Xanthan Gum vs Guar Gum: Consider the Differences
by Marion Desborough
Xanthan gum derives its name from the strain of bacteria used during the fermentation process xanthomonas campestris. This is the same bacteria responsible for causing black rot to form on broccoli, cauliflower, and other leafy vegetables. The United States Department of Agriculture ran a number of experiments involving bacteria and various sugars to develop a new thickening agent similar to corn starch or guar gum that would act as a “natural” stabilizer and be cheap to make. When xanthomonas campestris was combined with corn sugar, the result was a colourless slime they called xanthan gum.
Xanthan gum is considered a polysaccharide in scientific circles because it is a long chain of three different forms of sugar. What’s important to know is that all three of these natural sugars are present in corn sugar, a derivative of the more familiar corn syrup. The xanthomonas campestris bacteria literally eat a supply of this corn sugar under controlled conditions, and the digestion process converts the individual sugars into a single substance with properties similar to corn starch. Xanthan gum is used as a thickening agent and stabilizer in many dairy products and salad dressings. It also prevents ice crystals from forming in ice creams and also provides a “fat-feel” in low or no-fat dairy products.
In most foods, xanthan gum is used at 0.5% or less. The viscosity of xanthan gum solutions decreases with higher shear rates, this is called pseudoplasticity. This means that a product subjected to shear, whether from mixing, shaking, or even chewing, will thin it out. Once the shear force is removed, the food will thicken back up, which is excellent for making salad dressing. Thick enough in the bottle to keep the mixture fairly homogeneous, but the shear forces generated by shaking and pouring, thins it, so it can be pour easily. When it exits the bottle, the shear forces are removed and it thickens back up, so it clings to the salad. Unlike other gums, it is very stable under a wide range of temperatures and pH measures.
Another use for xanthan gum is in the stabilization and binding of cosmetic products. Here a little bit goes an incredibly long way and helps to keep the individual ingredients from separating. It is often used whenever a gel–like quality is sought and is used as a substitute for wheat gluten in gluten-free breads, pastas, and other flour-based food products. Despite the use of bacteria during processing, xanthan gum itself is said to not be generally harmful to human skin or digestive systems, although some individuals claim they are allergic to it. If you suffer from allergies you could test it for compatibility by cooking with it or avoiding eating products with it in for a week or two and see how you feel. Health food stores often carry a wide range of thickeners including corn starch, tapioca, xanthan and/or guar gum and digestibility is different for everyone.
According to a study that fed 15 grams a day for ten days to 18 volunteers, xanthan gum is considered a highly efficient laxative. Some people reacted with symptoms of intestinal gripe and diarrhea. There were no further studies investigating this.
One lesser-known use of xanthan gum is in the oil industry, which uses water as a lubricant for the oil-well pumps. The thickened water keeps the drill parts lubricated.
Guar gum is extracted from the guar bean, also called guaran or galactomannan. The guar seeds are dehusked, milled, and screened to obtain the guar gum. It is primarily the ground endosperm of guar beans. It is typically produced as a free flowing, off-white, finely ground powder. The guar bean is principally grown in India and Pakistan, with smaller crops grown in the US, Australia, China, and Africa. The drought-resistant guar bean, which can be eaten as a green bean, is often fed to cattle or used as a green manure in gardens.
Guar gum is a water-soluble fibre that acts as a bulk-forming laxative and, as such, it is claimed to be effective in promoting regular bowel movements and relieving constipation and chronic related functional bowel ailments such as diverticulosis, Crohn’s Disease, colitis, and irritable bowel syndrome, among others. In addition, because it is soluble, it is also able to absorb toxic substances like bacteria that cause diarrhea.
Several studies have found significant decreases in human serum cholesterol levels following guar gum ingestion. These decreases are thought to be a function of its high soluble fibre content. Guar gum has been of interest with regard to both weight loss and diabetic diets. It is a thermogenic substance. Moreover, its low digestibility lends its use in recipes as a filler, which can help to provide satiety, or slow the digestion of a meal, thus lowering the glycemic index of that meal. In the late 1980s, guar gum was heavily promoted in several weight loss products. The US Food and Drug Administration eventually recalled these products due to reports of esophageal blockage from insufficient fluid intake.
Guar gum is economical because it has almost eight times the water-thickening potency of cornstarch and only a small quantity is needed to produce viscosity. Thus, it can be used as an emulsifier because it helps to prevent oil droplets from coalescing, and/or as a stabilizer because it helps to prevent solid particles from settling. Guar gum retards ice crystal growth non-specifically by slowing mass transfer across the solid/liquid interface. It shows good stability during freeze-thaw cycles.
In baked goods it increases dough yield, gives greater resiliency, and improves texture and shelf life. In pastry fillings it prevents weeping of the filling and keeps the pastry crust crisp. It is often used to thicken milk, yogurt, kefir, ice cream, sherbet, and liquid cheese products as it maintains homogeneity. It also improves the stability and appearance of salad dressings, barbecue sauces, relishes, and ketchup. It can be found in dry soups, instant oatmeal, sweet desserts, canned fish in sauce, frozen food items, and animal feed.
Guar gum is used in many industrial applications including the textile and paper industry. In explosives, it is the waterproofing agent mixed with ammonium nitrate, nitroglycerin. In oil wells, it facilitates easy drilling and prevents fluid loss. The pharmaceutical, cosmetic, and toiletries industries also use a chemically-modified version of guar gum.
Sources: www.wikipedia.com and www.wisegeek.com. Look up guar gum or xanthan gum—both sites have lots of info.
Marion Desborough lives in Okangan Falls, BC, and along with many other wonderful things she does to better humanity, she writes articles on natural health topics for Issues Magazine, which is published by Angele Oretga in Kaslo, BC. This article was published in the April, May & June 2010 Issues Magazine (www.issuesmagazine.net) and is being reprinted in WHOLifE Journal with permission of the publisher and author.