Mechanism insights into tannic acid binding to ultrasound-pretreated myofibrillar protein and effect on its dynamic interfacial properties

Abstract

This study investigated the interaction between tannic acid (TA) and Ultrasound-pretreated Myofibrillar Protein (UMP), focusing on the molecular-level structural changes and interfacial behavior of UMP. Fluorescence spectroscopy revealed that the interaction was characterized by static quenching, with approximately 1.05 binding sites. Molecular docking simulation indicated that the main force between UMP and TA was hydrogen bonds, accompanied by hydrophobic and electrostatic interactions. Molecular dynamics analysis represented that after binding with TA, the protein conformation became more stable. Interface behavior studies demonstrated that after binding with TA, the interfacial tension of UMP decreased by 8.79%, while the oil-water interfacial diffusion rate and the adsorbed protein amount of UMP increased by 37.5 % and 31.81%, respectively. Emulsion performance analysis indicated that compared with UMP, the emulsion storage stability of UMP/TA complexes increased by 89.90%, while the lipid oxidation degree decreased by 51.55%, respectively. This study elucidated how natural polyphenols modify the structure and properties of myofibrillar Protein through non-covalent interactions on the molecular level and offered a reference path for enhancing the utilization value of marine proteins.