References of "Wathelet, Jean-Paul"
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See detailImprovement Of Enzymatic-Synthesis Yields Of Flavor Acetates - The Example Of The Isoamyl Acetate
Razafindralambo, Hary ULg; Blecker, Christophe ULg; Lognay, Georges ULg et al

in Biotechnology Letters (1994), 16(3), 247-250

Isoamyl acetate synthesis was chosen as a model to improve flavour acetate yields by optimising the enzymatic reaction. Alcohol:acid molar ratio, temperature, water content and amount of enzyme effects ... [more ▼]

Isoamyl acetate synthesis was chosen as a model to improve flavour acetate yields by optimising the enzymatic reaction. Alcohol:acid molar ratio, temperature, water content and amount of enzyme effects were analyzed. The optimum values were respectively 4, 45 degrees C, 0,1% (w/v) and 0,5 g. In these conditions, the synthesis yield reached 80% after 24 h of reaction and was found 15 times greater than those already reported in the literature. [less ▲]

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See detailL'analyse des glucosinolates, travaux réalisés par l'Organisation internationale de standardisation et la CEE
Wathelet, Jean-Paul ULg; Ribaillier, Daniel; Severin, Michel et al

in Bulletin du GCIRC (1994)

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See detailDetection des molecules responsables de l'activite biocide des feuilles de Boscia senegalensis (Pers.) Lam ex Poir. par echantillonage d'espace de tete et spectrometrie de masse couplee a la chromatographie en phase gazeuse.
Lognay, Georges ULg; Marlier, M.; Seck, D. et al

in Bulletin des Recherches Agronomiques de Gembloux (1994), 29(1),

Des échantillons de feuilles de Boscia senegalensis (Prns.) I.ev ex Porn. ont été tnaintenus dans des conditions contrôlées sous un flux d'hélium, à l'intérieur d'une.platine de désorption thermique ... [more ▼]

Des échantillons de feuilles de Boscia senegalensis (Prns.) I.ev ex Porn. ont été tnaintenus dans des conditions contrôlées sous un flux d'hélium, à l'intérieur d'une.platine de désorption thermique directement connectée à un GC-MS. A côté du trans-2-hexénal, responsable de la note "verte" des feuilles, l'isothiocyanate de méthyle et le cyanure de méthyle (acétonitrile) ont été détectés. Ces deux produits se sont formés par dégradation enzymatique in situ d'un précurseur, la glucocapparine. Ils ont été caractérisés par leur spectre de masse. La libération de cyanure de méthyle à partir d'échantillons biologiques est expliquée. [less ▲]

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See detailEssential oil production by Anthemis nobilis L. tissue culture.
Fauconnier, Marie-Laure ULg; Jaziri, M.; Marlier, Michel et al

in Journal of Plant Physiology (1993), 141(6), 759-761

The production of essential oil by tissue culture s ol Antbemis nobilis L. including cell suspension, shoot and crown-gall cultures is reported. The biosynthetic capability of these different cultures was ... [more ▼]

The production of essential oil by tissue culture s ol Antbemis nobilis L. including cell suspension, shoot and crown-gall cultures is reported. The biosynthetic capability of these different cultures was compared with that of plants grown in a field. The addition of crude polysaccharide fraction prepared from yeast extract and from the plant itself to shoot cultures affected the composition and total essential content (from 0.08 o/o to 0.3Qo/o dry weight). The essential oil content of the crown-gall tissue ol A. nobilis was 0.25 % of the dry weight and the composition of the essential oil was comparable to that of the flowers. [less ▲]

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See detailTHE CERTIFIED TOTAL GLUCOSINOLATE CONTENT IN 3 RAPESEEDS (CRM-190, CRM-366 AND CRM-367)
Wathelet, Jean-Paul ULg; WAGSTAFFE, P. J.; BOENKE, A. et al

in Fresenius' Journal of Analytical Chemistry (1993), 347(10-11), 396-399

The preparation of certified rapeseed reference materials and the steps taken to establish the certified values for total glucosinolate contents are described. Details are given of the studies to ... [more ▼]

