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Aflatoxin B1 (AFB1) is a mycotoxin considered a potent carcinogen for humans that contaminates a wide range of crops. Various strategies have been established to reduce or block the synthesis of AFB1 in food and feed. The use of aqueous extracts derived from plants with high antioxidant activity has been a subject of study in recent years due to their efficacy in inhibiting AFB1. In this study, we assessed the effect of Aloysia citrodora aqueous extract on Aspergillus flavus growth and on AFB1 production. A bio-guided fractionation followed by High Performance Liquid Chromatography (HPLC) and Mass spectrometry analysis of the active fraction were applied to identify the candidate molecules responsible for the dose-effect inhibition of AFB1 synthesis. Our results revealed that polyphenols are the molecules implicated in AFB1 inhibition, achieving almost a total inhibition of the toxin production (99%). We identified luteolin-7-diglucuronide as one of the main constituents in A. citrodora extract, and demonstrated that it is able to inhibit, by itself, AFB1 production by 57%. This is the first study demonstrating the anti-Aflatoxin B1 effect of this molecule, while other polyphenols surely intervene in A. citrodora anti-AFB1 activity.

Crop contamination by aflatoxin B1 (AFB1), an Aspergillus-flavus-produced toxin, is frequently observed in tropical and subtropical regions. This phenomenon is emerging in Europe, most likely as a result of climate change. Alternative methods, such as biocontrol agents (BCAs), are currently being developed to reduce the use of chemicals in the prevention of mycotoxin contamination. Actinobacteria are known to produce many bioactive compounds, and some of them can reduce in vitro AFB1 concentration. In this context, the present study aims to analyze the effect of a cell-free supernatant (CFS) from Streptomyces roseolus culture on the development of A. flavus, as well as on its transcriptome profile using microarray assay and its impact on AFB1 concentration. Results demonstrated that in vitro, the S.roseolus CFS reduced the dry weight and conidiation of A.flavus from 77% and 43%, respectively, and was therefore associated with a reduction in AFB1 concentration reduction to levels under the limit of quantification. The transcriptomic data analysis revealed that 5198 genes were differentially expressed in response to the CFS exposure and among them 5169 were downregulated including most of the genes involved in biosynthetic gene clusters. The aflatoxins’ gene cluster was the most downregulated. Other gene clusters, such as the aspergillic acid, aspirochlorine, and ustiloxin B gene clusters, were also downregulated and associated with a variation in their concentration, confirmed by LC-HRMS.

Mimosa tenuiflora aqueous extract (MAE) is rich in phenolic compounds. Among them, condensed tannins have been demonstrated to exhibit a strong antioxidant and antiaflatoxin B1 activities in Aspergillus flavus. Since antioxidant capacity can change with time due to environmental interactions, this study aimed to evaluate the ability of encapsulation by spray-drying of Mimosa tenuiflora aqueous extract to preserve their biological activities through storage. A dry formulation may also facilitate transportation and uses. For that, three different wall materials were used and compared for their efficiency. Total phenolic content, antioxidant activity, antifungal and antiaflatoxin activities were measured after the production of the microparticles and after one year of storage at room temperature. These results confirmed that encapsulation by spray-drying using polysaccharide wall materials is able to preserve antiaflatoxin activity of Mimosa tenuiflora extract better than freezing.

International audience; This work describes a process approach to study the oil leakage phenomenon in feeds for large Trout. Using a pilot vacuum coater, four experimental coating parameters were studied (stirring speed, pressure, filling rate, and time needed to restore atmospheric pressure) through an experimental design. The properties measured on the coated pellets were the oil leakage rate and three other important usage properties, i.e. durability, hardness, and floatability. The coating conditions had a significant influence on oil leakage rate, varying at 40 °C from 2.7 % to 1.2 % depending on the coating conditions used. Finally, the vacuum level was the most effective factor in reducing leakage. Indeed, a progressive reduction in oil leakage rate was observed as the pressure inside the coater was reduced during coating.

