Xanthan gum (or xanthum gum) is a natural gum polysaccharide used as a food additive and rheology modifier. It is produced by a biotechnological process involving fermentation of glucose or sucrose by the Xanthomonas campestris bacterium. It was discovered by an extensive research effort by the United States Department of Agriculture, which involved the screening of a large number of biopolymers for their potential uses.
One of the most remarkable properties of xanthan gum is its capability of producing a large increase in the viscosity of a liquid by adding a very small quantity of gum of the order of one percent. Unlike other gums it is very stable under a wide range of temperatures and pH, and is accepted as a safe food additive worldwide, with E number E415.
Produced from the fermentation of corn sugar, xanthan gum is used as a thickener, emulsifier and stabilizer in agriculture, foods such as dairy products and salad dressings.