Guar (derived from word guaran) is extracted from the seed of the Guar plant which is a leguminous shrub Cyamopsis tetragonoloba. Guar bean Gum is known for its water retention properties. It is an annual leguminous plant harvested at the end of year in semi-arid regions of India and Pakistan. Guar fruit is a pod; its beans have an average radius of approximately 2-3 mm. Guar seed comprise of hull, the albumen or endosperm, which is light cream in colour. Seed is made up of two hemispherical segments (splits) which surround the germ. Its major constituent is the polysaccharides and protein rich germ.
Gum of guar is an amazingly versatile and efficient high polymer hydrophilic hydrocolloid, economical in use and easy to handle. Its ability to form highly viscous colloidal dispersions at low concentrations, without heating, makes it one of the most interesting of the hydrocolloids. It is few of naturally available water-soluble gums, chemically classified as a galactomannan and possessing a molecular weight reported to be of order 200,000- 250,000. It is non-toxic and non-ionic, could be used with other synthetic and natural hydrocolloids. One of the most powerful water binder and viscosity enhancer, superior to practically all known water soluble gums.Chemical Structure:
Guar gum is a galactomannan similar to locust bean gum consisting of a (1-->4)-linked b-D-mannopyranose backbone with branch points from their 6-positions linked to a-D-galactose (i.e. 1-->6-linked-a-D-galactopyranose). There are between 1.5 - 2 mannose residues for every galactose. Higher Degree of substitution(D.S.) and Molar Substitution of guar gum gives by carboxyalkyl and hydroxyalkyl groups respectively gives improved solubility, dispersion and emulsification, this is the main reason for popularity of its derivatives in various Industries.Properties:
Guar Gum powder increase the viscosity of the aqueuos base even at small concentration of approximately 1%. Guar based gels are Non-Newtonian i.e. their viscosity changes with the change in temperature. It has a Galactose to Mannose ratio of 1:2.. Solubility rates of Guar Gum powder could be increased by choosing an appropriate manufacturing process, thus achieving the Quick/Fast Hydrating Guar grades. It is insoluble in organic solvents and soluble in water(hold and cold). Being non-Ionic Guar is not effected by pH, but it is sensitive to high acidic media.The viscosity of guar in water depends on temperature, concentration, pH, shear rate. Guar shows shear-thinning effect i.e. at high temperature it's solutions are less viscous but viscosity is regained when temperature is lowered.Food grade: (E412 Food Additive)
1. Baking : mixed with dough to increase the yield, give greater resiliency, improve texture and longer shelf life.
2. Dairy : an excellent binder for hard cheeses and provides firmness and stability to soft cheeses like brie etc.
3. Meat : binder for various meat products. Organic guar is used as a substitute to gluten and gelatin in Meat.
4. Dressing and sauces : as a thickener to improve the stability appearance of salad dressings, barbecue sauces, relishes, ketchup and others. It is compatible with acidic emulsions.
5. Beverages :stabilizer for chocolate drinks, fruit nectar, and juices. 6. Jams/jelly : holds the structure of Jams and jelly
7. Guar gum powder is used in various Dry soups, sweet dessert, canned fish in sauce, frozen food.
8. Noodles : enhances the texture and make noodles firmer. It checks the crystal formation in frozen noodles and the fat uptake in fried noodles.
9. Pharmaceutical : used as a binder for tablets. Researchers have found significant decrease in cholesterol levels after administration of Guar Gum in human consumption.Industrial grade:
• Textile printing : used as thickening agent for textile sizing, finishing and printing.
• Mining : Froth flotation/coagulation agent and depressant in Ore processing. Biopolymer based depressants are less hazardous and eco-freindly as compared to their Inorganic counterparts. Guar gum is used as gangue-mineral dipressant. Only a little amount is needed to depress talc, calicte etc. In Copper-Lead separations , Guar gum is utilised as lead depressant.
• Water treatment: as Flocculation agent for solid-Liquid separation in Water treatment/Recycling.
• Petroleum Industry : Used in Drilling muds and Fracturing Fluids .
• Tobacco Industry : Tobacco sheet binder.
• Explosives : as a thickener in slurry based explosives.
• Cosmetics/Personal Care: used as surfactant and emulsion stabiliser.
• Soil Erosion : Erosion Control, Landscaping.