Identification of small troponin T peptides generated in dry-cured ham

Troponin T (TnT) is a myofibrillar protein present in striated muscle that develops important structural and regulatory functions. This protein is easily degraded during post-mortem ageing but details of the TnT hydrolysis occurring during much longer processes, e.g. the dry-cured processing, as well as the specific sequences of the generated fragments, still remain undetermined. In the present study, the isolation and identification of 27 peptides, generated from TnT during dry-cured processing, are reported for the first time. This study has been developed using matrix-assisted laser desorption/ionisation time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF) and it evidences the extensive degradation of TnT occurring during the processing of dry-cured ham. Some of the cleavage sites, corresponding to these sequenced fragments, confirm the sites reported by other authors both in vitro and during post-mortem ageing of meat.