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

in European seminar on infrared spectroscopy (2006)

Synthese enzymatique d’esters de sucre au départ d’huiles végétales

Poster (2005, October 14)

Sugar esters lipase mediated synthesis from vegetable oils

Poster (2005, September)

Secondary metabolites in roots and implications for nematode resistance in banana (Musa spp.)

in Turner, David W.; Rosales, Franklin E. (Eds.) Banana Root System: towards a better understanding for its productive management (2005)

Heating effects on some quality characteristics of date seed oil

in Food Chemistry (2005), 91(3), 469-476

Effects of heating on some quality characteristics of date seed oil from two cultivars (Deglet Nour and Allig) has been investigated using an accelerated test in a Rancimat system. Fatty acid, viscosity ... [more ▼]

Effects of heating on some quality characteristics of date seed oil from two cultivars (Deglet Nour and Allig) has been investigated using an accelerated test in a Rancimat system. Fatty acid, viscosity, absorptivity at 232 and 270 nm, colour and total melting enthalpy of Deglet Nour seed oil were less changed compared to that of Allig seed oil, because the former contained a higher amount of total phenolic compounds (526 mug/g against 215 mug/g) and a lower content of unsaturated fatty acids. Viscosity and absorptivity at 232 nm and at 270 nm increased rapidly after reaching the oxidation induction time. Differential scanning calorimetry melting profiles of date seed oils were also changed after heating in the Rancimat. Melting enthalpies seemed to be constant during the initial stages of Rancimat treatment and then reduced after the induction time was reached. The obtained data shows that date seed oils were resistant to thermal treatment during a long period (similar to30-40 h). This may indicate that they could bear thermal treatments that could be applied in refining procedures or in culinary treatments such as frying and cooking conditions. We could also expect that they may have a good shelf life. (C) 2004 Elsevier Ltd. All rights reserved. [less ▲]

Analysis of Pollen and Nectar of Arbutus unedo as a Food Source for Bombus terrestris (Hymenoptera : Apidae)

in Journal of Economic Entomology (2005), 98(3), 656-663

Is the (E)-ß-farnesene only volatile terpenoid in aphids?

in Journal of Applied Entomology (2005), 129

Herbivore insects use a broad range of chemical cues to locate their host to feed or to oviposit. Whether several plant volatiles are effective allelochemicals for insects, the latter also emit molecules ... [more ▼]

Herbivore insects use a broad range of chemical cues to locate their host to feed or to oviposit. Whether several plant volatiles are effective allelochemicals for insects, the latter also emit molecules which have infochemical role. The (E)-beta-farnesene (EBF) is a well-known aphid alarm pheromone commonly found in all previously tested species. Analysis of the released molecules from 23 aphid species, mainly collected on their natural host plant from May to July, was performed by gas chromatography–mass spectrometry. While EBF was identified as the main volatile substance in 16 species, alone or associated with other molecules, the alarm pheromone was only a minor component of the volatile molecule pattern of five other species. Moreover, two species, Euceraphis punctipennis and Drepanosiphum platanoides, did not release EBF at all but other terpenes were identified. This original observation raised the question on the utility and the source of the non-EBF volatiles. Are these potential infochemical substances produced by the aphid or only absorbed from the host plant? Here we determined that terpenes released by insects were not only provided by the host plants. Indeed, Megoura viciae emitted additional molecules than the ones from several aphid species reared on the same host plant. Moreover, no systematic relation between the feeding behaviour of the aphid species and the volatile releases was observed. Aphid terpene composition and proportion would provide reliable cues to identify the emitting organism, plant or insect. The next step of this work will be to determine the infochemical role of terpenes found in the range of tested aphid samples to better understand the relations between the different tritrophic levels. [less ▲]

New Model For Performance Prediction In Fixed-Bed Reactors Based On The Approach Of The Unused Bed Zone

in Water Research (2005), 39(16), 4004-4010

Surface properties of two closely related sugar esters : glucose octanoate and octyl glucuronate.

Poster (2004, February 11)

Quality characteristics and oxidative stability of date seed oil during storage

in Food Science & Technology International (2004), 10(5), 333-338

Studies were conducted on some quality characteristics of date seed oil from two date palm cultivars (Phoenix dactylifera L.): Deglet Nour and Allig. The following values were obtained for Deglet Nour and ... [more ▼]

Studies were conducted on some quality characteristics of date seed oil from two date palm cultivars (Phoenix dactylifera L.): Deglet Nour and Allig. The following values were obtained for Deglet Nour and Allig cultivars respectively: unsaponifiable matter 8.92-7.76%, iodine value 45.49-44.08, total phenols 520.81-220.32 mug/g oil, chlorophylls 0.86-0.58 mug/g oil, viscosity 18.50-20.50 mPa.s, refractive index 1.457-1.462, acidity 1.06-2.10mg KOH/g oil and peroxide index 16.00-25.00 meq O-2/100g oil. Lipid fractionation of date seed oil yielded 98.30-97.30% neutral lipids, 97.26-96.90% triglycerides, 0.25-0.18% phospholipids and 0.36-0.31% sterols. Gas-liquid chromatography revealed that the major unsaturated fatty acid was oleic acid (39.17-42.13%) while the main saturated fatty acid was lauric acid (24.34-22.56%). Date seed oil showed high medium molecular weight triglycerides (C32-C42, about 27%). Extinction coefficients at 232 nm and 270 nm increased slightly during 40 days in oven (60degreesC) showing that date seed oil could be easily stored. The production of oil from date seeds provides the use of a renewable resource, and at the same time adding value to agricultural products. [less ▲]