Effects of transglutaminase on the physicochemical properties of surimi and kamaboko prepared by thermal and low level-pressure treatments

Abstract

We investigated the effects of the presence or absence of transglutaminase (TGase) on the quality of tilapia surimi and kamaboko prepared at different thermal temperatures and pressures. TGase promoted the formation of surimi gel and covalent cross-linking under thermal (30°C–60 °C) and high-pressure treatments (0.1–300 MPa). Under heat treatment, TGase promoted myosin heavy chain (MHC) aggregation to form a 3D protein network. The TGase reaction was optimized at 50 °C, with no significant dependence on pressure. While the white index (WI) of TGase-treated surimi monotonically increased with temperature, and the lowest WI showed at 100 MPa, the other conditions were higher than it, with a maximum WI at 300 MPa. In the presence of TGase, both thermal (50 °C) and high-pressure (200–300 MPa) treatments improved the rheological properties of surimi and kamaboko. However, the effects on G′, G″ and Tan δ values of kamaboko were insignificant, mainly since the processing at 90 °C broke the non-covalent bonds based on hydrogen bonds formed by high-pressure treatments. Moreover, TGase treatment promoted the water holding capacity (WHC) of surimi and kamaboko. Hence, this study showed that with thermal treatment (50°C–60 °C), pressurization (200–300 MPa) caused the protein solubility of surimi and kamaboko to increase, irrespective of the TGase treatment. Notably, the protein solubility of surimi exceeded that of kamaboko.