Guar gum, also called guaran, is a
galactomannan
Galactomannans are polysaccharides consisting of a mannose backbone with galactose side groups, more specifically, a (1-4)-linked beta-D-mannopyranose backbone with branchpoints from their 6-positions linked to alpha-D-galactose, (i.e. 1-6-linke ...
polysaccharide extracted from
guar beans that has thickening and stabilizing properties useful in food, feed, and industrial applications. The guar seeds are mechanically dehusked, hydrated, milled and screened according to application. It is typically produced as a free-flowing, off-white powder.
Production and trade
The guar bean is principally grown in
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
,
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
, the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
,
Australia and
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
. India is the largest producer, accounting for nearly 80% of the world production. In India,
Rajasthan
Rajasthan (; lit. 'Land of Kings') is a state in northern India. It covers or 10.4 per cent of India's total geographical area. It is the largest Indian state by area and the seventh largest by population. It is on India's northwestern s ...
,
Gujarat
Gujarat (, ) is a state along the western coast of India. Its coastline of about is the longest in the country, most of which lies on the Kathiawar peninsula. Gujarat is the fifth-largest Indian state by area, covering some ; and the ninth ...
, and
Haryana
Haryana (; ) is an Indian state located in the northern part of the country. It was carved out of the former state of East Punjab on 1 Nov 1966 on a linguistic basis. It is ranked 21st in terms of area, with less than 1.4% () of India's land a ...
are the main producing regions. The US has produced 4,600 to 14,000 tonnes of guar over the last 5 years. Texas acreage since 1999 has fluctuated from about 7,000 to 50,000 acres. The world production for guar gum and its derivatives is about 1.0 million tonnes. Non-food guar gum accounts for about 40% of the total demand.
Properties
Chemical composition
![Guaran](https://upload.wikimedia.org/wikipedia/commons/f/f6/Guaran.svg)
Chemically, guar gum is an exo-
polysaccharide composed of the
sugars
galactose
Galactose (, '' galacto-'' + ''-ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecu ...
and
mannose
Mannose is a sugar monomer of the aldohexose series of carbohydrates. It is a C-2 epimer of glucose. Mannose is important in human metabolism, especially in the glycosylation of certain proteins. Several congenital disorders of glycosylation ...
. 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. Guar gum has the ability to withstand temperatures of 80 °C (176 °F) for five minutes.
Solubility and viscosity
Guar gum is more soluble than
locust bean gum
Locust bean gum (LBG, carob gum, carob bean gum, carobin, E410) is a galactomannan vegetable gum extracted from the seeds of the carob tree and used as a thickening agent (gelling agent) in food technology.
Production
Locust bean gum is extr ...
due to its extra
galactose
Galactose (, '' galacto-'' + ''-ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecu ...
branch points. Unlike locust bean gum, it is not self-gelling.
[Martin Chaplin "Water Structure and Behavior: Guar Gum". April 2012. London South Bank University] Either
borax
Borax is a salt ( ionic compound), a hydrated borate of sodium, with chemical formula often written . It is a colorless crystalline solid, that dissolves in water to make a basic solution. It is commonly available in powder or granular for ...
or
calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...
can
cross-link
In chemistry and biology a cross-link is a bond or a short sequence of bonds that links one polymer chain to another. These links may take the form of covalent bonds or ionic bonds and the polymers can be either synthetic polymers or natural ...
guar gum, causing it to
gel
A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state, although the liquid phase may still dif ...
. In water, it is
nonionic
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...
and
hydrocolloid
A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend ...
al. It is not affected by ionic strength or
pH, but will degrade at extreme pH and temperature (e.g. pH 3 at 50 °C).
It remains stable in solution over pH range 5–7. Strong
acids cause
hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.
Biological hydrolys ...
and loss of viscosity and alkalies in strong concentration also tend to reduce viscosity. It is insoluble in most hydrocarbon solvents. The viscosity attained is dependent on time, temperature, concentration, pH, rate of agitation and particle size of the powdered gum used. The lower the temperature, the lower the rate at which viscosity increases, and the lower the final viscosity. Above 80°, the final viscosity is slightly reduced. Finer guar powders swell more rapidly than larger particle size coarse powdered gum.
