Dr. William V. Raszka, our Associate Editor, offers the following insight into a current topic in the news:What plant is as essential to good ice cream and creamy condiments as it is to the oil industry? Stumped? The answer is guar. According to an article in The Wall Street Journal (Commodities: November 25, 2011), guar is an annual legume principally grown in India and Pakistan. While the bean can be used in animal feeds, guar is the source of a ubiquitous food emulsifier or stabilizer. The guar beans have a large endosperm that contains galactomannan gum. It is this gum that is so valuable to food producers, textile manufacturers, and the textile and cosmetic industries. Guar gum has several interesting properties. It forms a gel in water. Tiny amounts increase water viscosity and in cooking, guar gum is almost eight times more potent than cornstarch in thickening water.
Guar gum impedes ice crystal growth. In the food industry, the largest commercial consumer, guar gum is used to thicken dairy products and help prevent crystals from forming in ice cream. It is used in condiments such as salad dressing to give the fluid a uniform appearance. In baked goods, guar gum is added to dough not only to make it more pliable but increase its shelf life. The gum also prevents water from seeping out of the dough. Guar gum is commonly found in toothpaste, cosmetics, and even pharmaceutical products as a binder. Now, demand for guar has dramatically jumped. As reported in the article, the oil industry also takes advantage of the unique properties of guar gum. Guar gum is added to water, thickening it, and suspending particles of sand and beads. Huge quantities of the resultant slurry are used in hydraulic fracturing to release oil and gas from shale formations.
While only tiny amounts of guar gum are necessary in a half gallon of ice cream, each shale well uses a huge amount of guar, roughly the amount generated from hundreds of acres cultivated vines. The demand for guar has caused prices to skyrocket, so much so that many food processors have had to turn to alternative agents. Fortunately, guar is renewable and amazingly, can tolerate very arid environments. Little is produced in the U.S., only about 2% of the world’s supply, probably because there is no commodities market for it here and the crop is not insured by the U.S. government. Still, given the appetite for this legume, one would expect that more vines will be planted.
Noted by WVR, MD
*This filler excerpt can be found in the January 2012 Pediatrics print journal p.140, or via online here.
