Combination effects of chicken plasma protein and setting phenomenon on gel properties and cross-linking of bigeye snapper muscle proteins

Effects of chicken plasma protein (CPP) in combination with setting on surimi gel properties and protein cross-linking were investigated. Addition of CPP (0.5 g/100 g), CaCl2 (10 mmole/kg) and 200 units of thrombin/g CPP in combination with setting at 40 °C for 30 min prior to heating at 90 °C for 20 min resulted in the highest breaking force and deformation (P<0.05). Regardless of CPP addition, myosin heavy chain (MHC) in surimi proteins and natural actomyosin (NAM) underwent polymerization to some extent in the presence of CaCl2 and thrombin. The cross-linking of MHC in surimi proteins were markedly suppressed by the addition of EGTA and NH4Cl, transglutaminase (TGase) inhibitors. No cross-linking of myosin was observed when CPP, CaCl2 and thrombin were added, even with the prolonged incubation time. The result revealed that CPP showed no cross-linking activity and gel strengthening effect of CPP was attributed to its filler effect and proteolytic inhibitory activity.