Model for the Temperature-Induced Conformational Change in Xanthan Polysaccharide

Area of Science:

• Polymer Science
• Biochemistry
• Food Science

Background:

• Xanthan gum is an extracellular bacterial polysaccharide produced by *Xanthomonas campestris*.
• It is widely used in food and other industries to control viscosity and texture.
• Its functional properties depend on its existence as both a rigid double-helical polymer and a branched network.

Purpose of the Study:

• To model the thermally induced conformational transition of xanthan gum in dilute aqueous solutions.
• To investigate the characteristics of double-helical and crosslinked aggregates using light scattering.
• To elucidate the role of structural degeneracy in xanthan's temperature-induced conformational changes.

Main Methods:

• Light scattering experiments were conducted on dilute aqueous solutions of xanthan gum.
• The study focused on the temperature-induced transformation between different polymer conformations.
• A model was developed to describe this transition process.

Main Results:

• The study characterized the double-helical and crosslinked aggregate forms of xanthan.
• The interconversion between these forms was observed through heating and cooling cycles.
• Xanthan's structural degeneracy was shown to significantly influence the conformational transition.

Conclusions:

• The model accurately describes xanthan's thermally induced conformational transition in dilute solutions.
• Structural degeneracy in xanthan's regular copolymer structure is crucial for its transition behavior.
• Understanding these transitions is key to optimizing its industrial applications.