Transglutaminase cross-linking of bovine cardiac myofibrillar proteins and its effect on protein gelation

Myofibrillar protein concentrate (MPC) was prepared from beef heart muscle (3 or 5% protein), and the sols were incubated with 0.5 unit/mL transglutaminase (TGase) at 5 and 15C for 0, 0.5, 2, 5, 10, and 15 h to determine the enzyme effect on MPC gelation. After each incubation time, dynamic gelling tests, differential scanning calorimetry, and electrophoresis (for sols and gels) were performed on all samples. MPC samples with TGase had greater (P<0.05) gelling ability, regardless ofpreincubation (time and temperature), showing increases in storage modulus (G′) from 600-900 Pa (control) to 1700-2000 (treated) at 70C. The results suggest that the gelation-enhancing effect by TGase was attributed to cross-linking of myosin, and that TGase can be used to improve the binding ability of beef heart myofibrillar proteins in restructured meats.