The extraction of essential oils is generally carried out by two main techniques: azeotropic distillation (hydrodistillation, hydrodiffusion, and steam distillation) and extraction with solvents. However, these traditional methods are a bit expensive, especially since they are extremely energy and solvent consuming. This work consists in studying two methods of extraction of the essential oils of Rosmarinus officinalis L.: microwave assisted hydrodistillation (MAH) and Clevenger hydrodistillation (CH). Several parameters have been studied: the extraction time, the yield, and the chemical composition of the essential oils as well as the efficiency and cost of each procedure. The results obtained revealed that microwave-assisted hydrodistillation makes it possible to minimize the extraction time of the essential oils in comparison with conventional hydrodistillation. Thus, the same yield of essential oils is obtained for 20 minutes only with MAH while it takes 180 minutes with CH. In addition, the quality of the essential oil is improved thanks to a 1.14% increase in oxygenates. In conclusion, the MAH method offers significant advantages over conventional hydrodistillation and can therefore replace it on a pilot and industrial scale.
The beetle Callosobruchus maculatus (F. 1775) (Chrysomelidae: Bruchinae) is a destructive pest of stored chickpea seeds. Bio-pesticides are pesticides of animal, plant and bacterial origin. Plant products are among the best known substances tested against insects. These products have an insecticidal and repellent effect on insects and can also affect certain biological parameters such as fecundity, life span and reproduction. In search of plant bio-pesticides to control Callosobruchus maculatus main pest of stored chickpea seeds, 18 plants traditionally used in Morocco to control insect pests have been tested in the laboratory, for their toxic effects against this beetle. A conventional synthetic insecticide was included as a positive control, while untreated seed was used as a control. The toxicity of the powders was assessed by measuring the parameters of the life cycle in a situation of non-choice maintained at a climatic chamber with a temperature of 25 ±1 degrees Celsius, a relative humidity of 75% and a photoperiod of 14h (light) / 10h (darkness) for several successive generations. The powders of Mentha pulegium and Syzygium aromaticum have completely wiped out the population of the bruches (% IR=100%) 2%, 1% and 0.5% p/p. Similarly, the powders of the two plants retained the weights of the seeds, which remain significantly different (P < 0.01) at the weight of the control. Also Origanum compactum , Mentha officinalis, Allium sativum Zingiber officinale, Urtica doica and Calamintha officinalis have significantly reduced (P < - 0.01) the population of bruches, the percentage reduction reached (97.5, 89.32, 72.84, 50.3, 46.52 and 39.24% by the highest 2%). The other plants show no significant difference from the control. The results therefore suggest that Syzygium aromaticum powder and Mentha pulegium have an insecticide potential similar to those of conventional insecticides and could be a biotechnological alternative against C. maculatus infestations and damag
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