Gum Arabic 500g
Gum Arabic 500g
Gum arabic, is a natural gum consisting of the hardened sap of two species of the acacia tree, Acacia senegal (now known as Senegalia senegal) and Vachellia (Acacia) seyal. The term “gum arabic” does not indicate a particular botanical source. In a few cases, the so-called “gum arabic” may not even have been collected from acacia species. But may originate from Combretum, Albizia, or some other genus. The gum is harvested commercially from wild trees, mostly in Sudan (80%) and throughout the Sahel, from Senegal to Somalia. The name “gum Arabic” (al-samgh al-‘arabi) was used in the Middle East at least as early as the 9th century. Gum arabic first found its way to Europe via Arabic ports, so retained its name.
It is a complex mixture of glycoproteins and polysaccharides predominantly consisting of arabinose and galactose. It is soluble in water, edible. It is 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. It is also used in printing, paint production, glue, cosmetics, and various industrial applications. The latest include viscosity control in inks and in textile industries, though less expensive materials compete with it for many of these roles.
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. Still, it remains an important ingredient in soft drink syrup. Also in “hard” gummy candies such as gumdrops, marshmallows, and M&M’s chocolate candies. For artists, it is the traditional binder in watercolor paint. 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 it 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. This treatment also helps to stop oxidation of aluminium printing plates in the interval between processing of the plate and its use on a printing press.
Food
Gum arabic is used in the food industry as a stabilizer, emulsifier, and thickening agent in icing, fillings, soft candy, chewing gum, and other confectionery. It is also used to bind the sweeteners and flavorings in soft drinks. A solution of sugar and gum arabic in water, gomme syrup, is sometimes used in cocktails to prevent the sugar from crystallizing and provide a smooth texture.
Painting and art
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.
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.