Biochemical and Conformation Changes of Actomyosin from Threadfin Bream Stored in Ice

Biochemical and conformational changes of actomyosin stored in ice were investigated. The K‐value of threadfin bream increased from 9% to 40% after storage for 12 d. Ca 2+ ‐, EDTA‐, Mg 2+ ‐, and Mg 2+ ‐Ca 2+ ‐ATPase activities of actomyosin decreased, whereas Mg 2+ ‐EGTA ATPase activities increased. Total SH content of actomyosin increased after 3 d and decreased thereafter. Surface hydrophobicity gradually increased within 6 d. Protein loss during washing increased with storage time. A significant reduction (50%) of breaking force of thrice‐washed mince was observed in fish stored in ice for 6 d. There was no evidence of proteolysis of muscle proteins stored up to 9 d as shown with SDS‐PAGE.