References of "Blecker, Christophe"
     in
Bookmark and Share    
See detailStrategy for the qualitative and quantitative analysis of crop syrup containing enzymatically produced Isomaltooligosaccharides known as emerging prebiotics.
Goffin, Dorothée ULg; Blecker, Christophe ULg; Wathelet, Bernard ULg et al

Poster (2006)

Isomaltooligosaccharides (IMOs) are non-digestible oligosaccharides, considered as prebiotics and therefore aim to selectively feed probiotics indigenous to the human colon. Recent data obtained in human ... [more ▼]

Isomaltooligosaccharides (IMOs) are non-digestible oligosaccharides, considered as prebiotics and therefore aim to selectively feed probiotics indigenous to the human colon. Recent data obtained in human subjects, support the involvement of dietary oligosaccharides in physiological processes in the different intestinal cell type and also outside the gastrointestinal tract (e.g. hormone production, lipid and carbohydrate metabolism). IMOs consists of glucose monomers linked by at least one α-1-6, or in a lower proportion α -1-3 (nigerose family) or α -1-2 (kojibiose family) glucosidic linkages. In our case they are produced enzymatically from corn starch. It results in a very complex mixture with molecules characterized at the same time by their DP value (from 2 to ~20), linkages types (α-1-2, 3 or 6) and the proportion and position of each type of linkage (only α -1-6 or combined types). The challenge of this study was to find a qualitative and quantitative method to characterize the syrups. In a subsequent study, every unidentified peak could be determined by NMR or Mass spectrometry. Three different chromatographic methods have been tested and compared over their selectivity, sensibility, robustness, applicability and their quantitative power. The HPLC-RID (Refractive Index Detector) used with a Prevail Carbohydrate column (Alltech), adapted for carbohydrates with a certain value of DP, appear to be poorly selective due to the obligation of working in isocratic conditions. The HPLC-ELSD (Evaporating Light Scattering Detector) used with the same column gave a very good separation upon the DP as the Prevail accepts a wide range of solvant changing and even a separation of the different DP 2 molecules. The sensibility was also improved due to the stability of the baseline. The quantitative analysis is a bit more awkward due to the relatively limited linear portion of the calibration curve. High-performance Anion Exchange Chromatography coupled with Pulsed Amperometric Detection (HPAEC-PAD) appeared to deserve a special mention, since it provides selective separation and sensitive detection. In fact, this technique is the only chromatographic one to separate with effectiveness homologue molecules having a difference only in their DP (up to high DPs) or linkage types. This is due to the separation mode based on the difference in ionic force of the sugars in alkaline conditions (mainly due to the DP and the structure of the molecule). However, during the detection, the electrochemical behavior of carbohydrates can be affected by molecular weight as well as by structural differences giving rise to different response factors; as a consequence, HPAEC-PAD is not generally considered as suitable for quantitative studies of complex mixtures of oligosaccharides. In this work a methodological approach is presented in order to get a quantitative response through a rigorous methodology for our IMOs. It also opens the way to the theoretical determination of the response factor for the homologue molecules in relation with their structure and DP. [less ▲]

Detailed reference viewed: 19 (9 ULg)
Full Text
See detailStrategy for the qualitative and quantitative analysis of crop syrup containing enzymatically produced Isomaltooligosaccharides known as emerging prebiotics
Goffin, Dorothée ULg; Blecker, Christophe ULg; Wathelet, Bernard ULg et al

Poster (2006)

Isomaltooligosaccharides (IMOs) are non-digestible oligosaccharides, considered as prebiotics and therefore aim to selectively feed probiotics indigenous to the human colon. Recent data obtained in human ... [more ▼]

Isomaltooligosaccharides (IMOs) are non-digestible oligosaccharides, considered as prebiotics and therefore aim to selectively feed probiotics indigenous to the human colon. Recent data obtained in human subjects, support the involvement of dietary oligosaccharides in physiological processes in the different intestinal cell type and also outside the gastrointestinal tract (e.g. hormone production, lipid and carbohydrate metabolism). IMOs consists of glucose monomers linked by at least one α-1-6, or in a lower proportion α -1-3 (nigerose family) or α -1-2 (kojibiose family) glucosidic linkages. In our case they are produced enzymatically from corn starch. It results in a very complex mixture with molecules characterized at the same time by their DP value (from 2 to ~20), linkages types (α-1-2, 3 or 6) and the proportion and position of each type of linkage (only α -1-6 or combined types). The challenge of this study was to find a qualitative and quantitative method to characterize the syrups. In a subsequent study, every unidentified peak could be determined by NMR or Mass spectrometry. Three different chromatographic methods have been tested and compared over their selectivity, sensibility, robustness, applicability and their quantitative power. The HPLC-RID (Refractive Index Detector) used with a Prevail Carbohydrate column (Alltech), adapted for carbohydrates with a certain value of DP, appear to be poorly selective due to the obligation of working in isocratic conditions. The HPLC-ELSD (Evaporating Light Scattering Detector) used with the same column gave a very good separation upon the DP as the Prevail accepts a wide range of solvant changing and even a separation of the different DP 2 molecules. The sensibility was also improved due to the stability of the baseline. The quantitative analysis is a bit more awkward due to the relatively limited linear portion of the calibration curve. High-performance Anion Exchange Chromatography coupled with Pulsed Amperometric Detection (HPAEC-PAD) appeared to deserve a special mention, since it provides selective separation and sensitive detection. In fact, this technique is the only chromatographic one to separate with effectiveness homologue molecules having a difference only in their DP (up to high DPs) or linkage types. This is due to the separation mode based on the difference in ionic force of the sugars in alkaline conditions (mainly due to the DP and the structure of the molecule). However, during the detection, the electrochemical behavior of carbohydrates can be affected by molecular weight as well as by structural differences giving rise to different response factors; as a consequence, HPAEC-PAD is not generally considered as suitable for quantitative studies of complex mixtures of oligosaccharides. In this work a methodological approach is presented in order to get a quantitative response through a rigorous methodology for our IMOs. It also opens the way to the theoretical determination of the response factor for the homologue molecules in relation with their structure and DP. [less ▲]

