flow, rapid thixotropic recovery, and higher yield stress. Dynamic tests confirmed that UHP20 maintained greater storage modulus during heating, reflecting strong gelation capacity. Functional assays showed higher emulsifying activity, lower cooking loss, and improved water-holding capacity. Textural analysis revealed increased hardness and cohesiveness, comparable to commercial sausages. 3D-printed prototypes retained dimensional accuracy and showed consistent structural fidelity after cooking. Among all treatments, UHP20 exhibited the most pronounced improvement in structural performance, showing approximately 23 % higher storage modulus, around 66 % lower cooking loss, and nearly complete dimensional fidelity (≈99 %) compared with the control. Collectively, ultrasound-assisted treatment produced emulsion inks with reliable printability and robust post-processing stability. These findings demonstrate the potential of ultrasound–3D printing integration as a practical strategy for making customized, high-protein foods.