Comparative Analysis of Gel Properties of Sodium Citrate-Treated Giant Squid and Pork for Surimi Production

The giant squid, despite its abundance as a resource, is underutilized for surimi production due to its distinctive odor and poor gel-forming ability. While soaking (e.g., in sodium citrate) can alleviate the odor, its impact on the gel properties remains unclear. This study employed a comparative approach using pork, a benchmark for high-quality gels, to critically evaluate the gel properties of deodorized giant squid. The rheological, textural, and microstructural properties, as well as the water-holding capacity and water distribution, of squid (after sodium citrate soaking) and pork gels were compared. The results demonstrated that the squid gels exhibited a significantly lower storage modulus and higher tan δ value than pork gels, indicating inferior rheological properties. After cooking, the squid gel exhibited a bent shape and markedly lower hardness (approximately 259.78 g) and chewiness (approximately 226.09 g) compared to the pork gels (approximately 3305.92 g and 2781.27 g, respectively). Microstructurally, the squid gels presented a coarse, porous, and discontinuous network with larger pores, contrasting sharply with the fine, dense, and uniform matrix of the pork gels. Correspondingly, the squid gels had inferior water-holding capacity and a higher proportion of free water. This comparison demonstrates that the gel from sodium citrate-soaked giant squid is weak. More importantly, it provides mechanistic insights by highlighting the specific structural and hydration deficiencies responsible for its poor performance. The findings underscore that targeted strategies to modify the protein network are necessary for the effective utilization of giant squid in surimi production.