Effects of ultrasound-assisted emulsification and carboxymethyl cellulose addition on the rheological and microstructure properties of myofibrillar protein-soybean oil emulsion gel

This study was designed to illustrate the effects and the mechanism of ultrasound-assisted emulsification (UAE) treatment and carboxymethyl cellulose (CMC) addition on the rheological behavior and microstructure of myofibrillar protein (MP)-soybean oil-based emulsion gels. Our results indicated that both CMC addition and UAE treatment enhanced the apparent viscosity, Hook and Voigt elastic modulus, storage modulus, and loss modulus of MP-based emulsion gels, especially for the combined CMC and UAE treatment. The size of emulsion gel droplets was decreased and the concentrations of protein and CMC in the emulsion gels were improved after UAE treatment. A protein-coated oil-filled gel network structure was formed for the non-UAE treated MP-based emulsion gel whilst a protein-coated oil-participated network structure was formed for the UAE treated sample. UAE treatment significantly increased the random coil content, surface hydrophobicity, and zeta potential while decreasing the free and total sulfhydryl groups of MP. In summary, UAE treatment and CMC addition could modify the gel network, change the electrostatic and hydrophobic interactions, and enhance the disulfide bonds to improve the rheological properties of MP-soybean oil-based emulsion gel.