Tesis sobre el tema "Extraction assistée par enzyme et ultrasons"
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Davidson, Morag. "Éco-extraction de composés bioactifs à partir de marcs de fruits rouges & étude de leur impact sur l'homéostasie intestinale". Electronic Thesis or Diss., Limoges, 2024. http://www.theses.fr/2024LIMO0020.
Texto completoSince 2010, 100 million tons of red fruits have been produced globally each year. 20% of wastes result from their first industrial transformation, which includes the seeds and the skins, known as pomace. While spreading and animal feeding are common ways to valorise these wastes, they are also a potential source of hydrophilic and lipophilic bioactive compounds (fibres, proteins, polyphenols, minerals & poly-unsaturated fatty acids, phytosterols, tocols). Therefore, it is interesting to design simultaneous extraction processes to extract simultaneously all of these biomolecules to fully exploit their biological activities.This thesis aimed to achieve two goals. The first goal was to develop an innovative extraction process by combining the use of an enzyme(s) with the use of ultrasounds to extract simultaneously, in an aqueous medium, the hydrophilic and lipophilic bioactive compounds of red fruit pomaces. The second goal was to assess in vitro the prebiotic properties of the extracts.The thesis was divided into four successive steps: (i) the characterisation of the proximate compositions of the raspberry, strawberry, blackberry and black currant pomaces, (ii) the design of one or several eco-extraction process(es), (iii) the global chemical characterization of the “eco-extracts” and (iv) the in vitro assessment of their potential prebiotic properties.The design of the eco-extraction process was divided into three steps. First, three enzymes (a cocktail of glycohydrolases, an acid protease and an alkaline protease) were tested, alone or sequentially combined. Secondly, the selected enzymatic systems were associated with ultrasounds, either simultaneously (enzyme + ultrasounds) or sequentially (enzyme → ultrasounds and ultrasounds → enzyme). The choice of the enzymatic system(s) and their combination with ultrasounds was based on their extraction efficiencies, ease of implementation and innovative character compared to existing literature. Finally, the selected combination(s) were optimised by an experimental design (Definitive Screening Design) by adjusting six parameters comprising three levels: ultrasound amplitude, pH, enzyme/substrate ratio, solid/liquid ratio, extraction time and temperature.The simultaneous combination “alkaline protease-ultrasounds” was selected and optimised for the raspberry, strawberry and blackberry pomaces. All of the polyphenols, with 75% of their antioxidant capacities, and 75% of the oil present in the pomaces were extracted in a single step in an aqueous medium. The optimised simultaneous combination “acid protease-ultrasounds” extracted 75% of the polyphenols, with the totality of the anthocyanins, and 50% of the oil of the black currant pomace.The eco-extracts demonstrated prebiotic properties towards probiotic bacteria (Lactobacillus plantarum 299v, Lactobacillus rhamnosus) by favouring their growth. This makes them potential candidates for the nutraceutical industry. The eco-extracts could be integrated into dietary complements to maintain or restore the intestinal microbiota balance
Puspita, Maya. "Extraction assistée par enzyme de phlorotannins provenant d’algues brunes du genre Sargassum et les activités biologiques". Thesis, Lorient, 2017. http://www.theses.fr/2017LORIS440/document.
Texto completoIn France and Indonesia, Sargassum is quite abundant yet this alga has not been optimally exploited. Sargassum contains macro and micro molecules and also bioactive compounds, the most known is phlorotannins, showing a wide range of pharmacological properties. Therefore, it is interesting to further valorize this alga. The heterogeneity and complexity of algal cell wall strongly reduces the extraction efficiency application of conventional extraction. Subjects of interest in this study were to characterize the seasonal variation of Sargassum biochemical composition and to extract phlorotannins using conventional and alternative method, i.e. solid-liquid and enzyme- assisted extraction. In this study, minerals represented a significant value with a content reaching 33% followed by proteins with 24% of algal dry material. In the contrary, sugars showed only 13% of algal dry material. Further, the biochemical composition of Sargassum, like most algae, was highly affected by the seasons and related to Sargassum life cycle. In terms of polyphenol compounds in Sargassum, season might be the most influential factor but suitable methods of extraction determine the efficiency to collect these compounds from Sargassum. Solid-liquid extraction, in certain extent, yielded lower (ranging from 5 to 24% of dry algal material) than the enzyme-assisted extraction (ranging from 21 to 38% of dry algal material). Concerning the polyphenol content of Sargassum extracted with these two methods, enzyme-assisted extraction, in certain extent, had higher content than the solid-liquid extraction. Enzymatic extracts showed a strong antiradical activity
Beaudor, Maxime. "Valorisation en cascade du marc de café via les procédés d'extraction assistée par ultrasons et de fermentation en milieu solide". Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILR044.