International audience; Carbohydrates are the most recurrent materials employed for active components encapsulation using twin-screw extrusion. However, the influence of process parameters on the properties of the final product remains a challenge. In this paper, special attention was given to the incorporation of a hydrophobic model compound (MCT-oil), in a maltodextrin matrix with a compatibilizing biopolymer. The effects of the extrusion parameters, as well as the influence of different formulations were analyzed. The mild extrusion conditions allowed obtaining blends with acceptable texture and viscosity to enhance the dispersion of the active compound. The encapsulation systems obtained were in a glassy state at room temperature and they remained stable at 60 % RH for a long time. Satisfactory incorporation rates of MCT-oil were found reaching encapsulation efficiencies up to 90 %. These results showed that the chosen compatibilizing agent enhanced the dispersion and stabilization of the MCT-oil within the matrix and significantly improved encapsulation.

Horseradish contains many bioactive compounds with antioxidant activity. The current study aimed to evaluate the effect of various wall materials and their ratios on the physical properties and bioactive-compound retention and stability in microencapsulated horseradish leaf and root juices. Horseradish juice was microencapsulated using maltodextrin, maltodextrin/gum Arabic, soy protein isolate, and starch with three different core-to-wall ratios. The total phenolic, total flavonoid, total flavan-3-ol, and total phenolic-acid contents, as well as antioxidant activity, were determined using spectrophotometric methods, whereas individual phenol profiles were determined by high-performance liquid chromatography (HPLC). Multivariate analysis of variance showed that plant material, wall material, and core-to-wall ratio had a significant effect on the bioactive-compound retention and antioxidant-activity preservation. Microcapsules produced from horseradish leaf juice had a significantly higher content of phenolic compounds and antioxidant activity compared to root-juice microcapsules. However, better retention was observed for microencapsulated horseradish root juice. Maltodextrin and maltodextrin/gum Arabic were the most effective wall materials for the retention of bioactive compounds, while they also had a smaller particle size and better solubility. The horseradish-juice microcapsules possess a high content of rutin. The highest stability of bioactive compounds after storage was found at a core-to-wall ratio of 20:80.

Horseradish contains many bioactive compounds with antioxidant activity. The current study aimed to evaluate the effect of various wall materials and their ratios on the physical properties and bioactive-compound retention and stability in microencapsulated horseradish leaf and root juices. Horseradish juice was microencapsulated using maltodextrin, maltodextrin/gum Arabic, soy protein isolate, and starch with three different core-to-wall ratios. The total phenolic, total flavonoid, total flavan-3-ol, and total phenolic-acid contents, as well as antioxidant activity, were determined using spectrophotometric methods, whereas individual phenol profiles were determined by high-performance liquid chromatography (HPLC). Multivariate analysis of variance showed that plant material, wall material, and core-to-wall ratio had a significant effect on the bioactive-compound retention and antioxidant-activity preservation. Microcapsules produced from horseradish leaf juice had a significantly higher content of phenolic compounds and antioxidant activity compared to root-juice microcapsules. However, better retention was observed for microencapsulated horseradish root juice. Maltodextrin and maltodextrin/gum Arabic were the most effective wall materials for the retention of bioactive compounds, while they also had a smaller particle size and better solubility. The horseradish-juice microcapsules possess a high content of rutin. The highest stability of bioactive compounds after storage was found at a core-to-wall ratio of 20:80.

