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, off-white powder. Chemically, guar gum is a polysaccharide composed of the sugars galactose and mannose. Guar gum is more soluble than locust bean gum and is a better emulsifier as it has more galactose branch points. In water it is nonionic and hydrocolloidal. It is not affected by ionic strength or pH, but will degrade at pH extremes at temperature (e.g. pH 3 at 50°C). It remains stable in solution over pH range 5-7. It is insoluble in most hydrocarbon solvents.

Preparation of Guar gum: Food-grade guar gum is manufactured in stages. Guar split selection is important in this process. The split is screened to clean it and then soaked to prehydrate it in a double-cone mixer. The prehydrating stage is very important because it determines the rate of hydration of the final product. The soaked splits, which have reasonably high moisture content, are passed through a flaker. The flaked guar split is ground and then dried. The powder is screened through rotary screens to deliver the required particle size. Oversize particles are either recycled to main ultra fine or reground in a separate regrind plant, according to the viscosity requirement.

Uses of Guar gum: Guar gum is used for sizing, finishing and printing; It improved sheet formation, folding and denser surface for printing; used as waterproofing agent mixed with ammonium nitrate, nitroglycerin etc. and as binder or as disintegrator in tablets.The largest market for guar gum is in the food industry. Applications include: Baked goods- increases dough yield, gives greater resiliency, and improves texture and shelf life; in pastry fillings, it prevents "weeping" (syneresis) of the water in the filling, keeping the pastry crust crisp; Dairy - thickens milk, yogurt, kefir, and liquid cheese products; helps maintain homogeneity and texture of ice creams and sherbets; Meat - functions as lubricant and binder; Dressing and sauces - improves the stability and appearance of salad dressings, barbecue sauces, relishes, ketchups and others.

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