The use of muscle enzymes as predictors of pork meat quality

Muscle endo-protease (calpains and cathepsins) and exo-protease (dipeptidyl-peptidases and aminopeptidases) activities were assayed at 2 h post-mortem in different meat qualities (PSE, RSE, RFN and DFD). The sensory characteristics of the different pork meat qualities were also evaluated in order to correlate them to the proteolytic activity. The assay of aminopeptidase and dipeptidylpeptidase activities (AAP, RAP, LAP, DPPI and DPPIV) at 2 h post-mortem discriminate between exudative and non-exudative classes explaining 74.6% of the variability. Also, at 24 h post-mortem 71.2% of the variability was detected by the measurement of PGAP, AAP, RAP, DPPII and DPPIV. Therefore, the exoprotease activities can constitute a novel and adequate technique to predict early post-mortem pork meat quality allowing its assay till 24 h post-mortem because of the good stability of the enzymes during this post-mortem time.