Standardization of commiphora abyssinica engl. Gum resin from kajiado, Kenya

Abstract

Information on the physical and chemical characteristics of Commiphora abyssinica gum resin is scanty. The aim of this work was to establish the composition and physicochemical properties of above mentioned gum resin and on that basis propose its standard specifications for commercial use. Samples from three sites in Kajiado in Kenya were characterized in terms of parameters commonly used in the evaluation of the quality of crude oleogumresins and their products. There was no substantial variability with collection location observed on most physical properties including pH, density, refractive index, viscosity and optical rotation. Composition parameters such as moisture, ash, nitrogen, metals, extraneous impurities, essential oils, ethanol and water soluble matter varied from location to location. The ethanol-soluble matter which is crucial in the formulation of traditional gum resin products varied significantly and ranged between 26.37 and 47.79%. The gum-resin was found to have 1.31 to 1.87% essential oils and the yield of water soluble matter was high at 82.25-84.50%. In general, the gum resin had relatively low content of extraneous impurities (2.27-3.17%) and ash (2.24-3.04%) in comparison with gum resins from related Commiphora species. Saponification value, acid value as well as free fatty acids also varied with location. Values of parameters obtained in this study were found suitable for proposing standard specifications of local Commiphora abyssinica gum resin from the location. From the results, standard specifications that can be used in commerce for identification and quality specification of Commiphora abyssinica gum resin sourced in Kenya were suggested. Magnesium could be used to identify the gum resin from the area due to its very low variability. It was also recommended that freshly harvested material be stored for a few months before processing.