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The MAD method appears to be more efficient than HD: after 30  min extraction time, the obtained yields (i.e. 0.002%) were comparable to those provided by HD after 3  h extraction. MAD seems to be more convenient since the volatile fraction is richer in oxygenated monoterpenes, species that are recognised for their olfactory value and their contribution to the fragrance of the essential oil.

For centuries, rosemary (Rosmarinus officinalis L.) has been used to prepare essential oils which, even now, are highly valued due to their various biological activities. Nevertheless, it has been noted that these activities often depend on the origin of the rosemary plant and the method of extraction. Since both of these quality parameters can greatly influence the chemical composition of rosemary oil, an original analytical method was developed where "dry distillation" was coupled to headspace solid-phase microextraction (HS-SPME) and then a data mining technique using the Kohonen self-organizing map algorithm was applied to the data obtained. This original approach uses the newly described microwave-accelerated distillation technique (MAD) and HS-SPME; neither of these techniques require external solvent and so this approach provides a novel "green" chemistry sampling method in the field of biological matrix analysis. The large data set obtained was then treated with a rarely used chemometric technique based on nonclassical statistics. Applied to 32 rosemary samples collected at the same time from 12 different sites in the north of Algeria, this method highlighted a strong correlation between the volatile chemical compositions of the samples and their origins, and it therefore allowed the samples to be grouped according to geographical distribution. Moreover, the method allowed us to identify the constituents that exerted the most influence during classification.

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Anacyclus clavatus is a plant used as food and remedy. The objective of this work was to study the effect of extraction technique on the antioxidant property, total phenol and flavonoid contents of crude extracts from A. clavatus flowers and their essential oil composition. 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, ferric-reducing power, β-carotene and total antioxidant capacity assays have demonstrated the significant antioxidant ability of different crude extracts obtained by using the following extraction methods: Soxhlet, microwave heating, heat reflux (HRE) and maceration. The activity of the extract obtained by HRE was the highest (112.06 ± 2.89 μg/mL) evaluated by the DPPH assay. Extraction of essential oil was performed by microwave-assisted hydro-distillation (MAHD) and by hydro-distillation (HD). A significant difference was observed in both essential oils, despite the common main family and major constituents, such as artemisia ketone (10.0 ± 0.8% for MAHD vs. 6.5 ± 0.5 for HD) and pinocarvone (4.1 ± 0.4% for MAHD vs. 1.1 ± 0.1% for HD).

Hawthorn (Crataegus spp.), belonging to the Rosaceae family, is rich in sugars, minerals, and vitamins A and C. The fruits and flowers of many hawthorn varieties are well known as a heart tonic, have hypotensive effects, and are considered to be generally safe and well tolerated [1]. Previous investigations indicate that Chinese Crataegus extracts have beneficial effects, e.g., anti-inflammatory [2], hypolipidemic [3], and antioxidant [4]. Other proprieties have also been elucidated such as anticarcinogenic [5] and antimicrobial [6]. In France, hawthorn is prescribed and marketed in pharmacies as gelatin capsules or as a sedative tea to treat nervosity and sleep disorders [7,8]. The pharmacological effects, including the antioxidant power of Crataegus, have mainly been attributed to polyphenolic compounds like flavonoids and phenolic acids. Currently, investigations on important bioactive and antioxidant phytochemicals in medicinal plants and herbal food materials have received great attention. The aim of the present work was, on the one hand, to highlight the volatile constituents of leaves and flowers of C. azarolus and, on the other hand, to evaluate the antioxidant property of the crude extract. Available information indicates that the essential oil of C. azarolus has not been studied to date. Essential oil extractions were performed using two different processes, initially by the relatively recent method of hydrodistillation assisted by microwave heating (HD-MW), afterwards by hydrodistillation (HD), the conventional technique recommended by AFNOR in the extraction of essential oils destined for the food and cosmetic industries. Many experiments have been performed in this study in order to optimize the yield of the (HD-MW) extract by studying: (a) the extraction time; (b) the radiation power of the microwave oven; (c) the used quantity of water, starting from a dried distillation, as stated in our previous investigations [9,10]. The extracts were analyzed by gas chromatography GC-FID and gas chromatography coupled to mass spectrometry GC-MS. The findings in terms of yield, extraction time, volatile profiling, and quality of the essential oil were compared.Regarding the assessment of the total antioxidant capacity of C. azarolus, we have estimated primarily the total phenolic and flavonoid contents in a methanolic crude extract, molecules to which the antioxidant property is related. Subsequently, two different methods have been used to evaluate this activity, namely the DPPH radical scavenging assay and the E-carotene bleaching test. Descriptive statistical analysis, analysis of correlation coefficients, and one-way analysis of variance were performed.Extraction Yield. The extraction yield was calculated from dry plant material after determining the sample moisture content (54%). An extraction time of 30 min with HD-MW provides yields 0.024 r 0.001% (w/w) slightly higher than HD yields 0.019 r 0.001% (w/w) obtained after 3 h.

Walnut (Juglans regia L.) leaves are used traditionally as an herbal tea indicated for non-insulindependent diabetics. In recent years, the type-II diabetes is occurring worldwide with increasing frequency. Thus, there is an urgent need to explore the new beneficial biomolecules on the human health. Our objective was to investigate, for the first time, the volatiles profile of Juglans regia L. leaves from Algiers region. The extraction of essential oil of fresh plant material was performed by microwaveassisted hydrodistillation (MAHD), for the first time, a relatively recent method, then by the conventional hydrodistillation technique (HD) for comparison. The collected extracts were analyzed by GC-FID and GC/MS using two capillary columns with different polarity. Extraction time of 1 h by MAHD provided higher yields (0.050 AE 0.001% (w/w)) than by HD (0.030 AE 0.006% (w/w)) after 3 h. A total of 38 compounds were identified using both techniques. Essential oils had similar qualitative but different quantitative composition in terms of chemical compounds. The MAHD method improved yield while reducing the extraction time. The sesquiterpenes were the dominant family in both MAHD and HD essential oils with b-caryophyllene being the major constituent. Monoterpenes, including hydrocarbon and oxygenated, prevail in HD volatile fraction with b-pinene and eucalyptol, respectively, as major components.