Understanding the Effect of Conformational Rigidity on Rheological Behavior and Formation of Polysaccharide-Based...

Area of Science:

• Polymer Science
• Rheology
• Biochemistry

Background:

• Macroscopic rheological properties of polysaccharides are influenced by their molecular conformation.
• Xanthan gum and hyaluronic acid serve as model systems to study these effects.

Purpose of the Study:

• To elucidate the role of conformational rigidity in determining the rheological behavior of polysaccharides.
• To compare the properties of rigid xanthan gum with flexible hyaluronic acid.

Main Methods:

• Comparative analysis of xanthan gum and hyaluronic acid structures.
• Rheological measurements under varying conditions.
• Investigation of gelation properties with chitosan.

Main Results:

• Xanthan gum's rigid double-helical tertiary structure forms a network/quaternary structure, unlike hyaluronic acid's random coil.
• Xanthan gum exhibits enhanced shear thinning and solid-like behavior.
• Xanthan gum demonstrates superior stability against environmental changes (salt, urea, temperature).
• Xanthan gum forms gels with chitosan via electrostatic interactions, a feat not achievable by hyaluronic acid.

Conclusions:

• Molecular conformational rigidity is critical for macroscopic rheological properties in polysaccharides.
• The network/quaternary structure of xanthan gum confers enhanced rheological performance and environmental stability.
• Conformational differences dictate the ability of polysaccharides to form gels with other polymers.