Biophysical and chemical investigations of frankincense of Boswellia papyrifera from North and Northwestern Ethiopia

This study was conducted to contribute to filling the existing knowledge gap on biophysical and chemical properties of frankincense towards revising the national grades being used in the export market. A biophysical and chemical study on resins (frankincense, also known as gum olibanum) of Boswellia species from five regions (Amhara, Benshangol, Oromia, Somali, and Tigray) with special emphasis on the Boswellia papyrifera (Tigray type frankincense) has been conducted using GC-MS, TLC, Pyrolysis methods and odor tests. 111 samples were subjected to different analytical treatments most of which were biophysical and some chemical investigations. GCMS analysis, odor tests by women of three cities (Harar, Nazareth and Addis Ababa), TLC runs and observations of Pyrolysis experiment at 400, below 1000 and over 1200oC were used to see if age of tree, origin (Provenance) and frequency of tapping have had any influence on the quality of frankincense, a major export product of Ethiopia. The data obtained, helped to see origin, age of tree and color of product to have influences on quality of frankincense. Headspace GC-MS analysis of frankincense of B. papyrifera at different collection sites and ages of the trees indicated the presence of n-octylacetate as a major component at varying relative percentage composition. The harvests resins of Boswellia species from Borena and Ogaden, while exhibiting same even better quality frankincense for purpose of similar use, were not processed for international market. This paper also presented the findings of the investigations in such a way that further biophysical and chemical works remain to be performed so as to see conclusively how the three resin types (Tigray, Borena and Ogaden) are similar and/or different for thepurpose (international trade) sought.