Fabrication and characterization of xanthan gum-modified silver carp (Hypophthalmichthys molitrix) and grass carp (Ctenopharyngodon idella) soft surimi gels

The effects of xanthan gum (XG) on the gelation, swallowing properties and mechanisms of silver carp (SC) surimi and grass carp (GC) surimi were investigated. The results showed that the composite modulus, hardness and chewiness of SC and GC samples decreased by 8.8%-50.7% as XG concentration increased from 0% to 4%. The SC and GC samples with 1% or 2% XG could be classified as level 6 diets according to the International Dysphagia Diet Standardization Initiative framework. Additionally, SC and GC samples exhibited a 6.4%-30.8% decrease in cooking loss and a 0.8%-3.9% increase in water holding capacity with the addition of XG. Moreover, the introduction of XG led to decreases in the hydrophobic interactions and disulfide bonds whithin SC and GC composite systems, resulting in softer and looser structures. Furthermore, the results of molecular dynamics simulation demonstrated myosin-XG interactions are driven primarily by significant electrostatic forces. These results highlighted the potential of XG as an effective textural modifier for producing freshwater fish soft surimi gels.