Emulsification properties and oil-water interface properties of L-lysine-assisted ultrasonic treatment in sea bass myofibrillar proteins: Influenced by the conformation of interfacial proteins

In this study, we aimed to investigate the influence of lysine-assisted ultrasonic treatment on the conformation, and interfacial and emulsification properties of sea bass myofibrillar proteins at the oil-water interface. It was observed that the modification treatment with lysine (1 g/L) combined with low-intensity ultrasound (200 W) enhanced the interfacial pressure and penetration rate. This enhancement could be attributed to the significant structural unfolding of myofibrillar proteins located at the oil-water interface (increase in beta-sheets and reduction in alpha-helices), which exposed the hydrophobic groups. The rate of interfacial protein adsorption subsequently increased, owing to the strengthening of protein-protein and protein-oil phase interactions. Additionally, the interfacial swelling rheology experiment showed an enhancement in the ordered structure of interfacial proteins, aiding in the development of a protein gel network structure. Consequently, the elastic modulus of the oil-water interface was larger, and the droplet interfacial structure was tight, which facilitated uniform distribution and improved the emulsification properties of the droplets, ultimately enhancing the ability of the emulsions to be stored at room temperature.