Structural studies on matrices of deacylated gellan with polydextrose

Area of Science:

• Polymer Science
• Materials Science
• Biomaterials Engineering

Background:

• Deacylated gellan gum is a polysaccharide used in various applications.
• Understanding its thermomechanical and physicochemical properties is crucial for material design.
• Co-solutes can significantly influence polysaccharide matrix behavior.

Purpose of the Study:

• To investigate the impact of polydextrose concentration on deacylated gellan matrices.
• To elucidate the structural transformations occurring within these matrices.
• To correlate thermomechanical properties with structural changes.

Main Methods:

• Modulated differential scanning calorimetry (mDSC) and micro DSC.
• Small deformation dynamic oscillation in shear.
• Fourier transform infrared spectroscopy (FTIR), wide angle X-ray diffraction (WAXS), and environmental scanning electron microscopy (ESEM).

Main Results:

• Storage modulus initially increased with polydextrose, then decreased, and finally increased again.
• Structural transformation observed from aggregated assemblies to a cross-linked polysaccharide network.
• Time-temperature superposition (TTS) applied to generate master curves for viscoelasticity.

Conclusions:

• Polydextrose concentration drives significant thermomechanical and structural changes in deacylated gellan.
• The free volume theory helps explain the observed viscoelastic behavior.
• These findings are relevant for developing advanced polysaccharide-based materials.