Degradation of structural proteins and their relationship with the quality of Mandarin fish (<i>Siniperca chuatsi</i>) during post‐mortem storage and cooking

Abstract

Abstract This study was carried out to investigate the changes in the microstructure and structural proteins (titin, nebulin, desmin and tropomyosin (TPM)) of mandarin fish muscle as well as the relationship between the structural proteins and the quality characteristics of fish muscle during post‐mortem storage and after cooking. During post‐mortem storage, titin was degraded initially, accompanied with an increase of the I‐band length. Subsequently, the degradation of desmin induced a gradual breakage of the myofibrils. The following degradation of nebulin accelerated the destruction of N 2 ‐lines, which occurred with a slightly fuzzy Z‐disc. Finally, TPM began to degrade, and the remaining desmin was also degraded further. Principal component analysis (PCA) and correlation analysis indicated that the changes in the quality characteristics of fish muscle were intimately related to the degradation of structural proteins. Hence, these structural proteins could be the biomarkers to monitor the quality characteristics of fish muscle.