Gum arabic ( gum acacia, gum sudani, Senegal gum and by other names) () is a tree gum exuded by two species of Acacia sensu lato: Senegalia senegal,
Gum arabic is a complex mixture of and , predominantly polymers of arabinose and galactose. It is Solubility in water, edible, and used primarily in the food industry and soft drink industry as a stabilizer, with E number E414 (I414 in the US). Gum arabic is a key ingredient in traditional lithography and is used in printing, , , Cosmetics, and various industrial applications, including viscosity control in and in Textile industry, though less expensive materials compete with it for many of these roles.
Definition
Gum arabic was defined by the 31st Codex Committee for Food Additives, held at
The Hague from 19 to 23 March 1999, as the dried exudate from the trunks and branches of
Acacia senegal or
Vachellia (Acacia) seyal in the family
Fabaceae (
Leguminosae).
A 2017 safety re-evaluation by the Panel on Food Additives and Nutrient Sources of the European Food Safety Authority (EFSA) said that although the above definition holds true for most internationally traded samples, the term "gum arabic" does not indicate a particular botanical source; in a few cases, so‐called "gum arabic" may not even have been collected from
Acacia (in the broad sense) species, instead coming from e.g.
Combretum or
Albizia.
Health benefits
Gum arabic is a rich source of
, and, in addition to its widespread use in food and pharmaceutical industries as a safe
Thickening agent,
Emulsion, and stabilizer, it also possesses a broad range of health benefits that have been proven through
in vitro and
in vivo studies.
Gum arabic is not degraded in the stomach, but
Fermentation in the large intestine into a number of short chain
. It is regarded as a prebiotic that enhances the growth and proliferation of beneficial intestinal
microbiota; therefore its intake is associated with many healthful effects.
These health benefits include:
-
Improved absorption of calcium from the gastrointestinal tract
-
Anti-diabetic
-
Anti-obesity (gum arabic lowers body mass index and body fat percentage)
-
Lipid-lowering potential (gum arabic decreases total cholesterol, LDL, and triglyceride)
-
Antioxidant activities
-
Kidney and liver support
-
Immune system via modulating the release of some Inflammation
-
Improving intestinal barrier function, preventing colon cancer, and alleviating symptoms of irritable bowel diseases
-
In rats, a protective effect on the intestine against the adverse actions of the NSAID drug meloxicam
Uses
Gum arabic's
mixture of
and
gives it the properties of a
Adhesive and binder that is
edible by humans. Other substances have replaced it where
toxicity is not an issue, as the proportions of chemicals in gum arabic vary widely and make it unpredictable. It remains an important ingredient in
soft drink syrup and "hard" gummy candies such as
,
, and M&M's chocolate candies. For
, it is the traditional binder in
watercolor paint and in photography for
gum printing, and it is used as a binder in
pyrotechnic compositions. Pharmaceutical drugs and
cosmetics also use the gum as a binder,
emulsifier, and
suspending agent or
viscosity-increasing agent.
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] (1992). 084933585X, CRC Press. 084933585X
Wine makers have used gum arabic as a
wine fining agent.
It is an important ingredient in shoe polish, and can be used in making homemade incense cones. It is also used as a lickable adhesive, for example on postage stamps, envelopes, and cigarette papers. Lithographic printers employ it to keep the non-image areas of the plate receptive to water.
Food
Gum arabic is used in the food industry as a stabiliser,
Emulsion, and
thickening agent in icing, fillings, soft candy,
chewing gum, and other
confectionery,
and to bind the
and
in
.
A solution of sugar and gum arabic in water,
gomme syrup, is sometimes used in cocktails to prevent the sugar from crystallising and provide a smooth texture.
Gum arabic is a complex polysaccharide and Solubility dietary fibre that is generally recognized as safe for human consumption. An indication of harmless flatulence occurs in some people taking large doses of or more per day.
Painting and art
Gum arabic is used as a binder for watercolor painting because it dissolves easily in water.
Pigment of any color is suspended within the acacia gum in varying amounts, resulting in watercolor paint. Water acts as a vehicle or a
diluent to thin the watercolor paint and helps to transfer the paint to a surface such as
paper. When all moisture evaporates, the acacia gum typically does not bind the pigment to the paper surface, but is totally absorbed by deeper layers.
If little water is used, after evaporation, the acacia gum functions as a true binder in a paint film, increasing luminosity and helping prevent the colors from lightening. Gum arabic allows more subtle control over washes, because it facilitates the dispersion of the pigment particles. In addition, acacia gum slows evaporation of water, giving slightly longer working time.
The addition of a little gum arabic to watercolor pigment and water allows for easier lifting of pigment from paper, thus can be a useful tool when lifting out color when painting in watercolor.
Ceramics
Gum arabic has a long history as additives to
ceramic glazes. It acts as a binder, helping the glaze adhere to the clay before it is fired, thereby minimising damage by handling during the manufacture of the piece. As a secondary effect, it also acts as a
flocculation, increasing the fluidity of the glaze mixture, but also making it more likely to sediment out into a hard cake if not used for a while.
The gum is normally made up into a solution in hot water (typically 10–25 g/L; ¼ to ½ oz per pint), and then added to the glaze solution after any ball milling in concentrations from 0.02% to 3.0% of gum arabic to the dry weight of the glaze.
