Abstract: In this study, single factor experiments and orthogonal array design were used to optimize blends of acetylated starch, κ-carrageenan, and low-acyl gellan gum based on the viscosity of shrimp paste and the breaking force of heat-induced shrimp surimi gel. Subsequently, the effect of the optimized formulation on the rheological and thermodynamic properties of shrimp paste, as well as the gel strength, texture, moisture distribution, and microstructure of its heat-induced gel were investigated in comparison with samples with no added gum blends (control) and commercial shrimp surimi gel. The results showed that the optimal formulation consisted of 8.00% (m/m) acetylated starch, 3.00% (m/m) κ-carrageenan, and 0.12% (m/m) low-acyl gellan gum. Rheological analysis indicated that the storage modulus (G’) and loss modulus of the experimental group were higher than those of the control group, while the G’ value at 95 ℃ was lower than that of the commercial group. The experimental group exhibited higher gel breaking force, hardness, and chewiness but lower breaking distance and elasticity than both the control and commercial groups (P < 0.05). Color analysis revealed that the brightness value of the experimental group (62.51) was between those of the control group (57.94) and the commercial group (67.92), while the redness and yellowness values were the highest. No significant difference in water-holding capacity was found between the experimental and commercial groups, nor was there any difference in water distribution as indicated by low-field nuclear magnetic resonance results (P > 0.05), although both groups were superior to the control group. Electrophoresis analysis showed that the addition of the gum blend did not induce polymerization or degradation of proteins in shrimp paste products. Scanning electron microscopic images revealed that the gum blend enhanced the compactness of the network structure of shrimp paste products. Therefore, the optimized blend of acetylated starch, κ-carrageenan, and low-acyl gellan gum can improve the quality of shrimp paste and its products, providing technical support for developing high-quality shrimp paste products that meet market demands.

Key words: shrimp paste; acetylated starch; κ-carrageenan; gellan gum; gel properties; network structure