Guar gum shows a clear low shear plateau on the flow curve and is strongly shear-thinning. The rheology of guar gum is typical for a random coil polymer. It does not show the very high low shear plateau viscosities seen with more rigid polymer chains such as xanthan gum. It is very
thixotropic
Thixotropy is a time-dependent shear thinning property. Certain gels or fluids that are thick or viscous under static conditions will flow (become thinner, less viscous) over time when shaken, agitated, shear-stressed, or otherwise stressed ( ...
above 1% concentration, but below 0.3%, the thixotropy is slight. Guar gum shows viscosity synergy with
xanthan gum
Xanthan gum () is a polysaccharide with many industrial uses, including as a common food additive. It is an effective thickening agent, emulsifier, and stabilizer that prevents ingredients from separating. It can be produced from simple sugars ...
. Guar gum and
micellar casein
Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins ( αS1, aS2, β, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of the proteins in human ...
mixtures can be slightly thixotropic if a biphase system forms.
Thickening
One use of guar gum is a thickening agent in foods and medicines for humans and animals. Because it is gluten-free, it is used as an additive to replace wheat flour in baked goods.
:41 It has been shown to reduce serum cholesterol and lower blood glucose levels.
Guar gum is also economical because it has almost eight times the water-thickening ability of other agents (e.g.
cornstarch
Corn starch, maize starch, or cornflour (British English) is the starch derived from corn (maize) grain. The starch is obtained from the endosperm of the kernel. Corn starch is a common food ingredient, often used to thicken sauces or so ...
) and only a small quantity is needed for producing sufficient
viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
. Because less is required, costs are reduced.
In addition to guar gum's effects on viscosity, its high ability to flow, or ''deform'', gives it favorable
rheological
Rheology (; ) is the study of the flow of matter, primarily in a fluid (liquid or gas) state, but also as "soft solids" or solids under conditions in which they respond with plastic flow rather than deforming elastically in response to an appli ...
properties. It forms breakable gels when cross-linked with boron. It is used in various multi-phase formulations for hydraulic fracturing, in some as an
emulsifier because it helps prevent oil droplets from coalescing, and in others as a
stabilizer to help prevent solid particles from settling and/or separating.
Fracking entails the pumping of sand-laden fluids into an oil or natural gas reservoir at high pressure and flow rate. This cracks the reservoir rock and then props the cracks open. Water alone is too thin to be effective at carrying
proppant
A proppant is a solid material, typically sand, treated sand or man-made ceramic materials, designed to keep an hydraulic fracturing, induced hydraulic fracture open, during or following a fracturing treatment, most commonly for Unconventional (oi ...
sand, so guar gum is one of the ingredients added to thicken the slurry mixture and improve its ability to carry proppant. There are several properties which are important 1.
Thixotropic
Thixotropy is a time-dependent shear thinning property. Certain gels or fluids that are thick or viscous under static conditions will flow (become thinner, less viscous) over time when shaken, agitated, shear-stressed, or otherwise stressed ( ...
: the fluid should be thixotropic, meaning it should gel within a few hours. 2. Gelling and de-gelling: The desired viscosity changes over the course of a few hours. When the fracking slurry is mixed, it needs to be thin enough to make it easier to pump. Then as it flows down the pipe, the fluid needs to gel to support the proppant and flush it deep into the fractures. After that process, the gel has to break down so that it is possible to recover the fracking fluid but leave the proppant behind. This requires a chemical process which produces then breaks the gel cross-linking at a predictable rate. Guar+boron+proprietary chemicals can accomplish both of these goals at once.
Ice crystal growth
Guar gum retards ice crystal growth by slowing mass transfer across the solid/liquid interface. It shows good stability during freeze-thaw cycles. Thus, it is used in egg-free ice cream. Guar gum has synergistic effects with locust bean gum and
sodium alginate
Alginic acid, also called algin, is a naturally occurring, edible polysaccharide found in brown algae. It is hydrophilic and forms a viscous gum when hydrated. With metals such as sodium and calcium, its salts are known as alginates. Its colou ...