Texto completoCoffee is one of the most popular beverages. According to the International Coffee Organization, between 2017 and 2022, its production increased by 2.2%, while consumption grew by 7.7%. The sole solid co-product resulting from aqueous extraction to obtain the caffeinated hot beverage is spent coffee grounds. This bio-waste represents approximately 6 million tons annually.The primary objective of this thesis is to define and evaluate a cascade valorization approach for spent coffee grounds, aiming to progressively and efficiently exploit this resource to generate various industrially valuable products. To achieve this goal, two processes were selected. Firstly, solid-liquid eco-extraction, including ultrasound-assisted extraction, was used for the recovery of antioxidant phenolic compounds from spent coffee grounds. Subsequently, in a sequential manner, solid-state fermentation was implemented on the depleted grounds with the assistance of Penicillium solitum to produce a hydrolytic enzyme cocktail.The valorization cascade was applied to a type of spent coffee grounds collected and stored by the Gecco company (SCG-1), sourced from bars and restaurants in the Hauts-de-France region. Fresh marc from the thesis host laboratory (SCG-2) was also investigated to gain a better understanding of the industrial constraints related to storage. The comparison of two extraction methods applied to SCG-1, conventional extraction (CE) and ultrasound-assisted extraction (UAE), revealed the positive influence of ultrasound on the recovery of antioxidant phenolic compounds. UAE enabled the extraction of approximately 30% more total polyphenols (11.8 vs. 9.1 mg GAE/g) and consumed at least 3 times less energy (170 vs. 630 Wh) under optimal extraction conditions (50-50 (v/v) water-ethanol, 40 mL/g, power of 571 W/L for UAE, or temperature of 70°C for CE). The application of these optimized conditions to SCG-2 resulted in a 23% additional antioxidant activity (77.9 vs. 63.5 µmol Trolox/g) in the extract compared to SCG-1.The phenolic compound extract obtained from SCG-2 under optimized UAE conditions showed the presence of chlorogenic acids commonly found in spent coffee grounds, with concentrations of 4.3 mg/g, 5.9 mg/g, and 0.4 mg/g for 3-CQA, 5-CQA, and 3,5-diCQA, respectively. These three compounds were absent in the extract obtained under the same conditions from SCG-1, which exhibited the presence of other antioxidant compounds formed during storage by various colonizing micro-organisms.Following the isolation and identification of around forty filamentous fungi present on SCG-1, Penicillium solitum was selected for optimizing solid-state fermentation (SSF) to produce a hydrolytic enzyme cocktail. The optimized extraction conditions (7 mL/g, 55 minutes) and fermentation conditions (74.1% moisture, 7 days of incubation, and an inoculum of 10^7 spores/g) obtained through modeling allowed for the production of an enzymatic complex with lipase, mannanase, and glucanase activities on SCG-1. Regarding the production of these same enzymes on SCG-2, the optimal fermentation conditions were (75% humidity, 7 days of incubation, and an inoculum of 8.1x10^6 spores/g). The activities calculated under these conditions for both types of spent coffee grounds were 65.3 and 49.5 U/g for lipase activity, 948 and 939 mU/g for mannanase activity, and 295 and 206 mU/g for glucanase activity, respectively, for extracts obtained from fermentations on SCG-1 and SCG-2. Additionally, the optimized extract produced on SCG-1 by Penicillium solitum also exhibited other measured activities, with 56.4 U/g, 626 mU/g, and 856 mU/g, respectively, for protease, xylanase, and pectinase activities
Burlot, Anne-Sophie. "Valorisation des métabolites d'algues proliférantes par voie enzymatique : applications dans les domaines de la nutrition et santé animale, végétale et humaine, de la cosmétique et de l'environnement". Thesis, Lorient, 2016. http://www.theses.fr/2016LORIS428/document.