International audience; The objective of this work was to evaluate soy protein isolate (SPI) and acylated soy protein (SPA) as spray-drying encapsulation carriers for oral pharmaceutical applications. SPI acylation was performed by the Schotten–Baumann reaction. SPA, with an acylation rate of 41%, displayed a decrease in solubility in acidic conditions, whereas its solubility was unaffected by basic conditions. The drug encapsulation capacities of both SPI and SPA were tested with ibuprofen (IBU) as a model poorly soluble drug. IBU-SPI and IBU-SPA particles were obtained by spray-drying under eco-friendly conditions. Yields of 70 to 87% and microencapsulation efficiencies exceeding 80% were attained for an IBU content of 20 to 40% w/w, confirming the excellent microencapsulation properties of SPI and the suitability of the chemical modification. The in vitro release kinetics of IBU were studied in simulated gastrointestinal conditions (pH 1.2 and pH 6.8, 37°C). pH-sensitive release patterns were observed, with an optimized low rate of release in simulated gastric fluid for SPA formulations, and a rapid and complete release in simulated intestinal fluid for both formulations, due to the optimal pattern of pH-dependent solubility for SPA and the molecular dispersion of IBU in soy protein. These results demonstrate that SPI and SPA are relevant for the development of pH-sensitive drug delivery systems for the oral route.

International audience; The potential value of succinylated soy protein (SPS) as a wall material for the encapsulation of ibuprofen (IBU), a model hydrophobic drug, by spray-drying was investigated. A succinylation rate of 93% was obtained for soy protein isolate, with a molar ratio of 1/1.5 (NH2/succinic anhydride). The solubility profile at 37°C showed that this chemical modification decreased the solubility of the protein below its isoelectric point, whereas solubility increased in alkaline conditions. Various SPS/IBU ratios (90/10, 80/20, and 60/40) were studied and compared with the same ratio of soy protein isolate (SPI/IBU). High encapsulation efficiency was achieved (91–95%). Microparticles were spherical and between 4 and 8 μm in diameter. The spray-drying of protein/IBU solutions appeared to be beneficial, as it resulted in an amorphous solid dispersion of IBU within the microparticles, coupled with an increase in the thermal stability of IBU. In vitro release was evaluated in acidic (pH 1.2 in the presence of pepsin) and neutral (pH 6.8) conditions similar to those in the gastrointestinal (GI) tract. IBU was released significantly more slowly at pH 1.2, for both proteins. However, this slowing was particularly marked for SPS, for which rapid (within 2 h) and complete release was observed at pH 6.8. These results validate the hypothesis that SPS is suitable for use as a coating material for hydrophobic active pharmaceutical ingredients (APIs) due to its pH sensitivity, which should delay IBU release in the gastrointestinal tract.

Aflatoxin B1 (AFB1) is a potent carcinogenic mycotoxin that contaminates numerous crops pre- and post-harvest. To protect foods and feeds from such toxins without resorting to pesticides, the use of plant extracts has been increasingly studied. The most interesting candidate plants are those with strong antioxidative activity because oxidation reactions may interfere with AFB1 production. The present study investigates how an aqueous extract of Mimosa tenuiflora bark affects both the growth of Aspergillus flavus and AFB1 production. The results reveal a dose-dependent inhibition of toxin synthesis with no impact on fungal growth. AFB1 inhibition is related to a down-modulation of the cluster genes of the biosynthetic pathway and especially to the two internal regulators aflR and aflS. Its strong anti-oxidative activity also allows the aqueous extract to modulate the expression of genes involved in fungal oxidative-stress response, such as msnA, mtfA, atfA, or sod1. Finally, a bio-guided fractionation of the aqueous extract demonstrates that condensed tannins play a major role in the anti-aflatoxin activity of Mimosa tenuiflora bark.

International audience; Encapsulation of flavor and aroma compounds has been largely explored in order to meet appraisal demands from consumers by improving the impact of flavor during the consumption of food products. Even though several techniques have been used for encapsulating volatile compounds, i.e., spray drying, fluidized bed coating, coacervation, and melt extrusion, those most frequently used in the food industry are spray drying and melt extrusion. In this article, the different techniques of encapsulation of flavors and fragrances in polymer-based matrices by extrusion are reviewed and partly re-defined, emphasizing the differences between the various techniques reported so far and the role of matrix types, additives, and operative conditions. Also, the role of water as a key parameter for controlled release and shelf stability of the delivery system will be discussed.

