Desmin as molecular chaperone for myofibrillar degradation during freeze-thaw cycles

Abstract

This study investigated the relationship of secondary protein structures with textural attributes of chicken breast subjected to 6 freeze (−20 °C) thaw (4 °C for 12 h) cycles. 2DE identified 78 distinct protein spots. Moreover, WB indicated a remarkable increase in the degree of desmin degradation during multiple freeze–thaw (MFT). In addition, the TEM micrographs revealed that MFT remarkably increased the spacing between the muscle fibers, especially from cycles 3 to 5, slightly decreased H-zone, but a remarkable shrinkage of Z-lines, as well as degradation of myofibril structures (Z-line, I-bands, and M-lines). DSC showed shifts in first and second endothermic transition peaks during the 3rd and 5th cycles. Viscoelastic graphs revealed a cycle-dependent decrease in gel-forming ability (G′) during MFT. Finally, the MFT chicken breast samples exhibited significantly decreased shear force in a cycle-dependent manner. This study highlighted the critical role of desmin in regulating myofibrillar degradation through various routes and mechanisms.