Texto completoThese last decades, Solieria chordalis (Rhodophyta, Gigartinales), a red and proliferative macroalga appears every year in south of Brittany on the peninsula of Rhuys. It is a question of removing more than 2 000 tons of red seaweeds, mainly composed of S. chordalis. These proliferations represent a true ecological problem and an economic constraint for the affected communities. This project aims to study S. chordalis in order to find a way to add more value to this seaweed by proposing a rational and sustainable management as well as potential applications. From October 2013 to October 2015, S. chordalis was collected monthly. Results have shown seasonal variations of the biomass on the shores, in the macro- and microscopic morphologies, in the dry matter rate and in the biochemical composition. In relation with the seasonal environmental factors, it is now possible to estimate the quantity and the biochemical composition of the seaweed and to propose potential applications. With characteristics of high catalytic efficiency, specificity, the environmental-friendly process of Enzyme-Assisted Extraction was chosen to produce water- soluble extracts with antiviral, antibacterial and immunostimulant activities. The commercial protease Alcalase improved the extraction yield with a significant gain of 30 % of the water-soluble and free compounds compared to an extraction without the action of enzymes. Almost 60 % of the dry matter of algae was liquefied and water-solubilized after the optimization of extraction parameters. Water-soluble extracts produced after the action of enzymes have shown anti- herpetic activities (EC50 from 86.0 to 145.9 µg/mL) and no cytotoxicity was detected. The immunostimulant activity was evaluated by using the pathogenicity model Caenorhabditis elegans Pseudomonas aeruginosa. The life span of infected nematods by pathogen bacteria increased after the application of water-soluble extracts from S. chordalis. Some immune genes of C. elegans were stimulated (zk6.7, spp-1, f28d1.3 and f38a1.5). Produced extracts present antiviral and immunostimulant activities that allow to anticipate applications for diverse domains
Fournière, Mathilde. "Extraction et évaluation des propriétés biologiques des ulvanes et oligo-ulvanes de l'algue verte Ulva sp. : actions sur le métabolisme de cellules cutanées et sur le microbiote cutané". Electronic Thesis or Diss., Lorient, 2021. http://www.theses.fr/2021LORIS593.
Texto completoUlvans are matrix sulfated polysaccharides constitutive of green seaweed Ulva sp. cell wall. Although proliferative and quantitatively available, Ulva sp. is little valued with applications in low added value sectors. The objective of this project is to produce fractions enriched in ulvans and oligo-ulvans in order to evaluate their biological properties on cutaneous system. Ulvan fractions were produced by maceration and enzyme-assisted extraction followed by different purification processes: ethanolic precipitation and dialysis. Radical and acid depolymerization processes allowed to obtain oligo-ulvan fractions. Ulvan and oligo-ulvan fractions have been shown to stimulate human dermal fibroblasts proliferation. An increase in the synthesis of extracellular matrix components such as type I and III collagens, and glycosaminoglycans has been demonstrated. Fractions also stimulate the expression, synthesis and MMP-1 enzymatic activity. At the skin microbiota level, the fractions do not alter the growth of commensal bacteria S. epidermidis, S. aureus and C. acnes, but may modify the biofilm formation. Ulvan and oligo-ulvan fractions also reduce the inflammatory potential of HaCaT keratinocytes induced by C. acnes. Thus, this work has shown that the ulvan and oligo-ulvan fractions exhibit promising biological activities for dermo-cosmetic applications in tissue repair, anti-ageing or anti-inflammatory strategies while preserving commensal skin microbiota
Khan, Muhammad Kamran. "Polyphénols d'agrumes (flavanones) : extraction de glycosides de la peau d'orange, synthèse de métabolites chez l'homme (glucuronides) et étude physico-chimique de leur interaction avec la sérum albumine". Phd thesis, Université d'Avignon, 2010. http://tel.archives-ouvertes.fr/tel-00543792.
Texto completoDary, Chhavarath. "Mise au point des espèces du genre Stephania au Cambodge : études systématique, phytochimique et pharmacologique". Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM5502/document.
