Effect of multiple-frequency ultrasound-assisted transglutaminase dual modification on the structural, functional characteristics and application of Qingke protein

•Ultrasound-assisted TGase improved the cross-linking degree of Qingke protein.•Multiple-frequency ultrasound has stronger assistant effect of TGase cross-linking.•The functional properties were affected by protein conformation changes.•Dual modified Qingke protein can be used in noodle production.