Modification of Spanish Mackerel (Scomberomorus niphonius) Surimi Gels by Three Anionic Polysaccharides

This study investigated the gel performance of Spanish mackerel surimi gels (SMSGs) modified by three anionic polysaccharides: κ-carrageenan (KC), ι-carrageenan (IC), and gellan gum (GG). By incorporating polysaccharides, SMSGs showed a 24.9–103.4% improvement in gel and textural properties, in which KC and IC had more improvement effects than GG. Moreover, polysaccharides led to a 10.7–13.1% increment in WHC, a shortened water migration from 61.34 to 52.43–55.93 ms in T22, and enhanced thermal stability of SMSGs. The content of α-helix in SMSGs reduced markedly accompanied by a concurrent enhancement of β-sheet and β-turn by adding polysaccharides, where β-sheet and β-turn are positively correlated with hardness being favorable for gelling. The microstructure of SMSGs/polysaccharides showed a homogeneous network mainly due to hydrophobic interactions and disulfide bonds in SMSG-based gels. This study will demonstrate the effectiveness of KC, IC, and GG in improving the texture and functionality as well as expanding the application of surimi products.