Plant-based foods frequently utilize hydrocolloid systems to achieve desired textural and structural properties through controlled biopolymer interactions. This study investigates enzymatic crosslinking between wheat bran arabinoxylan (WBAX), a hemicellulosic hydrocolloid, and plant proteins to develop double-network hydrogels with enhanced functionality. Ferulic acid groups present on WBAX and aromatic amino acids (tyrosine) in proteins serve as reactive sites for oxidative enzyme-catalyzed coupling. We examined how protein source, chemical functionality, and enzyme specificity (laccase versus peroxidase/glucose oxidase) modulate the formation, organization, and viscoelastic properties of arabinoxylan-protein composite hydrogels, and we evaluated their potential as network-forming hydrocolloids in plant-based systems.

Plant proteins from different sources (pea, potato, faba, soy, and oat) were enzymatically crosslinked with WBAX at varying pH conditions, followed by incubation and thermal treatment. The resulting composite hydrogels were characterized using rheological analysis (time sweeps, temperature-dependency, and large amplitude oscillatory shear), molecular-level characterization (SDS-PAGE, FTIR spectroscopy), and microscale visualization (confocal microscopy). Enzymatic treatment increased viscoelastic moduli compared to untreated or single-component systems, demonstrating synergistic biopolymer interactions and formation of intermolecular WBAX-protein bonds. The enhancement was most significant with originally weak-gelling proteins, demonstrating the utility of this hydrocolloid engineering approach. Molecular analysis confirmed high-molecular-weight conjugate formation and hydrogen bonding interactions between WBAX and all protein types. Microstructural visualization revealed interconnected network architectures whose organization varied with ingredient ratio, WBAX ferulic acid content, and reaction parameters.

The enzymatic crosslinking strategy substantially improved gel strength across all tested plant protein types. Network development was primarily dependent on WBAX ferulic acid availability and reaction conditions, while gel microstructure was additionally influenced by different ingredient ratios. These findings establish enzymatically-coupled arabinoxylan-protein complexes as a novel hydrocolloid system for engineering the next generation of plant-based meat analogues.