Analytical evaluation of virgin olive oils produced from three varieties Koroneiki , Arbequina and Arbosana grown in east of Morocco

Poster (2013, April)

Les composés organiques volatils d'origine végétale: médiateurs chimiques des interactions plantes-plantes?

Diverse speeche and writing (2013)

Optimization of the formation of vinyldithiins, therapeutic compounds from garlic

in European Food Research & Technology (2013)

Allyl sulfides, ajoenes and vinyldithiins are the three main groups of volatile organosulfur compounds that are formed when garlic is crushed. The manner garlic is processed (nature of the extraction ... [more ▼]

Allyl sulfides, ajoenes and vinyldithiins are the three main groups of volatile organosulfur compounds that are formed when garlic is crushed. The manner garlic is processed (nature of the extraction medium, temperature…) has a major influence on their relative proportion and the amounts produced. It has been proven recently that the vinyldithiins are at the origin of garlic’s capacity to prevent adipocytes development. Their incorporation in garlic-based nutraceuticals is thus particularly interesting. In this context, this work aims to optimize the production of vinyldithiins from garlic. After having determined the best garlic origin (Spanish) and the best oil for the extraction (olive or sunflower oil), the extraction conditions were optimized (1/2 (w/w garlic oil), 37 °C, 6 h) and 133 mg of vinyldithiins was obtained from 100 g of fresh garlic. Carrying out the extraction under microwave irradiation allowed increasing the yield 3.6-fold (yield 486 mg of vinyldithiins from 100 g of fresh garlic). This study may also contribute to the development of new garlic derived high value products by enhancing the comprehension of their formation. [less ▲]

Improvement of Ylang-Ylang Essential Oil Characterization by GCxGC-TOFMS

in Molecules (2013), 18(2), 1783-1797

A single fraction of essential oil can often contain hundreds of compounds. Despite of the technical improvements and the enhanced selectivity currently offered by the state-of-the-art gas chromatography ... [more ▼]

A single fraction of essential oil can often contain hundreds of compounds. Despite of the technical improvements and the enhanced selectivity currently offered by the state-of-the-art gas chromatography (GC) and mass spectrometry (MS) instruments, the complexity of essential oils is frequently underestimated. Comprehensive two-dimensional GC coupled to time-of-flight MS (GC×GC-TOFMS) was used to improve the chemical characterization of ylang-ylang essential oil fractions recently reported in a previous one-dimensional (1D) GC study. Based on both, the enhanced chromatographic separation and the mass spectral deconvolution, 161 individual compounds were identified and labeled as potentially characteristic analytes found in both low and high boiling fractions issued from distillation of mature ylang-ylang flowers. Compared to the most recent full GC-MS characterization, this represents 75 new compounds, essentially consisting of terpenes, terpenoid esters, and alcohols. [less ▲]

Therapeutic compounds in garlic oil: production and evolution after preparation

Poster (2012, November 15)

Allyl sulfides, the main constituents of garlic oil, have been studied in the past decades for their effects against cancer. Since cancers are not all healed, ways to prevent it, especially with natural ... [more ▼]

Allyl sulfides, the main constituents of garlic oil, have been studied in the past decades for their effects against cancer. Since cancers are not all healed, ways to prevent it, especially with natural products that could be included in food preparation, are more than welcome. The synthesis and separation of allyl sulfides can provide larger amount of allyl sulfide than the extraction in order to make biological tests. Furthermore, the improvement of the synthesis conditions helps the understanding of the formation of allyl sulfide while garlic is processed. Finally, the study of the products allows a deeper understanding of the conversion between the allyl sulfides. A parallel can then be done with the conservation conditions of garlic-based products. The first part of this work describes the synthesis optimization using the design of experiment. The reaction of allyl bromide and sodium disulfide was carried under different conditions: the reaction duration, the heating (in microwave oven or in oil bath, at different temperature), the presence of catalyst, and the agitation were assessed. In the second part of the study, extractions are performed on garlic. The composition of the extracts is followed during time under the conditions established in the first part. The results give an optimized way to synthesize allyl sulfides, as much as an idea of the reactions happening on them in garlic preparations under various conditions. [less ▲]

Conservation and management of a threatened traditional agroresource, ylang-ylang Cananga odorata [Lam.] Hook f. & Thomson forma genuina, in the Indian Ocean islands

in Crop Science (2012), 52(6), 2606-2618

In order to handle future economic, social and environmental changes, the assessment, management and conservation of the local genetic resources of cash crop species is a fundamental requirement. We ... [more ▼]

In order to handle future economic, social and environmental changes, the assessment, management and conservation of the local genetic resources of cash crop species is a fundamental requirement. We investigated the pattern of genetic and morphological diversity of Cananga odorata (Lam.) Hook f. & Thomson forma genuina, an important essential oil tree for the perfume industry in the introduction area of the western Indian Ocean islands. We sought to identify key elements for developing a conservation and management strategy for ylang-ylang genetic resources. Genetic and morphological variations were assessed using Amplified Fragments Length Polymorphism and morphometrics traits and information about farmers' practices were collected. The existence of substantial overall genetic diversity (HT = 0.2599) and the grouping of plantations into different genetic groups suggest that there have been a series of introduction events in the area, with limited exchanges of genetic material within and between islands, which is not what is suggested in the historical records. The morphological study revealed high phenotypic variability despite very similar agronomical practices throughout the studied area. The morphological and genetic variability might have been created and maintained without any planned or conscious management, and this has largely determined the genetic structuring in the area (11.74% genetic variation among islands and 20.68% among plantations). With this species, where past introduction events and farmers’ practices have shaped the genetic variation, on-farm preservation and the maintenance of the current management practices is recommended. Ex situ conservation efforts should also be undertaken, if economically affordable. [less ▲]

