Chemical composition of the bark extracts of Coula edulis was investigated to find potential antioxidant,anti-termite and antifungal compounds which can find useful applications in the fields of food,nutraceuticals,co...Chemical composition of the bark extracts of Coula edulis was investigated to find potential antioxidant,anti-termite and antifungal compounds which can find useful applications in the fields of food,nutraceuticals,cosmetics or agrochemical.Phytochemical screening revealed the presence of several groups of active molecules such as alkaloids,polyphenols,flavonoids,saponins and sterols and/or terpenes in the different extracts.Total phenols,condensed tannins and flavonoids contents corroborated phytochemical screening.Gas chromatographymass spectrometry(GC-MS)analysis revealed compounds in dichloromethane extract different from those obtained with all the other solvents.Hexadecanoic and trans-9-octadecenoic acids,as well as stigmasterol andβ-sitosterol have been identified as the major compounds in the dichloromethane extract.Extracts obtained with acetone and toluene/ethanol mixture(2/1,v/v)indicated the presence of few amounts of fatty acids and sugars,catechin in small amount and huge amounts of phenolic acids like gallic and ellagic acids.The radical 2,2-diphenyl-1-picrylhydrazyle(DPPH)and the cationic radical 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS+)were used for evaluation of antioxidant properties of the different extracts.The dichloromethane extracts had a very low antioxidant activity,while acetone and toluene/ethanol extracts presented EC50 values similar to those of catechin and BHT used as reference antioxidant compounds.Effect of the different extracts of the bark of C.edulis on fungal growth inhibition indicated better inhibition of the mycelium growth of brown rot fungi compared to white rot fungi.Low anti-termite activities were recorded with the aqueous extracts,while stronger activities were recorded with dichloromethane,acetone and toluene/ethanol extracts.展开更多
Coula edulis is non-timber forest product (NTFP) used in Africa for its hazelnuts, which contain edible seeds with a demonstrated nutritional potential. However, there have been very few scientific studies of this spe...Coula edulis is non-timber forest product (NTFP) used in Africa for its hazelnuts, which contain edible seeds with a demonstrated nutritional potential. However, there have been very few scientific studies of this species in the Republic of Congo. Thus, the aim of the current study was therefore to determine the fatty acid composition of the oil extracted from Coula edulis hazelnut seeds collected at random in the Republic of Congo. The oil was extracted using the Soxhlet method and its fatty acid composition was determined by gas chromatography. The extracted oil from Coula edulis hazelnut kernels is rich in monounsaturated fatty acids (95.28%), particularly oleic acid (94.5%), which classifies it as an oleic oil and gives it interesting nutritional and therapeutic properties. On the other hand, saturated fatty acids (4.15%) and polyunsaturated fatty acids (0.35%) are not well represented. Its low poly-unsaturated fatty acid content makes it more stable when stored at room temperature.展开更多
This work aims to characterize the physical,chemical,and thermal properties of hazelnut shells of the“Coula edulis”variety,originating from the south of Cameroon.The samples were divided into two zones(polar and equ...This work aims to characterize the physical,chemical,and thermal properties of hazelnut shells of the“Coula edulis”variety,originating from the south of Cameroon.The samples were divided into two zones(polar and equatorial)to study absorption and drying under four isotherms.The analyses allowed for the determination of the diffusion coefficient,the corrected diffusion coefficient,the relative humidity rate(RHR),and the activation energy using the gravimetric method.The results show that the relative humidity rate(RHR),of the polar region is higher than that of the equatorial region,while the diffusion coe-fficients and corrected diffusion gradually decrease.Among the models tested,the Page model best predicts humidity variations,while the Newton and Lewis models stand out for describing the drying phenomenon.“Coula edulis”has a dense structure with low porosity and limited water absorption,demonstrating their mechanical strength and dimensional stability.FTIR analysis highlights the presence of major lignocellulosic compounds(cellulose,hemicellulose,and lignin),while XRD reveals moderate crystallinity associated with mineral phases.ATG/DTG confirms good thermal stability up to high temperatures.These properties position the“Coula edulis”shells as a promising material for appli-cations in bio-composites,thermal and acoustic insulation,or even as sustaina-ble materials with a view to a circular economy.展开更多
