SYNTHESIS, CHARACTERIZATION, AND RHEOLOGICAL PROPERTIES OF MODIFIED XANTHAN GUM

Xanthan gum (XG) is a microbial exo-polysaccharide (biocompatible, biodegradable, and hydrophilic) produced industrially from the fermentation of simple carbon sources under aerobic conditions by Gram-negative bacteria Xanthomonas campestris. As a great commercial significance, it has demonstrated interesting properties like biodegradability, high viscosity at a low shear rate and stability under a wide range of temperature and pH which leads to the wide range of applications such as pharmaceutical, cosmetic, biomedical, petroleum and agriculture, especially in food applications. However, certain limitation such as high solution viscosity even at a lower concentration due to its high molecular weight can hinder its uses in specific functional food applications considering its prebiotic features. Therefore, this review focuses on the rheological properties alterations of xanthan gum modified by various non-thermal emerging technologies, targeting the product with the lower molecular weight to obtain xanthan-derived oligosaccharides with the antibacterial, and antioxidant activities. Xanthan polymer with the low molecular weight also provides a variety of applications. The steady and dynamic flow behavior as rheological properties of XG in aqueous solutions which is closely associated with the polymer concentration has been studied extensively. In this review, high pressure treatment in varied ways, ultrasound and radiation technologies were considered to explain the change of xanthan gum flow behaviors, based on previously published researches.