The preparation of certified rapeseed reference materials and the steps taken to establish the certified values for total glucosinolate contents are described. Details are given of the studies to demonstrate the homogeneity and stability of the material. The results of the certification exercise for total glucosinolate content, which involved European laboratories who applied a variety of methods (high-pressure liquid chromatography, gas liquid chromatography, determination of enzymatically released glucose and sulphate), are presented and discussed. The certified values for the glucosinolate content (mumol/g of non-defatted whole seeds) and the 95% confidence level are the following: CRM 366 (12.1 +/- 0.8 mumol/g), CRM 190 (25.5 +/- 0.9 mumol/g) and CRM 367 (102.4 +/- 3 mumol/g) (CRM = certified reference material). Indicative values (not certified) for individual glucosinolates are also given. Certified sulphur values (mg/g of non defatted whole seeds) have been determined by other laboratories: CRM 366 (3.41 +/- 0.12 mg/g), CRM 190 (4.93 +/- 0.15 mg/g) and CRM 367 (10.5 +/- 0.40 mg/g). [less ▲]

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See detailCHARACTERIZATION OF 3 LABDANE DITERPENES FROM AFRAMOMUM-ALBOVIOLACEUM
Marlier, Michel; LEGUELLEC, G.; Lognay, Georges ULg et al

in Planta Medica (1993), 59(5), 455-457

Two labdane diterpenes were isolated from the seeds and the rhizomes of Aframomum alboviolaceum (Ridley) K. Schum (Zingiberaceae) and identified by GC-MS, H-1-, and C-13-NMR as (E)-labda-8(17),12-diene-15 ... [more ▼]

Two labdane diterpenes were isolated from the seeds and the rhizomes of Aframomum alboviolaceum (Ridley) K. Schum (Zingiberaceae) and identified by GC-MS, H-1-, and C-13-NMR as (E)-labda-8(17),12-diene-15,16-dial (1) and (E)-8beta,17-epoxylabd-12-ene-15,16-dial (2). A third minor compound could be the methyl (E)-14xi,15-epoxylabd-8(17), 12-dien-16-oate. The simultaneous occurrence of these three molecules has been mentioned only in one other species of the same genus, Aframomum daniellii (1). [less ▲]

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See detailBIOLOGICAL-ACTIVITY OF THE SHRUB BOSCIA-SENEGALENSIS (PERS) LAM EX-POIR (CAPPARACEAE) ON STORED GRAIN INSECTS
SECK, D.; Lognay, Georges ULg; Haubruge, Eric ULg et al

in Journal of Chemical Ecology (1993), 19(2), 377-389

Biological activity of leaves, fruits and extract of the African shrub Boscia senegalensis (PERS.) LAM. ex Poir. was evaluated against five stored-grain insects. When added to cowpeas at 2-4% (w/w), fresh ... [more ▼]

Biological activity of leaves, fruits and extract of the African shrub Boscia senegalensis (PERS.) LAM. ex Poir. was evaluated against five stored-grain insects. When added to cowpeas at 2-4% (w/w), fresh ground fruits and leaves caused 80-100% mortality in Callosobruchus maculatus (F.) adults and significantly reduced both emergence and damage of the F1 progeny. Acetone fruit extract exhibited a potent fumigant effect on Prostephanus truncatus HORN., C maculatus, and Sitotroga cerealella OLIV.: with LT50 values of 3.8, 2.3, and below 1.5 hr, respectively. LC50 determination for B. senegalensis fruits and leaves as well as pure methylisothiocyanate (MITC) on Tribolium castaneum HERBST, Sitophilus zeamais MOTSCH. and C. maculatus showed a differential response of the insects to plant parts or MITC. Quantitative dosage of Boscia active components and LC50 values obtained for the plant tissues, compared to those of pure molecules, indicate that the biological activity of B. senegalensis is due to the liberation of MITC from a glucosinolate precursor glucocapparin contained in Boscia fruits and leaves. [less ▲]

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See detailProduction of essential oil by in vitro culture of Anthemis nobilis L. and characterization by GC-MS.
Marlier, M.; Fauconnier, Marie-Laure ULg; Jaziri, M. et al

Poster (1992, September 21)

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See detailProduction et utilisation du colza en Belgique.
Cartrysse, C.; Cors, F.; Wathelet, Jean-Paul ULg

in GCIRC Bulletin (1991)

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See detailExperiences with the X-RF method for the determination of total glucosinolate content in rapeseed
Schnug, E.; Haneklaus, S.; Wathelet, Jean-Paul ULg

in Bulletin du GCIRC (1990), 9

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See detailDetermination of total glucosinolate in rapeseed (colza). Activities of BCR-programme Community Bureau of Reference .
Wathelet, Jean-Paul ULg; Severin, M.; Wagstaffe, P. J.

in GCIRC Bulletin (1990)

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See detailLe renouveau de colza d'hiver en Belgique.
Cartrysse, C.; Cors, F.; Wathelet, Jean-Paul ULg

in GCIRC Bulletin (1989)

