No doubt it has these 2 acids but these are in bound form and not in ionic forms and hence the solution has neutral pH.

Dr. Ghosh, thank you for your answer. However, as I know, xanthan gum is an anionic polysaccharide that is easily dissolve in water. Therefore, xanthan gum should be negatively charged in aqueous solutions.

True it is anionic and gets negative charge in water but does not produce protons to acidify the solution.