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).

WHAT IS
GUM ARABIC?

Also known as acacia gum, kordofan, meska, char goond is a natural gum made of he hardened sap of various species of the acacia tree. Gum Arabic is harvested from two types of wild Acacia trees, one is Acacia Senegal tree and other is Acacia Seyal. This resin is obtained through special tapping’s made on the trunk of the tree. The resinous liquid which comes out of the tapping’s to heal the cuts on the bark, thickens on contact with the air, forming a hard and glassy gum. Gum Arabic is edible and has E number (E 414)

Usage

Gum Arabic’s mixture of polysaccharides and glycoproteins gives it the properties of a glue and binder that is edible by humans. Other substances have replaced it where toxicity is not an issue, as the proportions of the various chemicals in gum Arabic vary widely and make it unpredictable. Still, it remains an important ingredient in soft drink syrup and "hard" gummy candies such as gumdrops, marshmallows, and M&M's chocolate candies. For artists, 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, emulsifying agent, and a suspending or viscosity-increasing agent. 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 lockable 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. This treatment also helps to stop oxidation of aluminum printing plates in the interval between processing of the plate and its use on a printing press.

Hundreds of thousands of Sudanese people are dependent on gum arabic for their livelihoods. After market reforms, Sudan's exports of gum arabic are now (2019) at about 160,000 tonnes.

Food

Gum arabic is used in the food industry as a stabiliser, emulsifier, and thickening agent in icing, fillings, soft candy, chewing gum, and other confectionery, and to bind the sweeteners and flavourings in soft drinks. 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 soluble dietary fibre that is generally recognized as safe for human consumption. An indication of harmless flatulence occurs in some people taking large doses of 30 g (1 oz) or more per day. It is not degraded in the intestine, but fermented in the colon under the influence of microorganisms; it is a prebiotic (as distinct from a probiotic). No regulatory or scientific consensus has been reached about its caloric value; an upper limit of 2 kcal/g was set for rats, but this is not valid for humans. The US FDA initially set a value of 4 kcal/g for food labelling, but in Europe no value was assigned for soluble dietary fibre. A 1998 review concluded that "based on present scientific knowledge, only an arbitrary value can be used for regulatory purposes". In 2008, the USFDA sent a letter of no objection in response to an application to reduce the rated caloric value of gum arabic to 1.7 kcal/g.

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 deflocculant, 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.[20] On firing, the gum burns out at a low temperature, leaving no residues in the glaze. More recently, particularly in commercial manufacturing, Gum Arabic is often replaced by more refined and consistent alternatives, such as carboxymethyl cellulose.