References of "Richel, Aurore"
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See detailExtraction by three processes of arabinoxylans from wheat bran and characterization of the fractions obtained
Aguedo, Mario ULg; Fougnies, Christian; DERMIENCE, Michael ULg et al

in Carbohydrate Polymers (2014), 105

Arabinoxylans (AXs) were extracted from destarched wheat bran (DWB) according to different processes, with a view to their production at industrial scale. Two fractions (F3a and F3b, respectively purified ... [more ▼]

Arabinoxylans (AXs) were extracted from destarched wheat bran (DWB) according to different processes, with a view to their production at industrial scale. Two fractions (F3a and F3b, respectively purified on 10 kDa and 100 kDa ultrafiltration membranes) were obtained with low yields by treating DWB with an endoxylanase and this process left a solid residue exhausted in enzyme-extractable AXs (EDWB). F1 and F2 AX fractions were obtained by treatment with sodium hydroxide of respectively DWB and EDWB. The fraction F4 resulted from a hydrothermal treatment of EDWB in a pressure reactor, followed by ethanol precipitation. The different AX fractions were characterized and compared for the composition in monosaccharides, for the contents in fats and in ferulic, phytic and uronic acids, for the molecular mass distribution and the degrees of methylation and acetylation. The alkaline extractions gave one desesterified AX population with molecular mass (MM) higher than 670 kDa and arabinose/xylose ratios (Ara/Xyl) around 1. The enzyme and thermal treatments yielded AXs with two main populations in size-exclusion chromatography (the largest one at 5-12.5 kDa and a second one at 140-160 kDa), having overall Ara/Xyl of respectively 0.7 and 0.5 for both processes. These data bring information about the influence of the process on the characteristics of AX fractions obtained from pretreated wheat bran. Here are also reported processes that enabled to recover enzyme-unextractable AXs from DWB, including an original and up-scalable hydrothermal extraction. Phytate contents of isolated AXs are described for the first time. [less ▲]

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See detailEvaluation of bio-based additives in architectural paints
Wenkin, M.; Delvaux, M.H.; de Lame, C. et al

Poster (2014)

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See detailImpact of purification and fractionation process on the chemical structure and physical properties of locust bean gum
Gillet, Sébastien ULg; Blecker, Christophe ULg; Aguedo, Mario ULg et al

in Carbohydrate Polymers (2014)

Crude locust bean gum (CLBG) was purified and fractionated into two parts : the first was obtained by solubilization in water at 25 °C (GM25) and the second consisted in a further extraction at 80 °C on ... [more ▼]

Crude locust bean gum (CLBG) was purified and fractionated into two parts : the first was obtained by solubilization in water at 25 °C (GM25) and the second consisted in a further extraction at 80 °C on the residual impoverished fraction (GM80). The complete structural characterization has shown that GM80 possessed relatively longer chain lengths than GM25, a slightly lower degree of galactose substitution and a somewhat sharper galactosyl distribution in substituted and unsubstituted regions. A physical behavior analysis was carried out on solubilization kinetics, viscosity, viscoelasticity and formation of associated gels with xanthan or carrageenan. The average structure of GM80 generated larger intra-chain, inter-chain and inter-molecular interactions, resulting in the appearance of a stronger network. Small structural differences therefore generated very different physical behaviors. This study thus allowed to establish, in a precise and complete manner, fractionation-purification-structure-function relationships of galactomannans extracted from carob. [less ▲]

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See detailSynthese bibliographique de l'influence du procédé d'extraction et de purification sur les caractéristiques et les propriétés d'une gomme de caroube
Gillet, Sébastien ULg; Simon, mathilde; Paquot, Michel ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18(1),

The carob tree is a species cultivated, in mediterranean countries, for its seeds. These seeds contain an endosperm rich in galactomannans used by the food industry for its texturing properties. After ... [more ▼]

