Abstract: In order to improve the gel quality of giant squid (Dosidicus gigas) surimi and illustrate the underlying mechanism, this study determined the effects of laver powder addition on the sensory quality, whiteness, gel strength, water-holding capacity (WHC), microstructure and the conformation and secondary structure of myofibrillar protein (MP) in giant squid surimi. The results showed that laver powder had a significant effect on the whiteness of surimi gel, which made the surimi gel turn slightly yellow-green. The gel strength and WHC of surimi gel significantly increased with increasing addition of laver powder up to 0.4%–0.6%, and then declined and did not change significantly, respectively. Furthermore, compared with the control group, the addition of 0.4%–0.6% laver powder caused an increase in the α-helix content and a decrease in the β-sheet content of MP in the surimi gel. Laver powder could reduce the transformation from α-helix to β-sheet in MP, as well as strengthen the three-dimensional network structure of surimi gel and improve the gel strength and WHC. In conclusion, appropriate laver powder addition (0.4%–0.6%) could significantly affect the gel characteristics and secondary structure of MP in giant squid surimi, thereby improving product quality.

Key words: Dosidicus gigas; laver powder; myofibrillar protein; gel properties; secondary structure