Effects of deacetylation on properties and conformation of xanthan gum

Abstract

The presence of acetyl groups in xanthan gum can significantly influence the conformation and properties of xanthan molecules. We employed various techniques, including X-ray diffraction, interface tensiometry, fluorescence spectroscopy, electron spin-resonance spectroscopy (ESR), and rheometry, to assess the influence of deacetylation on the conformation and properties of xanthan. The results showed that the degrees of fibrosis, interfacial tension, and hydrophobicity of deacetylated xanthan were different from those of xanthan. The ESR results demonstrated that the ordered helix conformation of xanthan became disordered in deacetylated xanthan. The rheological data further illustrated that the gel strength and viscosity of deacetylated xanthan were higher than those of xanthan. Collectively, acetyl groups help to sustain the ordered conformation of xanthan by maintaining the interactions between the backbone and side chain of xanthan molecules.