Detailed reference viewed: 39 (9 ULg)
Full Text
Peer Reviewed
See detailDéfense végétale, biotechnologies et développement de bio-insecticides
Francis, Frédéric ULg; Blecker, Christophe ULg; Deroanne, Claude et al

in Abstract book (2006)

Detailed reference viewed: 18 (2 ULg)
See detailSynthese enzymatique d’esters de sucre au départ d’huiles végétales
Detry, J.; Destain, Jacqueline ULg; Lognay, Georges ULg et al

Poster (2005, October 14)

Detailed reference viewed: 21 (4 ULg)
Full Text
See detailSugar esters lipase mediated synthesis from vegetable oils
Destain, Jacqueline ULg; Detry, Jean; Lognay, Georges ULg et al

Scientific conference (2005, September 19)

Detailed reference viewed: 34 (3 ULg)
See detailSugar esters lipase mediated synthesis from vegetable oils
Destain, Jacqueline ULg; Detry, J.; Lognay, Georges ULg et al

Poster (2005, September)

Detailed reference viewed: 25 (5 ULg)
Full Text
Peer Reviewed
See detailHeating effects on some quality characteristics of date seed oil
Besbes, S.; Blecker, Christophe ULg; Deroanne, Claude ULg et al

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 ▲]

Detailed reference viewed: 29 (12 ULg)
Full Text
Peer Reviewed
See detailHeating Effects On Some Quality Characteristics Of Date Seed Oil
Besbes, Souhail; Blecker, Christophe ULg; Deroanne, Claude et al

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 lg/g against 215 lg/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 ( 30–40 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. [less ▲]

Detailed reference viewed: 66 (9 ULg)
Full Text
Peer Reviewed
See detailVoies de valorisation des écarts de triage des dattes : valorisation des noyaux.
Besbes, Souhail; Hentati, B.; Blecker, Christophe ULg et al

in Microbiol. Hyg. Alim. (2005), 17(50), 3-11

Detailed reference viewed: 63 (2 ULg)
Full Text
Peer Reviewed
See detailAnalisis y evaluacion del contenido de acido grasos y tocoferoles de un aceite de anchevata desodorizado.
Edilberto, Flores; Lognay, Georges ULg; Blecker, Christophe ULg et al

in Veritas (2005), 8(8),

The quality of an oil is evaluated of anchoveta desodorizado taking into account ils composicion in acidos greasy particularly thé acidos greasy polinsaturados such as EPA and DHA important for thé human ... [more ▼]

The quality of an oil is evaluated of anchoveta desodorizado taking into account ils composicion in acidos greasy particularly thé acidos greasy polinsaturados such as EPA and DHA important for thé human heallh, thé resulls indicate a high content of thèse acidos greasy, comparable with oils ofother marine species inside them thé anchoveta black of Peruvian origin, other analisis hâve been performed like thé détermination of tocoferoles, theResults indicate thé absence of thèse substances in thé oil desodorizado of anchoveta evaluated; thèse analisis are important when is desired to evaluate stability oxidativa of oils employing antioxidants and whoseprésence can influence in thé results of stability oxidativa. The cromatogramas indicate thé absence ofâ, à y à/à tocoferol. [less ▲]

Detailed reference viewed: 42 (16 ULg)
Peer Reviewed
See detailCharacterization of inulin stored at different relative humidities by MDSC and X-ray diffraction, related to soption isotherms.
Ronkart, Sébastien; Fougnies, C.; Paquot, Michel ULg et al

Poster (2004, December)

Detailed reference viewed: 29 (15 ULg)
Full Text
Peer Reviewed
See detailHeating effects on some quality caracteristics of date seed oil.
Besbes, Souhail; Blecker, Christophe ULg; Danthine, Sabine ULg et al

Poster (2004, September)

Detailed reference viewed: 16 (4 ULg)
Full Text
Peer Reviewed
See detailLipids composition of milk fat globule membrane extracted from cream
Bodson, Pascal; Danthine, Sabine ULg; Blecker, Christophe ULg

Poster (2004, September)

Detailed reference viewed: 17 (1 ULg)
Full Text
See detailPropriétés de surface et techno-fonctions
Blecker, Christophe ULg

Scientific conference (2004, May 05)

Detailed reference viewed: 20 (2 ULg)
Full Text
Peer Reviewed
See detailLes émulsifiants dans les produits de boulangerie industrielle : modes d'action, rôles et utilisations.
Delacharlerie, Sophie ULg; Blecker, Christophe ULg; Kegelaers, Yves et al

in Industries Alimentaires et Agricoles (2004), (Mai), 8-14

Detailed reference viewed: 132 (8 ULg)
See detailNoyaux de dattes: étude de la composition physico-chimique et des profils caractéristiques de la fraction lipidique
Besbes, S.; Blecker, Christophe ULg; Deroanne, C. et al

Conference (2004, March 21)

Detailed reference viewed: 436 (1 ULg)