Toxicity Of Some Terpenoids Of Essential Oils Of Xylopia Aethiopica From Cameroon Against Sitophilus Zeamais Motschulsky

in Journal of Applied Entomology (2007), 131(4), 269-274

The acute toxicity of essential oils from the whole fruit (EF) or from the fibres of the fruit (FF) of the local aromatic plants Xylopiα αethiopicα Dunal (Annonaceae) collected in north Cameroon was ... [more ▼]

The acute toxicity of essential oils from the whole fruit (EF) or from the fibres of the fruit (FF) of the local aromatic plants Xylopiα αethiopicα Dunal (Annonaceae) collected in north Cameroon was evaluated on Sitophilus zeαmαis adults. A concentration of 1 ml of essential oil per 100 g of maize seeds was tested to determine weevil mortality after 24 h of exposure. Under these conditions, the essential oil derived from both EF and FF of X. αethiopicα led to 100% mortality. In a second step, proportions of active compounds present in the oil of both EF and FF of X. αethiopicα were quantified. The toxicity of the four main compounds was tested against S. zeαmαis: α-pinene, β-pinene, -3-carene and terpinen-4-ol according to their proportion in the essential oil of the concerned plant part. β-pinene and terpinen-4-ol were responsible for 50% of the mortality at the proportion found in EF and FF essential oils respectively. When mixed, a synergic effect of the compounds was observed that restored the mortality percentage observed for the crude oil. It appears that X. αethiopicα essential oil could be a potential source of natural and low-cost insecticide to control storage pests. [less ▲]

Electrophysiological and behavioral responses of the multicolored asian lady beetle, Harmonia axyridis pallas, to sesquiterpene semiochemicals

in Journal of Chemical Ecology (2007), 33(11), 2148-2155

The role of two volatile sesquiterpenes, (E)-beta-farnesene and (-)-beta-caryophyllene, in the chemical ecology of the multicolored Asian lady beetle, Harmonia axyridis Pallas, was investigated by using ... [more ▼]

The role of two volatile sesquiterpenes, (E)-beta-farnesene and (-)-beta-caryophyllene, in the chemical ecology of the multicolored Asian lady beetle, Harmonia axyridis Pallas, was investigated by using both electrophysiological and behavioral techniques. (E)-beta-Farnesene is the major component of the alarm pheromone of most aphid species, which are preyed on by H. axyridis. (-)-beta-Caryophyllene was previously isolated from the headspace volatiles above overwintering and aggregated H. axyridis females. These sesquiterpenes elicited significant electroantennogram (EAG) activity from both H. axyridis male and female antennae. In a four-arm olfactometer, male and female H. axyridis were highly attracted toward (E)-beta-farnesene, whereas only males were attracted to (-)-beta-caryophyllene. In a bioassay technique that used a passively ventilated plastic box, both male and female H. axyridis aggregated in the (-)-beta-caryophyllene-treated side of the box. These results support the potential usefulness of (E)-beta-farnesene and (-)-beta-caryophyllene in push-pull strategies that use H. axyridis as a biological control agent in aphid-infested sites or to control this new urban pest in residential structures. [less ▲]

Enrichment of anhydrous milk fat in polyunsatured fatty acid residues from linseed and rapeseed oil through enzymatic interesterification

Poster (2007)

The interesterification, or ester exchange, between two fats leads to the rearrangement of acyl moieties in both. The use of a sn-1,3-specific lipase confines the exchange of fatty acid residues to the sn ... [more ▼]

The interesterification, or ester exchange, between two fats leads to the rearrangement of acyl moieties in both. The use of a sn-1,3-specific lipase confines the exchange of fatty acid residues to the sn-1 and sn-3 positions of triacylglycerides (TAG), generating products with characteristics that cannot be obtained through a chemical process or a blending. Such reactions require mild conditions with no solvent needed and they yield no unhealthful trans fatty acids, justifying the stepped-up interest of enzymatic interesterification for the production of margarines and other food fats. The aim of this work was to use enzymatic interesterification to enrich anhydrous milk fat (AMF) with unsaturated fatty acid C18 residues from linseed oil (LO) and eventually from rapeseed oil (RO) through some binary blends and one ternary blend. For that, the 1,3-specific lipase from Thermomyces lanuginosa (Lipozyme TL IM) was used in solvent-free batch and micro-aqueous reactions and fat blends with different mass ratios were tested. The evolution of TAG profiles, of interesterification degre (ID) and of free fatty acids (FFA), was followed along the reactions. Determination of dropping points (DP) and solid fat contents (SFC) enabled a rheological characterization of the products. The end products were also characterized for their oxidative stability and their textural properties. [less ▲]

Chromatographic, Spectrometric and NMR Characterization of a New Set of Glucuronic Acid Esters Synthesized by Lipase

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2007), 11(1), 9-17

Lutte biologique par l'utilisation de médiateurs chimiques : apports des techniques chromatographiques

Diverse speeche and writing (2007)

Potential Physical And Chemical Barriers To Infection By The Burrowing Nematode Radopholus Similis In Roots Of Susceptible And Resistant Banana (Musa Spp.)

in Plant Pathology (2007), 56(5), 878-890

Estimating fatty acid content in cow milk using mid-infrared spectrometry

in Journal of Dairy Science (2006), 89(9), 3690-3695

Estimation of fatty acid profile in cow milk by mid-infrared spectrometry

Poster (2006, April 03)

Potential of mid-infrared spectrometry for prediction of fatty acid contents in cow milk

Poster (2006)

Chemical Composition Of The Leaf Oil Of Mentha Rotundifolia (L.) From Algeria

in Journal of Essential Oil Research (2006), 18(6), 663-665