Photography
The historical
photography process of
gum printing uses gum arabic mixed with ammonium or potassium dichromate and
pigment to create a coloured photographic
emulsion that becomes relatively insoluble in water upon exposure to
ultraviolet. Unreacted gum remains soluble and can be washed off in warm water so that the reacted gum arabic permanently binds the pigments onto the paper in the final print.
Printmaking
Gum arabic is also used to protect and
etching an image in
lithography, both from traditional stones and aluminum plates. In lithography, gum by itself may be used to etch very light tones, such as those made with a number-five crayon.
Phosphoric acid, nitric, or tannic acid is added in varying concentrations to the acacia gum to etch the darker tones up to dark
. The etching process creates a gum adsorb layer within the matrix that attracts water, ensuring that the oil-based ink does not stick to those areas. Gum is also essential to what is sometimes called paper lithography, printing from an image created by a laser printer or photocopier.
Pyrotechnics
Gum arabic is also used as a water-soluble binder in
composition.
Composition
Arabinogalactan is a biopolymer consisting of arabinose and galactose monosaccharides. It is a major component of many plant gums, including gum arabic. 8-5' Noncyclic diferulic acid has been identified as covalently linked to carbohydrate moieties of the arabinogalactan-protein fraction.
Production
While gum arabic has been harvested in
Arabia and
West Asia since antiquity, sub-Saharan acacia gum has a long history as a prized export. The gum exported came from the band of acacia trees that once covered much of the Sahel region, the southern littoral of the
Sahara Desert that runs from the
Atlantic Ocean to the
Red Sea. Today, the main populations of gum-producing
Acacia species are found in
Mauritania,
Senegal,
Mali,
Burkina Faso,
Niger,
Nigeria,
Chad,
Cameroon,
Sudan,
Eritrea,
Somalia,
Ethiopia,
Kenya, and
Tanzania.
Acacia is tapped for gum by stripping bits off the bark, from which gum then exudes. Traditionally harvested by seminomadic desert pastoralists in the course of their
transhumance cycle, acacia gum remains a main export of several African nations, including Mauritania, Niger, Chad, and Sudan. Total world gum arabic exports were estimated in 2019 at 160,000 tonnes, having recovered from 1987 to 1989 and 2003–2005 crises caused by the destruction of trees by the
desert locust.
History
Political aspects
West Africa
In 1445, Prince Henry the Navigator set up a trading post on
Arguin Island (off the coast of modern Mauritania), which acquired acacia gum and
slaves for Portugal. With the merger of the Portuguese and Spanish crowns in 1580, the Spaniards became the dominant influence along the coast. In 1638, however, they were replaced by the Dutch, who were the first to begin exploiting the acacia gum trade. Produced by the acacia trees of
Trarza and
Brakna, this acacia gum was considered superior to that previously obtained in
Arabia. By 1678, the French had driven out the Dutch and established a permanent settlement at Saint Louis at the mouth of the Senegal River.
Gum Arabic came to play an essential role in textile printing and therefore in pre-industrial economies of France, Great Britain and other European countries. Throughout the 18th century, their competition over the commodity was so fierce, that some have referred to it as the gum wars.
For much of the 18th and 19th centuries, gum arabic was the major export from French and British trading colonies in modern Senegal and Mauritania. West Africa had become the sole supplier of world acacia gum by the 18th century, and its export at the French colony of Saint-Louis doubled in the decade of 1830 alone. A threat to bypass Saint-Louis and taxes by sending gum to the British traders at Portendick, eventually brought the Emirate of Trarza into direct conflict with the French. In the 1820s, the French launched the Franco-Trarzan War of 1825. The new emir, Muhammad al Habib, had signed an agreement with the Waalo, directly to the south of the river. In return for an end to raids in Waalo territory, the emir took the heiress of Waalo as a bride. The prospect that Trarza might inherit control of both banks of the Senegal struck at the security of French traders, and the French responded by sending a large expeditionary force that crushed Muhammad's army. The war incited the French to expand to the north of the Senegal River for the first time, heralding French direct involvement in the interior of West Africa.
Sudan
Since the 1950s, the global supply of gum arabic has been dominated by Sudan.
In the early 2020s, about 70% of the global supply has been sourced from Sudan,
with approximately 5 million Sudanese people (more than 10 percent of a country's population) being directly or indirectly dependent on gum arabic for their livelihoods.
After market reforms in 2019, official figures showed that Sudan's exports of gum arabic were at about 60,000 tonnes in 2022, but exact numbers are difficult to ascertain because some production is in regions that are hard to access.
Before the reforms, the production of gum arabic was heavily dominated by the Sudanese government and in some periods there were attempts of using its importance to the global market as a leverage against other countries.
Since the 2023 Sudan conflict, the export of gum arabic has been interrupted, causing a crash in its price in Sudan because of a reduced ability to export the product, whereas international companies that rely on it are attempting to diversify the supply chain of gum arabic and find alternative ingredients that can be used as a replacement.
Pharmacology
Gum arabic slows the rate of absorption of some drugs, including
amoxicillin, from the gut.
Symbolic value
In the works of English playwright William Shakespeare, Dutch poet
Jacob Cats and other European poets of the 13th to 17th centuries, gum arabic represented the "noble Orient". In the Sahel, it is a symbol of the purity of youth.
See also
Notes
External links
