Chemical characterization of sapwood and heartwood of Fraxinus angustifolia growing in Algeria

Abstract

The result of this study is the chemical characterization of sapwood (SW) and heartwood (HW) of Fraxinus angustifolia native to Algeria. Lipophilic and hydrophilic extractives were isolated by means of an accelerated solvent extractor (ASE) using hexane and the acetone/water mixture respectively. The acid hydrolysis and methanolysis methods were used to determine cellulose and hemicelluloses contents. The Tappi Standards T 222 and UM 250 allowed Klason and acid-soluble lignin quantification respectively. Alkaline hydrolysis of wood samples followed by HPLC analysis was performed to determine the acetyl groups. The method detailed in TAPPI T 211 (2002) for determining the ash content was used. It was found that the SW and HW of Fraxinus A. had almost similar amounts of the main components, averaging 40.00 wt% cellulose, 28.00 wt% hemicelluloses within 18.00 wt% of xylan, 22.00 wt% lignin, 3% extractives and 0.83 wt% ash. However, the HW contained more triglycerides (0.08 wt%) than the SW (0.02 wt%). On the other hand, mannitol was the most predominant hydrophilic extractive in SW (1.60 wt%) than in HW (1.02 wt%). These findings are useful for practitioners in the paper, biofuel, cosmetics, food, pharmaceutical and chemical industries for the assessment of Fraxinus A. wood chemical treatment parameters.