References of "Blecker, Christophe"
     in
Bookmark and Share    
Full Text
See detailScaphandre La science rencontre l'art: L'art
Haubruge, Eric ULg; Bay, Daniel ULg; Semal, Jean et al

in Haubruge, Eric; Bay, Daniel; Semal, Jean (Eds.) Scaphandre La science rencontre l'art (2012)

Detailed reference viewed: 61 (14 ULg)
Full Text
Peer Reviewed
See detailInfluence of the water content in the synthesis of fructose laurate by immobilized lipase B of Candida antarctica (Novozym 435)
Olive, Gilles ULg; Pompeu Torezan, Gabriela A.; Blecker, Christophe ULg

in Bulletin de la Société Royale des Sciences de Liège (2012), 81(2012), 82-89

New synthesis conditions for a direct esterification of fructose by lauric acid with Novozym 435 as a catalyst are reported in this paper. With these new conditions, a conversion rate of 72% was achieved ... [more ▼]

New synthesis conditions for a direct esterification of fructose by lauric acid with Novozym 435 as a catalyst are reported in this paper. With these new conditions, a conversion rate of 72% was achieved, which is almost the same value as in the case of transesterification where no water as by-product is produced (74.6 %). The conversion rate of these reactions can be modeled as a function of the initial water content by a three-parameter power law for the esterification and by an exponential law for the transesterification. The influence of the water content on the mono over di-ester ratio will also be discussed to a lesser extent. [less ▲]

Detailed reference viewed: 47 (20 ULg)
Full Text
Peer Reviewed
See detailSynthèse enzymatique d'esters de fructose
Olive, Gilles ULg; Pompeu Torezan, Gabriela; Blecker, Christophe ULg

in Comptes Rendus Chimie (2012), 15(11-12), 1037-1047

The enzymatic synthesis of esters is well documented in the literature. A number of parameters have been revised to optimize the operating conditions, in view of a more industrial approach. The ... [more ▼]

The enzymatic synthesis of esters is well documented in the literature. A number of parameters have been revised to optimize the operating conditions, in view of a more industrial approach. The experimental conditions presented here are now superior to those of literature and the yields of esters show 78% of fructose laurate. Analytical methods have been perfected and rapid methods (based on different TLC conditions depending on the desired information), accurate methods (based on HPLC) and several purification methods were developed. [less ▲]

Detailed reference viewed: 13 (1 ULg)
Full Text
Peer Reviewed
See detailKinetics of the hydrolysis of polysaccharide galacturonic acid and neutral sugars chains from flaxseed mucilage
Happi Emaga, Thomas; Rabetafika, Holy-Nadia ULg; Blecker, Christophe ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(2), 139-147

Detailed reference viewed: 38 (15 ULg)
Full Text
See detailEnzymatic process development for the extraction of ferulic acid from wheat bran
Giet, Jean-Michel ULg; Blecker, Christophe ULg

Poster (2012)

The agro-industries generate each year thousands of tons of by-products, such as cereal bran or sugar beet pulps. For instance, Walloon wheat transformation industry provides annually about 200.000 tons ... [more ▼]

The agro-industries generate each year thousands of tons of by-products, such as cereal bran or sugar beet pulps. For instance, Walloon wheat transformation industry provides annually about 200.000 tons of bran. Most of those by-products are under-valorized as cattle feed. By the use of biorefinery, this biomass may constitute a renewable source for various value-added molecules like dietary fibres, proteins, antioxidants, and more. [less ▲]

Detailed reference viewed: 38 (4 ULg)
Full Text
See detailL'homme produit - L'alimentation
Blecker, Christophe ULg

in Haubruge, Eric; Bay, Daniel; Semal, Jean (Eds.) Scaphandre - La science rencontre l'art (2012)

Detailed reference viewed: 19 (8 ULg)
Full Text
Peer Reviewed
See detailLiquid Crystalline Phases Induced by the Hydroxyl Group Stereochemistry of Amphiphilic Carbohydrate Bicatenary Derivatives
Razafindralambo, Hary ULg; Richel, Aurore ULg; Paquot, Michel ULg et al

in Journal of Physical Chemistry B (2012), 116(13), 3998-4005

Liquid-crystals (LC) may exist in different phases depending upon the orientational and positional orders of molecules in the material. Here, we demonstrate that the class of LC state induced by ... [more ▼]

