Preparation, characterization and potential mechanisms of 3D-printed meat analogs based on soy protein isolate-wheat gluten protein by L-cysteine cross-linking

3D printing has promising applications for producing plant-based meat analogs (PBMA) with excellent texture and unique structure. Therefore, the potential mechanisms of L-cysteine on texture and structural properties of 3D-printed PBMA were explored in this study. Results indicated that PBMA samples containing 0–0.15 % L-cysteine exhibited higher apparent viscosity, impeding the uniform extrusion process and resulting in incomplete printed-structure. Upon the incorporation of L-cysteine, a novel protein gel-network structure was established, which significantly enhanced the hardness, chewiness, water holding capacity (WHC), and tensile properties of PBMA samples. The content of hydrogen and disulfide bonds along with L-cysteine increases, which facilitates a transition in protein secondary structure from disordered to more-ordered conformation, thereby promoting protein aggregation. Notably, when L-cysteine concentration was optimized to 0.20–0.25 %, the microstructure within PBMA exhibited a relatively regular and dense arrangement. These innovative findings provide a prospective approach to developing well-structured, nutritious meat alternatives.