Stabilizing emulsions by ultrasound-treated pea protein isolate - tannic acid complexes: Impact of ultrasonic power and concentration of complexes on emulsion characteristics

This work aimed to investigate the feasibility of stabilizing oil-in-water (O/W) emulsions by ultrasound-treated pea protein isolate-tannic acid (UPPI-TA) complex. The stability and microstructure of the O/W emulsions were evaluated at different ultrasonic powers (0-1000 W) and UPPI-TA complex concentrations (0.25-2.0 wt%). The contact angle (θ) of UPPI-TA was 59.6°, which was suitable for stabilizing O/W emulsions. At an ultrasonic power of 800 W, the droplet size and creaming index (CI) of emulsions decreased, and the apparent viscosity and interfacial protein adsorption content increased with increasing UPPI-TA concentration. In particular, emulsions with 1.5 % UPPI-TA showed the lowest CI, the highest interfacial protein adsorption content and viscoelasticity, as well as the best storage and thermal stability. These results showed that the suitable modifications of ultrasonic emulsification power and particle concentrations were a new potential approach to stabilize the O/W emulsions by ultrasound-treated pea protein isolated-tannic acid complex.