Effects of high-pressure processing on physicochemical, structural and emulsifying properties of chicken myofibrillar proteins

To investigate high-pressure processing (HPP) effects on myofibrillar protein (MP) structure, physicochemical properties, and emulsifying performance, chicken MP was treated at 150/300/450 MPa for 10–20 min. HPP caused structural shifts from ordered (α-helix, β-sheet) to disordered (β-turns, random coil) conformations, with concurrent elevation of surface hydrophobicity in a pressure-dependent manner. At 150 MPa, HPP treatment enhanced MP solubility, reduced particle size, and exposed reactive thiol groups. These structural changes enhanced the Emulsifying Activity Index (EAI) by 10.75 % and the Emulsifying Stability Index (ESI) by 25.24 %, primarily through hydrophobic domain exposure and improved interfacial adsorption capacity. Conversely, pressures ≥300 MPa triggered protein aggregation via hydrogen/disulfide; bond crosslinking, which masked functional groups and reduced solubility, thereby; impairing emulsification via heterogeneous particle formation. Extended durations amplified pressure-specific effects: 150 MPa/20 min optimized emulsification with homogenized, reduced droplet sizes, while ≥300 MPa exacerbated aggregation. The findings demonstrate that HPP strategically balanced conformational unfolding and aggregation to enhance MP functionality. Optimal synergy occurred at 150 MPa, where structural opening maximized emulsification, whereas higher pressures compromised interfacial stability. Duration amplified dual effects: enhancing beneficial structural changes or promoting aggregation, establishing 150 MPa/20 min as optimal for MP emulsification via controlled structural adjustments.