Development of quinoa (Chenopodium quinoa Willd) protein isolate-gum Arabic conjugates via ultrasound-assisted wet heating for spice essential oils emulsification: Effects on water solubility, bioactivity, and sensory stimulation

Quinoa protein isolate-gum Arabic (QPI-GA) conjugates were developed by ultrasound-assisted wet heating to improve the water solubility and bioactivity of spice essential oils (EOs) in this study. The optimal conditions for QPI-GA conjugates preparation were found to be: heating temperature of 72 celcius, ultrasound power of 450 W, and reaction time of 46 min. QPI-GA conjugates displayed significantly higher emulsifying efficiency and stronger tolerance to pH variation, high salt concentration, and storage than raw materials. The emulsifying efficiency of emulsions was also influenced by the pH and viscosity of EOs, zeta potential of the emulsion as well as the relative density and lipid/water partition coefficient (P) of EOs were the possible factors impacting the stability of EO emulsions. The water solubility, antioxidant ability, and antibacterial ability of tested EOs were improved after emulsification. Meanwhile, encapsulation with QPI-GA conjugates played a good effect on reducing the sensory stimulation of EOs.