xanthan gum

xanthan gum, water-soluble polysaccharide compound that is produced by the bacterium Xanthomonas campestris and is best known for its use as a food additive, typically as an emulsifier, a stabilizer, or a thickener. Xanthan gum often is used in conjunction with other thickening agents to improve the stability and texture of food, pharmaceuticals, and cosmetics.

Production

Xanthan gum is derived naturally from X. campestris, which is a plant pathogen, being responsible for diseases such as black rot in brassica crops (e.g., cauliflower and cabbage). The gum is produced when sugar, commonly from corn, wheat, or soy, is fermented by X. campestris. The gum is then processed, through pasteurization, drying, and milling, to create a fine white powder or, occasionally, granules. The final product, a kind of hydrocolloid, disperses and creates a gel when added to water.

Applications

Xanthan gum thickens without the application of heat, which distinguishes it from certain other thickening agents, such as cornstarch and gelatin. It also retains its thickening properties when cooled, and it is tasteless—features that make it especially useful for canned foods and shelf-stable foods like soups, sauces, gravies, and salad dressings. Xanthan gum commonly is used with other thickening agents, including guar gum, locust bean gum, carrageenan, gelatin, agar, and pectin. It may also be paired with starches, such as potato starch, which amplifies its thickening and gelling effects.

As an emusifier, xanthan gum affects viscosity by aiding emulsification and keeps particles from clumping and settling. It also allows pourable foods, such as salad dressings and barbecue sauces, to flow consistently from their containers. A very small percentage of xanthan gum—as little as 0.1 percent by weight of the finished product—is needed to produce thickening and emulsifying effects.

The application of xanthan gum as a gelling agent can be seen in jams and jellies. It is also common in dairy products and ice cream, where it contributes to texture, creating a smooth and creamy mouthfeel by helping to inhibit the formation of water crystals. Xanthan gum often is used as an ingredient in gluten-free food products, where it acts as an emulsifier and a binder to replicate the lift, tenderness, and elasticity of gluten in doughs. Because it attracts water, it also helps baked goods retain moisture.

Other applications of xanthan gum include use as a suspension agent in certain medications, such as antibiotics, to ensure proper dosing. It is also found in personal care products, such as makeup, lotions, and shampoos. It is slowly replacing carboxymethyl cellulose as a more affordable primary hydrocolloid in toothpaste, where it provides consistency so that the gel can be squeezed from the tube in a solid strand; it also enables the gel to cling to the toothbrush while being spread on teeth. In the petroleum industry, xanthan gum is added to mud during the hydraulic fracturing process. When added to drilling mud, because of its thickening properties, xanthan gum facilitates the movement of drill cuttings—pieces of rocks and other solid materials that are removed from boreholes when drilling wells—up to the surface for disposal. Xanthan gum is also used in some industrial products, including use as a glue in wallpaper paste and as a stabilizer in paint.

Health effects

The consumption of xanthan gum can result in minor digestive issues in some individuals. The most common digestive problems encountered include stomachache, bloating, and increased bowel movements. Individuals with severe allergies to corn, from which the bulk of xanthan gum is derived in the United States, may experience a reaction, with very trace amounts of the original sugar substance sometimes remaining in the finished product. In general, however, xanthan gum is well tolerated by most individuals.

Research has suggested that in some instances xanthan gum may have health benefits. For example, by increasing the viscosity of fluids in the stomach, it may slow the absorption of sugar in the digestive tract. By limiting the rate at which sugar enters the bloodstream, xanthan gum potentially helps moderate blood sugar levels. The laxative effect of xanthan gum may also be beneficial in some persons.

Historical development

Xanthan gum was discovered in the early 1960s by American carbohydrate chemist Allene R. Jeanes and her research team at the U.S. Department of Agriculture (USDA). Jeanes and her colleagues discovered the substance while searching for a microbial gum that could be used in food and industrial products but that—unlike other plant gums at the time—could be produced domestically. Jeanes and her team were recognized with the USDA Superior Service Award in 1968 for their discovery of xanthan gum.

Xanthan gum was first marketed under the name Kelzan, an industrial-grade version of the product. Xanthan gum was approved by the U.S. Food and Drug Administration in 1968 for use in food production and subsequently was accepted as a safe food additive in many other countries. It became widely available for both home and commercial use, with its relatively long shelf life and ease of use.