Investigation of the effects of high pressure processing on the process of rigor in pork

This study was conducted to determine whether the application of high pressure processing (HPP) could prevent the process of rigor in fresh pork and to identify the physical and chemical changes occurring in the meat that are responsible for this effect. Pressure (0-400 MPa) and time (10 min) were applied to the pork loin and enzyme samples. The effects of treatment on shear force, myofibrillar fragmentation, enzyme activity and meat texture were measured. The results showed that, compared with untreated samples, HPP treatment inhibited the occurrence of rigor in pork. The myofibrillar fragmentation indices of HPP treated samples were higher than those of control samples and increased linearly with increasing pressure. Application of HPP prevented the process of rigor at 0-300 MPa, reduced calpain activity and markedly decreased calpastatin activity, resulting in an increase of total calpains. Above 300 MPa, the mechanical action of pressure led to continuous prevention of rigor.