Texto completoThe thesis aims to provide update on species of the genus Stephania recorded in Cambodia by systematic, phytochemical and pharmacological studies.The systematic study allowed to list seven species and two varieties of Stephania in Cambodia: S. cambodica, S. japonica var. discolor and var. timoriensis, S. oblata, S. pierrei, S. rotunda (type species), S. suberosa and S. venosa. The presence of S. japonica var. timoriensis and S. oblata is reported for the first time in Cambodia. According to the phylogenetic results, only S. pierrei is monophyletic, which represents less than 10% of species in the genus Stephania. Chemical studies on the tubers of five species were carried out using chromatographic methods (HPLC, UHPLC) and spectroscopic methods. Different isolated alkaloids have been proposed as markers: palmatine, roemerine and tetrahydropalmatine for S. cambodica and S. rotunda, cepharanthine, tetrahydropalmatine, and xylopinine for S. suberosa, cepharanthine for S. pierrei, crebanine, and tetrahydropalmatine for S. venosa. Nine alkaloids belonging to five classes were isolated from the tuber of S. cambodica and a new compound namely "angkorwatine" was described. Ultrasound assisted extraction of alkaloids was developed and optimized by Design of Experiment for this species. This innovative extraction is a good alternative to conventional methods. An analytical UHPLC method was developed and validated for the quality control of S. cambodica. Results show that hydroethanolic extracts obtained by maceration of S. suberosa, S. rotunda and S. venosa exhibit significant anti-inflammatory activity with high anti-inflammatory ratio (selectivity index)
Khadhraoui, Boutheina. "éco-extraction assistée par ultrasons des plantes médicinales : mécanisme(s), intensification et industrialisation ULTRASOUND TECHNOLOGY FOR FOOD PROCESSING, PRESERVATION AND EXTRACTION Histo-cytochemistry and scanning electron microscopy for studying spatial and temporal extraction of metabolites induced by ultrasound. Towards chain detexturation mechanism Microscopic imaging as a tool to target spatial and temporal extraction of bioactive compounds through ultrasound intensificationUltrason. Review of Alternative Solvents for Green Extraction of Food and Natural Green solvents for analytical chemistry". Thesis, Avignon, 2019. http://www.theses.fr/2019AVIG0715.
Texto completoWith recent trends in the increasing interest to environmental, economic and safety considerations,extraction techniques have largely focused on finding solutions with sustainable and green values toimplement in food processing, cosmetic and pharmaceutical industries. In this context, new “green”extraction techniques were developed such as Ultrasound-Assisted Extraction (UAE). The mainobjective of this thesis is industrial implementation of this new process in substitution to theconventional (CV) process. It has been shown in this work that the extraction of compounds ofinterest from rosemary and other plant matrices could be intensified using ultrasound, and thatdifferent performance gain could be achieved according to the plant matrix structural properties.Indeed, macroscopic and microscopic investigation of untreated and treated raw materials provedthat US act through different mechanisms and its resulting impacts can be extremely limited by plantstructural morphological and chemical properties, especially those of the specialized structures.Significant variability in performance gain was also observed at the industrial scale. Overall, USappears as a promising technique with a significant performance gain in terms of extraction yield andselectivity. Moreover, this process presents low environmental footprint compared to the CV one.Finally, it has been shown that natural products, such as honey and fruit juices, can be used toimprove solubilization and extraction of molecules that are poorly soluble in water. Encouragingresults were obtained in terms of solubilization and extraction abilities, especially from ground rawmaterials. However, these results raise questions related to the feasibility of industrialimplementation of this new process
Elagli, Adil. "Contribution à l'intensification de procédés appliqués à la protéolyse enzymatique : Étude microcinétique en réacteur microfluidique et conception assistée par plasma froid d'un microréacteur à enzyme immobilisé". Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10032/document.