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See detailPreparation of A Rapeseed Sample With A Certified Content In Total Glucosinolates (CRM 190)
Wathelet, Jean-Paul ULg; Marlier, M.; Severin, M. et al

in Revue Française des Corps Gras (1989), 36(7-8),

The preparatton af one rapeseed with known content tn total glucosinolates (CRM 190) and the steps taken to confirm their homogeneity and stabtlity are described. Details are presented of the ... [more ▼]

The preparatton af one rapeseed with known content tn total glucosinolates (CRM 190) and the steps taken to confirm their homogeneity and stabtlity are described. Details are presented of the collaborative exercice which led to the certification. lndicative values are given for the content of individual glucosinolates, amino acids, and fatty acids. [less ▲]

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See detailFAST ANALYSIS OF RAPESEED GLUCOSINOLATES BY NEAR-INFRARED REFLECTANCE SPECTROSCOPY
Biston, R.; Dardenne, P.; Cwikowski, M. et al

in Journal of the American Oil Chemists' Society (1988), 65(10), 1599-1600

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See detailRAPESEED REFERENCE MATERIALS FOR GLUCOSINOLATE ANALYSIS - DEVELOPMENT OF RAPESEED BCR RM-190 AND THE RESULTS OF THE INTERCOMPARISON OF METHODS
Wathelet, Jean-Paul ULg; Wagstaffe, P. J.; Biston, R. et al

in Fresenius Zeitschrift Fur Analytische Chemie (1988), 332(6), 689-693

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See detailCOMPARISON BETWEEN 4 METHODS TO MEASURE GLUCOSINOLATES IN RAPESEEDS
Wathelet, Jean-Paul ULg; Cwilowski, M.; Severin, M. et al

in Revue Française des Corps Gras (1988), 35(4), 177-179

Total glucosinolate content in rapeseeds cultivated in France. Germany. Denmark, United Kingdom and Belgium has been determined by high performance liquid chromatography (HPLC), gas liquid chromatography ... [more ▼]

Total glucosinolate content in rapeseeds cultivated in France. Germany. Denmark, United Kingdom and Belgium has been determined by high performance liquid chromatography (HPLC), gas liquid chromatography (GLC),measurement of glucose released by myrosinase and Pd glucosinolate complex after purification on an ion exchange column. Methods are well correlated. Glucose method and HPLC give similar results r: O.995, bias: O.055 µM/gr). ln most cases. GLC results are lower than HPLC (r: O.995, bias: - 2.482 µM/gr). Palladium method gives systematically higher results than HPLC (t: 0.99O, bias: 6.763 µM/gr). [less ▲]

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See detailSTUDY OF THE LIPIDS FROM IVY (HEDERA-HELIX L) - IDENTIFICATION OF ISOMERIC MONOUNSATURATED FATTY-ACIDS
Lognay, Georges ULg; Marlier, Michel; Séverin, Michel et al

in Revue Française des Corps Gras (1987), 34(9), 407-411

In the present study, fatty acids from Hedera helix L. are identified and measured. After epoxidation, monoenic fatty methyl esters (81.6 %) of the total fatty acids) are separated by mean of very ... [more ▼]

In the present study, fatty acids from Hedera helix L. are identified and measured. After epoxidation, monoenic fatty methyl esters (81.6 %) of the total fatty acids) are separated by mean of very resolutive capillary columns with cyanopropylsiloxane stationnary phase. ldentification are achieved with the help of GC-MS. Electron impact and more conveniently chemical ionisation (NHi are both used. Observation of characteristic mass fragments from fatty epoxides allow us to identify three octadecenoic positionnal isomers . petroselinic acid (C 1 8. 1 delta 6 cis), oleic acid (C18:1 delta 9 cis) and vaccenic acid (C18:1 delta 11 c i s ) . This last one i s rare in vegetable o i l s . [less ▲]

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See detailAnalysis of individual glucosinolates in rapeseeds. Comparison between different methods
Wathelet, Jean-Paul ULg; Biston, R.; Marlier, M. et al

in Wathelet, Jean-Paul (Ed.) Glucosinolates in Rapeseeds: Analytical Aspects (1987)

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See detailGlucosinolates in Rapeseeds: Analytical Aspects
Wathelet, Jean-Paul ULg

Book published by Martinus Nijhoff Publishers (1987)

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See detailAnalysis of quality parameters of whole rapeseed by NIRS
Biston, R.; Dardenne, P.; Cwikowski, M. et al

in Wathelet, Jean-Paul (Ed.) Glucosinolates in Rapeseeds: Analytical Aspects (1987)

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