Postmortem Changes of Desmin, Talin-2, Vinculin, and Integrin β1 in Chicken Breast and Their Effects on Tenderness

Costameres are essential for maintaining the integrity of muscle fibers, which affects the meat tenderness. To explore the pattern of alteration in costameres after slaughter, this study investigated the distribution of costamere proteins (desmin, talin-2, vinculin, and integrin β1), their impact on tenderness, and the involved enzymes. Western blot analysis showed that talin-2 significantly degraded in postmortem, while integrin β1 significantly increased at 48 h (P < 0.05). Warner-Bratzler shear force was positively correlated with desmin, vinculin, and talin-2 expression and transcription levels of their genes but negatively correlated with pH, integrin β1 expression, and ITGB1 transcription level in terms of the overall trend. Multiplex immunohistochemistry revealed that these proteins were mainly distributed in the sarcolemma and cytoplasm, and the spatial interactions of them in the costameres began to weaken at 24 h. Caspase-3 and cathepsin B colocalized with these proteins at 3 and 24 h and may contribute to the degradation of costameres.