Texto completoNew economic and environmental issues previously introduced the concept of process intensification since some years ago. Dealing with the control and the intensification of enzyme processes, this thesis was divided into two parts. The first part focused on the study of enzyme reactions in microreactor from a microkinetic perspective. It was intended to optimize the preparation of an opioid peptide from a proteolytic reaction, the hydrolysis of bovine hemoglobin by porcine pepsin. Firstly, a modulation of the reaction kinetic selectivity was highlighted. Then, on the basis of a sustainable approach, the enzymatic process was coupled to a separative process. It allowed the selective and continuous recovery of the hemorphin LVV-h7 by a sequence of two consecutive liquid-liquid extractions. Through all of the results, the first part of this thesis attempts to highlight some attractive benefits derived of the use of microfluidics in process engineering. Finally, the second part of this thesis has been extended to the design of a microstructured reactor with immobilized enzyme by exclusively using an organosilicon material, TetraMethylDiSiloxane. First, cold plasma technology allowed the development of an original methodology for enzyme immobilization by steric entrapment. Then, by using plasma-assisted polymerization, this protocol was used to design an immobilized enzyme microreactor according to a “bio-integrating” methodology
Bouras, Meriem. "Etude comparative et optimisation de prétraitements des écorces de bois pour l'extraction des composés phénoliques". Thesis, Compiègne, 2015. http://www.theses.fr/2015COMP2245.
Texto completoThis research work focuses on the intensification of polyphenols extraction from Quercus robur and Norway spruce barks using innovative technologies : pulsed electric field (PEF), ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE). These pre-treatments enhance the release of intracellular compounds by damaging the membrane and/or cell wall. The effect of each of these technologies (PEF, UAE and MAE) on polyphenols extraction has been highlighted in a quantitative and qualitative optimization analysis by evaluating the polyphenols concentration, antioxidant activity and by the chemical characterization of the extracted compounds.A comparative study of pre-treatments (PEF, UAE and MAE) coupled with an extraction step in an alkaline hydro-alcoholic medium allowed us to better understand the involved phenomena. The induced process efficiency is independent of the tree family to which the bark belongs (coniferous and hardwood). For bark valorization, the application of PEF treatment (20 kV/cm, 200 pulses, 3.2 kJ/g bark) followed by a diffusion step seems to be an alternative to ultrasound and microwave assisted extractions and to the extraction from grinded barks. In fact, the electrical and mechanical effect of PEF treatment allow to obtain an extract rich in polyphenols (10.5 g GAE/100g DM and an efficiency of 83 % for Norway spruce and 5 g GAE /100g DM and an efficiency of 82 % for Quercus robur bark)
Soukarieh, Banan. "Monitoring des HAPs et des PCBs dans le sol et les sédiments au Liban. Implantation d'une méthode optimisée et validée d'extraction et d'analyse". Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0357.
Texto completoCurrently, the public and especially in industrialized countries is increasingly aware that environmental degradation can outweigh the benefits of rapid progress in the industrial and technological fields and that serious and irreversible damage can be imposed on the future generations. The occurrence of POPs in the environment, which results mainly from anthropogenic activities, is one of the permanent concerns of scientists. These compounds have been found in all environmental matrices such as air, soil, water and sediments and because of their lipophilic properties, they are likely to rebound in the human food chain. During the past decade, Lebanon has experienced a large population explosion that has been accompanied by various anthropogenic activities. The degradation of the quality of the environment is felt by the local population and the consequences for human health are heavy and horrendous. The work of this thesis allowed to evaluate concretely the effect of POPs on the quality of the environment in Lebanon, this work led to the determination of the levels of some POPs most widely studied such as PAHs, PCBs and OCPs in the different environmental compartments in Lebanon. To this end, analytical protocols including a GC/MS method for the separation and detection of PAHs, a UAE method for the extraction of PAHs from soil and sediments and an SPE method for the extraction of PAHs from water were developed. These methods were then applied to evaluate the levels of 17 PAHs in soils of different uses and study the distribution of PAHs in the aqueous phase and sediments on the Lebanese coasts and in coastal and inner rivers. The main results showed that soil contamination levels by PAHs decreased in the following order: industrial, urban, transport and agricultural and that industrial and urban soils were 777 and 256 times more toxic than rural reference soils according to the TEF approach. In addition, water and sediments from coastal sites affected by industry and shipping have shown higher contamination by PAHs. Some sediment samples showed concentrations of a few individual PAHs greater than the ERL, which could occasionally cause negative ecological effects. The work of this thesis also includes the determination of levels of PCBs and OCPs in the sediments of the Litani River which is a source of great environmental concern currently in Lebanon
Hardouin, Kévin. "Production d'extraits aqueux à partir d'Ulva sp, au moyen de procédés d'hydrolyse enzymatique : caractérisatin, valorisation et perspectives de développement". Thesis, Lorient, 2015. http://www.theses.fr/2015LORIS373.
