Guar gum, also called guaran, is a galactomannan. It is primarily the ground endosperm of guar beans. The guar seeds are dehusked, milled and screened to obtain the guar gum. It is typically produced as a free-flowing, pale, off-white colored, coarse to fine ground powder.
Guar gum is extracted from the guar bean, where it acts as a food and water store. The guar bean is principally grown in India and Pakistan, with smaller crops grown in the U.S., Australia, China, and Africa. The drought-resistant guar bean can be eaten as a green bean, fed to cattle, or used in green manure.
According to a Reuters report, India accounts for about 80 percent of the global trade in guar products. India exported 11 billion rupees worth of guar products in 2007/08 financial year ending March 2008. Pakistan trails India in the global trade. Industrial guar gum is the most sought after guar product, and accounts for about 45 percent of the total demand. Industrial gum is used as a controlling agent in oil wells to facilitate easy drilling and prevent fluid loss.
In 2007, the Indian industry was hit by a contamination crisis when the European Union suspended imports of Indian guar gum after excessive levels of dioxins were found in one shipment.
Chemically, guar gum is a polysaccharide composed of the sugars galactose and mannose. The backbone is a linear chain of β 1,4-linked mannose residues to which galactose residues are 1,6-linked at every second mannose, forming short side-branches.
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