Abstract
Frozen walleye pollack surimi blocks were thawed and heated at 30°C for up to 120min to induce thermal denaturation. The heat-treatment decreased an endogenous TGase and myofibrillar Ca-AT-Pase activities to 14% and 37% of the initial values, respectively. The surimi gel formability and setting response were almost completely lost. Although the addition of MTGase to the heat-denatured surimi completely recovered myosin cross-linking reaction, the gel strength and setting response were only partially recovered. In the presence of EGTA, an inhibitor of the endogenous TGase, the gel formability and setting response of the native surimi paste were remarkably reduced. However, these properties were completely recovered by the addition of MTGase together with EGTA. These results apparently demonstrate that the maximum gel strength of a final gel reflects the development of an elastic gel network which formed by a two-step heating procedure depending on a combination of thermal gelling ability of native myosin molecules and TGase reaction in the surimi paste.
