Food-Grade Emulsions and Emulsion Gels Prepared by Soy Protein-Pectin Complex Nanoparticles and Glycyrrhizic Acid Nanofibrils

Glycyrrhizic acid (GA) and GA nanofibrils (GN) have been shown to be efficient natural emulsifiers for formation and stabilization of food emulsions. In this work, the emulsion properties of GN in the presence of soy protein isolate-pectin complex nanoparticles (SPNPs) were studied to understand the impact of the nanofibril-nanoparticle interactions on emulsion stabilization. In the presence of low GN concentrations (0.1-0.5 wt%), the synergy in reducing the interfacial tension was observed due to the SPNPs-GN complexation in bulk and at the interface by hydrogen bonding, endowing the prepared emulsions with overall smaller droplet size. However, obvious flocculation and clustering of oil droplets occurred in these emulsions (especially at 0.25 and 0.5 wt% GN), which are probably induced by a depletion mechanism. At high GN concentrations (1-2 wt%), due to the preferential adsorption, the GN mainly dominated the interface and the subsequent formation and properties of emulsions. Accordingly, the self-stan...