Aged pork loins were selected to have similar ultimate pH, color, lipid content, and purge. The star probe values (kg) obtained from these loins were evaluated and loins were sorted into either a low star probe (LSP) group or a high star probe (HSP) group. Loins were evaluated for autolysis of calpain-1 and degradation of troponin-T, desmin, and titin. Results showed calpain-1 was completely autolyzed in all samples. LSP pork loins exhibited more degradation of troponin-T, desmin, and titin, demonstrating proteolysis influences measured tenderness in aged pork.