Abstract: To investigate the potential of fish oil as a solid fat substitute in surimi products, the effects of adding different amounts of pea protein isolate-curdlan (PPI-CL)-based emulsion gel on the gel properties, microstructure, and odor of Nemipterus virgatus myofibrillar protein (MP) were studied. The results indicated that, compared with the control group without PPI-CL-based emulsion gel, addition of fish oil (FO) led to a significant reduction in the strength, hardness, and water-holding capacity of MP gels (P < 0.05). Additionally, the chemical interaction between MPs was markedly weakened, and the microstructure became noticeably coarser and looser. Compared with the FO group and the control group, addition of the emulsion gel markedly enhanced the texture properties, gel strength, and water holding capacity of MP gels, the effect being most pronounced at an addition level of 8%. Incorporation of the emulsion gel promoted the conformational transformation of MP from α-helix to β-sheet, thereby enhancing the intermolecular interaction between MPs. Meanwhile, the filling effect of the emulsion gel contributed to the formation of a more compact and dense gel network. However, addition of the emulsion gel at levels greater than 8% disrupted the interaction between protein molecules, leading to the deterioration of the network structure of protein gels and the conversion of bound water to free water within the gel matrix, consequently reducing the gel strength. Furthermore, electronic nose (E-nose) analysis could effectively differentiate the odor profiles of different MP gel samples. This study provides a theoretical reference for the application of emulsion gels as fat substitutes in surimi gel products.

Key words: emulsion gel; Nemipterus virgatus; myofibrillar protein; gel properties