Xanthan Gum is secreted by the bacterium Xanthomonas campestris through the fermentation of glucose, sucrose, or lactose. After a fermentation period of one to four days, the polysaccharide is extracted from the growth medium with isopropyl alcohol, before being dried and ground into a powder.
Xanthan Gum is usually sold as a powder that is water-soluble and forms a gum when added to water (hydrocolloid). It is stable under a wide range of temperatures and acidity and can thicken liquids without materially changing the colour or flavour of foods or beverages. Adding a small quantity of the gum can produce a large increase in the viscosity of a liquid, so in most foods it is used at concentrations of only 0.5%. The viscosity of the liquid to which the gum has been added increases while being vigorously mixed or shaken, but thickens back up once this stops.
Xanthan Gum is a food additive and rheology (flow) modifier, commonly used as a thickening agent (e.g. in sauces and salad dressings). Although it is not an emulsifier, it helps to prevent oil separation by stabilising emulsions. Xanthan Gum also helps suspend spices and other solid particles. It can help to enhance the texture of frozen foods and beverages, and is often used in ice creams and other dairy products. Xanthan Gum is used in gluten-free baking to give the dough or batter a stickiness otherwise achieved by the gluten. Xanthan Gum can also help thicken egg substitutes made from egg whites, replacing the fat and emulsifiers found in egg yolks.
Xanthan Gum is used as a laxative due to its ability to bind water.
In the Oil industry, Xanthan Gum is used to thicken the drilling mud which carries the solids cut by the drilling bit back to the surface and helps suspend them when the drilling stops. Its use has expanded since the widespread use of horizontal drilling technology. It is also added to concrete poured underwater to increase its viscosity and prevent it washing back out.
In the Personal Care industry, Xanthan Gum is used as a stabiliser in shampoos and hair colour to prevent ingredients from separating, and as a thickener and binder in toothpaste to keep the product uniform. It is also used in water-based gels and personal care products due to its skin hydrating properties. Xanthan Gum is also used in oil-water emulsions to help stabilise the oil droplets against coalescence. It is commonly used in gunge/slime and fake blood recipes.