Extraction, identification et mise en évidence des propriétés des huiles de graines des espèces d’Acacia (A. arabica et A. raddiana) des zones arides algériennes

Abstract

Both native Ahaggar forest species "Acacia arabica and Acacia raddiana" (W. Tamanrasset) multiple interests are overexploited in Algeria by rural populations with the exception of some traditional uses of seeds and pods. They are a resource containing several active organic compounds such as tannins and oleoresins that require given their state of degradation a particular incentive for their development and preservation. The main objective of this study is to assess the potential phytochemicals by GC and HPLC oils from seeds of both species, as well as highlighting their antioxidant power test DPPH ° (2,2-diphénylpycrylhydrazyl) and their biological activities by the techniques of diffusion in the liquid and solid (method disc and well) environment. The results obtained show that the yields extracted from the seeds by petroleum oils are 12% for A. arabica and 9% for A. raddiana with physicochemical parameters corresponding to the standards of vegetable oils. GC showed that these oils are rich in unsaturated fatty acids Omega 6 and Omega 9 (74.58; 79.58%) with a predominance of linoleic acid (C18: 2). In addition, HPLC showed that these oils have high levels of tocopherols (Vitamin E) ranging respectively 71.47 ± 1.32 and 86.49 ± 0.34 mg/100 g oil of A. arabica and A. raddiana. The chemical composition of oils exerted a strong antioxidant activity at low concentrations (EC50: 564 and 264 mg AO / g DPPH), which have reduced 50% of the free radical DPPH ° an DPPHH with average reaction time (23 and 27mn). The biological tests also showed strong antimicrobial activity overlooked fungal strains Aspergillus Niger and Candida albicans. So this activity was observed for bacterial strains of Gram- E. coli and Gram + S. aureus except two bacillus used (B. cereus and B. subtilis). The different minimum inhibitory concentrations were recorded in the range 0.077 ≤ MIC ≤ 0.158mg/ml. From these results it appears that the phytochemical properties of the oils and their antioxidant and antimicrobial potency may be interesting research opportunities for rational exploitation.