Gel properties of soy protein isolate-potato protein-egg white composite gel: Study on rheological properties, microstructure, and digestibility

In order to improve the nutritional and gelling properties of soy protein isolate (SPI) gel system, potato protein (PP), egg white (EW) and PP-EW mixtures were added. The texture properties, intermolecular forces, and secondary structures of the gels were examined. Then the microstructure observation, rheological measurement and digestibility assay were conducted. The results showed that the gel of 3PP-3EW had the highest proportion of β-sheet (47.04%), the most ordered gel structure, and the highest proportion of immobilized water (96.03%). The digestibility of SPI-PP-EW gels was higher than that of SPI-PP gel or SPI-EW gel. With the increase of EW proportion, the gel hardness increased along with the increased proportion of covalent bonds. This study is conducive to the development of meat analogues with better amino acid pattern.