文摘Chemical composition of the bark extracts of Coula edulis was investigated to find potential antioxidant,anti-termite and antifungal compounds which can find useful applications in the fields of food,nutraceuticals,cosmetics or agrochemical.Phytochemical screening revealed the presence of several groups of active molecules such as alkaloids,polyphenols,flavonoids,saponins and sterols and/or terpenes in the different extracts.Total phenols,condensed tannins and flavonoids contents corroborated phytochemical screening.Gas chromatographymass spectrometry(GC-MS)analysis revealed compounds in dichloromethane extract different from those obtained with all the other solvents.Hexadecanoic and trans-9-octadecenoic acids,as well as stigmasterol andβ-sitosterol have been identified as the major compounds in the dichloromethane extract.Extracts obtained with acetone and toluene/ethanol mixture(2/1,v/v)indicated the presence of few amounts of fatty acids and sugars,catechin in small amount and huge amounts of phenolic acids like gallic and ellagic acids.The radical 2,2-diphenyl-1-picrylhydrazyle(DPPH)and the cationic radical 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS+)were used for evaluation of antioxidant properties of the different extracts.The dichloromethane extracts had a very low antioxidant activity,while acetone and toluene/ethanol extracts presented EC50 values similar to those of catechin and BHT used as reference antioxidant compounds.Effect of the different extracts of the bark of C.edulis on fungal growth inhibition indicated better inhibition of the mycelium growth of brown rot fungi compared to white rot fungi.Low anti-termite activities were recorded with the aqueous extracts,while stronger activities were recorded with dichloromethane,acetone and toluene/ethanol extracts.
文摘Coula edulis is non-timber forest product (NTFP) used in Africa for its hazelnuts, which contain edible seeds with a demonstrated nutritional potential. However, there have been very few scientific studies of this species in the Republic of Congo. Thus, the aim of the current study was therefore to determine the fatty acid composition of the oil extracted from Coula edulis hazelnut seeds collected at random in the Republic of Congo. The oil was extracted using the Soxhlet method and its fatty acid composition was determined by gas chromatography. The extracted oil from Coula edulis hazelnut kernels is rich in monounsaturated fatty acids (95.28%), particularly oleic acid (94.5%), which classifies it as an oleic oil and gives it interesting nutritional and therapeutic properties. On the other hand, saturated fatty acids (4.15%) and polyunsaturated fatty acids (0.35%) are not well represented. Its low poly-unsaturated fatty acid content makes it more stable when stored at room temperature.
文摘This work aims to characterize the physical,chemical,and thermal properties of hazelnut shells of the“Coula edulis”variety,originating from the south of Cameroon.The samples were divided into two zones(polar and equatorial)to study absorption and drying under four isotherms.The analyses allowed for the determination of the diffusion coefficient,the corrected diffusion coefficient,the relative humidity rate(RHR),and the activation energy using the gravimetric method.The results show that the relative humidity rate(RHR),of the polar region is higher than that of the equatorial region,while the diffusion coe-fficients and corrected diffusion gradually decrease.Among the models tested,the Page model best predicts humidity variations,while the Newton and Lewis models stand out for describing the drying phenomenon.“Coula edulis”has a dense structure with low porosity and limited water absorption,demonstrating their mechanical strength and dimensional stability.FTIR analysis highlights the presence of major lignocellulosic compounds(cellulose,hemicellulose,and lignin),while XRD reveals moderate crystallinity associated with mineral phases.ATG/DTG confirms good thermal stability up to high temperatures.These properties position the“Coula edulis”shells as a promising material for appli-cations in bio-composites,thermal and acoustic insulation,or even as sustaina-ble materials with a view to a circular economy.
