Abstract: The effects of two reducing agents including ascorbic acid and cysteine and two calcium compounds including calciumlactate and calcium gluconate on the gel properties of bighead surimi were investigated. The breaking force,. deformation, gelstrength, water-holding ability, and whiteness were used as assay indicators together with the analysis of the microstructure ofthe gels with scanning electron microscopy. Also, SDS-polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyzethe relevant mechanisms. The results showed that the addition of these four substances could enhance the gel-forming ability ofbighead surimi. The optimal concentrations of these additives were 0.05%, 0.1%, 0.1%, and 0.05% respectively, under which thegel strengths of bighead surimi gels were 917.8, 893.3, 851.9 and 679.9g•cm, or about 1.97, 1.92, 1.77 and 1.42 times of thecontrol respectively. Furthermore these compounds had no adverse effect on the color and whiteness of the product. SDS-PAGEassay indicated that these four compounds had no effect on the myosin heavy chain while scanning electron microscopyindicated that the addition these additives could make bighead surimi form firm and uniform gel network. The above resultsshowed that these four additives were good quality-enhancing compounds for bighead surimi, which could be used in practicalapplications.

Key words: reducing agent, calcium compounds, bighead surimi, gel properties