. May be synergistic with
xanthan
Xanthan gum () is a polysaccharide with many industrial uses, including as a common food additive. It is an effective thickening agent, emulsifier, and stabilizer that prevents ingredients from separating. It can be produced from simple sugar ...
: together with xanthan gum, it produces a thicker product (0.5% guar gum / 0.35% xanthan gum), which is used in applications such as soups, which do not require clear results.
Guar gum is a hydrocolloid, hence is useful for making thick pastes without forming a gel, and for keeping water bound in a sauce or emulsion. Guar gum can be used for thickening cold and hot liquids, to make hot gels, light foams and as an emulsion stabilizer. Guar gum can be used for cottage cheeses, curds, yoghurt, sauces, soups and frozen desserts. Guar gum is also a good source of fiber with 80% soluble dietary fiber on a dry weight basis.
Grading
Guar gum is analysed for
Guar gum powder standards are:
* HS-Code- 130 232 30
* CAS No.- 9000-30-0
* EEC No.- E 412
* BT No.- 1302 3290
* EINECS No. - 232-536-8
* Imco Code- Harmless
Manufacturing process
Depending upon the requirement of end product, various processing techniques are used. The commercial production of guar gum normally uses roasting, differential attrition, sieving, and polishing. 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 pre-hydrate 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.
This stage helps to reduce the load at the grinder. The soaked splits are difficult to grind. Direct grinding of those generates more heat in the grinder, which is not desired in the process, as it reduces the hydration of the product. Through the heating, grinding, and polishing process, the husk is separated from the endosperm halves and the refined guar split is obtained. Through the further grinding process, the refined guar split is then treated and converted into powder. The split manufacturing process yields husk and germ called “guar meal”, widely sold in the international market as cattle feed. It is high in protein and contains oil and albuminoids, about 50% in germ and about 25% in husks. The quality of the food-grade guar gum powder is defined from its particle size, rate of hydration, and microbial content.
Manufacturers define different grades and qualities of guar gum by the particle size, the viscosity generated with a given concentration, and the rate at which that viscosity develops. Coarse-mesh guar gums will typically, but not always, develop viscosity more slowly. They may achieve a reasonably high viscosity, but will take longer to achieve. On the other hand, they will disperse better than fine-mesh, all conditions being equal. A finer mesh, such as a
200 mesh, requires more effort to dissolve. Modified forms of guar gum are available commercially, including enzyme-modified, cationic and hydropropyl guar.
Industrial applications
*
Textile
Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...
industry –
sizing,
finishing and
printing
Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The ...
*
Paper
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distrib ...
industry – improved sheet formation, folding and denser surface for printing
*
Explosives industry – as waterproofing agent mixed with
ammonium nitrate
Ammonium nitrate is a chemical compound with the chemical formula . It is a white crystalline salt consisting of ions of ammonium and nitrate. It is highly soluble in water and hygroscopic as a solid, although it does not form hydrates. It is ...
,
nitroglycerin, etc.
*
Pharmaceutical
A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field an ...
industry – as binder or as disintegrator in tablets; main ingredient in some bulk-forming
laxative
Laxatives, purgatives, or aperients are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation.
Laxatives vary as to how they work and the side effects they may have. Certain stimulant, lubri ...
s
*
Cosmetics
Cosmetics are constituted mixtures of chemical compounds derived from either natural sources, or synthetically created ones. Cosmetics have various purposes. Those designed for personal care and skin care can be used to cleanse or protect ...
and toiletries industries – thickener in
toothpaste
Toothpaste is a paste or gel dentifrice used with a toothbrush to clean and maintain the aesthetics and health of teeth. Toothpaste is used to promote oral hygiene: it is an abrasive that aids in removing dental plaque and food from the teeth, ...
s, conditioner in
shampoo
Shampoo () is a hair care product, typically in the form of a Viscosity, viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in solid bar format. Shampoo is used by applying it to wet hair, massaging the product ...
s (usually in a chemically modified version)
*
Hydraulic fracturing – Shale oil and gas extraction industries consumes about 90% of guar gum produced from India and Pakistan.
