Xanthan Gum

Xanthan gum, made up of complex, branched polysaccharides, is produced by the action of a bacteria (Xanthomonas campestris). It is soluble in both cold and warm water, where it serves as a thickener in concentrations as small as 0.1–0.3 percent. Liquids stiffened with xanthan gum exhibit shear thinning, an effect well known from ketchup and dressings, which are usually made with it. This imparts a tough, stable consistency during storage, but these products flow easily, without dripping, when they are poured out of the bottle or when they are put in the mouth. The viscosity of a product thickened with xanthan gum changes very little in a temperature range between 32°F (0°C) and 212°F (100°C). Xanthan gum can also stabilize emulsions, such as ice cream, and it is not affected by acidity. The mouthfeel of products incorporating xanthan gum is lingering and somewhere between sticky and smooth. Either xanthan gum or guar gum is typically added to gluten-free baked goods to keep the alternative flours and starches from crumbling and to add chewiness.