Liquid-crystals (LC) may exist in different phases depending upon the orientational and positional orders of molecules in the material. Here, we demonstrate that the class of LC state induced by amphiphilic carbohydrate bicatenary derivatives is strictly a hydroxyl group stereochemistry-dependent. This statement results from the experimental and theoretical investigations of surface film (2D) and bulk solid (3D) thermal behavior of synthetic stereoisomers n-tetradecyl (-D-n-tetradecyl) galacto- and gluco-pyranosiduronate, with an axial (GalA-C14/14) or equatorial (GlcA-C14/14) hydroxyl group at the fourth carbon, respectively. Surface pressure-area isotherms (283 K to 310 K), differential scanning calorimetry thermograms (223 K to 573 K), and polarized optical textures (298-363 K) reveal that GlcA-C14/14 organizes as a smectic LC-like phase (positional or lateral order) whereas the analogous stereoisomeric GalA-C14/14 behaves as a nematic LC-like phase (orientational order). Thermodynamic investigations and molecular dynamics models computed under similar temperature conditions provide consistent data with physical properties resulting from experimental approaches. [less ▲]

Detailed reference viewed: 54 (23 ULg)
Full Text
Peer Reviewed
See detailAgronomical factors influencing the legumin/ vicilin ratio in pea (Pisum sativum L.) seeds
Mertens, Cécile ULg; Dehon, Lydie; Bourgeois, Audrey et al

in Journal of the Science of Food and Agriculture (2012)

BACKGROUND: Many research studies have investigated the impact of agronomical factors on the protein content of pea (Pisum sativum). This study aimed to establish if a correlation exists between protein ... [more ▼]

BACKGROUND: Many research studies have investigated the impact of agronomical factors on the protein content of pea (Pisum sativum). This study aimed to establish if a correlation exists between protein content and legumin/vicilin (L/V) ratio in pea seeds and to identify agronomical factors that have an impact on this ratio. RESULTS: The L/V ratio was positively correlated with protein content (r = 0.58, P ≤ 0.01), but no linear regression was applicable (adjusted R² = 0.31). Both variety and cultivation year had a highly significant effect on the ratio (P < 0.001). The interaction between these two factors was also highly significant (P < 0.001), some varieties being less sensitive to climatic conditions than others. Cultivation location had a highly significant effect (P < 0.01). There was no interaction between variety and location. Seeding density had a highly significant effect on the ratio (P < 0.01),with a saturation effect above 60 seeds/m². CONCLUSION: Further studies should establish if a linear regression model can be applied to pea varieties independently. Varieties with a stable L/V ratio can prove to be useful in the food industry. Other agronomical factors (soil type and seeding density) should be considered for the production of pea seeds with a specific L/V ratio. [less ▲]

Detailed reference viewed: 49 (12 ULg)
Full Text
Peer Reviewed
See detailOptimization of formic/acetic acid delignification of Miscanthus ×giganteus for enzymatic hydrolysis using response surface methodology
Vanderghem, Caroline ULg; Brostaux, Yves ULg; Jacquet, Nicolas ULg et al

in Industrial Crops & Products (2012), 35

A Box–Behnken experimental design and response surface methodology were employed to optimize the pretreatment parameters of a formic/acetic acid delignification treatment of Miscanthus ×giganteus for ... [more ▼]

A Box–Behnken experimental design and response surface methodology were employed to optimize the pretreatment parameters of a formic/acetic acid delignification treatment of Miscanthus ×giganteus for enzymatic hydrolysis. The effects of three independent variables, namely cooking time (1, 2 and 3 h), formic acid/acetic acid/water ratio (20/60/20, 30/50/20 and 40/40/20) and temperature (80, 90 and 107 ◦C) on pulp yield, residual Klason lignin content, concentration of degradation products (furfural and hydroxymethylfurfural) in the black liquor, and enzymatic digestibility of the pulps were investigated. The major parameter influencing was the temperature for pulp yield, delignification degree, furfural production and enzymatic digestibility. According to the response surface analysis the optimum conditions predicted for a maximum enzymatic digestibility of the glucan (75.3%) would be obtained using a cooking time of 3 h, at 107 ◦C and with a formic acid/acetic acid/water ratio of 40/40/20%. Glucan digestibility was highly dependent on the delignification degree. [less ▲]

Detailed reference viewed: 79 (36 ULg)
Full Text
Peer Reviewed
See detailStructure, properties and obtention routes of flaxseed lignan secoisolariciresinol
Sainvitu, Pauline ULg; Nott, Katherine ULg; Richard, Gaetan ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(1), 115-124

Following a brief description of the structure and nomenclature of the lignan family, this review focuses on the flaxseed lignan secoisolariciresinol (SECO). The main properties, the analysis methods and ... [more ▼]

