# Curdlan-Induced Significant Enhancement of Lipid Oxidation Control and Gelling Properties of Low-Salt Marine Surimi Gel Containing Transglutaminase and Lysine

## TL;DR

This study shows that adding curdlan to low-salt surimi gels improves their texture and reduces lipid oxidation, making them a better alternative to egg-white protein.

## Contribution

The novel use of curdlan in low-salt surimi gels with transglutaminase and lysine is shown to enhance gel properties and reduce lipid oxidation.

## Key findings

- Adding 0.4% curdlan significantly inhibits lipid oxidation and improves color and texture in surimi gels.
- Curdlan at 0.4% enhances gel crosslinking and resistance to shear stress, promoting a denser structure.
- Excessive curdlan (0.6%-1.0%) deteriorates gel performance and causes structural and color issues.

## Abstract

In this study, curdlan was investigated as a substitute for egg-white protein, and the effects of different concentrations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%) on lipid oxidation and the physicochemical properties of a novel low-salt surimi gel containing transglutaminase (TGase) and lysine were evaluated. The results indicated that adding appropriate curdlan concentrations (0.2%–0.4%, especially 0.4%) significantly inhibited lipid oxidation in the surimi gel, achieving the highest L* and whiteness values. The fracture strength, WHC, hardness, and chewiness of the gel increased by 23.87%, 6.70%, 32.80%, and 13.49%, respectively, compared to the control gel containing egg-white protein (p < 0.05). At 0.4% curdlan, the gel also enhanced the crosslinking within the surimi, improved its resistance to shear stress, significantly increased the G’ value, and shortened the T21, T22, and T23 relaxation times, inhibiting the conversion of immobilized to free water in the gel and promoting a denser three-dimensional network structure. However, excessive curdlan amounts (0.6%–1.0%) led to a notable deterioration in the gel performance, causing a more irregular microstructure, the formation of larger cluster-like aggregates, and a negative effect on color. In conclusion, the combination of 0.4% curdlan with TGase and Lys is effective for preparing low-salt surimi products.