Guar

The guar (from : gvār) or cluster bean, with the botanical name Cyamopsis tetragonoloba, is an annual legume and the source of guar gum. It is also known as gavar, gawar, or guvar bean.

The genus name Cyamopsis means bean-like (from : "bean" + : "view"). The specific name is from and (itself being a loanword of Ancient Greek λοβός) meaning four-squared-lobed.

The origin of Cyamopsis tetragonoloba is unknown, since it has never been found in the wild. It is assumed to have developed from the African species Cyamopsis senegalensis. It was further domesticated in South Asia, where it has been cultivated for centuries.

Guar is drought-tolerant and grows well in semiarid areas.

This legume is a valuable plant in a crop rotation cycle, as it lives in symbiosis with nitrogen-fixing bacteria.

Agriculturists in semi-arid regions of Rajasthan follow crop-rotation and use guar to replenish the soil with essential fertilizers and nitrogen fixation, before the next crop. Guar has many functions for human and animal nutrition, but the gelling agent in its seeds (guar gum) is the most important use.

The seeds of guar beans have a remarkable characteristic. Its kernel consists of a protein-rich germ (43–46%) and a relatively large endosperm (34–40%), containing large amounts of the galactomannan. Thus, it exhibits a great hydrogen bonding activity Frequent drought periods can lead to delayed maturation. Australia and Africa. The most important growing area centers on Jodhpur in Rajasthan, India, where demand for guar for fractionation produced an agricultural boom as in 2012. Currently [When? As of 2023?], India is the main producer of cluster bean, accounting for 80% production of the world's total, while the Rajasthan, Gujarat and Kutch regions occupy the largest areas (82.1% of total) dedicated to guar cultivation. In addition to its cultivation in India, the crop is also grown as a cash crop in other parts of the world. Several commercial growers have converted their crops to guar production to support the increasing demand for guar and other organic crops in the United States. Guar can be an economically viable crop even in the ongoing drought conditions of the southwest United States.

Varieties

Pusa Naubahar and Pusa Sadabahar. Seeds at the rate of 30 kilograms/hectare (9–11 lb/acre) are planted at a spacing of 45–60 × 20–30 cm (18–24 × 8–12 in) in February–March and June–July. During the rainy season, seeds are sown 2–3 cm (~1 in) deep on ridges and in furrows during summer months. FYM is applied at the rate of 25 tonnes/ha (11.1 tons/acre). N, P2O5 and K2O recommendation for the crop is 20:60:80 kg/ha (18:53:71 lb/acre). Average yield is 5 to 6 tonnes/ha (2.2–2.6 tons/acre). Meager information is available for genetic variability in cluster bean addressing the qualitative traits (Pathak et al. 2011).

Uses

Guar plant

Agriculture

Forage: Guar plants can be used as cattle feed, but due to hydrocyanic acid in its beans, only mature beans can be used.

| Cheese || Texture improver

| Ice Cream || Smaller ice crystals

| Fried Products|| Oil uptake reduction

Partially hydrolyzed guar gum (PHGG) is produced by the partial enzymatic hydrolysis of guaran, the galactomannan of the endosperm of guar seeds (guar gum). It is a neutral polysaccharide consisting of a mannose backbone chain with single galactose side units occurring on almost two out of every three mannose units. The average molecular weight is about 25,000 daltons. This gives a PHGG that still assays and functions as a soluble dietary fiber.

PHGG as sold commercially is completely soluble, acid and heat stable, unaffected by ions, and will not gel at high concentrations. Commercial PHGG is approximately 75% dietary fiber and has minimal effect on taste and texture in food and beverage items. PHGG is fully fermentable in the large bowel, with a high rate of volatile fatty acid formation. The pH of the feces is lowered along with an increase in fecal bulk that mainly consists of bacterial cell mass and water. Clinical studies have demonstrated a prebiotic effect of PHGG. Studies have shown that PHGG can be used to maintain regularity. PHGG is used in foods for particulate suspension, emulsification, antistaling, ice crystal control, and reduced fat baked goods.

thumb|250px|Gawar phali with aaloo (guar bean with potatoes) (India)

alt=Guar Chibhad ji bhaaji is a popular Thari dish|thumb|333x333px|Guar chibhad ji [[Curry|bhaaji is a popular Thari dish]]

Industry

Derivatives of guar gum that have been further reacted are used in industrial applications, such as the paper and textile industries, ore flotation, the manufacture of explosives and hydraulic fracturing (fracking) of oil and gas formations. Guar gum is often crosslinked with boron or chromium ions to make it more stable and heat-resistant. The crosslinking of guar with metal ions results in a gel that does not block the formation and helps efficiently in formation cleaning process. Guar and its derivatives make gel complexes with ions of aluminium, zirconium, titanium, chromium and boron. The borate–guar reaction is reversible, and depends on the pH (hydrogen ion concentration) of the solution. This reaction is used to give the toy "slime" its consistency. Crosslinking of guar with borate occurs at high pH (approximately 9–10) of the solution. Guar gum has proven as useful substitute for locust bean gum (made from carob seeds).

Feeds

Guar meal korma and guar meal churi are widely used as raw material for producing various kinds of cattle feeds, aqua feeds, fish feeds, poultry feeds, dairy feeds, swine feeds, etc.

Fracking agent

The use of guar gum in the hydraulic fracturing (fracking) extraction of oil and shale gas has increased demand substantially. Only 10% of Indian production is used domestically. The remaining 90% is exported for shale gas and oil industries. Consequently, many former cotton or wheat fields are converted into guar fields as production costs are lower. The increase of guar gum prices also has other reasons.