Effects of high pressure on the myofibrillar proteins of cod and turkey muscle

When turkey breast muscle and isolated myofibrillar protein and myosin of c od or turkey (pH approximate to 7) were subjected to pressures up to 800 MP a for 20 min, DSC and electrophoresis (SDS-PAGE) indicated that high pressu re-induced denaturation of myosin led to the formation of structures that c ontained hydrogen bonds and were additionally stabilized by disulfide bonds . Disulfide bonds were also important in heat-induced myosin gels. Hardness of whole cod muscle, estimated by texture profile analysis, showed pressur e-treated samples (400 MPa) to be harder than cooked (50 degrees C) or cook ed and then pressure-treated or pressure-treated and then cooked samples, s upporting the suggestion that pressure induces the formation of heat labile hydrogen-bonded structures while heat treatment gives rise to structures t hat are primarily stabilized by disulfide bonds and hydrophobic interaction s. As expected, turkey myosin is more stable than that of cod; however, it seems their pressure-induced gelation mechanisms are similar.