The instability of dietary flavonoids is currently a challenge for their incorporation in functional foods.

• Combination of ultrasound and enzymatic method improved extraction yield of pecans protein. • Ultrasound-assisted enzymatic method promote the tryptophan residues in protein to be more easily exposed to the protein surface. • Ultrasound reduce the diameter of protein particles to improve the dispersion of pecans protein. • Ultrasound-assisted enzymatic method changed the unfolding of protein and exposure of hydrophobic groups and sulfhydryl groups.