Feasibility of polysaccharide addition for constructing soft golden threadfin bream (Nemipterus virgatus) surimi gels as a dysphagia food

Abstract

The effect of different polysaccharides including pectin (PC), xanthan gum (XG), guar gum (GM) and gum arabic (GA) on the gelation and dysphagia diet potential of golden threadfin bream (GTB) surimi gels was investigated. The four polysaccharides reduced the gel properties and improved the water retention of GTB surimi gels, reflected by 38.2–69.6% reduction in gel strength, a 49.7–55.5% decrease in the cooking loss rate (CLR) and a 22.9–24.3% increment in water holding capacity (WHC). Furthermore, GTB surimi gels complied with level 7 and the GM group and the XG group could be classified as level 6 (soft and bite-sized) dysphagia food according to International Dysphagia Dietary Standardization Initiative (IDDSI) testing. Moreover, the G′ values of the GM group and the XG group were reduced by 12.2% and 29.3% compared with the control. Meanwhile, T₂₂ significantly shifted toward higher relaxation times with the addition of GM. Indeed, the amide I band of GTB surimi gels exhibited a redshift from 1652.2 cm⁻¹ to 1657.1 cm⁻¹ and 1657.2 cm⁻¹ with the addition of GM and XG, revealing weaker electrostatic interactions between GTB surimi and polysaccharides. GM and XG enhanced hydrophobic interactions and disulfide bonds of GTB surimi by 12.3–22.3% and 21.4–28.6%, respectively. GM and XG promoted a looser microstructure of GTB surimi gels, with vessel percentage area, the total number of junctions, and total vessel length decreasing by 41.5–73.8% and lacunarity increasing by 70.9–72.5%. These findings could provide GTB surimi gels with addition of GM and XG for developing soft surimi products for people with dysphagia.