Abstract: The gel properties of giant squid surimi (Dosidicus gigas) fermented by Lactobacillus coryniformis Lz153 were determined by a texture analyzer. Changes in chemical forces including ionic bond, hydrogen bond, hydrophobic interaction, disulfide bond and non-disulfide covalent bond were examined during the gel formation process, and changes in myofibrillar protein were monitored by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The aim of this study was to determine the mechanism of gel formation. The results showed that the best gel characteristics were achieved between 24 and 36 h of fermentation. Ionic bond content decreased gradually during the fermentation process, and the contents of hydrogen bond and hydrophobic force reached the maximum values at 36 and 30 h, respectively. The contents of disulfide bond and non-disulfide covalent bond increased with the prolongation of fermentation time. Hydrogen bond, hydrophobic force, disulfide bond and non-disulfide covalent bond were the main driving forces for gel formation. SDS-PAGE showed that the myosin heavy chain and actin were degraded gradually during fermentation. Meanwhile, a new salt-soluble protein band within the range of 100–135 kDa appeared at 24 h and was gradually degraded till 48 h. Our results provide a basis for the production of lactic acid bacteria fermented surimi from giant squid muscle.

Key words: giant squid surimi, Lactobacillus coryniformis, gel formation, chemical forces, myofibrillar proteins