Effect of starch addition on the physicochemical properties, molecular interactions, structures, and in vitro digestibility of the plant-based egg analogues

This study investigated the gelling mechanisms of plant-based eggs modified with corn starch (CS), glutinous rice starch (GS), or potato starch (PS) at soy protein isolate (SPI)/starch ratios of 10:4, 8:6, and 6:8 (w/w). A plant -based omelet with SPI/PS 8:6 matched the texture (especially cohesiveness (0.75 vs 0.79)) and specific volume (1.28 vs 1.32 cm3/g) of an egg omelet best. This was attributed to greater protein-starch interactions (H-bonding, ionic bonding) that supported its strong structure. SPI/CS 8:6, SPI/GS 8:6, SPI/PS 10:4, and SPI/PS 6:8 demonstrated more ruptured granules and formed weaker gels. These proposed models were verified by nuclear magnetic resonance (NMR)-based metabolomics, where the stronger SPI/PS 8:6 gel released less metabolites after in vitro digestion. Through understanding different roles of starch in plant-based egg systems, this study suggests more potential applications of starch in modifying food properties.