FOOD HYDROCOLLOIDS Food Hydrocolloids 23 (2009) 175–180 Characteristics and quality of gum arabic from naturally grown Acacia senegal (Linne) Willd. trees in the Central Rift Valley of Ethiopia Dagnew Yebeyen a , Mulugeta Lemenih b,Ã , Sisay Feleke c a Forest Research Centre, Ethiopian Institute of Agricultural Research, P.O. Box 30708, Addis Ababa, Ethiopia b Wondo Genet College of Forestry, P.O. Box 128, Shashamane, Ethiopia c Forest Research Centre, Ethiopian Institutes of Agricultural Research, P.O. Box 2322, Addis Ababa, Ethiopia Received 25 March 2007; accepted 20 December 2007 Abstract Drylands of Ethiopia, including those in the Rift Valley, host good potential for commercial production of natural gums such as gum arabic. However, little researches have assessed the qualities of these gums for their commercial and industrial promotions. The objectives of this study were to assess the (i) quality of gum arabic collected from naturally grown Acacia senegal trees in the Central Rift Valley of Ethiopia and (ii) evaluate these quality characteristics against reported quality attributes of the same kind of gum from known destinations such as the Sudan and with international specifications. Gum samples were collected from randomly identified 10 trees of A. senegal in the study area and composited into one big sample by putting all in one plastic bag. The characteristics analyzed included: color, odor, moisture content, ash content, viscosity, pH, specific rotation, N and tannin contents, and concentration of several metals using standard laboratory procedures. The results yielded moisture content of 15%, ash content of 3.56%, intrinsic viscosity of 1.19 ml g 1 , pH on 25% solution of 4.04, specific rotation of 32.5, nitrogen content of 0.35%, protein content of 2.31% and with no tannin content. Mineral contents of the gum arabic (g/100 g) are Ca 0.7, Mg 0.2, Na 0.01, K 0.95, Fe 0.001, P 0.6 and non-detectable traces of Pb, Co, Cu, Zn, Ni, Cd, Cr and Mn. These values agree well with values of same quality characteristics of gum arabic reported from Sudan and other exporting countries, and also conform well to international standards in all aspects. Indeed, it is possible to utilize the gum arabic resource of the Central Rift Valley of Ethiopia for commercial and/or industrial purposes. r 2008 Elsevier Ltd. All rights reserved. Keywords: Drylands; International specifications; Physico-chemical characteristics; Industrial application 1. Introduction The dryland vegetation in the Central Rift Valley of Ethiopia is under severe threat of degradation. The major driving force for their degradation is socio-economic pressures particularly population growth, which is trigger- ing unsustainable utilization of the natural resources in the form of subsistence mixed agriculture. Together with recurrent droughts, deforestation and land degradation in the drylands of Ethiopia are leading to desertification of significant scale (Hawando, 1997; Lemenih & Teketay, 2004; Mengistu, Teketay, Hulten, & Yemishaw, 2005). Consequently, there is a need for urgent measures to abate the situation. Managing the woodlands to offer alternative economic incentive, other than unsustainable harvest for fuelwood or clearance for subsistence farming, is probably a viable and lasting strategy for the problem. One of the recognized development options for the dryland areas in Africa in general is to manage them for the production of gums and incenses such as gum arabic (Lemenih & Teketay, 2004; Teketay & Lemenih, 2004). International specification identifies gum arabic as a dried exudate obtained from the stems and branches of Acacia senegal (L.) Willd. or Acacia seyal (FAO, 1999). The vast majority of gum arabic that enters international trade originates from an area described as ‘gum belt’ in Sub-Saharan Africa. This belt extends from the northern ARTICLE IN PRESS www.elsevier.com/locate/foodhyd 0268-005X/$ - see front matter r 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodhyd.2007.12.008 Ã Corresponding author. Tel.: +252 46109914/251 912066839; fax: +252 461109983. E-mail address: elerohi@yahoo.com (M. Lemenih).