Following a brief description of the structure and nomenclature of the lignan family, this review focuses on the flaxseed lignan secoisolariciresinol (SECO). The main properties, the analysis methods and two routes for the preparation of SECO, i.e. extraction from renewable raw material and (hemi)-synthesis, are reviewed. Green methods recently developed for the first route and chemical syntheses inspired from biosyntheses for the second one are the main subjects of this paper. [less ▲]

Detailed reference viewed: 122 (41 ULg)
Full Text
Peer Reviewed
See detailDietary fibre characteristics and antioxydant activity of sesame seed coats
Elleuch, M.; Bedigian, D.; Besbes, S. et al

in International Journal of Food Properties (2011), 15(1), 25-37

The dietary fibre contained in the seed coats (testae) of sesame, by-products of the dehulling processes during the manufacture of sweetened sesame paste (halaweh), were evaluated with two assays: the ... [more ▼]

The dietary fibre contained in the seed coats (testae) of sesame, by-products of the dehulling processes during the manufacture of sweetened sesame paste (halaweh), were evaluated with two assays: the AOAC enzymatic-gravimetric method and the enzymatic-chemical method. Functional properties and antioxidant activity of sesame seed coats were also determined. The total, insoluble, and soluble dietary fibre contents measured were significantly higher using the AOAC method, than with the enzymatic-chemical method. The dietary fibre contained high amounts of neutral sugars (15.11 g/100 g seed coat dry matter), insoluble uronic acids (10.52 g/100 g seed coat dry matter), and lignin (5.42 g/100 g seed coat dry matter). Physical property analyses showed a high positive correlation between particle size reduction of seed coat, water holding capacity, and oil holding capacity; however, there was a negative correlation with bulk density. Sesame testae showed a relatively high polyphenol content (9.9 mg/g of seed coat dry matter). Aqueous methanol, ethanol, and acetone extracts of seed coats yielded similar polyphenol levels (75 mg/g of extract), higher than those found in aqueous extracts (52.7 mg/g of extract). Aqueous organic solvent extracts possessed higher antioxidant activity than water extracts. Our results suggested that sesame seed coats can be used in the preparation of low calorie, high fibre, and antioxidant-rich foods. [less ▲]

Detailed reference viewed: 105 (20 ULg)
Full Text
Peer Reviewed
See detailInfluence des traitements de steam explosion sur la dégradation thermique des fibres de cellulose
Jacquet, Nicolas ULg; Quievy; Vanderghem, Caroline ULg et al

Poster (2011, December)

La présente étude a pour but d’identifier l’impact de différents traitements de steam explosion sur les propriétés de dégradation thermique des fibres de cellulose. Dans un premier temps, les intensités ... [more ▼]

La présente étude a pour but d’identifier l’impact de différents traitements de steam explosion sur les propriétés de dégradation thermique des fibres de cellulose. Dans un premier temps, les intensités des traitements appliqués ont été définies sur base d’un facteur de sévérité (SF), établi par une corrélation entre le temps de séjour et la température du process. Les résultats obtenus montrent que la dégradation thermique des fibres de cellulose reste limitée lorsque la valeur du facteur de sévérité est inférieure à 4.0. Aux intensités supérieures, le dosage des produits de dégradation montre une croissante importante des concentrations en hydroxyméthylfurfurals (5-HMF) dans les phases liquides issues des différents traitements. Lorsque la valeur du facteur de sévérité dépasse 5.2, les analyses TGA indiquent que l’augmentation des produits de dégradation est couplée à une croissance importante du taux de résidus carbonés, indiquant une forte dégradation thermique de la cellulose [less ▲]

Detailed reference viewed: 61 (26 ULg)
Full Text
Peer Reviewed
See detailInfluence des traitements de steam explosion sur la dégradation thermique des fibres de cellulose
Jacquet, Nicolas ULg; Quievy, Nicolas; Vanderghem, Caroline ULg et al

in Récents Progrès en Génie des Procédés (2011), 101

The aim of this study is to identify the impact of different steam explosion treatments on the thermal degradation of cellulose fibers. The intensities of the treatments were defined by a severity factor ... [more ▼]

The aim of this study is to identify the impact of different steam explosion treatments on the thermal degradation of cellulose fibers. The intensities of the treatments were defined by a severity factor (SF), based on the residence time and the process temperature. The results obtained show that thermal degradation of cellulose fibers is limited when the severity factor value is below 4.0. At higher intensities, determination of thermal degradation products shows a significant increase of the hydroxymethylfurfural (5-HMF) amount when increasing the intensity of the treatment. When the severity factor reached 5.2, TGA analysis shows that the increase of degradation products is coupled to an increase of the char level meaning a strong degradation of the cellulose. [less ▲]

