Changes of physicochemical properties of greater lizardfish (Saurida tumbil) surimi gels treated with high pressure combined with microbial transglutaminase

Abstract

Effects of high-pressure treatment combined with microbial transglutaminase (MTGase) on the physicochemical properties of greater lizardfish surimi gels were investigated. Five samples were prepared: heating treatment (control), optimal high-pressure treatment (P), optimal MTGase treatment (M), MTGase combined with high pressure (MP), MTGase combined with setting, and high pressure (MSP). MSP exhibited the highest gel strength, a higher water-holding capacity than the control sample. A fibrous structure was viewed in MSP sample under scanning electron microscope, which was due mainly to the greater proportion of hydrogen bonds formed during setting prior to high-pressure treatment and non-disulfide covalent bonding catalyzed by MTGase under high-pressure treatment. The result of sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis showed that with the addition of MTGase, surimi protein established a tridimensional network. The dynamic rheological results showed that the addition of MTGase enhanced the solid-like nature of the gels. Practical applications The optimal process for improving surimi gels of greater lizardfish was determined. The effect of high-pressure treatment after setting could promote the ability of the MTGase to form covalent bonds. A lower pressure was recommended for surimi processing combined with MTGase. The combined treatment offers a technological possibilities for low valued fishes.