Xinlian Su, Xin Hu, Ping Li, Kai Zhou, Hui Zhou, Baocai Xu
High-moisture extrusion is an important technology for producing fibrous plant-based meat analogs, yet the relative contributions of different processing variables to quality formation remain unclear. In this study, wheat gluten and Morchella esculenta mycelium were used as raw materials to investigate the effects of moisture content, barrel temperature, screw speed, and cooling temperature on the quality characteristics of high-moisture extrudates. Moisture content was identified as the key factor affecting texture, color, and water distribution. Excessively high cooling temperature (100°C) led to an increase in fibrous degree but a reduction in hardness. LF-NMR analysis showed that processing conditions significantly altered water distribution and mobility in the extrudates. FTIR results indicated that the major functional groups were not markedly changed, whereas protein secondary structures underwent pronounced rearrangement, suggesting that suitable processing conditions favored ordered chain reorganization and the formation of stable structures. Protein solubility further revealed that network formation and restructuring were mainly governed by hydrogen bonding and hydrophobic interactions. Consistently, correlation analysis indicated that moisture content was closely associated with several quality attributes of the extrudates. Overall, the quality formation of high-moisture extrudates was jointly driven by intermolecular protein interactions, water migration behavior, and structural reorganization.