Compact hydrogels network structures reinforced by soy protein amyloid fibrils and sodium alginate

High-stretch plant protein hydrogels exhibit significant potential for application in the food industry and have attracted widespread attention. Inspired by the structure of fascia, we constructed a soy protein‑sodium alginate (SA) hydrogel exhibited enhanced mechanical performance through compression molding. Soy protein amyloid fibrils (SAFs), which exhibited a highly ordered cross-β structure, were selected as the protein source due to their functional properties. SA was a vital compound capable of constructing a hydrogel network in the presence of Ca²⁺. The results indicated that this method successfully facilitated a more compact network structure. Moreover, hydrogen bond interactions, along with the uniform distribution of Ca²⁺ within the hydrogel network, played a crucial role in determining the structural properties of the system, as proved by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The most strained performance (SAFs-2% SA-Ca²⁺) was obtained, exhibiting superior tensile properties with a tensile strain reaching up to 91.2%. This study introduced a unique method for utilizing SAFs in the development of mixture hydrogel systems, while providing a robust scientific foundation for the development of innovative food protein structures.