Abstract: In order to investigate the changes in the microstructure and quality of scallop (Patinopecten yessoensis) striated adductor muscle during chilling storage, live scallops with good vitality were shucked and then the striated adductor muscle was taken and stored at 4 ℃ for 5 days. The pattern of changes in its microstructure, the contents of ATP and related compounds, salt-soluble protein content, and myofibrillar ATPase activity was analyzed. The results showed that the striated adductor muscle contracted obviously, and its texture became harder accompanied by high drip loss on day 5 of storage. The abundant mitochondria in the muscle become vacuolate. However, the microstructure of the muscle remained relatively intact and no myofibrillar protein degradation was detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). After storage for 5 days, the ATP content remained at 1.07 μmol/g, while the Ca2+-ATPase activity of myosin increased from 0.41 to 0.50 μmol/(mg·min). The solubility of striated muscle protein remained at only about 60% in 1.0 mol/L NaCl, and at 25% in 0.4 mol/L NaCl, increasing to 70% when ATP was added to the homogenate or ethylenebis(oxyethylenenitrilo)tetraacetic acid was added to chelate Ca2＋ before homogenization. These results indicate that the binding of actin to myosin can activate myosin ATPase activity in vitro and affect the salt solubility of striated adductor muscle proteins.

Key words: Patinopecten yessoensis; adductor muscle; rigor mortis; microstructure; myofibrillar protein stability