Impact of metal-phenolic networks on the structural and functional properties of soy protein

The modification of soy protein refers to the process of altering the physical, chemical, or functional properties of soy protein through various methods to improve its applicability in various food and non-food industries. Metal-phenolic networks have been proven effective in modifying proteins. In this study, the metal-phenolic networks (MPNs) consisting of (−)-epigallocatechin-3-gallate (EGCG) and Fe3+ were used to modify SPI for the first time. The successful assembly of the MPNs and structural properties of SPI were investigated with UV, FTIR, energy-dispersive X-ray spectroscopy and fluorescence spectroscopy. Results indicated that the modified SPI by MPNs showed reduced surface hydrophobicity and improved foaming properties. Additionally, the emulsions stabilized by MPNs showed smaller droplet size and higher modulus with increasing complex concentration. This study demonstrates the feasibility of MPNs as a novel modification method to improve the functional properties of soy protein.