Effect of transglutaminase on the gelation of heat-denatured surimi

Frozen walleye pollack surimi blocks were thawed and heated at 30 degrees C for up to 120 min to induce thermal denaturation. The heat-treatment decre ased an endogenous TGase and myofibrillar Ca-ATPase activities to 14% and 3 7% of the initial values, respectively. The surimi gel formability and sett ing response were almost completely lost. Although the addition of MTGase t o the heat-denatured surimi completely recovered myosin cross-linking react ion, the gel strength and setting response were only partially recovered. I n the presence of EGTA, an inhibitor of the endogenous TGase, the gel forma bility and setting response of the native surimi paste were remarkably redu ced. However, these properties were completely recovered by the addition of MTGase together with EGTA. These results apparently demonstrate that the m aximum gel strength of a final gel reflects the development of an elastic g el network which formed by a two-step heating procedure depending on a comb ination of thermal gelling ability of native myosin molecules and TGase rea ction in the surimi paste.