ABSTRACT
Senegal gum arabic is by far the primary source of gum arabic. It is a spiny, deciduous shrub or tree up to 20 m (66 ft.) tall, with a §at to rounded crown. The bark is typically yellow-brown and smooth on younger trees, changing to dark gray, gnarled and cracked on older trees. The branchlets have thorns. The leaves are made up of numerous small lea§ets in 7 to 25 pairs along the leaf midrib. The §owers are white to yellowish, in spikes 5 to 12 cm (2-4¾ in.) long. The seeds pods are 7.5 to 18 cm (3-7 in.) long and 1 to 3.4 cm (0.4-1.3 in.) wide, light brown or gray, papery or woody, with ve to six (rarely as many as 15) greenish-brown seeds. Senegal gum is widespread in tropical Africa
from Mozambique and Zambia to Somalia, Sudan, Ethiopia, Kenya, and Tanzania. It is cultivated in Nigeria, India, Pakistan, Australia, and South America. The main producing and exporting countries in the “gum belt” include Cameroon, Chad, Mali, Nigeria, and Sudan. Sudan dominates the world gum trade with a market share of approximately 60%. In Sudan, usually around mid-October, gum arabic specialists make cuts in the bark of the trees, and gum subsequently exudes where the bark has been cut. Six weeks later, the rst gum collection is made, and up to three further collections are carried out at 3-week intervals. Substitutes such as modied starches, other gums, and sugars made from microorganisms threaten the market for gum arabic.