Comparative Chemical and Molecular Variability of Cananga odorata (Lam.) Hook.f. Thomson forma genuina (Ylang-Ylang) in the Western Indian Ocean Islands: Implication for Valorization

in Chemistry & Biodiversity (2012), 9(7), 13891402

Cananga odorata (Lam.) Hook.f. Thomson forma genuina (Annonaceae) is a tropical tree, grown for the production of ylang-ylang essential oil, which is extracted from its fresh and mature flowers. Despite ... [more ▼]

Cananga odorata (Lam.) Hook.f. Thomson forma genuina (Annonaceae) is a tropical tree, grown for the production of ylang-ylang essential oil, which is extracted from its fresh and mature flowers. Despite its economic and social importance, very little information is available on its variability and the possible factors causing it. Therefore, the relationship between the genetic structure, revealed by amplified fragment length polymorphism (AFLP), and the essential oil chemical composition, determined by GC/MS analysis, of ylang-ylang grown in semi-managed systems in three Indian Ocean islands (Grande Comore, Mayotte, and Madagascar) was investigated. Our results revealed a low genetic variation within plantations and contrasted situations between islands. Variations of the chemical composition could be observed within plantations and between islands. The genetic differentiation pattern did not match the observed pattern of chemical variability. Hence, the chemical variation could not be attributed to a genetic control. As Grande Comore, Madagascar, and Mayotte present different environmental and agronomic conditions, it can be concluded that the influence of these conditions on the ylang-ylang essential oil composition is consistent with the patterns observed. Finally, several strategies were proposed to valorize the chemical composition variations. [less ▲]

Do root-emitted volatile organic compounds interact with wireworms?

Scientific conference (2012, May 22)

Wireworms are the soil dwelling larvae of click beetles (Coleoptera: Elateridae). Their importance as crop pests increases since the efficient chemical means to control them cannot be considered anymore ... [more ▼]

Wireworms are the soil dwelling larvae of click beetles (Coleoptera: Elateridae). Their importance as crop pests increases since the efficient chemical means to control them cannot be considered anymore. Therefore, many integrated pest management strategies have been investigated in the past few years. Most of them rely on the understanding of the ecology of the click beetles during their whole life cycle. We focus our work on the chemical ecology of wireworms, more precisely on the root-emitted volatile organic compounds (VOCs) that might intervene in the food-searching process of the larvae by helping them to find a suitable host-plant or by acting as key factors in the belowground defence mechanism of the plant. Here, we present our first results of dual-choice orientation tests in olfactometric pipes. Wireworms (Agriotes sordidus Illiger) were submitted individually to a variety of olfactory baits ranging from entire barley roots (Hordeum vulgare L. var. Quench) to isolated VOCs identified as part of the emitting profile. The latter was described thanks to HS-SPME samplings and GC-MS analysis, for roots grown in the exact same conditions as for the olfactometric experimentations with entire roots. Most of the experimentations gave significant results. When confronted to volatiles emitted by entire roots, wireworms significantly orientated towards the bait (χ²-goodness-of-fit test, χ²=8, P-value=0.005). This result allowed us to follow up with the same device and to progressively vary the nature of the baits. Our protocol should be used for other plant-wireworm species combinations. Our results should be taken into account in varietal selection, in crop rotation, or in trapping systems aiming at the reduction of the populations of wireworms. [less ▲]

Development of a headspace solid-phase microextraction method coupled to gas chromatography (HS-SPME GC-MS) to capture and analyze the volatile organic compounds emitted by barley roots (Hordeum vulgare cv. Quench)

Poster (2012, February 10)

Growth modelling and profiling of volatile organic compounds in Barley (Hordeum distichon L.) roots

Poster (2012, February 10)

The roles played by root volatile organic compounds (VOC) remain essentially unknown. This study aims at identifying VOC contained by H. distichon roots at selected growth developmental stages. As an ... [more ▼]

The roles played by root volatile organic compounds (VOC) remain essentially unknown. This study aims at identifying VOC contained by H. distichon roots at selected growth developmental stages. As an original contribution, these were positioned on growth models calibrated for barley plants cultivated in our growth conditions. By SPME-GC/MS, a total of 110 compounds were detected and 70% of them were tentatively identified based on their mass spectra and retention time. Alcohols, aldehydes, ketones and organic acid esters accounted for 55,5% of the total number of detected VOC. Multivariate analysis revealed qualitative and quantitative changes in such profiles according to the developmental stage. In general, the VOC content was the highest when young roots just emerged from the coleorhiza. [less ▲]