Structure and functionalities changes in high-pressure homogenized clam protein isolate

High-pressure homogenization (HPH) under 0-100MPa was performed to treat clam protein isolate (CPI) for three cycles. Results indicated that HPH treatment resulted in significant improvements of CPI functional properties. Absolute zeta potential, emulsifying activity index, and emulsion stability index significantly increased by 19.37mV, 33.26 m(2)/g, and 14.00min after HPH under 100MPa. Solubility of CPI dramatically increased by 70.8% under 80MPa. Foaming ability and foaming stability increased by 33.8% and 14.4% under 60MPa. HPH resulted in significant decrease in percentage of both -helix and -turn, but percentage of -sheet greatly improved as the pressure increased. Free sulfhydryl and surface hydrophobicity increased but fluorescence intensity decreased significantly after HPH treatment. Improvements of these functionalities were due to protein structure changes and particle size reduction. This study demonstrated that HPH has the potential to improve functional properties of shellfish protein through modifying protein structure. Practical applicationsA nonthermal processing technique using HPH can improve functional properties of CPI, including solubility, emulsifying properties, and foaming properties. Therefore, HPH can be potentially used to process shellfish proteins to improve their functional properties.