Revealing the synergistic mechanism of ionic strength and cassava starch-lauric acid complexes in driving the transition of myofibrillar protein emulsion to emulsion gel.

The synergistic effects of ionic strength and cassava starch-lauric acid complexes (CS-LA) concentration on the emulsifying and gelling properties of myofibrillar proteins (MPs) were investigated. At low ionic strength, dispersion was promoted and ζ-potential increased by CS-LA, whereas excessive aggregation and larger particles were induced by 2.0% CS-LA. At high ionic strength, MPs were dispersed into monomers or oligomers, leading to the exposure of hydrophobic sites and facilitated binding with CS-LA. The emulsion containing 1.0% CS-LA exhibited optimal emulsifying activity and storage stability. CS-LA may bind to the myosin hydrophobic pocket, inducing local conformational expansion, while a more compact structure was stabilized at high ionic strength. In gel systems, a dense network was formed by 1.0% CS-LA through enhanced hydrogen bonding and hydrophobic interactions, resulting in increased gel quality. These findings may provide worthwhile insights for the regulation of MP gelation by starch-lipid complexes under varying ionic strengths.