Fracturing fluids normally consist of many additives that serve two main purposes, firstly to enhance fracture creation and proppant carrying capability and secondly to minimize formation damage. Viscosifiers, such as polymers and crosslinking agents, temperature stabilizers, pH control agents, and fluid loss control materials are among the additives that assist fracture creation. Formation damage is minimized by incorporating breakers, biocides, and surfactants. More appropriate gelling agents are linear polysaccharides, such as guar gum, cellulose, and their derivatives.
Guar gums are preferred as thickeners for enhanced oil recovery (EOR). Guar gum and its derivatives account for most of the gelled fracturing fluids. Guar is more water-soluble than other gums, and it is also a better emulsifier, because it has more galactose branch points. Guar gum shows high low-shear viscosity, but it is strongly shear-thinning. Being non-ionic, it is not affected by ionic strength or pH but will degrade at low pH at moderate temperature (pH 3 at 50 °C). Guar's derivatives demonstrate stability in high temperature and pH environments. Guar use allows for achieving exceptionally high viscosities, which improves the ability of the fracturing liquid to transport proppant. Guar hydrates fairly rapidly in cold water to give highly viscous pseudoplastic solutions of, generally, greater low-shear viscosity than other hydrocolloids. The colloidal solids present in guar make fluids more efficient by creating less filter cake. Proppant pack conductivity is maintained by utilizing a fluid that has excellent fluid loss control, such as the colloidal solids present in guar gum.
Guar has up to eight times the thickening power of starch. Derivatization of guar gum leads to subtle changes in properties, such as decreased hydrogen bonding, increased solubility in water-alcohol mixture, and improved electrolyte compatibility. These changes in properties result in increased use in different fields, like textile printing, explosives, and oil-water fracturing applications.
Crosslinking Guar
Guar molecules have a tendency to aggregate during the hydraulic fracturing process, mainly due to intermolecular hydrogen bonding. These aggregates are detrimental to oil recovery because they clog the fractures, restricting the flow of oil. Cross-linking guar polymer chains prevents aggregation by forming metal – hydroxyl complexes. The first crosslinked guar gels were developed in the late ‘60s. Several metal additives have been used for crosslinking, among them are chromium, aluminium, antimony, zirconium, and the more commonly used, boron. Boron, in the form of B(OH)4, reacts with the hydroxyl groups on the polymer in a two step process to link two polymer strands together to form bis-diol complexes.
1:1 1,2 diol complex and a 1:1 1,3 diol complex, place the negatively charged borate ion onto the polymer chain as a pendant group. Boric acid itself does not apparently complex to the polymer so that all bound boron is negatively charged. The primary form of crosslinking may be due to ionic association between the anionic borate complex and adsorbed cations on the second polymer chain . The development of cross-linked gels was a major advance in fracturing fluid technology. Viscosity is enhanced by tying together the low molecular weight strands, effectively yielding higher molecular weight strands and a rigid structure. Cross-linking agents are added to linear polysaccharide slurries to provide higher proppant transport performance, relative to linear gels.
Lower concentrations of guar gelling agents are needed when linear guar chains are cross-linked. It has been determined that reduced guar concentrations provide better and more complete breaks in a fracture. The breakdown of cross-linked guar gel after the fracturing process restores formation permeability and allows increased production flow of petroleum products .
*
Mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic ...
*
Hydroseeding
Hydroseeding (or hydraulic mulch seeding, hydro-mulching, hydraseeding) is a planting process that uses a slurry of seed and mulch. It is often used as an erosion control technique on construction sites, as an alternative to the traditional pro ...
– formation of seed-bearing "guar tack"
* Medical institutions, especially
nursing homes - used to thicken liquids and foods for patients with
dysphagia
Dysphagia is difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right.