Texto completoThis PhD Thesis works, conducted in the Laboratoire de Biotechnologie et Chimie Marines of the Université de Bretagne-Sud and in the Olmix Group, was included in a national project for the upgrading of green seaweed biomasses, the Ulvans project. This project results in the collaboration of five industrial companies and two academic research laboratories. The objectives of this thesis works had been i) the characterization of the raw material, particularly the soluble matrix polysaccharides (ulvans) and proteins, ii) the development of an enzyme-assisted extraction process of algal metabolites, iii) the biochemical and molecular characterization of the enzymatic hydrolyzates, with the aim of understanding the effect of enzymes on algae thallus, iv) the screening of antioxidant and antiviral activities of hydrolyzates, v) the study of the influence of hydrolysis parameters to determine the optimum conditions for the extraction of metabolites of interest and finally vi) to conclude, according to the results provided by this study, on the viability of the industrial upscaling of the process. In conclusion of this work, enzymatic hydrolysis appeared to be an effective process for biorefinery of green seaweeds. Although commercial enzymatic preparations were not specific of algal compounds, protéases led to a significant increase in the extraction yields, whereas the effect of carbohydrases were moderate. The study of hydrolysis parameters confirmed the preliminary results and showed that the temperature, the concentration of enzyme and the grinding method had no effect on the protease used. A major result of this study has been the highlighting of anti-oxidant and anti-herpetic compounds in hydrolyzates. The antiviral activity of ulvans had several times been demonstrated but the biochemical characterization of actives fractions showed that the activity could be associated to proteins or glycoproteins. This result is very interesting because, a priori, any antiviral activity has also been related to this type of compounds in Ulva sp
Khan, Muhammad Kamran. "Polyphénols d’agrumes (flavanones) : extraction de glycosides de la peau d’orange, synthèse de métabolites chez l’homme (glucuronides) et étude physico-chimique de leur interaction avec la sérum albumine". Thesis, Avignon, 2010. http://www.theses.fr/2010AVIG0238/document.
Texto completoA bunch of epidemiological studies provides good evidence on the inverse relationship associated with the consumption of fruits and vegetables and the chronic diseases importantly cardiovascular diseases and some types of cancers. After the long years of study on phytomacronutrients, the role of phytomicronutrients such as polyphenols is now highly studied and appreciated in the control of such degenerative diseases. The present study combines the extraction, synthetic and analytical studies on the major polyphenols of citrus fruits, FLAVANONES.Awareness of nutritional and health facts has increased the production of citrus fruits from last few decades. These higher productions generate higher by-products. For their alternative utilisation to have antioxidants rich extracts, the ultrasound-assisted extraction (UAE) of polyphenols especially flavanones from orange (Citrus sinensis L.) peel by using ethanol as afood grade solvent has been proved its efficiency when compared with the conventional method. A central composite design (CCD) approach revealed that the optimized conditions for UAE were a temperature of 40°C, a sonication power of 150W and a 4:1 (v/v) ethanol:water ratio. Furthermore, the antioxidant activity determined by the DPPH and ORAC tests confirmed the suitability of UAE for the preparation of antioxidant-rich plant extracts. Flavanone glucuronides are the major phenolic metabolites detected in human plasma after consumption of citrus fruits. Up to now all cell studies related to cancer or cardiovascular diseases were conducted either on the aglycones or on their glycosides. Hence, there is great need of pure flavanone glucuronides to demonstrate the real potential of flavanones in the prevention of these diseases. In this work, glucuronides of naringenin (4′- and 7-O-β-D-glucuronides) and hesperetin (3′- and 7-O-β-D-glucuronides), the major flavanone aglycones in grapefruit and orange respectively, have been chemically synthesized by selective protection and deprotection of flavanone and glucuronic acid moieties. The complete structural characterisation of purified compounds were realised by nuclear magnetic resonance and mass spectrometry.The affinity of the four glucuronides for human serum albumin (HSA) was tested via their ability to quench the intrinsic fluorescence of HSA (single Trp residue in sub-domain IIA). Their binding constants (K) were estimated in the range of 30 – 60 × 103 M-1 and compared with those of the aglycones (70 – 90 × 103 M-1). Investigations of competitive or noncompetitive binding of the glucuronides in the presence of fluorescent probes (dansyl sarcosine) allowed us to get some insight in the binding sites. The study was also extended to the hesperetin and naringenin chalcones (synthesised using optimized alkaline conditions), which are the biosynthetic precursors of flavanones
Bouchez, Alice. "Optimisation multicritère de procédés incluant les impacts environnementaux : cas de l'éco-extraction de biomolécules antioxydantes à partir de coproduits agroalimentaires". Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1R023.