The carob tree is a species cultivated, in mediterranean countries, for its seeds. These seeds contain an endosperm rich in galactomannans used by the food industry for its texturing properties. After harvesting, the seeds pass through a decutilation and a degermination. Cleaned endosperms are then milled to give crude locust bean gum. The purification step consists in a flour solubilization and then a precipitation of the galactomannans. Purification influences the characteristics of the resulting gum. The solubilization temperature is the parameter that affects the most on the final characteristics of the product. If it is hot or cold, galactomannans with different structural characteristics (and thus very different physical properties in aqueous solutions) will be selected. [less ▲]

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See detailLignin as a raw material for industrial materials applications
Richel, Aurore ULg; Vanderghem, Caroline ULg; Jacquet, Nicolas ULg et al

Poster (2014)

Native lignin is an abundant biopolymer on earth and represents 15-30% by weight of the lignocellulosic biomass. Lignin is a heterogeneous cross-linked polymer composed of phenylpropane units (guaiacyl ... [more ▼]

Native lignin is an abundant biopolymer on earth and represents 15-30% by weight of the lignocellulosic biomass. Lignin is a heterogeneous cross-linked polymer composed of phenylpropane units (guaiacyl, syringyl or p-hydroxyphenyl) linked together by a panel of specific ether or carbon-carbon bonds.[1] Nowadays, large amounts of lignins and lignin-based wastes are available and originate either from the pulp and paper manufacturing or from the production of bioethanol from lignocellulose. [2] Typically, these lignins are dedicated to energetic purposes by combustion. In recent years however, novel axes for high added value applications have emerged and concern, notably, the use of lignin as performance products (e.g. polymer additives, binders) or specialty chemicals (e.g. surface-active agents) for materials applications.[3] Herein, several applications of lignin in materials sciences with industrial issues are presented. A correlation is established between the extraction processes from lignocellulosic materials and the chemical structure and physico-chemical properties of lignins.[4] Our research group has also developed new methodologies for the extraction of highly pure lignins from several starting materials, including food wastes, herbaceous raw materials and wood biomass. These methodologies include microwave-assisted extraction and two-step conventional pretreatment involving steam explosion. These methodologies are described in this presentation. [less ▲]

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See detailBio-based paints
Olive, Gilles ULg; Richel, Aurore ULg

Poster (2013, November 27)

Paints, at the coating meaning, are known since a long time. Typically, paint is a dispersion of one or more powders (pigments and fillers) in a macromolecular substance ("resin"), called film-forming ... [more ▼]

Paints, at the coating meaning, are known since a long time. Typically, paint is a dispersion of one or more powders (pigments and fillers) in a macromolecular substance ("resin"), called film-forming material, diluted in solvents. [less ▲]

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See detailOld inks: plant-based inks
Wymeersch, Noémie; Despy, Jessica; Bouchat, Isabelle et al

Poster (2013, November 27)

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A ... [more ▼]

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A significant example of this is the Cosquer cave (-19,000 to -27,000 years) located near Marseilles (France). Pigments and dyes can be classified into two broad categories: natural pigments and dyes and those called artificial. These categories are then subdivided into five families. The first one of these five families includes the mineral pigments. Among these we can find the clays (yellow ochre, red ochre, green clay, brown clay) and the stones like lapis lazuli (blue) and malachite (green). The second and third families gather the organic dyes and pigments. Those that have vegetal origins like indigo (blue), weld (yellow) and madder (red) compose the family 2 and those that have animal origins like cochineal (red) and kermes dyers (carmine) form the family 3. One family includes pigments and dyes stemming from chemical reactions such as verdigris or red lead (family 4) and the other one is made of the miscellaneous inks such as iron-gall type who are vegetal and mineral one (family 5). All these pigments, although they have been used for centuries, have been replaced by synthetic dyes from the oil industry at the end of the 19th century. Indeed, they have the advantage of reproducibility of the properties unlike natural pigments. But the scarcity of oil causes a renewed interest in natural preparations. In such purpose, our laboratory in conjunction with the Abbey of Villers-la-Ville has decided to study natural derivatives for inks and focuses in particular on the extraction of pigments from plants. [less ▲]