It may be a sensation that suggests difficulty in the passage of solids or liq ...
*
Fire retardant
A fire retardant is a substance that is used to slow down or stop the spread of fire or reduce its intensity. This is commonly accomplished by chemical reactions that reduce the flammability of fuels or delay their combustion. Fire retardants m ...
industry – as a thickener in
Phos-Chek
Phos-Chek is a brand of long-term fire retardants, class A foams, and gels manufactured by Perimeter Solutions, headquartered in Clayton, Missouri.
Products Fire retardants
Phos-Chek fire retardants are manufactured as dry powders or as con ...
*
Nanoparticles industry – to produce silver or gold nanoparticles, or develop innovative medicine delivery mechanisms for drugs in pharmaceutical industry.
*
Slime (toy)
Slime was a toy product manufactured by Mattel, sold in a plastic trash can and introduced in February 1976. It consisted of a non-toxic viscous, squishy and oozy green or other color material made primarily from guar gum. Different variatio ...
, based on guar gum crosslinked with sodium tetraborate.
Food applications
The largest market for guar gum is in the
food industry. In the US, differing percentages are set for its allowable concentration in various food applications. In Europe, guar gum has
EU food additive code
E numbers ("E" stands for "Europe") are codes for substances used as food additives, including those found naturally in many foods such as vitamin C, for use within the European Union (EU) and European Free Trade Association (EFTA). Commonly f ...
E412.
Xanthan gum
Xanthan gum () is a polysaccharide with many industrial uses, including as a common food additive. It is an effective thickening agent, emulsifier, and stabilizer that prevents ingredients from separating. It can be produced from simple sugars ...
and guar gum are the most frequently used gums in gluten-free recipes and gluten-free products.
Applications include:
*In
baked goods
Baking is a method of preparing food that uses dry heat, typically in an oven, but can also be done in hot ashes, or on hot stones. The most common baked item is bread but many other types of foods can be baked. Heat is gradually transferred ...
, it increases
dough
Dough is a thick, malleable, sometimes elastic paste made from grains or from leguminous or chestnut crops. Dough is typically made by mixing flour with a small amount of water or other liquid and sometimes includes yeast or other leavenin ...
yield, gives greater resiliency, and improves texture and shelf life; in
pastry
Pastry is baked food made with a dough of flour, water and shortening (solid fats, including butter or lard) that may be savoury or sweetened. Sweetened pastries are often described as '' bakers' confectionery''. The word "pastries" sugges ...
fillings, it prevents "weeping" (
syneresis) of the water in the filling, keeping the pastry crust crisp. It is primarily used in hypoallergenic recipes that use different types of whole-grain flours. Because the consistency of these flours allows the escape of gas released by leavening, guar gum is needed to improve the thickness of these flours, allowing them to rise as a normal flour would.
*In
dairy products, it thickens
milk
Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digest solid food. Immune factors and immune-modula ...
,
yogurt
Yogurt (; , from tr, yoğurt, also spelled yoghurt, yogourt or yoghourt) is a food produced by bacterial fermentation of milk. The bacteria used to make yogurt are known as ''yogurt cultures''. Fermentation of sugars in the milk by these bac ...
,
kefir
Kefir ( ; also spelled as kephir or kefier; ; ; ) is a fermented milk drink similar to a thin yogurt or ayran that is made from kefir grains, a specific type of mesophilic symbiotic culture. The drink originated in the North Caucasus, in p ...
, and liquid
cheese products, and helps maintain
homogeneity
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the Uniformity (chemistry), uniformity of a Chemical substance, substance or organism. A material or image that is homogeneous is uniform in compos ...
and texture of
ice cream
Ice cream is a sweetened frozen food typically eaten as a snack or dessert. It may be made from milk or cream and is flavoured with a sweetener, either sugar or an alternative, and a spice, such as cocoa or vanilla, or with fruit such as ...
s and
sherbets. It is used for similar purposes in
plant milks.
*For
meat, it functions as a binder.
