Physicochemical and rheological changes of oyster (Crassostrea gigas) protein affected by high-pressure homogenization

For better application of oyster protein (OP), high-pressure homogenization (HPH) (0, 20, 40, 60, 80 or 100 MPa) was used to explore the physicochemical changes and enhance the gelling properties effectively. The results showed that HPH altered secondary structures of OP with a decrease of α-helixes but an increase of β-sheets; as well as tertiary structures with higher free sulfhydryl (SHF) and higher surface hydrophobicity (H0). Compared to the control, the reduced mean particle size and the increased surface net charge promoted the solubility of OP after HPH treatment. Moreover, HPH also changed static rheological properties of OP suspensions with fewer shear stress values at 1 s−1 (τ1) but higher flow index values (n). Stronger HPH significantly improved gelling properties and enhanced the intensity and stability of OP gels. These might be ascribed to changes in structures and the promotion of solubility. The results suggested a way to expand the utilization of oyster protein.