International audience; Mexican oregano and clove essential oils are widely used as antimicrobial, insecticidal, antifungal and antioxidant compounds. To reduce their volatility and their hydrophobicity, they were encapsulated in β-cyclodextrin (β-CD) complexes by co-precipitation method, and the physicochemical and microbiological properties of these inclusion complexes were characterized. Different essential oil (EO) to β-CD weight ratios were tested (4:96, 8:92, 12:88, and 16:84w/w) and encapsulation efficiency and rate were determined. GC–MS and GC-FID analysis were also performed to determine the main oil constituents, which were eugenol and carvacrol in clove and Mexican oregano essential oils respectively and to quantify their ratio in inclusion complexes. 1H NMR spectroscopy confirmed essential oil inclusion. The 4:96 ratio (clove essential oil:β-CD) gave the highest eugenol content and greatest microencapsulation efficiency; and the 8:92 and 12:88 ratios (Mexican oregano essential oil: β-CD) the highest carvacrol content. Complexes antimicrobial activity was tested against two food-related microorganisms: Listeria monocytogenes ATCC 19114 and Escherichia coli ATCC 25922 by means of agar disk diffusion assay. The results demonstrated the inclusion of the majority of biologically active clove and Mexican oregano essential oil molecules, providing increased stability by reducing their volatility and preserving their biological properties.

Biopolymer based microparticles were efficiently prepared from sunflower protein (SP) wall material and α-tocopherol (T) active core using a spray-drying technique. Protein enzymatic hydrolysis and/or N-acylation were carried out to make some structural modifications to the vegetable protein. Native and hydrolyzed SP were characterized by Asymmetrical Flow Field-Flow Fractionation (AsFlFFF). Results of AsFlFFF confirmed that size of proteinic macromolecules was influenced by degree of hydrolysis. The effect of protein modifications and the influence of wall/core ratio on both emulsions and microparticle properties were evaluated. Concerning emulsion properties, enzymatic hydrolysis involved a decrease in viscosity, whereas acylation did not significantly affect emulsion droplet size and viscosity. Microparticles obtained with hydrolyzed SP wall material showed lower retention efficiency (RE) than native SP microparticles (62–80% and 93% respectively). Conversely, acylation of both hydrolyzed SP and native SP allowed a higher RE to be reached (up to 100%). Increasing T concentration increased emulsion viscosity, emulsion droplet size and microparticle size, and enhanced RE. These results demonstrated the feasibility of highly loaded (up to 79.2% T) microparticles.

International audience; This work deals with the modifications resulting from the dissolution of four commercial cellulosic samples, with different crystallinity rates and degrees of polymerization (DPs), in four solvent systems, known and used to dissolve cellulose. The dissolution conditions were optimized for the 16 various systems and followed by turbidity measurements. After regeneration, the samples were analyzed by thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffractometry (XRD) to study their modification. Viscosimetry measurements were used to evaluate the potential decrease of the DP after dissolution. The observed structural modifications established that, for low DP, all the solvent systems were efficient in dissolving the cellulose without altering the DP, except BMIM [Cl], which provoked a decrease of up to 40 % and a decrease of around 20 % of the degradation temperature (onset temperature, T o). For high molecular weight (MW) celluloses, DMSO/TBAF was the only system to allow a complete dissolution without any molar mass loss and degradation temperature modification.

Aqueous poly(urethane‐urea) dispersions were prepared by the prepolymer mixing technique without the use of any organic solvent. Most of the work focused on the use of two aliphatic diisocyanates (α,α, α', α'‐tetramethyl‐1,3‐xylylene diisocyanate and isophorone diisocyanate) and two macrodiols (α,ω‐poly(propylene glycol) (Mn = 1000) and α,ω‐poly(caprolactone) (Mn = 530)) in conjunction with a fixed proportion of emulsifying agent (dimethylol propionic acid, neutralized with triethyl amine) and the same chain extender (1,2‐ethylene diamine). The properties of both the dispersions and the dried polymer films, as well as those of some model prepolymers, were characterized as a function of the initial composition to establish criteria leading to the optimized performance in terms of dispersion stability and particle size and polymer properties. The most important parameter in this search was found to be the [NCO]/[OH] ratio, which gave the best results when it approached a value of 2.

