High-speed shearing assisted genipin crosslinking of soybean lipophilic protein: insights into conformational rearrangement and interfacial modulation

High-speed shearing induced the unfolding of soybean lipophilic protein (SLP). • Primary amino groups of SLP served as reactive sites for genipin crosslinking. • Genipin facilitated intermolecular crosslinking of SLP after shearing. • Shearing and genipin treatment enhanced SLP adsorption at the oil-water interface. • Modified SLP improved emulsion stability and enhanced its viscoelasticity. Native soybean lipophilic protein (SLP) readily forms compact aggregates through strong hydrophobic interactions, impairing its water solubility and interfacial adsorption capacity. This study investigated the effects of high-speed shearing followed by genipin crosslinking on the structural and functional properties of SLP. Spectroscopic analyses revealed enhanced exposure of tryptophan and tyrosine residues, indicating that shearing induced conformational unfolding of SLP. Subsequent genipin crosslinking resulted in a clear blue shift of the amide II band, confirming the formation of covalent crosslinks. The treatment consisting of shearing at 12,000 rpm for 4 min and 0.004% genipin yielded the highest SLP solubility of 76.29%. Under these conditions, the emulsifying activity index and emulsion stability index of modified SLP increased by 14.33 m 2 /g and 135.88 min compared with native SLP. In summary, this study provides an important reference for addressing the stability issues of plant protein emulsions in the food industry. Download: Download high-res image (170KB) Download: Download full-size image