High-intensity ultrasonication treatment improved physicochemical and functional properties of mussel sarcoplasmic proteins and enhanced the stability of oil-in-water emulsion

This study investigated the effects of high-intensity ultrasonication (HIUS) treatment (0, 5, 10, 20, 30 min) on the physicochemical and functional properties of mussel sarcoplasmic proteins (MSP). MSP dispersion was treated by HIUS (20 kHz) at 600 W for 5, 10, 20 and 30 min. The results showed that HIUS treatment changed the physicochemical properties of MSP, thereby increasing the stability of the emulsion stabilized by ultrasonicated MSP. HIUS treatment improved the functional properties of MSP, including solubility, foaming ability, foaming stability, emulsifying activity index, emulsifying stability index, percentage of adsorbed proteins. More uniform emulsions with smaller droplets and higher stability were observed. There was a decrease in particle size, zeta-potential and turbidity of ultrasonicated MSP. Proteins partially unfolded as a result of HIUS treatment. Associations between conformation structure, physicochemical properties and functional properties were also found. It can be speculated that improvements in functional properties were caused by the changes in conformation structure and physicochemical properties. The results suggested that HIUS treatment has great potential in modifying the foaming and emulsifying properties of shellfish proteins, and ultrasonication treatment at 20 kHz, 600 W for 20 min was the optimum condition for modification.