Physicochemical modulation of soy-hemp-wheat protein meat analogues prepared by high-moisture extrusion using...

Transglutaminase (TGase) is widely used in the production of high-moisture extruded meat analogues (HMEMA) to enhance fiber structure by promoting protein cross-linking. However, its impact on the structure, quality, and protein configuration across different extrusion zones during the preparation of meat analogues (MA) from various proteins remains unclear. This study aimed to investigate the effects of TGase on the physicochemical properties and texture of HMEMA made from soy protein (SP), hemp protein (HP), and wheat gluten (WG). A "dead stop" experiment was conducted to analyze the microstructure, protein structure, and intermolecular interaction forces of MA at different extrusion zones. The results showed that the addition of 0.18 % TGase increased the degree of texturization by 15.4 % and improved the water holding capacity (WHC) by 42.5 %. MA prepared with TGase exhibited a more distinct fiber structure, whereas those without TGase displayed a layered morphology. Furthermore, TGase significantly enhanced hydrogen bonding and hydrophobic interactions between proteins. Notably, the presence of 0.18 % TGase reduced the proportion of protein α-helix and β-sheet structures in the melting zone from 60.4 % to 46.0 %, while in the extrusion zone, these structures increased from 58.2 % to 69.2 %. These findings suggest that TGase facilitates protein expansion and recombination during extrusion, thereby promoting superior fiber formation. This study underscores the crucial role of TGase in improving the textural properties of MA derived from various plant proteins, offering valuable insights for the development of MA from diverse plant protein sources.