Written and photographed by Charles O. Cecil
 |
| Although some gum will naturally flow out of cracks in the tree's barkAcacia SenegalTree, commercial tappers stimulate flow by removing thin strips of bark, an operation that requires some skill if the tree is not to be injured. It is usually tapped once a year from October, the end of the rainy season in Niger. Gum harvesting begins about four weeks after stripping and may be repeated every few weeks for several months thereafter. Most trees provide rubber for about 10 years. |
Gum arabic can be almost completely dissolved in its own volume of water - a very unusual property. I added the resulting solution to the pancake syrup and in less than half a minute the sugar crystals dissolved.
Gum arabic is the hardened juice of theAcacia SenegalTree found in the arid regions stretching from Senegal on the west coast of Africa to Pakistan and India. Just as the Arabic numerals got their name because the Europeans learned about them from the Arabs who had taken them from India, so we owe the name of gum arabic not so much to its origins as to Europe's early trade contacts with the Middle East East.
According to Sudanese sources, gum arabic was used as early as the 12th century BC. an article of commerce. It was collected in Nubia and exported north to Egypt for the manufacture of inks, watercolors, and dyes. Herodotus, who lived in the fifth century B.C. wrote about its use in embalming in Egypt. In the ninth century AD, the Arab physician Abu Zayd Hunayn ibn Ishaq al-Ibadi wrote in hisTen treatises on the eye, described gum arabic as an ingredient in poultices or eye compresses.
Until the Middle Ages, gum arabic was valued by scribes and illustrators in Europe. After the gilding of letters in illuminated manuscripts, the application of paint was the last step. To do this, illustrators mixed pigments in a binder. Until the 14th century, glair was the most common medium derived from egg white. However, Glair was not only difficult to produce, but also reduced the intensity of the colors. When it was discovered that gum arabic, which was so water-soluble, could be applied thinner and the resulting colors were more transparent and intense, gum replaced gloss.
 |
| Acacia Senegalis one of more than 1100 species of acacia. Most common in the African grass savannas on the southern edge of the Sahara, it occurs east as far as Oman and India. Seedlings need protection from weeds and livestock for the first two years, but need little care after that. Trees are drought tolerant and can survive sandstorms and temperatures up to 45 degrees Celsius (113 °F), but cannot tolerate frost. When fully grown they reach a height of two to six meters (6–20'). Their lateral root system makes them soil stabilizers useful for erosion control, and researchers give their mineral-rich leaf litter high marks for remediating degraded soils. in several countries,Acacia Senegalis part of large-scale strategies for sustainable agriculture, forest management and rural economic development. |
In Turkey, illuminators used gum arabic to apply gold to manuscripts by mixing 24-karat gold leaf with melted gum arabic to create a gold paste. They applied this with fine brushes dipped in a gelatine solution. The ability to judge the correct density of the gold paste and gelatin before application was one of the hallmarks of a skilled illuminator. Too much gelatin would dull the gold, while too little could crack the gold foil.
Gum arabic was also important to Turkish scribes for making lampblack ink, which was obtained by burning linseed oil, beeswax, naphtha, or kerosene in a restricted airflow. The resulting incomplete combustion produced a fine black soot that could collect on the inside of a cone or tent made of paper or sheepskin placed over the flame. The soot - lampblack - was then mixed with gum arabic and water. The carbon particles in the ink did not dissolve but remained suspended in the water thanks to the gum's emulsifying properties. When the ink was applied to the paper, the particles stayed on the surface and presented a smooth appearance. In the event of a fault, they could simply be wiped off or scraped away. In contrast, most modern inks are solutions that are absorbed into the fibers of the paper.
 |
| In Niger, Boureima Wankoye and his brother Boubacar are leading the development of private sector production of gum arabic. With seedlings imported from Sudan, her farm provides work for around 6,000 rural families. In 2003, the United Nations Environment Program included Wankoye in its Global 500 Roll of Honor, one of eight people selected as outstanding contributors to sustainable development worldwide. |
In Africa, individual farmers now use gum arabic for other, more traditional purposes, and heaps of gum arabic can be found in most local markets. It is said to relieve a sore throat, relieve stomach and intestinal disorders, treat eye problems and fight bleeding and colds. It can be used as an emollient, astringent or cosmetic. The seed pods ofAcacia Senegal, 8–13 centimeters long (3–5") with flat seeds inside, make excellent cattle fodder. Unprotected, the trees are browsed by sheep, goats, camels, impala, and giraffes. Dried and preserved seeds are eaten by some people as Vegetables. When the trees are past their rubbery age, the wood is used both for fuel and to make charcoal. The dark heartwood is so hard that it makes excellent shuttles for weaving. Root bark fibers can be used to make rope.
