Hofmeister effect on the local structure, network mechanics, and water retention of soy protein isolate-tannic acid-κ-carrageenan ternary gels.

This study investigated the effects of Cl- and SCN- at different concentrations on the structural characteristics and gel properties of soy protein isolate-tannic acid-κ-carrageenan ternary composite gels. Ion type and concentration exerted distinct effects on gel aggregation, mechanical strength, surface charge, and water retention. At 10% KCl, the gel exhibited the smallest particle size (382 nm), the highest hardness (2008 g), and the highest absolute zeta potential (34.5 mV), whereas the maximum water-holding capacity (91.5%) was observed at 20% KCl. For the KSCN-treated gels, the smallest particle size (450 nm) and highest hardness (848 g) were observed at 10% KSCN, the highest absolute zeta potential (42.1 mV) at 20% KSCN, and the maximum water-holding capacity (87.1%) at 25% KSCN. Overall, Cl- produced a stronger and more compact gel network than SCN-. These findings demonstrate the potential of the Hofmeister effect for tailoring protein-based composite gels.