Filamin is necessary to maintain the integrity of muscle structure. Postmortem degradation of filamin results in loss of organizational structure at the Z-disk and improves meat tenderness. Intact and degraded filamin was successfully identified in aged pork loin. The removal of amino acids to form this degradation product is likely the first cleavage of intact filamin observed in postmortem muscle. A significant decrease in abundance of intact filamin in low star probe (SP) value samples demonstrates that degradation of filamin varies when aging period and pH are similar. Filamin degradation was significantly different in SP groups, suggesting that filamin proteolysis and formation of degradation products may have an impact on the SP values of aged pork loin.