22 research outputs found

    Extraction de lipides en voie aqueuse par bioréacteur enzymatique combiné à l'ultrafiltration (application à la valorisation de co-produits de poisson (Sardina pilchardus))

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    L OBJECTIF DE CE TRAVAIL EST DE VALORISER LES CO-PRODUITS DE SARDINE (SARDINA PILCHARDUS) PAR LA MISE EN ƒUVRE DE TECHNIQUES DOUCES AVEC UN INVESTISSEMENT ET UNE DEPENSE ENERGETIQUE MODERES AFIN D OBTENIR DES COMPOSES D INTERET MAJEUR. LES TECHNIQUES D HYDROLYSE ENZYMATIQUE ET DE SEPARATION MEMBRANAIRE ONT ETE CHOISIES POUR CETTE ETUDE. LES ENZYMES RETENUES POUR CETTE ETUDE ONT TOUT D ABORD ETE ETALONNEES DE FAÇON A DETERMINER LEURS CONDITIONS OPERATOIRES OPTIMALES. LES HYDROLYSES ONT ENSUITE ETE MENEES EN DEUX ETAPES, UNE PREMIERE POUR DETERMINER L EFFICACITE DES ENZYMES SUR LES MATRICES VISEES ET CIBLER LE DOMAINE D ETUDE, LA SECONDE ETAPE A QUANT A ELLE PORTE SUR L OPTIMISATION DE L HYDROLYSE PAR PLAN D EXPERIENCES AVEC POUR OBJECTIF D OBTENIR LA LIBERATION DE LIPIDES LA PLUS IMPORTANTE POSSIBLE EN JOUANT SUR LES PARAMETRES INFLUENTS DE L HYDROLYSE. UNE FOIS CES CONDITIONS DETERMINEES, LA PHASE SOLUBLE RESULTANT DE L HYDROLYSE OPTIMISEE A ETE TRAITEE PAR ULTRAFILTRATION AFIN DE SEPARER LES LIPIDES DES PEPTIDES. LES LIPIDES DES CO-PRODUITS DE SARDINE ONT MAJORITAIREMENT ETE RECUPERES DANS LES PHASES LIQUIDES RESULTANTES DE L HYDROLYSE. LA FRACTION AQUEUSE A DE PLUS MONTRE UNE FORTE TENEUR EN PHOSPHOLIPIDES. LES ACIDES GRAS DE LA FAMILLE DES w3 SONT REPRESENTE A HAUTEUR DE 20% DANS CES FRACTIONS. CONCERNANT LES MATRICES DIFFICILES A BROYER, L EXTRACTION DES LIPIDES A ETE AMELIOREE EN REALISANT UNE HYDROLYSE ENZYMATIQUE PAR RAPPORT A UNE EXTRACTION CLASSIQUE. LE TRAITEMENT PAR ULTRAFILTRATION DE LA PHASE SOLUBLE A PERMIS, APRES DETERMINATION DES PARAMETRES OPERATOIRES, DE SEPARER LES FRACTIONS LIPIDIQUES ET PEPTIDIQUES EN CONCENTRANT LES PHOSPHOLIPIDES DANS LE RETENTAT.THE MAIN GOAL OF THIS WORK WAS TO UP-GRADE SARDINE (SARDINA PILCHARDUS) BY-PRODUCTS USING MILD PROCEDURE, ENVIRONMENTALLY SOUND, IN ORDER TO OBTAIN VALUABLE COMPOUNDS INVOLVING MODERATE INVESTMENT AND LOW ENERGY CONSUMPTION. HYDROLYSIS AND ULTRAFILTRATION TECHNIQUES HAVE BEEN INVESTIGATED. FIRSTLY, SELECTED ENZYMES HAVE BEEN CALIBRATED IN ORDER TO DETERMINE THEIR OPTIMAL CONDITIONS WITH A MODEL SUBSTRATE AND TO PERMIT THE COMPARISON BETWEEN THEM. THEN, HYDROLYSIS ON SARDINE HEAD AND VISCERA HAVE BEEN CARRIED OUT IN TWO STEPS. THE FIRST ONE HAD THE OBJECTIVE TO DETERMINE THE ENZYME EFFICIENCY AND THE STUDY AREA. THE SECOND STEP WAS TO OPTIMISE ENZYMATIC HYDROLYSIS USING EXPERIMENTAL DESIGNS. THE AIM OF THIS SECOND STEP WAS TO OBTAIN THE HIGHEST LIPID RECOVERY IN THE LIQUID FRACTIONS USING THE VARIATION OF THE INFLUENTS HYDROLYSIS PARAMETERS SUCH AS TEMPERATURE, HYDROLYSIS TIME AND ENZYME CONCENTRATION. THE SOLUBLE PHASE OBTAINED AFTER THIS OPTIMISED STEP HAVE BEEN FILTERED USING ULTRAFILTRATION TECHNIQUE IN ORDER TO SEPARATE LIPIDS FROM PEPTIDES. LIPIDS FROM SARDINE BY-PRODUCTS HAVE BEEN MAINLY RECOVERED IN THE LIQUID FRACTIONS OF THE HYDROLYSATES. MOREOVER, AQUEOUS FRACTION HAS SHOWN A HIGH CONTENT OF PHOSPHOLIPIDS. w3 FATTY ACIDS REPRESENT AROUND 20% OF THE TOTAL FATTY ACIDS INTO THOSE FRACTIONS. REGARDING VISCERA, WHICH IS A HARDLY CRUSHING MATRIX, THE LIPID EXTRACTION YIELDS HAVE BEEN IMPROVED USING ENZYMATIC TREATMENT COMPARED TO TRADITIONAL EXTRACTION. THE ULTRAFILTRATION TREATMENT OF THE SOLUBLE PHASE HAS ALLOWED, AFTER THE DETERMINATION OF OPERATING CONDITIONS, TO SEPARATE LIPIDS FROM PEPTIDES AND TO CONCENTRATE THE PHOSPHOLIPIDS IN THE RETENTATE.NANTES-BU Sciences (441092104) / SudocNANTES-Ecole Centrale (441092306) / SudocNANTES-BU Technologie (441092105) / SudocSudocFranceF