*In
condiment
A condiment is a preparation that is added to food, typically after cooking, to impart a specific flavor, to enhance the flavor, or to complement the dish. A table condiment or table sauce is more specifically a condiment that is served separat ...
s, it improves the stability and appearance of
salad dressings
A salad dressing is a sauce for salads. Used on virtually all '' leafy salads'', dressings may also be used in making salads of beans (such as three bean salad), noodle or pasta salads and antipasti, and forms of potato salad.
Salad dressings ...
, barbecue
sauce
In cooking, a sauce is a liquid, cream, or semi-solid food, served on or used in preparing other foods. Most sauces are not normally consumed by themselves; they add flavor, moisture, and visual appeal to a dish. ''Sauce'' is a French wor ...
s, relishes,
ketchup
Ketchup or catsup is a table condiment with a sweet and tangy flavor. The unmodified term ("ketchup") now typically refers to tomato ketchup, although early recipes used egg whites, mushrooms, oysters, grapes, mussels, or walnuts, among o ...
s and others.
*In canned soup, it is used as a thickener and stabilizer.
*It is also used in dry soups, instant oatmeal, sweet desserts, canned fish in sauce, frozen food items, and animal feed.
*The FDA has banned guar gum as a weight loss pill due to reports of the substance swelling and obstructing the intestines and esophagus.
*For Cattle Feed, as it enhances in the production of more milk as well as more percentage of fat in the milk.
Nutritional and medicinal effects
Guar gum, as a water-
soluble fiber
Dietary fiber (in British English fibre) or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition, and can be grouped generally by the ...
, acts as a bulk-forming
laxative
Laxatives, purgatives, or aperients are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation.
Laxatives vary as to how they work and the side effects they may have. Certain stimulant, lubri ...
. Several studies have found it decreases
cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...
levels. These decreases are thought to be a function of its high soluble fiber content.
Moreover, its low digestibility lends its use in recipes as a filler, which can help to provide
satiety or slow the digestion of a meal, thus lowering the
glycemic index
The glycemic (glycaemic) index (GI; ) is a number from 0 to 100 assigned to a food, with pure glucose arbitrarily given the value of 100, which represents the relative rise in the blood glucose level two hours after consuming that food. The GI of ...
of that meal. In the late 1980s, guar gum was used and heavily promoted in several weight-loss drugs. The
US Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
eventually recalled these due to reports of
esophageal blockage from insufficient fluid intake, after one brand alone caused at least 10 users to be hospitalized, and a death. For this reason, guar gum is no longer approved for use in over-the-counter weight loss drugs in the United States, although this restriction does not apply to supplements. Moreover, a
meta-analysis
A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting me ...
found guar gum supplements were not effective in reducing body weight.
Guar-based compounds, such as
hydroxypropyl guar, have been in
artificial tears
Artificial tears are lubricating eye drops used to relieve dryness and irritation of the ocular surface.
Dry eye syndrome ( keratoconjunctivitis sicca) is a common ocular surface disorder and is characterized by disruption of the tear film and i ...
to treat
dry eye
Dry or dryness most often refers to:
* Lack of rainfall, which may refer to
**Arid regions
**Drought
* Dry or dry area, relating to legal prohibition of selling, serving, or imbibing alcoholic beverages
* Dry humor, deadpan
* Dryness (medical)
* ...
.
Allergies
Some studies have found an allergic sensitivity to guar gum developed in a few individuals working in an industrial environment where airborne concentrations of the substance were present. In those affected by the inhalation of the airborne particles, common adverse reactions were occupational rhinitis and asthma.
Dioxin contamination
In July 2007, the European Commission issued a health warning to its member states after high levels of
dioxins were detected in a food additive – guar gum – used as thickener in small quantities in meat, dairy, dessert or delicatessen products. The source was traced to guar gum from India that was contaminated with
pentachlorophenol, a pesticide no longer in use. PCP contains dioxins as contamination. Dioxins damage the human immune system.
References
{{reflist
Natural gums
Edible thickening agents
Pyrotechnic chemicals
E-number additives