Improvement of gelling properties of surimi from threadfin bream (Nemipterus spp.) using saponin

• Saponin at various concentrations was added in surimi to improve gel property. • Addition of saponin at 1% increased both breaking force and deformation of gel. • Saponin above 1.5% led to the formation of poorer gel with coarser gel network. • Rheological property of surimi paste added with 1% saponin was better than control. Gelling property of surimi determines the acceptability and price. Several additives have been added to improve the gelling property of surimi. The use of a multifunctional additive with nutraceutical properties as a protein cross-linker should be beneficial for surimi gel improvement. This study aimed to elucidate the impact of saponin on the gelling characteristics of surimi from threadfin bream ( Nemipterus spp.) Surimi samples added with saponin at concentrations ranging from 0 to 2.5% (w/w) were prepared. The gels were evaluated for breaking force, deformation, whiteness, expressible moisture content, protein pattern, rheology, FTIR spectra, and textural profile. Surimi gel containing 1% SPN (SPN1) had higher breaking force and deformation ( p <0.05) than others. Whiteness of gels was reduced with the augmentation of saponin levels. Saponin concentrations had no effect on band intensity of myosin heavy chain. SPN1 had a compact network with higher elastic modulus (Gʹ) and gel strength than others. A minor change of the amide I band in FTIR spectra was found in SPN1. A higher percentage of β-sheets was observed in SPN1. Overall, the incorporation of 1% saponin could enhance surimi gel characteristics, while excessive levels impeded gel network integrity. Therefore, saponin could be used as a new additive for surimi.