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Introduction
Publications
Publications (67)
Low (20 kHz) and intermediate (100 kHz) frequency ultrasound (US) were studied for their efficiency on cell destruction and metabolites extraction of the microalga T. suecica. This study revealed different levels of cell destruction. Firstly, the prolonged irradiation of US at low frequency allowed the extraction of 90% of total proteins and 70% of...
Microalgae fractionation was investigated combining supercritical carbon dioxide extraction of lipids and pigments and protein extraction from the residues, on Chlorella vulgaris and Nannochloropsis oculata. The results indicated that for N. oculata, chlorophyll (a) is extracted rapidly and selectively apart from Chlorophyll (b), representing 34% a...
The nature of the main primary mechanisms involved in lignocellulosic fast pyrolysis is often assumed to be radical mechanisms. Here we demonstrate that thermal depolymerization of native hemicelluloses can undergo several primary and secondary concerted reactions leading to light oxygenates that can compete with radical mechanisms. To model these...
Fractionation of lignocellulose is a fundamental step in the valorization of cellulose, hemicelluloses, and lignin to produce various sustainable fuels and chemicals. Mineral acid fractionation is one of the most applied process and leads to the solubilization and hydrolysis of cellulose and hemicelluloses, whereas most of the lignin remains insolu...
A fungal biofilm of Scedosporium dehoogii was successfully elaborated and used as a bio anode in a microbial fuel
cell device. The cathode was a carbon felt electrochemically modified by electrodeposition of a film of poly-Ni(II)
tetrasulphonated phthalocyanine (poly-NiTSPc). The elaborated biofilm, formed by electrodeposition of a suspension
of Sc...
Extrusion is a widely used process in the industry to produce foods with specific technological properties (color, texture, aroma, etc.). Its use dates back to the 1950s, mainly in extrusion cooking. Extrusion cooking is considered as a thermoplastic process, whose treatment is done at high temperature and with a short residence time. The mechanica...
Mild alkaline treatment (1.5% NaOH (w/v), solid:liquid ratio of 1:20, 60 °C, 6 h) of sugarcane bagasse (SCB) produced an extract composed of hemicelluloses, lignin, phenolic monomers and acetic acid. The purification of this extract, usually considered a by-product in lignocellulosic biorefineries, is of major importance to give value to the whole...
Sugarcane bagasse (SCB) was treated under mild alkaline conditions (solid:liquid ratio of 1:20 (w/v), 1.5% NaOH (w/v), 60 °C, 6 h) to fractionate the lignocellulose in order to produce a typical mild alkaline extract from a lignocellulosic biomass. The solid residue was enriched in cellulose, while the SCB alkaline extract contained lignin and hemi...
This study deals with the selective extraction of neutral lipids from microalgae. We investigated the consequences of bypassing cell-wall disintegration before supercritical carbon dioxide extraction. Different operating parameters (use of co-solvent, pressure, and time) were tested on freeze-dried Chlorella vulgaris and Nannochloropsis oculata. Th...
Spirulina sp. is a marine biomass with high valuable molecules content, such as proteins and pigments difficult to recover. Low frequency ultrasound has been investigated as selective extraction method in order to reduce the number of downstream steps. In the case of Spirulina, the results indicate that protein extraction was high, at a value of al...
A Doehlert experimental design was conducted and surface response methodology was used to determine the effect of temperature, contact time and solid liquid ratio on isoflavone extraction from soybean flour or Soybean Protein Isolate in pressurized water system. The optimal conditions conducted gave an extraction yield of 85% from soybean flour. Fo...
Biorefinery for Food, Fuels and Materials 2015 symposium - BFFM 2015, 15 June 2015 - 17 June 2015 (Montpellier, France)
A two-stage ultrafiltration process was applied to the aqueous phase of Tetraselmis suecica after breaking its cell wall by high-pressure homogenization. Microscopic observation revealed that the cells were completely disrupted from 600 bar and cell fragmentation of the cells was also noticeable after 800 bar. In addition, the highest concentration...
