Abstract: This study was undertaken in order to explore the effect of ultra-high pressure (UHP) treatment, applied within 150?350 MPa for 3 min on the shelling efficiency, and biochemical characteristics and structure of myofibrillar protein in Patinopecten yessoensis. Manual shelling and steam shelling were used as controls for comparison. The shelling efficiency was evaluated by measuring the shelling time and flesh yield. The pattern of changes in myofibrillar protein concentration, total sulfhydryl content, carbonyl content, surface hydrophobicity, Ca2+-ATPase activity and secondary structure was investigated. The results showed that high shelling efficiency was achieved by holding at 250 MPa for 3 min, and UHP treatment caused certain changes in the myofibrillar protein from Patinopecten yessoensis adductor muscle. Specifically, after the treatment, the surface hydrophobicity and hydroxyl content increased, whereas total sulfhydryl content and Ca2+-ATPase activity decreased. In addition, the relative contents of α-helix and β-turn decreased, whereas the contents of β-sheet and random coil increased. Overall, UHP treatment had only a limited impact on the myofibrillar protein, maintaining its biochemical properties and consequently maintaining the eating quality and processing performance of Patinopecten yessoensis adductor muscle. These results will provide references for the quality control of shellfish myofibrillar protein during ultra-high pressure treatment.

Key words: ultra-high pressure; Patinopecten yessoensis; shelling efficiency; myofibrillar protein; protein secondary structure