Detailed reference viewed: 50 (23 ULg)
Full Text
See detailCombination of lipase catalysis and thiol-Michael addition for the synthesis of carbohydrate esters used as stabilizers in supercritical carbon dioxide emulsions
Boyère, Cédric ULg; Favrelle, Audrey; Broze, Guy ULg et al

Poster (2011, November 21)

The use of aqueous dispersed media, such as emulsions and miniemulsions, has many advantages over solution processes for chemical transformations and polymerization reactions, i.e. limited environmental ... [more ▼]

The use of aqueous dispersed media, such as emulsions and miniemulsions, has many advantages over solution processes for chemical transformations and polymerization reactions, i.e. limited environmental impact, ease of products recovery and increased reaction rate. Although, dispersed media are usually implemented from water/solvent mixtures, supercritical carbon dioxide (scCO2) (Pc =74 bars; Tc = 31°C) constitutes an interesting alternative to the traditional organic solvents because it is inexpensive, non-toxic, non-flammable and environmentally friendlier. In this context, we develop a novel class of surface active compounds able to stabilize water/scCO2 emulsions, i.e. fluorinated modified carbohydrates. The hydrophilic head of the surfactant consists in a sugar moiety whereas the fluorinated tail has a strong affinity for the scCO2 phase. These carbohydrate esters are prepared by a two-step strategy which takes advantage of the selectivity of enzymatic catalysis and the versatility of the thiol-Michael addition reaction. The new thiolated mannose intermediate is a useful building block for the incorporation of unprotected sugar moieties into complex molecules. The surface active properties of the fluorinated derivatives have been evaluated as well as their use as stabilizers for the preparation of microparticles and highly porous polymer materials in scCO2. [less ▲]

Detailed reference viewed: 48 (5 ULg)
Full Text
Peer Reviewed
See detailKinetics of the hydrolysis of polysaccharide galacturonic acid and neutral sugars chains from flaxseed mucilage
Happi Emaga, Thomas; Rabetafika, Holy-Nadia ULg; Blecker, Christophe ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2011), (2012 16(2)), 139-147



Detailed reference viewed: 10 (6 ULg)
Full Text
Peer Reviewed
See detailLipase catalysis and thiol-Michael addition: a relevant association for the synthesis of new surface active carbohydrate esters
Boyère, Cédric ULg; Favrelle, Audrey ULg; Broze, Guy ULg et al

in Carbohydrate Research (2011), 346(14), 2121-2125

A novel class of surface-active carbohydrate esters is prepared by a two-step strategy that takes advantage of the selectivity of enzymatic catalysis and the versatility of the thiol-Michael addition ... [more ▼]

A novel class of surface-active carbohydrate esters is prepared by a two-step strategy that takes advantage of the selectivity of enzymatic catalysis and the versatility of the thiol-Michael addition reaction. The surfactant performance of the produced aliphatic, fluorinated and silicon based sugar esters are evaluated by surface tension measurements. The novel thiolated mannose, made available in this work, appears as a powerful building block for the incorporation of unprotected sugar moieties into complex molecules. [less ▲]

Detailed reference viewed: 32 (10 ULg)
Full Text
Peer Reviewed
See detailChemical composition and functional properties of Ulva lactuca seaweed collected in Tunisia
Yaich, H.; Garna, H.; Besbes, S. et al

in Food Chemistry (2011), 128(4), 895-901

The chemical composition and some functional properties of the dried "Ulva lactuca" algae, collected from the littoral between the Taboulba and Sayada area, were determined. The dried "U. lactuca" algae ... [more ▼]

The chemical composition and some functional properties of the dried "Ulva lactuca" algae, collected from the littoral between the Taboulba and Sayada area, were determined. The dried "U. lactuca" algae were investigated for their soluble, insoluble and total dietary fibre content, mineral amount, amino acid and fatty acid profiles, swelling capacity (SWC), water holding capacity (WHC) and oil holding capacity (OHC). Results showed that "U. lactuca" alga powder was characterised by a high content of fibres (54.0%), minerals (19.6%), proteins (8.5%) and lipids (7.9%). The neutral fibres contain hemicellulose (20.6%), cellulose (9.0%) and lignin (1.7%). The proteinic fraction analysis indicated the presence of essential amino acids, which represent 42.0% of the total amino acids. The fatty acids profile was dominated by the palmitic acid, which represents about 60.0% of the total fatty acids, followed by oleic acid (16.0%). The study of the functional properties proved that SWC, WHC and OHC of this alga varied with temperatures and that were comparable to those of some commercial fibre rich products. (C) 2011 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 284 (7 ULg)