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See detailLignocellulosic biomass pretreatment impact on the extracted lignins chemical structure
Manara, Panagiota; Zabaniotou, Anastasia; Vanderghem, Caroline ULg et al

Poster (2013, October)

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See detailLignin as a raw material for industrial materials applications
Richel, Aurore ULg; Vanderghem, Caroline ULg; Jacquet, Nicolas ULg et al

Poster (2013, October)

Native lignin is an abundant biopolymer on earth and represents 15-30% by weight of the lignocellulosic biomass. Lignin is a heterogeneous cross-linked polymer composed of phenylpropane units (guaiacyl ... [more ▼]

Native lignin is an abundant biopolymer on earth and represents 15-30% by weight of the lignocellulosic biomass. Lignin is a heterogeneous cross-linked polymer composed of phenylpropane units (guaiacyl, syringyl or p-hydroxyphenyl) linked together by a panel of specific ether or carbon-carbon bonds.[1] Nowadays, large amounts of lignins and lignin-based wastes are available and originate either from the pulp and paper manufacturing or from the production of bioethanol from lignocellulose. [2] Typically, these lignins are dedicated to energetic purposes by combustion. In recent years however, novel axes for high added value applications have emerged and concern, notably, the use of lignin as performance products (e.g. polymer additives, binders) or specialty chemicals (e.g. surface-active agents) for materials applications.[3] Herein, several applications of lignin in materials sciences with industrial issues are presented. A correlation is established between the extraction processes from lignocellulosic materials and the chemical structure and physico-chemical properties of lignins.[4] Our research group has also developed new methodologies for the extraction of highly pure lignins from several starting materials, including food wastes, herbaceous raw materials and wood biomass. These methodologies include microwave-assisted extraction and two-step conventional pretreatment involving steam explosion. These methodologies are described in this presentation. [less ▲]

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See detailGrowth of Chlorella in vanillin enriched medium
Miazek, Krystian ULg; Goffin, Dorothée ULg; Richel, Aurore ULg

Poster (2013, August)

In this work the effect of different concentration of vanillin on the growth of Chlorella culture was evaluated. Two concentrations of vanillin: 60 mg/L and 300 mg/L in Bold Basal Medium (BBM) were tested ... [more ▼]

In this work the effect of different concentration of vanillin on the growth of Chlorella culture was evaluated. Two concentrations of vanillin: 60 mg/L and 300 mg/L in Bold Basal Medium (BBM) were tested and an inoculum from a two month Chlorella sp. (CCBA) culture was used. Vanillin at concentration of 60 mg/L showed to possess stimulating effect on Chlorella growth during 11 days of cultivation. Stimulation of Chlorella started on 3rd day of growth and was accompanied by 87% decrease of vanillin concentration within first 3 days of cultivation and its complete removal from growth media after 7 days. The acceleration of Chlorella growth in vanillin containing medium was detected due to biomass density, up to 1.2 times bigger than in the control culture, but also by measurement of chlorophyll content. Increased amount of chlorophyll content, up to 1.35 times higher than in control, was found between 4th and 11th day of cultivation. The response of Chlorella towards higher concentration of vanillin (300 mg/L) was different when compared to experiments where only 60 mg/L was used. During first 4 days of cultivation, strong inhibition of Chlorella exposed to 300 mg/L vanillin was observed and vanillin concentration maintained at the same initial concentration. During next days, a recovery effect occurred as biomass density and chlorophyll content gradually increased in comparison to the onset of growth and vanillin concentration decreased to 2 % of its initial value. Biomass density measured in Chlorella culture on 11th day was much higher than at the beginning of cultivation but still by 40% smaller than in control and by 50% smaller than in the culture growing in medium with 60 mg/L of vanillin. Chlorophyll content at the end of cultivation constituted 50% of control value and 35% of chlorophyll culture with 60 mg/L vanillin in medium. [less ▲]

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See detailImpact d'un fractionnement soustractif sur la relation structure-fonction de la gomme de caroube
Gillet, Sébastien ULg; Blecker, Christophe ULg; Aguedo, Mario ULg et al

Poster (2013, July 02)

Le choix d'une température de fractionnement de la gomme de caroube va conditionner les caractéristiques des fractions obtenues et par conséquent les potentialité d'applications de ces dernières.