International audience; The use of soy proteins (SoyP) and sunflower proteins (SunP) in the microencapsulation by spray-drying technique of α-tocopherol (T) with a core/wall ratio of 2/1 was studied. SoyP and SunP were used as wall material in an unmodified and modified state. The enzymatic (hydrolysis and cross-linking) and chemical (acylation and cationization) modifications were carried out on vegetable proteins in order to improve their encapsulating properties. The results obtained demonstrated that in the native state, SunP showed higher retention efficiency for T microencapsulation (92.6%) compared to SoyP (79.7%), which could be connected to the different composition of protein extracts. Hydrolysis, acylation and cationization of protein resulted in reduced emulsion viscosity. The retention efficiency of T was improved up to 94.8–99.5% after protein acylation, which was attributed to improved affinity between core and wall material.

International audience; Microencapsulation of hydrophobic (α-tocopherol) and hydrophilic (ascorbic acid) vitamins by native (non-modified) and modified soy protein isolate (SPI) was carried out using a spray-drying technique. Proteins' functional properties were modified by acylation and cationization reactions in aqueous alkaline media. The results obtained demonstrated that SPI modification resulted in decreased emulsion droplet size and viscosity. All preparations with ascorbic acid (AA) had lower viscosity and microparticle size than those with α-tocopherol (T). Moreover, grafting of fatty acid chains to SPI by acylation improved its amphiphilic character and affinity with hydrophobic substances. Thus, the microencapsulation efficiency of T was increased from 79.7% to 94.8% and the microencapsulation efficiency of AA was reduced from 91.8% to 57.3% compared to native SPI. Conversely, attachment of quaternary ammonium cationic groups to proteinic chains by cationization, increased SPI solubility and favored the AA microencapsulation. This study illustrated that an appropriate modification of SPI can improve the microencapsulation efficiency of suitable active cores.

International audience; Proteins from vegetable seeds are interesting for research at present because they are an abundant alternative to animal-based sources of proteins and petroleum-derived polymers. They are a renewable and biodegradable raw material with interesting functional and/or physico-chemical properties. In microencapsulation, these biopolymers are used as a wall forming material for a variety of active compounds. In most cases, two techniques of microencapsulation, spray-drying and coacervation, are used for the preparation of microparticles from vegetable proteins. Proteins extracted from soy bean, pea and wheat have already been studied as carrier materials for microparticles. These proteins could be suitable shell or matrix materials and show good process efficiency. Some other plant proteins, such as rice, oat or sunflower, with interesting functional properties could be investigated as potential matrices for microencapsulation.

International audience; Enzymatic and chemical modifications of soy protein isolate (SPI) were studied in order to improve SPI properties for their use as wall material for α-tocopherol microencapsulation by spray-drying. The structural modifications of SPI by enzymatic hydrolysis and/or N-acylation were carried out in aqueous media without any use of organic solvent neither surfactant. Emulsions from aqueous solutions of native or modified SPI and hydrophobic α-tocopherol, were prepared and spray-dried to produce α-tocopherol microparticles. The effect of protein modifications and the influence of the core/shell ratio on both emulsion and microparticle properties were characterized. The obtained results demonstrated that oil-in-water emulsions prepared with modified proteins had lower droplet size (0.5–0.9 μm) and viscosity (3.6–14.8 mPa⋅s) compared to those prepared with native proteins (1.1 μm and 15.0 mPa⋅s respectively). Efficiency of oil retention decreased after protein hydrolysis from 79.7 to 38.9%, but the grafting of hydrophobic chain by acylation improved efficiency of α-tocopherol retention up to 94.8%. Moreover, higher emulsion viscosity, particle size and process efficiency were observed with the increase of α-tocopherol amount.

