Changes in proteolysis during the dry-cured processing of refrigerated and frozen loin

The influence of frozen storage of dry-cured loin before its processing has been evaluated in terms of proteolysis, pH, dry matter (DM), NaCl and sensorial acceptance. The frozen storage did not affect total nitrogen (TN), non-protein nitrogen (NPN), or proteolysis index (PI), showing values at day 50 of 1.14 and 1.11 g nitrogen/kg of DM; 0.093 and 0.091 g nitrogen/kg of DM and 8.2-8.2, in refrigerated (R) and pre-cure frozen (PF), respectively. Initially, PF loin values of DM were higher (2.91 g/kg of dry-cured loin) than R (2.71 g/kg of dry-cured loin). NaCl content of PF loin was higher than R throughout the processing (1.15 and 1.38 g/kg of DM at day 50, respectively). The total amino acid ((TFAA) concentration was higher in PF than in R, with the major differences at day 50 (27.5 and 19.9 g/kg, respectively). The concentration of all free amino acids (FAA) was affected by the freeze-thaw process. From day 30 onwards, the concentration of FAA increased in PF to such an extent that after 50 days significantly higher values were observed for all FAA except arginine, methionine and valine. There were no differences in consumer acceptance between R and PF dry-cured loin.