Xanthan Gum

Xanthan gum (XG) is a white or light yellow powder with remarkable thickening, emulsification, and suspension properties. This water-soluble compound has great stability against alkaline solutions, acids, and heat. These features make it a versatile and important reagent (Zhong et al. in Powder Technol 388:158–165, 2021). Additionally, XG is a high-molecular-weight (around 2 × 106 g/mol) polysaccharide produced by bacteria containing abundant carboxyl (–COOH) and hydroxyl (–OH) functionalities (Fig. 3.1). In many areas of industry, specifically in the food industry, XG is extensively used because it is affordable, biodegradable, non-toxic, highly soluble, and stable. Hydroxyl and carboxyl functionalities in the XG structure interact with metal ions and are chelated (Zeng et al. in Appl Surf Sci 551, 2021). The rheological behavior of XG in the aqueous environment at ambient temperature shows a shear-thinning behavior related to the orientation of molecules along the flow (Xu et al. in Carbohydr Polym 92:516–522, 2013).