International audience; Our objective is to prove the feasibility of transforming the chemical energy of molecules that are naturally present in the organism in a mechanical energy that can be used to compensate for failure of physiological functions. We propose to explore the potential of osmotic energy, which is an interesting intermediate between chemical energy and mechanical energy, and to test an OSMOTOR (OSMOTic MOTOR). The (patented) principle of OSMOTOR is to induce cyclic variations of osmolarity in two compartments that are separated by a semi-permeable membrane. The variation of osmolarity results in movements of liquid under pressure, which corresponds to a retrievable mechanical work. The device is designed to be implanted in the human organism, from which it is separated by semi-permeable membranes that let nutriments necessary for the activity of the OSMOTOR flow in, and that let waste flow out. The membranes also protect the organism from the substances contained inside the OSMOTOR, and the latter from the defence mechanisms of the organism.

Aqueous poly(urethane‐urea) dispersions were prepared by the prepolymer mixing technique, without any organic solvent, using two aliphatic diisocyanates (α,α,α′,α′‐tetramethyl‐1,3‐xylylene diisocyanate and isophorone diisocyanate) and various macrodiols, in conjunction with a fixed proportion of emulsifying agent (dimethylol propionic acid, neutralised with triethylamine) and the same chain extender (1,2‐ethylene diamine). The properties of both the dispersions and the dried polymer films were characterised as a function of the two main parameters studied in this investigation, viz the structure of the macrodiols and their molecular weight, in order to establish criteria leading to optimised performances in terms of dispersion stability, particle size, and polymer film properties.

