PRESSURE-INDUCED CONVERSION OF ALPHA-CONNECTIN TO BETA-CONNECTIN

The mechanism of the pressure-induced tenderization of meat has not been fully established in spite of its beneficial effect. To detect the changes in the large structural proteins of the myofibrils induced by pressurization without heat treatment, high hydrostatic pressure (100-300 MPa) was applied to rabbit at-death skeletal muscle for 10 min at low temperature (0-2-degrees-C). Significant differences in the electrophoretic pattern of connectin (also called titin) in isolated myofibrils were observed between the control and pressurized muscle samples. The conversion of alpha-connectin (2800 kDa) to beta-connectin (2100 kDa) was accelerated with increasing pressure applied to the muscle; also nebulin (800 kDa) was degraded by pressure treatment. From the results it is clear that the degradation of connectin is induced by pressurization alone without heat treatment. If the conversion of alpha-connectin to beta-connectin during conditioning has some influence on meat tenderization, the pressure-induced conversion of alpha- to beta-connectin is possibly one of the causes of pressure-induced tenderization of meat.