Influence of polyol Cosolvents on the stability, texture, thermal properties and rheology of Furcellaran-based composite gels.

Furcellaran-based hydrogels and emulsion gels containing low-molecular-weight polyols were investigated to clarify how polyol type, concentration and matrix structure affect hydration, mechanical and thermal behaviour of composite gels. Polyols were added at 1-20%, and the systems were analysed using water activity, swelling ratio, texture profile analysis, oscillatory rheology, DSC and FT-IR. Increasing polyol concentration systematically reduced water activity and swelling, with the strongest effect observed for erythritol and the weakest for sorbitol. Mechanical and rheological measurements revealed opposite responses of the two matrices: polyols softened hydrogels, whereas in emulsion gels they contributed to structural reinforcement, particularly in xylitol-containing systems. Thermal and spectroscopic results confirmed that these effects originated from changes in hydration and polymer-water interactions rather than chemical modification of the polysaccharide network. Overall, polyols modulate furcellaran gel properties through competing hydration and phase-confinement mechanisms, providing a basis for tailoring composite gels for food applications.