Xanthan gum is a food additive commonly found in a wide array of products, from salad dressings to baked goods. It is a polysaccharide, a type of carbohydrate, used by food manufacturers to alter the texture and stability of their products. This ingredient helps improve qualities like thickness and uniformity in many of the foods consumed daily.
How Xanthan Gum Is Made
Xanthan gum is the product of a controlled fermentation process. The procedure begins with a simple sugar, which can be derived from sources like corn, soy, wheat, or whey. This sugar serves as a food source for a specific species of bacteria called Xanthomonas campestris.
The bacteria are introduced into a nutrient-rich liquid containing the sugars. Over the course of one to four days, the bacteria metabolize the sugar and, as a byproduct, produce a slimy, gel-like substance.
Once the fermentation period is complete, the resulting gel is pasteurized to stop the bacterial activity. It is then separated from the rest of the fermentation mixture, precipitated using an alcohol, and milled into a fine, off-white powder. This powder is the final form of xanthan gum that is readily soluble in water and used in food production.
The Function of Xanthan Gum in Food
In the food industry, xanthan gum serves several purposes related to modifying the texture and consistency of products. As a thickening agent, even small amounts, often less than 0.5%, can significantly increase the viscosity of a liquid. This property is valuable in items like sauces, gravies, and soups, giving them a richer and more uniform consistency.
It also acts as a stabilizer, helping to prevent ingredients that do not naturally mix, like oil and water, from separating over time. In salad dressings, for example, xanthan gum keeps the oil, vinegar, and spices evenly suspended. In frozen foods like ice cream, it helps prevent the formation of large ice crystals, contributing to a smoother texture.
An important application of xanthan gum is in gluten-free baking. Gluten, a protein found in wheat, provides elasticity and structure to traditional baked goods. In its absence, doughs and batters can be dry and crumbly. Xanthan gum mimics some of the properties of gluten, providing the necessary stickiness to hold the ingredients together and trapping air bubbles to allow the product to rise. This results in gluten-free breads and cakes with improved moisture, structure, and a softer crumb.
Safety and Consumption of Xanthan Gum
Xanthan gum is widely recognized as safe for consumption by international regulatory bodies, including the U.S. Food and Drug Administration (FDA), which approved its use as a food additive in 1969. Daily intake for the average person is less than one gram, an amount well below the levels that have been studied and proven safe.
As a type of soluble fiber, xanthan gum is not digested by the human body. It absorbs water in the digestive tract, which can soften stool. For most people, the small quantities in food cause no issues. However, consuming very large amounts, such as over 15 grams per day, may lead to digestive discomfort like bloating, gas, or diarrhea.
A consideration for some individuals is the potential for allergic reactions, although this is rare. The sugars used to create xanthan gum are often derived from corn, soy, or wheat. While the final product is highly purified, people with severe allergies to these source materials may want to exercise caution. The risk is low, but individuals with known sensitivities should be mindful of ingredient labels.