11 research outputs found
Water as a green solvent combined with different techniques for extraction of essential oil from lavender flowers
Using water as a green solvent with a variable geometry makes use of physical and chemical phenomena that are fundamentally different from those applied in conventional extraction techniques such as hydro-distillation, steam distillation or solvent extraction. Advantages and drawbacks of using water as a solvent with different physical and chemical states have been compared. A total of ten extraction techniques: hydro-distillation (HD), steam distillation (SD), turbo-hydro-distillation (THD), salt-hydro-distillation (NaCL-HD), enzyme-hydro-distillation (Enzyme-HD), micelle-hydro-distillation (Micelle-HD), ultrasound-hydro-distillation (US-HD) or subcritical water-hydro-distillation (SW-HD), solvent-free microwave extraction (SFME) and microwave steam distillation (MSD) were used to extract the essential oil from lavender (Lavandula L.) and their results were compared. The quantity was measured by the yield of essential oil and the quality was evaluated using the oil composition especially the content of linalyl acetate, linalool and terpin-4-ol compared with the corresponding control sample: Hydro-distillation. For environmentally friendly of the process: extraction time, total energy consumption and CO2 emission were considered and compared with conventional hydro-distillation. The mechanism explaining the linalyl acetate degradation has been resolved by using COSMORS software. Based on the present experimental conditions, it is recommended that lavender oil may be produced preferably by steam distillation assisted by microwave extraction to reduce the by-product formation by various chemical reactions and to getbetter oil recoveries
Les solvants alternatifs pour l'extraction des composés volatiles : modélisation et expérimentation
The field of chemistry, in general, and extraction, in particular, has entered a new era with “green” chemistry approach using less solvent, less energy and reducing emissions, while ensuring the quality of finished products. The awareness of the environmental and health risks associated with use petroleum solvents. Make urgent the need to find alternatives solvents with good ESH (Environment, Safety and Health) profiles. In the first part of the thesis, we foccussed to be determined what are a "green" or "sustainable" solvents? The use of alternatives solvents has been possible for the extraction of odorous components from natural substances containing different types of extracts. Green method for the extraction of essential oil from aromatic herbs have been performed with water as solvent, with different physical and chemical states, but also without solvent by technical SFME. As regards obtaining concrete or resinoïd, The study of varies “green” solvents has been performed via experimentation and simulation through the use of decision support tools HSPiP (Hansen parameters solubility) and COSMO-RS (Conductor like screening model - realistic solvatation) for comprehension of dissolving mechanism. Advantages and drawbacks using alternatives solvents have been compared with conventional method in terms of yield, environmental impacts, aromatic profile and quality of extracts: essential oil, concrete, resinoïd, absolute.Le domaine de la chimie en général et de l’extraction, en particulier, sont entrés dans une démarche de chimie « verte » utilisant moins de solvants, moins d’énergie et diminuant les rejets, tout en assurant la qualité des produits finis. Une prise de conscience des risques environnementaux et sanitaires liés à l’utilisation des solvants pétroliers, a conduit à la recherche de nouveau solvants présentant un meilleur profil (HSE). Dans la première partie de cette thèse, il convient de déterminer qu’est-ce qu’un solvant « vert »? L'utilisation de solvants alternatifs a été possible pour l'extraction de composants odorants issus de substances naturelles convenant à différents types d’extraits. L’extraction d’huile essentielle à partir de plante aromatique a été possible en utilisant l’eau comme solvant, avec différents états physiques et chimiques, mais aussi sans solvant par la technique SFME. En ce qui concerne l’obtention d’une concrète, d’une résinoïde, l’étude de divers solvants verts a été réalisées selon deux approches : expérimentale et simulation grâce à l’utilisation d’outils d’aide à la décision : HSPiP (Parametres de solubilité de HANSEN) et COSMO-RS afin de comprendre les mécanismes de dissolution. Les avantages et les inconvénients utilisant les solvants alternatifs ont été comparés avec les méthodes classiques en termes de cinétique, de rendement, d’impacts environnementaux, de profil aromatique et de qualité de l’extrait : huile essentielle, concrète, résinoïde, absolue
Extraction of α-mangostin from <em>Garcinia mangostana</em> L. using alternative solvents: Computational predictive and experimental studies
International audienceThis study evaluated the performance of alternative green solvents, i.e. D-limonene, dimethylcarbonate (DMC), ethanol, ethyl acetate, ethyl lactate and methyltetrahydrofuran (MeTHF) compared to the petroleum based dichloromethane, for extraction of alpha-mangostin from Garcinia mangostana pericarps. The Hansen solubility parameters (HSPs) were used to explain the dissolution behavior of the solutes and solvents, and the conductor-like screening model for realistic solvation. The (COSMO-RS), a statistical thermodynamic approach based on the results of quantum chemical calculations for comprehending the dissolving mechanisms were used to predict the extraction prediction. On the basis of the Hansen analysis, dichloromethane was the most suitable solvent for extraction of alpha-mangostin. However, COSMO-RS analysis showed a higher solubility of alpha-mangostin in ethyl lactate, DMC, MeTHF, ethyl acetate and ethanol. Moreover, the experimental studies using a classical reflux extraction followed by a quantitative HPLC analysis of alpha-mangostin showed similar results to the predictive values from the COSMO-RS model. The alpha-mangostin levels extracted by ethyl lactate, DMC, MeTHF, ethyl acetate and ethanol were higher than those using dichloromethane and D-limonene. The results support the potential use of ethyl lactate, DMC, MeTHF, and ethanol as alternative green solvents for the preparation of alpha-mangostin extracts
Extraction by solvent using microwave and ultrasound-assisted techniques followed by HPLC analysis of Harpagoside from Harpagophytum procumbens and comparison with conventional solvent extraction methods
This research paper presents a quick and ecofriendly technique for the extraction of harpagoside (HS), the active marker of Harpagophytum procumbens (HP), along with a comparison with conventional methods so as to propose an efficient HPLC method. HP is widely used as an anti-inflammatory in phytotherapy. The quality control of the herbal drug and extract calls for a time consuming method of conventional extraction, which involves a high
consumption of solvents. In this study, HP has been extracted using conventional ultrasound (UAE) and microwave (MAE)-assisted methods. The effects have been examined based on several parameters of HS extraction efficiencies. An HPLC method with a core-shell column was developed in order to calculate the HS in HP. The flowratewas reduced by 4. The method of validation used is specific, linear, precise and accurate. MAE and UAE saved solvent consumption, time and energy. It has, therefore, been found that the combined UAE-HPLC process is convenient and appropriate for the quality control of HP
Extraction of aroma compounds in blackcurrant buds by alternative solvents: Theoretical and experimental solubility study
International audienceThis study was designed to evaluate the performance of nine alternative solvents (α-pinene, MeTHF, ethyl acetate, methyl acetate, ethyl lactate, butanol, isopropanol, ethanol and CO2 supercritical fluid) for extracting aromas from blackcurrant buds (Ribes nigrum L) compared to that of n-hexane, commonly used. This study has been performed via experimentation and simulation using Hansen solubility methodology for the comprehension of the dissolving mechanism. Experimentally, the extracts were analysed to compare the solvents performance in terms of aroma compositions. The results indicated that an alternative solvent, i.e. MeTHF, could be the most promising one for n-hexane substitution with good yield and selectivity of aromas