The influence of bead milling on the extraction of lipids and pigments by supercritical carbon dioxide was investigated in this study. Different operating parameters for the 3-h process were first tested on raw Chlorella vulgaris; 600 bar was the optimum pressure at 60 °C with a carbon dioxide flow rate of 30 g min−1. Under these operating conditio...
The objective of this study was to manufacture new thermal insulation fiberboards by thermo-pressing. The starting material was a slightly deoiled cake (17.6% oil content), generated during the biorefinery of sunflower (Helianthus annuus L.) whole plant in a co-rotating (Clextral BC 45, France) twin-screw extruder. All fiberboards produced were coh...
The microalgal structure has been investigated to evaluate the release of proteins in aqueous media from
five microalgae after conducting different cell disruption techniques: manual grinding, ultrasonication, alkaline treatment, and high-pressure treatment. After conducting cell disruption, the protein concentration in water was determined for all...
Alfalfa was studied to define a new approach for green plant fractionation using twin-screw extrusion, leading to the production of a green filtrate, rich in proteins and a solid fibrous residue, rich in cellulose. The influence of the screw profile on protein recovery in the liquid extract and on plant dehydration was characterised. Three screw pr...
Biorefinery of sunflower whole plant is conducted according to an aqueous process using a twin-screw extruder. Aqueous extraction of oil is looked upon as an environmentally cleaner alternative technology to solvent extraction. Twin-screw extruder carries out three unit operations continuously: conditioning and grinding of whole plant, liquid/solid...
The aim of this study is to develop a new approach to green plant fractionation using twin-screw extrusion, leading to the production of a green filtrate, rich in proteins and a solid fibrous residue, rich in cellulose. The influence of the screw profile on protein recovery in the liquid extract and on plant dehydration was characterized. Two screw...
Purpose
Life cycle assessment (LCA) methodology is a well-established analytical method to quantify environmental impacts, which has been mainly applied to products. However, recent literature would suggest that it has also the potential as an analysis and design tool for processes, and stresses that one of the biggest challenges of this decade in...
L'invention concerne un procédé de fabrication d'un matériau solide à partir d'une composition de plante oléagineuse, dans lequel : - on soumet d'abord ladite composition de plante oléagineuse à un traitement, dit traitement thermo-mécano-chimique, dans lequel on réalise une trituration de ladite composition de plante oléagineuse dans l'eau de faço...
The amino acid profile of the red microalga Porphyridium cruentum and its protein extract have been determined in order to assess the nutritional quality of this biomass for human consumption. Total protein determined by elemental analysis represented 56 % of its dry weight. Hydro-soluble proteins extracted at pH 12 and 40 °C were analysed by the L...
Additional evidence about the influence of the cell wall physical and chemical characteristics on protein extractability was determined by calculating the conversion factors of five different microalgae known to have different cell wall composition, and their protein extracts. The conversion factors obtained for crude rigid cell walled Chlorella vu...
A process for hemicelluloses fractionation and purification from wheat straw and bran has been investigated and technical considerations (yields, purity) have been coupled to environmental characterizations (water consumption, carbon dioxide emissions) in order to develop an environment-friendly process. Extraction by twin-screw extrusion gave a yi...
Production of avocado oil could be a way of reducing avocado post-harvest losses in Cameroon. The optimization of extraction of oil from five varieties of avocado was conducted using the Response Surface Methodology (RSM). The five varieties were Booth 7, Booth 8, Collinson, Hickson and Lula. The extraction efficiency (EE) was investigated with res...
Twin-screw extrusion is an original solution for the biorefinery of sunflower whole plant according to an aqueous extraction process. In best operating conditions, oil yield is 57% and residual oil content in the cake meal is 14%. Oil is extracted in the form of two oil-in-water emulsions stabilized by phospholipids and proteins at interface.
The c...
A filtration unit composed of two reverse osmosis membranes in series was evaluated for haemodialysis water production. For this purpose, hard and soft water were formulated based on European drinking water directives. The study showed that the double reverse osmosis process is efficient to produce haemodialysis water with the quality defined by th...
A twin-screw extruder was used for the extraction of wheat bran hemicelluloses by the co-extrusion of wheat straw and bran. As compared with a stirred reactor extraction, a twin-screw extruder resulted in a lower extraction rate (only about 24% of hemicelluloses in the wheat bran), but it has the advantages of a shorter residence time for the veget...
