One-pot dual-crosslinked gelatin/alginate hydrogels for microstructure and texture regulation in 3D-printed meat analogues.

3D printing technology can precisely simulate the complex structure of natural meat, but balancing the viscosity and mechanical properties of printing inks remains challenging. This study proposes a one-pot dual-crosslinking strategy. CaCO3/GDL-mediated ionic crosslinking provides immediate structural support for 3D printing, while temperature regulation delays the TG enzyme crosslinking rate. This enables the interpenetration of covalent and ionic networks to form a composite network structure, ensuring long-term product stability. The effects of crosslinking sequence and gelatin concentration were investigated. Separating the crosslinking sequence significantly enhanced hydrogel viscoelasticity and structural recovery, improving print fidelity. Synergistic ion and delayed enzymatic crosslinking formed a uniform, dense honeycomb structure. Increasing gelatin concentration (2.5%-10%) markedly elevated the hydrogel's storage modulus, compressive modulus, hardness, and chewiness. Furthermore, water holding capacity approached 100%, with thawing loss and cooking loss reduced to 2.83% and 7.27%, respectively. This study provides novel strategies for texture regulation in 3D-printed meat analogues.