The modern industrial age has seen an explosion of manufacturing applications for gum arabic. In the 19th century it was important to early photography as a component of gum bichromate prints. Today it is used in lithography, where its ability to emulsify highly uniform, thin liquid films makes it desirable as an antioxidant coating for photosensitive plates. The same quality also makes it useful in spray glazes and high-tech ceramics, and as a flocculant in the refining of certain ores. It's a binder for colored pigments in crayons, a coating for papers, and a key ingredient in the microencapsulation process that makes carbonless carbonless paper, scratchable and sniffable perfume advertisements, detergents, baking mixes, and aspirins. It is used for sizing and finishing textiles, inhibiting metal corrosion, and in adhesives and pesticides. Moisture-sensitive stamp adhesives depend on it.
 |
| Gum arabic is unique among natural gums due to its extreme water solubility and tastelessness. It has been extensively tested as a food additive and appears to be one of the safest for human consumption. In beverages, gum arabic helps citrus and other oil-based flavors stay evenly suspended in water. In confectionery, icing and artificial whipping cream, gum arabic evenly distributes flavor oils and fats, delays sugar crystallization, thickens chewing gum and jellies, and imparts a desirable mouthfeel to soft candies. In cough drops and lozenges, gum arabic soothes irritated mucous membranes. Many dry-packaged products such as instant drinks, dessert mixes, and soup bases use it to improve flavor shelf life. In cosmetics, too, it smoothes creams, fixatives and lotions. |
Gum arabic is also used in sweeteners and as an additive in foods and beverages, as a thickener in liquids including soft drinks, and in food flavorings. It is used to make pharmaceutical capsules and to coat pills, as well as to make vitamins, lotions and mascara and other cosmetics. Gum arabic is also a valuable addition to candy, adds one supplier's website, "including chocolate, jujubes and biscuits."
 |
 |
 |
| At the Wankoye company, the women who work in the warehouse are the main points of quality control, as they are at most other gum arabic sorting plants in Africa. They screen and pick the gum bags, removing sand, dirt, bark, twigs, and other unwanted debris, as well as other less desirable pieces of gum that individual collectors may mix with the gum arabic. The rubber is not damaged when stored dry and can therefore be transported over long distances. |
"New industrial applications are likely to increase demand," says Drew Davis of the US National Soft Drink Association. “The soft drink industry is constantly growing. The production of chocolate and other sweets is growing. A growing global middle class with increasing education is driving demand for printed media. Better health care increases the consumption of medicines. Hardly any industry that now uses gum arabic is in decline,” he noted.
World trade in gum arabic reached about US$90 million in 2000. About 56 percent of the volume traded came from Sudan, and much of the rest was exported from Chad and Nigeria. Sudan's historically dominant position in the modern gum arabic trade is the result of excellent soil conditions forAcacia Senegalin large parts of the country and the many years of experience many Sudanese have in collecting and sorting the chewing gum to achieve the consistent quality that high-tech manufacturers rely on. A large US importer told me that "the tree can grow in Australia, New Mexico, Benin - but the rubber isn't right."
Mussa Mohamed Karama, former executive director of the Gum Arabic Company of Sudan, points out that several million Sudanese - the country's population is 29 million - are involved in some aspects of the gum arabic trade. "The tree doesn't need any foreign components to produce," says Karama. “You don't have to fertilize it; You don't have to water it or add any chemicals. It grows naturally, and with minimal effort, the gum is collected.” Anthony Nwachukwu, president of Atlantic Gums Corporation, a Connecticut importer of gum arabic from Connecticut, adds, “Employment opportunities at the collection centers are really important for women. The gum harvest season gives them one of the few opportunities to make real money.”
So a drop of juice cured in the hot African sun is picked, sorted, packed, shipped, ground into powder and added to a product you buy to enhance its properties. Also "improved" are the farmer who owns the trees, the worker who gathered the gum, and the women who sorted it -- a chain of beneficiaries that has been around for at least two millennia, since Arab traders first introduced gum arabic to the world have introduced western world .
 | After 35 years in the United States Foreign Service,Charles O. Cecilretired to pursue photography and writing. He first became interested in gum arabic while serving as ambassador to Niger, where local businessmen are working to increase gum arabic exports. Cecil can be reached at[Email Protected]. |
This article appeared on pages 36-39 of the March/April 2005 print editionSaudi-Aramco-Welt.
See also:Chad description and travel,Chad - Trade,Chad industry,RUBBER ARABIC,NIGER-HANDEL,NIGERIA-HANDEL,SUDAN - TRADE
Search the Public Affairs Digital Image ArchiveMarch/April 2005Pictures.