A new application of twin-screw extruder as a machine to conduct a thermo-mechanical pressing and a solvent extraction of sunflower oil in a single step and in a continuous mode was studied. Experiments were conducted using a CLEXTRAL BC 45 co-rotating twin-screw extruder and whole sunflower seeds with fatty acid methyl esters as a solvent. The inf...
The objective of this study is to evaluate the feasibility of an aqueous process for the biorefinery of sunflower whole plant using a co-rotating twin-screw extruder. Traditionally, aqueous extraction of oil is looked upon as an environmentally cleaner alternative technology to the solvent extraction (Rosenthal et al., 1996) and the twin-screw extr...
Twin-screw extrusion has been used for the protein extraction from sunflower and alfalfa. Thermo-mechanical fractionation and aqueous extraction are conducted simultaneously to collect separately a liquid extract and a solid raffinate.
From sunflower whole plant, squeezing in the reversed screws is favored by the fibers abundance in the stalk, and...
The objective of this study was to evaluate the feasibility of an aqueous process for the biorefinery of sunflower whole plant using a twin-screw extruder. Aqueous extraction of oil was chosen as an environment-friendly alternative to the solvent extraction. The extruder was used to carry out three essential unit operations: grinding, liquid/solid...
Biorefinery of sunflower whole plant can be realized using a twin-screw extruder. Thermo-mechanical fractionation and aqueous extraction are conducted simultaneously. A filter section is outfitted along the barrel to collect continuously an extract and a raffinate (cake meal). Oil yield obtained is 53%. Proteins are partly extracted at the same tim...
Biorefinery of sunflower whole plant can be conducted with water by thermo-mechano-chemical fractionation in a Clextral BC 45 (France) co-penetrating and co-rotating twin-screw extruder. An extract and a raffinate are produced separately and in a single continuous step.
The arrangement of screw profile makes possible to define three successive zone...
Fractionation of sunflower whole plant is carried out with water in a twin-screw extruder. An extract and a raffinate are produced in a single step. Oil extraction yield is 55%. Lipids are extracted in the form of two oil-in-water emulsions: the higher hydrophobic phase and the lower one.
Stability of both hydrophobic phases is ensured by the prese...
Twin-screw extrusion is a powerful solution for biorefinery of sunflower whole plant. Thermomechanical fractionation and aqueous extraction are conducted simultaneously. A filter is outfitted along the barrel to collect a filtrate and a cake meal. Best oil yield is 57%. Proteins are also partly extracted, just as pectins. The cake meal is relativel...
The objective of this study was to evaluate the feasibility of an aqueous process to extract the residual oil from sunflower press cakes using a co-rotating twin-screw extruder. Two different configurations were tested: the expression from whole seeds followed by the aqueous extraction, in two successive apparatus or in the same one. For the aqueou...
The objective of this study was to evaluate the feasibility of an aqueous process to extract sunflower seed oil using a co-rotating twin-screw extruder. Aqueous extraction was carried out using whole seeds and the influence of the operating conditions on oil yield was examined. Operating conditions included screw profile, screw rotation speed, and...
Aqueous extraction process is an alternative to the solvent oil extraction process from oilseeds. It enables simultaneous recovery of oil and protein. Water extraction of sunflower oil is carried out with a mixer (model Waring Blendor, USA) as batch reactor (seeds/water: 15/85). This only apparatus carries out two essential unit operations: conditi...
Aqueous extraction of sunflower oil is a reasonable environment-friendly alternative to the solvent extraction. It can even be realized directly from the whole plant using the twin-screw extrusion technology. Co-rotating twin-screw extruder behaves like a chemo-thermo-mechanical reactor. Equipped with a filtration module, it allows to separate extr...
Aqueous extraction process using water alone as medium is an alternative to the solvent oil extraction process from oilseeds. It enables simultaneous recovery of oil and protein. The implementation of a co-rotating twin-screw extruder allows the aqueous extraction of oleic sunflower oil from whole plant.
Screw configuration, screw rotation speed an...
