Alkali-heat treatment synergistic gelation of yeast protein and konjac glucomannan/xanthan gum: Molecular mechanism and its application in 3D-printed meat analogs.

Although 3D-printed meat simulation has achieved a satisfactory level of visual similarity, significant differences in textural properties compared to real meat remain a critical challenge in this field. This study proposed a "alkali-heat treatment protein-polysaccharide synergistic gel structure reinforcement" strategy to enhance the consistency between high-fidelity 3D printed full-block steak analogs and real steak. Yeast protein (YP) was used as the matrix and combined with konjac glucomannan (KGM) and xanthan gum (XG), achieving optimal printability and structural stability at a KGM/XG ratio of 1:1. Sodium carbonate (Na₂CO₃) incorporation significantly restructured the gel network, thereby improving the unnatural texture of simulated meat. This effect was optimized at a 0.15% (w/w) addition level, yielding maximal gel strength and enhanced structural recovery. The formulation led to a 90.15% water-holding capacity, and the hardness, springiness and chewiness were closely aligned with those of real steak. Multiscale characterization analysis revealed that Na₂CO₃ induced protein self-assembly into spherical aggregates, which were uniformly embedded in the polysaccharide network to form a robust honeycomb-like 3D structure. Mechanistic studies indicated that alkali-heat synergy strengthened disulfide bonds and hydrogen bonding while reducing electrostatic repulsion, promoting compact protein-polysaccharide association.