BACKGROUNDThe limited physicochemical properties (such as low foaming and emulsifying capacity) of mung bean protein hydrolysate restricted its application in food industry. Ultrasound treatment could change the structures of protein hydrolysate to accordingly affect its physicochemical properties. The aim of this study was to investigate the effects of ultrasound treatment on the structural and physicochemical properties of mung bean protein hydrolysate of protamex (MBHP). Herein, the structural characteristics of MBHP were evaluated by tricine sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (Tricine‐SDS‐PAGE), laser scattering, fluorescence spectrometer etc.. Solubility, fat absorption capacity, foaming, emulsifying and thermal properties were determined to characterize the physicochemical properties of MBHP.RESULTSMBHP and ultrasonicated‐MBHPs (UT‐MBHPs) all contained five main bands of 25.8, 12.1, 5.6, 4.8 and 3.9 kDa, illustrating that ultrasound didn't change the subunits of MBHP. Ultrasound treatment increased the contents of α‐helix, β‐sheet, random coil and enhanced the intrinsic fluorescence intensity of MBHP, but decreased the content of β‐turn, which demonstrated that ultrasound modified the secondary and tertiary structures of MBHP. UT‐MBHPs exhibited higher solubility, foaming capacity, emulsifying properties than MBHP, among which MBHP‐330 W had the highest solubility (97.32%), foaming capacity (200%), emulsification activity index (306.96 m2/g) and emulsion stability index (94.80%) at pH 9.0.CONCLUSIONUltrasound treatment enhanced the physicochemical properties of MBHP, which could broaden its application as a vital ingredient in food industry.This article is protected by copyright. All rights reserved.