The objective of this study was to investigate the screw configuration allowing oil extraction from sunflower seeds with a twin-screw extruder. Experiments were conducted using a co-rotating twin-screw extruder. Five screw profiles were examined to define the best performance (oil extraction yield, specific mechanical energy and oil quality) by stu...
The objective of this study was to investigate the effects of screw configuration, position of screw elements and spacing between them allowing to realize oil extraction of oleic sunflower seeds on a twin-screw extruder. Experiments were conducted using a co-rotating twin-screw extruder (Model Clextral BC 45, France). Twelve screw profiles were exa...
Diester manufacturing plants produce large quantities of glycerol solutions. Their economic development requires sodium sulfate elimination to obtain glycerol rates over 80% of the initial content. Conventional electrodialysis (ED) and bipolar electrodialysis (BED) were investigated for their performances in the demineralisation of effluents. Resul...
Diester manufacturing plants produce large quantities of glycerol solutions. Their economic development requiressodium sulfate elimination to obtain glycerol rates over 80% of the initial content. Conventional electrodialysis (ED) and bipolar electrodialysis (BED) were investigated for their performances in the demineralisation of effluents. Result...
Xylans can be coextracted from wheat straw and bran in a twin-screw extruder. The best results for both the production yield and the extract properties are obtained with low alkali content, as the majority of the xylans comes from bran. The desired concentration of the extract solution can be achieved by ultrafiltration. The membrane configuration...
Diester plants produce large quantities of glycerin solutions, whose commercial exploitation requires sodium sulphate elimination. Bipolar electrodialysis (BED) has been investigated for its capability to both demineralize solutions and to produce alkali and acid solutions. Demineralization rates above 80% were achieved with glycerin loss below 2%....
Ultrafiltration has been investigated for the concentration of diluted biopolymer solutions. Trials were realized with membranes of different molecular weight cut off (MWCO) and configuration modules. Results indicates that hollow fiber module gives the best results with the membrane of 6 kilodalton (kD). Arabinoxylan solutions were concentrated wi...
A model is developed which describes mass transfer through the combination of convective–diffusive flux in the pores and a diffusive flux in the membrane material. This model takes into account membrane (membrane permeability, pore size) and solution (charge and size of the molecule) characteristics via five parameters which can be estimated from e...
Three membranes with a molecular weight but off (MWCO) of respectively 100 Da, 200 Da and 400 Da were tested for whey permeate treatment. The 400 Da membrane can perform a partial demineralisation of whey permeate with an optimal pressure of 15 MPa and a tangential velocity of 0.7 m/s. Under these conditions, the 400 Da membrane realises an extract...
Two tight nanofiltration membranes of 100 and 400 Da were tested at different operating conditions. The results show that the selective properties of nanofiltration membranes come from a combination of several physicochemical mechanisms. Mass transport is mainly diffusive in the 100 Da membrane, while two mechanisms of segregation exist in the 400...
Les membranes de nanofiltration sont caractérisées par leurs propriétés de séparation soit de molécules organique de bas poids moléculaire et des sels, soit des sels de valence différentes. Leur capacité de fractionnement est de plus en plus utilisée dans le traitement de l'eau ou le traitement d'effluents polluants d'origine industriel mais aussi...
Food industry by-products such as molasses and vinasses may provide an important source of organic acids. The aim of this study is to compare three processes, precipitation, chromatography and liquid-liquid extraction, for the recovery of carboxylic acids from sugarcane molasses from Réunion Island. Precipitation was performed with different temper...
Ultrafiltration is a very efficient concentration method prior to the atomization of biopolymers extracted from plants. Trials for the concentration of rhamnogalacturonan solutions were realized with PES membrane cassettes with a molecular weight cut-off (MWCO) ranging from 1kDa to 50 kDa. The higher rejection rates were obtained by the two membran...
La synthèse d’esters à partir d’acides gras naturels est un enjeu très important dans le cadre du développement de l’utilisation des ressources renouvelables. Ces réactions peuvent être catalysées avec des enzymes, dont le coût d’utilisation reste néanmoins une limitation. L’immobilisation des enzymes augmente leur stabilité mais peut diminuer le r...