    Optimization of R-Phycoerythrin Extraction by Ultrasound-Assisted Enzymatic Hydrolysis: A Comprehensive Study on the Wet Seaweed <i>Grateloupia turuturu</i>

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    Enzyme-assisted extraction (EAE) and ultrasound-assisted extraction (UAE) are both recognized as sustainable processes, but little has been done on the combined process known as ultrasound-assisted enzymatic hydrolysis (UAEH), and even less on seaweed. The present study aimed to optimize the UAEH of the red seaweed Grateloupia turuturu for the extraction of R-phycoerythrin (R-PE) directly from the wet biomass by applying a response surface methodology based on a central composite design. Three parameters were studied: the power of ultrasound, the temperature and the flow rate in the experimental system. Data analysis demonstrated that only the temperature had a significant and negative effect on the R-PE extraction yield. Under the optimized conditions, the R-PE kinetic yield reached a plateau between 90 and 210 min, with a yield of 4.28 ± 0.09 mg·g−1 dry weight (dw) at 180 min, corresponding to a yield 2.3 times higher than with the conventional phosphate buffer extraction on freeze-dried G. turuturu. Furthermore, the increased release of R-PE, carbohydrates, carbon and nitrogen can be associated with the degradation of G. turuturu constitutive polysaccharides, as their average molecular weights had been divided by 2.2 in 210 min. Our results thus demonstrated that an optimized UAEH is an efficient method to extract R-PE from wet G. turuturu without the need for expensive pre-treatment steps found in the conventional extraction. UAEH represents a promising and sustainable approach that should be investigated on biomasses where the recovery of added-value compounds needs to be improved

    Ultrasound-assisted extraction of R-phycoerythrin from Grateloupia turuturu with and without enzyme addition

    No full text
    The aim of this study was to compare two processes for the extraction of R-phycoerythrin (R-PE) from the red seaweed Grateloupia turuturu: ultrasound-assisted extraction (UAE) and ultrasound-assisted enzymatic hydrolysis (UAEH). Process efficiencies were both evaluated by the yield of R-PE extraction and by the level of liquefaction. Experiments were conducted at 40 and 22 °C, for 6 h, using an enzymatic cocktail and an original ultrasonic flow-through reactor. R-PE appeared very sensitive to temperature, thus 22 °C is strongly recommended for its extraction by UAEH or UAE. However, the higher processing temperature (40 °C) clearly increased the extraction of water-soluble compounds (up to 91% of liquefaction). These two new processes are thus promising alternatives for the extraction of water-soluble components including R-PE, from wet seaweeds, with extraction yields at least similar to conventional solid–liquid extraction

    Soft liquefaction of the red seaweed Grateloupia turuturu Yamada by ultrasound-assisted enzymatic hydrolysis process

    No full text
    Ultrasound-assisted enzymatic hydrolysis is a recent process, increasingly employed for plant biomass liquefaction and the recovery of soluble biomolecules. However, to our knowledge, it has never been used on seaweeds, particularly wet ones. The aim of this study was to compare the efficiency of three processes on the liquefaction of the red seaweed Grateloupia turuturu Yamada: enzyme-assisted extraction (EAE), ultrasound-assisted extraction (UAE), and their combination, ultrasound-assisted enzymatic hydrolysis (UAEH). These comparisons will allow the identification as to which process achieves the highest extraction yield of water-soluble compounds. For this purpose, experiments were conducted at 40 °C for 6 h using an enzymatic cocktail of four industrial carbohydrases and an original ultrasonic flow-through reactor. After 6 h, similar profiles were observed between EAE and UAE with the recovery of 71–74 % of the initial material into the soluble phase. However, when these processes were combined, up to 91 % solubilized material was observed in the same time, with a synergistic effect after 2 h. From a biochemical point of view, UAEH improved the extraction of nitrogen and carbon compounds and, more precisely, carbohydrates and amino acids. This study demonstrates that ultrasound improved the enzymatic hydrolysis, probably by an increase in the mass transfer and a disruption of the thallus due to the implosion of the cavitation bubbles generated. UAEH is clearly an efficient procedure for the liquefaction of wet seaweeds, enabling the recovery of valuable components
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