Structural Analysis of Gum from Acacia senegal (Gum Arabic)

Abstract

Gum arabic is an exudate obtained principally from the Acacia senegal tree, which grows widely across the Sahelian belt of Africa. The major producing country is Sudan, followed by Nigeria and Chad (Islam et al 1997). The gum oozes from the stems and branches of the tree when it is subjected to stress conditions such as drought and wounding. To stimulate production, sections of the bark are removed at particular periods during the year. This process is known as tapping. The gum is produced in the tree within a zone between the inner bark and the cambial zone (Joseleau and Ullmann 1990). The trees must be 5 years of age or more for gum production to occur, suggesting, therefore, that gummosis is in direct competition with tree growth. The sticky gummy substance dries on the branches to form hard nodules, which are picked from the tree by hand and are sorted according to color and size. The gum is used to stabilize flavor oils for soft drinks, as an encapsulator for spray dried flavors for use in dried food mixes, and in the production of certain confectionery, notably fruit gums and pastilles.