Abstract:To improve the extraction efficiency of wild rice protein and enhance its functional properties， ultrasound-assisted alkaline extraction was employed to extract wild rice protein. The extraction process was optimized using response surface methodology and compared with the traditional alkaline extraction method. By determining functional properties including water-holding capacity， oil-holding capacity， emulsifying properties， and foaming properties， combined with particle size， Zeta potential， and infrared spectroscopy analysis，the effects of ultrasound treatment on the structure and function of wild rice protein were investigated. The results showed that the optimal extraction conditions were as follows： liquid-to-solid ratio of 28∶1 （mL/g）， extraction time of 30 min， pH12， and extraction temperature of 38 ℃， under which the protein extraction rate reached 87.81%. Ultrasound treatment reduced the particle size of wild rice protein and increased the absolute value of the Zeta potential. Meanwhile， the contents of α-helix and β-sheet in the secondary structure decreased， whereas the proportions of β-turn and random coil increased， indicating a looser and more extended structure. The water-holding capacity， oil-holding capacity， emulsifying property， emulsion stability， and foaming stability of wild rice protein extracted by the ultrasound-assisted alkaline method were all significantly higher than those obtained by the traditional alkaline method （P＜0.05）.