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See detailDéveloppement de nouveaux bioproduits générant une valeur ajoutée
Richel, Aurore ULg

Scientific conference (2013, May 30)

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See detailAmphiphilic structure-surface property relationships of monosaccharide-based surfactants
Razafindralambo, Hary ULg; Nicks, Francois ULg; Richard, Gaetan ULg et al

Poster (2013, April 08)

A set of monosaccharide-based renewable surfactants has been prepared, structurally checked, and systematically screened for different activities and functionalities. These compounds vary in the polar ... [more ▼]

A set of monosaccharide-based renewable surfactants has been prepared, structurally checked, and systematically screened for different activities and functionalities. These compounds vary in the polar head group, linker, and hydrophobic tail. Beyond the goal to find out the most potential valuable surfactants for each measurement, relationships between chemical structure, basic properties, and functionalities have been examined by comparing compounds differing in a single structural variable. In this paper, we show and explain the impact of the anomeric alpha or bêta, neutral or acid sugar derivatives, equatorial or axial position of hydroxyl group, alkyl chain substitute attachment position, number, and length on surface properties of sugar-based surfactants. [less ▲]

Detailed reference viewed: 74 (29 ULg)
See detailExtraction of lignin from Mediterranean agro-wastes: correlation between pretreatment conditions and lignin chemical structure
Manara, Panagiota; Zabaniotou, Anastasia; Richel, Aurore ULg

Conference (2013, January)

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See detailFast and high yield recovery of arabinose from destarched wheat bran
Aguedo, Mario ULg; Vanderghem, Caroline ULg; Goffin, Dorothée ULg et al

in Industrial Crops & Products (2013), 43

Enzymatically destarched wheat bran (DWB) contained 13.8% of arabinose and 23.1% xylose. Up to a maximum of 70% of the arabinose was progressively released from DWB when heated at 80 or 100°C in media ... [more ▼]

Enzymatically destarched wheat bran (DWB) contained 13.8% of arabinose and 23.1% xylose. Up to a maximum of 70% of the arabinose was progressively released from DWB when heated at 80 or 100°C in media acidified with HCl. Whereas microwave irradiation at higher temperatures in pressure vessels could lead to higher yields of extraction. A Box-Behnken experimental design established an efficient model describing the effects of temperature, irradiation duration and pH on arabinose extraction. The pH appeared as the most important factor of the process. 4-5 min of microwave heating at 150ºC and pH 1 appeared as a fast and highly efficient method to recover more than 90% of the arabinose of DWB. When plotting the percentages of arabinose against the combined severity factors LogR’0 (calculated from the temperature/duration/pH conditions applied), two different fitting profiles were obtained for both the heating techniques. Under microwave heating, high free xylose’s release could also occur. The experimental design led to a quadratic model predicting the release of xylose from DWB. A range of conditions enabled to minimize xylose and hydrolyze around 50% of the total arabinose, yielding a high purity fraction. An alternative would be to release more than 90% of both arabinose and xylose, for further arabinose purification or for a common valorization of both pentoses. [less ▲]

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See detailExtraction de molécules à haute valeur ajoutée dans un but de maximisation de la valeur créée
Richel, Aurore ULg

Conference (2013)

Les recherches académiques dans le domaine du bioraffinage sont présentées au travers de schémas complets de valorisation. Les matières premières ciblées sont les résidus agricoles et forestiers, les ... [more ▼]

Les recherches académiques dans le domaine du bioraffinage sont présentées au travers de schémas complets de valorisation. Les matières premières ciblées sont les résidus agricoles et forestiers, les cultures énergétiques et les résidus des industries alimentaires. Le cracking et la conversion ultérieure de ces matières premières permettent l'obtention de biocarburants, bioproduits ou nouvelles formulations (filière biomasse-chimie). [less ▲]

Detailed reference viewed: 24 (7 ULg)