The synergistic effects of soy protein isolate and curdlan on salt-reduced hairtail sausages: Investigation into saltiness perception and quality characteristics

This study explored the effects of the synergistic action of soy protein isolate (SPI) with curdlan (Cur) or gellan gum (GL) on the quality and flavor of salt-reduced hairtail sausage. Compared with the directly reduced-salt sausage (RS), the texture properties, rheological properties, and water retention capacity of RS-SPI-Cur or RS-SPI-GL were significantly improved due to the formation of a stable three-dimensional network structure. This network microstructure caused the uneven distribution of sodium ions, thereby enhancing saltiness perception. Sensory evaluation and e-tongue analysis confirmed that SPI and polysaccharides were beneficial for the release of sodium ions and enhanced saltiness perception. Chemical interaction and FT-IR analysis indicated that the observed improvements were driven by enhanced hydrogen bonding and protein cross-linking and promoted the shift of α-helix and random coil to β-sheet. These findings provided critical insights into the potential of SPI and polysaccharides as functional ingredients for developing high-quality, reduced-salt surimi products.