Chahrazed Boutekedjiret

Improved microwave steam distillation apparatus for isolation of essential oils Comparison with conventional steam distillation

Steam distillation (SD) is routinely used by analysts for the isolation of essential oils from herbs, flowers and spices prior to gas chromatographic analysis. In this work, a new process design and operation for an improved microwave steam distillation (MSD) of essential oils from aromatic natural products was developed. To demonstrate its feasibility, MSD was compared with the conventional technique, SD, for the analysis of volatile compounds from dry lavender flowers (Lavandula angustifolia Mill., Lamiaceae). Essential oils isolated by MSD were quantitatively (yield) and qualitatively (aromatic profile) similar to those obtained by SD, but MSD was better than SD in terms of rapidity (6 min versus 30 min for lavender flowers), thereby allowing substantial savings of costs in terms of time and energy. Lavender flowers treated by MSD and SD were observed by scanning electron microscopy. Micrographs provide evidence of more rapid opening of essential oil glands treated by MSD, in contrast to conventional SD.

The Essential Oil from Rosmarinus officinalis L. in Algeria

Abstract The essential oil of Rosmarinus officinalis L. from Algeria was analyzed by GC and GC/MS. More than 90% of the components were identified with 1,8-cineole (52.4%) and camphor (12.6%) being the major components.

Study of Rosmarinus officinalis L. Essential Oil Yield and Composition as a Function of the Plant Life Cycle

Abstract The yield and composition variation of the Algerian Rosmarinus officinalis as a function of plant life cycle was studied. Best period to collect the plant was found to be at full flowering stage. However, to obtain required oil quality, a compromise between oil yield and composition must be considered.

Isolation of Rosemary Oils by Different Processes

Abstract Rosemary oil may be isolated by three different processes, including steam distillation, water distillation and controlled instantaneous decompression. The concrete resulting from extraction by volatile organic solvents was also made using hexane, dichloromethane and ethanol. The oils and extracts obtained were analyzed by gas chromatography (GC) and gas chromatography coupled to mass spectroscopy (GC/MS) in order to determine their chemical composition. A scanning electron microscope was used to observe the impact of different processes on the structure of leaves and essential oil bearing trichomes.

Chemical Composition and Insecticidal Properties of Thymus numidicus (Poiret) Essential Oil from Algeria

Abstract Essential oils of thyme (Thymus numidicus (Poiret)) from Algeria were isolated by steam distillation, analysed by gas chromatography coupled with the mass spectrometry (GC-MS) and investigated for their insecticidal activities against Rhizopertha dominica. Contact toxicity of global oil recovered after one hour of extraction and its fraction F1 recovered after 2.5 minutes of extraction were tested using the filter paper method. Analysis of the essential oil made it possible to identify 14 components, representing 75.4 % of the oil. The major components were thymol (51.0 %) followed by carvacrol (9.4 %), linalool (3.3 %), thymol-methyl-ether (3.2 %) and iso-caryophyllene (2.7 %). The evolution of the yield and the composition of essential oil as function of time extraction show that steam distillation is a very rapid process and the duration of extraction could be limited to 15 minutes, since more than 94 % of oil are extracted. The toxicity tests show that thyme oil and its fraction F1 have an insecticidal activity, nevertheless, the mortality obtained for global oil are weaker compared with those obtained for the F1 fraction. This toxicity would be allotted to the presence in strong proportion of linalool and thymol.

First approach on edible oil determination in oilseeds products using alpha-pinene

Traditional solvents are generally volatile organic compounds, harmful for health and environment. Among these solvents, n-hexane is the most recommended solvent for Soxhlet extraction of fatty acids. It is obtained from the petroleum industry and classified as very hazardous. Due to the new drive in the environment protection, such a solvent has to be avoided as much as possible. Therefore, there is increasing interest in new green solvents resulting from renewable raw materials. In this context, the aim of the present study is to investigate the possibility of using alpha-pinene as a substitute solvent to n-hexane for Soxhlet extraction of fatty acids of food products. The results obtained with the two solvents were comparable; however, in addition to being a bio-solvent resulting from renewable raw materials, the efficiency of extracting the fatty acids and a high recycling rate of alpha-pinene make it more interesting, more reliable and safer for the environment.

Kinetic Study and Optimization of the Operating Conditions of the Extraction by Steam Distillation of the Essential Oil of Thymus numidicus (Poiret) of Algeria

Abstract In order to study the process of extraction of the essential oil of Tymus numidicus kabylica extracted by steam distillation, kinetic studies as well as an optimization of the operating conditions were achieved. The optimization was carried out by a parametric study and experiments planning method. Three operational parameters were chosen: thyme mass, steam water flow rate and porosity of the bed. The obtained results underscored a kinetic of order one with two steps. The first is faster with a recovery of more than 94 % of essential oil. The optimal conditions obtained by the parametric study correspond to a : mass of 35 g, steam flow rate of 6.3 g/min. and porosity of 0.9155. The study by experiments planning realized by adopting the factorial planning of two levels of the three parameters 23, allowed on one hand, the estimation of the simple, combined interactions and triple effects of the parameters on the essential oil yield, and on the other hand, the establishment of a mathematical model describing the variations of the yield according to the studied parameters. The results reveal that the simple effect of the bed porosity is preponderant in comparison to the simple effects of the mass and the steam water flow rate. Concerning the combined effects of two parameters, the steam water flow rate and the bed porosity, is the more important. The yield is also affected by the interaction of the three parameters.

Effects of microwave heating on the antioxidant and insecticidal activities of essential oil of Origanum glandulosum Desf. obtained by microwave steam distillation

Abstract Response surface methodology (RSM) was used for the first time to investigate the efficiency of a new process developed in our laboratory: Microwaves Steam Distillation (MSD) on the oregano essential oil extraction. The selected parameters are steam flow, microwave power and extraction time, the response is essential oil yield. According to the statistical method, a second-order polynomial function was assumed to approximate the yield. The coefficient of determination R2 (91.33%), revealed a quite agreement between experimental and predictive values. Optimal conditions were: 6 g. min-1 for steam flow, 300 W for microwave power and 8 min for time. DPPH tests showed that MSD oil was the most efficient than eugenol, SD oil and the main compounds (carvacrol and thymol), and has comparable antioxidant activity to that of BHT. In the other hand, MSD and SD oils have an insecticidal effect against Rhizopertha dominica, but SD oil was most efficient.

Innovative Process of Essential Oil Extraction: Steam Distillation Assisted by Microwave

This study focuses on the extraction of essential oil of Thymus pallescens, using a new extraction process developed in our laboratory: steam distillation assisted by microwaves also called microwave steam distillation (MSD). This process is a combination of traditional techniques, namely, a steam distillation (SD) and an innovative technology, a microwave heating. Indeed, heating by microwaves helped initiate and build the mass and heat transfer inside the plant matrices outward which results in a considerable reduction in the extraction time. Kinetic study of extraction, optimization of operating conditions, and antioxidant activity of essential oil were conducted. The selected operating parameters are the steam flow rate and the microwave heating power.

Terpenes as Green Solvents for Natural Products Extraction

This chapter presents a complete picture of current knowledge on useful and green bio-solvent “terpenes” obtained from aromatic plants and spices through a steam distillation procedure followed by a deterpenation process. Terpenes could be a successful substitute for petroleum solvents, such as dichloromethane, toluene, or hexane, for the extraction of natural products. This chapter provides the necessary theoretical background and some details about extraction using terpenes, the techniques, the mechanism, some applications, and environmental impacts. The main benefits are decreases in extraction times, the amount of energy used, solvents recycled, and CO2 emissions.