Mechanism, kinetics, and physicochemical properties of ultrasound-produced emulsions stabilized by lentil protein: a non-dairy alternative in food systems

Replacement of dairy proteins by plant proteins is a current trend to produce stable colloidal systems critical to the food and beverage industry. In this study, we compared commercial samples of lentil protein concentrate (LPC) and whey protein concentrate (WPC) to stabilize ultrasound-produced sunflower oil-in-water emulsions. The effects of high-intensity ultrasound (HIUS) (0, 300, 600, 900, and 1200 W) on the LPC-stabilized emulsion properties were evaluated and compared to the emulsion stabilized by WPC, with the aim to assess the challenges and drawbacks of using LPC. Steric stabilization mechanism predominated over electrostatic mechanism. The interfacial tension results showed the ability of LPC to adsorb into the oil–water interface. HIUS processing reduced surface charge density of protein-adsorbed oil droplets, decreasing its contribution to kinetic stabilization. The mean droplet diameter of fresh emulsions showed a significant reduction from 5.44 µm at 0 W nominal power to 2.07 µm at 600 W. However, HIUS process intensification by increasing nominal power up to 1200 W increased mean droplet diameter due to starch and dietary fiber aggregation. Although LPC and WPC had distinctive technological properties due to their composition, our results demonstrated that LPC is a promising plant protein to stabilize colloidal systems.