Effects of high hydrostatic pressure treatment on the emulsifying behavior of myosin and its underlying mechanism

Myosin, a protein originating from muscle, is traditionally used for meat products for its ability to generate emulsions. Small changes in the emulsifying and conformational characteristics of proteins greatly influence the gel-emulsifying meat products. The effect of high hydrostatic pressure (HHP) on the emulsifying behavior of myosin prepared at different pressures (0.1, 100, 150, and 200 MPa) was investigated. The particle size, microstructure, interfacial tension, emulsifying properties, and secondary structure of myosin were analyzed. The results showed that as pressure increased from 0.1 to 150 MPa, the size of oil drops was reduced, the viscoelasticity of interfacial protein film improved, and the emulsifying activity and stability of myosin increased. Meanwhile, as the pressure increased from 0.1 to 150 MPa, the α helix content of the protein decreased significantly (P < 0.05), which was beneficial for the intermolecular interaction between proteins. A further increase in pressure (to 200 MPa) was detrimental to emulsifying activity and stability. As the pressure increased to 200 MPa, the emulsion displayed a decreased interfacial elasticity and increased protein random coil contents, and the particle size noticeably increased (P < 0.05). Therefore, it is concluded that HHP treatment at 150 MPa improves the stability of myosin emulsions.