Texto completoTo meet the current major challenge of improving the environmental performance of processes, a methodology for the multi-criteria optimisation of green processes including productivity, energy and environmental aspects has been proposed. In this study, it was applied to the case of antioxidant polyphenols recovery from an agri-food by-product. The optimisation takes into account the total polyphenol yield and the antioxidant activity of extracts obtained from declassified beet seeds, as well as the energy consumption of the equipment involved and the environmental impacts generated during the process life cycle. Extraction processes assisted by ultrasound (US), microwave (MO) and a combination of these two technologies were studied. For each process, a global model was developed as a tool for multi-criteria optimisation, integrating parameters such as time, solvent composition, solvent/by-product ratio, US power, MO power and solvent volume, depending on the study. The model was obtained by combining kinetic equations to the methods of experimental design and life cycle assessment. This tool allows to predict the optimal operating conditions for each process while respecting specific constraints such as maximising extraction yield and/or minimising extraction time, energy consumption and/or environmental impacts. This methodology could easily be adapted for multicriteria optimisation of other processes
Bouchez, Alice. "Optimisation multicritère de procédés incluant les impacts environnementaux : cas de l'éco-extraction de biomolécules antioxydantes à partir de coproduits agroalimentaires". Electronic Thesis or Diss., Université de Lille (2018-2021), 2020. http://www.theses.fr/2020LILUR023.
Texto completoTo meet the current major challenge of improving the environmental performance of processes, a methodology for the multi-criteria optimisation of green processes including productivity, energy and environmental aspects has been proposed. In this study, it was applied to the case of antioxidant polyphenols recovery from an agri-food by-product. The optimisation takes into account the total polyphenol yield and the antioxidant activity of extracts obtained from declassified beet seeds, as well as the energy consumption of the equipment involved and the environmental impacts generated during the process life cycle. Extraction processes assisted by ultrasound (US), microwave (MO) and a combination of these two technologies were studied. For each process, a global model was developed as a tool for multi-criteria optimisation, integrating parameters such as time, solvent composition, solvent/by-product ratio, US power, MO power and solvent volume, depending on the study. The model was obtained by combining kinetic equations to the methods of experimental design and life cycle assessment. This tool allows to predict the optimal operating conditions for each process while respecting specific constraints such as maximising extraction yield and/or minimising extraction time, energy consumption and/or environmental impacts. This methodology could easily be adapted for multicriteria optimisation of other processes
Péroumal, Armelle. "Caractérisation des fruits et de la pulpe de six accessions de Mammea americana : Aptitude à la transformation des fruits et caractérisation des composés phénoliques de la pulpe". Thesis, Antilles-Guyane, 2014. http://www.theses.fr/2014AGUY0702/document.
Texto completoOur work focuses on the physical and chemical properties of six mamey apple cultivars in order to select elite cultivars suitable for food processing or as table fruit. The antioxidant activity of the fruit pulp, the identification and quantification of the polyphenols responsible for it, and ultrasound assisted extraction method were also investigated.According to our results, the postharvest routes for every cultivar could be different. Pavé 11, Lézarde and Ti Jacques were found to be good for consumption, giving sweeter fruits with high total phenolic and carotenoid contents. Sonson, pavé 11 and Lézarde had suitable characteristics for the manufacturing of mamey products. The polyphenolic composition of the pulp determined by HPLC-DAD and UPLC-MS showed the presence of phenolic acids, condensed tannins, flavonols and flavanols. The results of the antioxidant test (DPPH and ORAC) point out that the most antioxidant cultivar was Ti Jacques. The design and optimization of the ultrasound assisted extraction method has done for polyphenols extraction. The results showed that the polyphenols rich extract contains the same content of phenolic acids and flavonols in comparison to the conventional method. Additionally, the dry extract obtained with a “green” solvent, had good organoleptic properties