Effect of gellan and calcium chloride on properties of surimi gel with low and high setting phenomena

摘要

The properties of bigeye snapper surimi gel as affected by gellan (GL) at different levels (2–6% based on solid content of surimi) in combination with calcium chloride (CaCl₂) at various concentrations (25–75 mmol kg?1) were examined. The breaking force, hardness and whiteness of surimi gel increased but the expressible moisture content decreased as both levels of GL and CaCl₂ increased (p < 0.05). Electrophoretic studies showed that GL and CaCl₂ at all levels had no effect on polymerization of myosin heavy chain (MHC). The highest overall likeness score was found in the gel containing 4% GL and 75 mmol CaCl₂ per kg (p < 0.05). The effects of GL and CaCl₂ in the absence of endogenous transglutaminase (TGase) on surimi gel properties were also evaluated. Both GL and CaCl₂ increased the breaking force, water holding capacity and whiteness of TGase free surimi gels (p < 0.05). Based on rheological study, GL and CaCl₂ could enhance the interconnection between chains during heating as indicated by the higher G′. Different G′ curves were obtained between surimi in the presence and absence of TGase. The protein pattern revealed an important role of TGase in the MHC cross-linking of surimi gel. Microstructure studies demonstrated that a finer and denser network was observed in the surimi gel containing 4% GL and 75 mmol CaCl₂ per kg in the presence of TGase, whereas a coarser network was obtained in gels free of TGase. Therefore, GL and CaCl₂ at an appropriate level could be used to improve the gel properties of surimi with either low or high setting phenomenon mediated by endogenous TGase.