In the pharmaceutical field, the oral route remains the preferred route of administration because it is simpler and better accepted by patients. However, this mode of administration is problematic for many active pharmaceutical ingredients (API) with low solubility, low permeability and/or instability in the gastrointestinal environment. Their microencapsulation in polymeric matrices can make them able to respond to these factors, especially if the microparticles generated resist the environments encountered during the gastrointestinal tract and then play a protective role, both for the API and for the mucous membranes encountered. The search for new excipients, from agroresources such as natural polymers, is booming. Vegetable proteins, thanks to their functional properties such as good solubility, relatively low viscosity, and emulsifying and film-forming properties, are preferred candidates. In addition, the great diversity of their functional groups makes it possible to envisage various chemical or enzymatic modifications. The aim of this work was to study the interest of soy protein as a coating material for API intended for the oral route, and more particularly as a candidate for the development of gastro-resistant forms. A soy protein isolate (SPI) was used as a coating material and the atomization as a process. Ibuprofen, a nonsteroidal anti-inflammatory drug, was chosen as a model molecule because of its low solubility requiring an improvement in its bioavailability, and its gastric side effects requiring an enteric shaping. Two chemical modifications of proteins (acylation and succinylation) have been studied in order to modify the solubility of the soy protein. These modifications were carried out in accordance with the principles of Green Chemistry, especially in the absence of organic solvent. The microcapsules obtained by spray-drying were characterized in terms of rate and encapsulation efficiency, morphology and size distribution of the particles, physical state of the encapsulated API and capacity of release in simulated gastric and intestinal medium. The results obtained validated the interest of the chemical modifications of the soy protein to modulate the release kinetics of API. The chemical modifications appeared particularly suitable for the encapsulation of hydrophobic active ingredients, and allowed to obtain ibuprofen release kinetics decreased to acidic pH (gastric). The last part of this work allowed to validate this last hypothesis by the realization of gastro-resistant forms on the model of MUPS tablets (multiple unit pellet system). The results of this exploratory work demonstrate that soy protein, combined with a multiparticle shaping process coupled with direct compression, can be a biosourced, environmentally friendly alternative (aqueous solvent handling, drying and compression steps reduced) and confident to the coating used in traditional gastroresistant forms., Dans le domaine pharmaceutique, la voie orale demeure la voie d’administration de prédilection, car plus simple et mieux acceptée par les patients. Cependant, ce mode d’administration pose problème pour de nombreux principes actifs (PA) présentant une faible solubilité, une faible perméabilité et/ou une instabilité dans l’environnement gastro-intestinal. Leur micro-encapsulation dans des matrices polymériques peut permettre d’y répondre, notamment si les microparticules générées résistent aux environnements rencontrés lors du tractus gastro-intestinal et jouent alors un rôle protecteur, tant pour le principe actif que pour les muqueuses rencontrées. La recherche de nouveaux excipients, issus des agro-ressources tels que les polymères naturels, est en plein essor. Les protéines végétales, grâce à leurs propriétés fonctionnelles telles qu’une bonne solubilité, une viscosité relativement basse, et des propriétés émulsifiantes et filmogènes, représentent des candidats privilégiés. De plus, la grande diversité de leurs groupements fonctionnels permet d’envisager des modifications chimiques ou enzymatiques variées. L’objectif de ce travail était d’étudier l’intérêt de la protéine de soja en tant que matériau enrobant de principes actifs pharmaceutiques destinés à la voie orale, et plus particulièrement en tant que candidat pour l’élaboration de formes gastro-résistantes. Un isolat protéique de soja (SPI) été utilisé comme matière enrobante et l’atomisation comme procédé. L’ibuprofène, anti-inflammatoire non stéroïdien, a été choisi comme molécule modèle du fait de sa faible solubilité nécessitant une amélioration de sa biodisponibilité, et de ses effets indésirables gastriques nécessitant une mise en forme entérique. Deux modifications chimiques des protéines (l’acylation et la succinylation) ont été étudiées dans le but de modifier la solubilité de la protéine de soja. Ces modifications ont été effectuées dans le respect des principes de la Chimie Verte, notamment en absence de solvant organique. Les microcapsules obtenues par atomisation ont été caractérisées en termes de taux et efficacité d'encapsulation, morphologie et distribution de tailles des particules, état physique du PA encapsulé et capacité de libération en milieu gastrique et intestinal simulé. Les résultats obtenus ont permis de valider l’intérêt des modifications chimiques de la protéine de soja pour moduler les cinétiques de libération d’actif. Les modifications chimiques sont apparues particulièrement adaptées pour l’encapsulation de principes actifs hydrophobes, et ont permis de l’obtention de cinétiques de libération d’ibuprofène ralenties à pH acide (gastrique). La dernière partie de ce travail a permis de valider cette dernière hypothèse par la réalisation de formes gastro-résistantes sur le modèle des comprimés MUPS (multiple unit pellet system). Les résultats de ce travail exploratoire démontrent que les protéines de soja, associées à un procédé de mise en forme multi-particulaire couplé à de la compression directe, peuvent constituer une alternative biosourcée, respectueuse de l’environnement (manipulation en solvant aqueux, temps de séchage et étapes de compression réduits) et sûre à l’enrobage utilisé dans les formes gastro-résistantes traditionnelles.

Nowadays, scientific and political communities are focused on ways to better preserve and manage the natural resources of our planet. In order to reduce consumption of fossil resources, and to develop more environmentally friendly industrial processes, the industry of flavors and fragrances became interested in developing new bio-based encapsulating materials. In the present work, maltodextrins have been chosen as main component of the matrix, and pea protein isolate and a modified starch were selected as compatibilizing additives. The incorporation of volatile odorant compounds and the elaboration of the new bio-based delivery systems were performed, all in one single step, by low temperature twin-screw extrusion. The physicochemical, thermal and morphological properties of these matrices were studied, as well as the encapsulation efficiency and the release profile of the active compounds. These investigations have led to a better understanding of the impact of the formulations and of the incorporation of the active compound on the process parameters. The interactions between the wall and the encapsulated materials were also analyzed. The characteristics of the new bio-based delivery systems and the established extrusion process conditions were found to be very promising to be employed in the field of perfumery., Dans le contexte actuel, les communautés scientifiques et politiques sont centrées sur les différentes manières de mieux préserver et utiliser les ressources naturelles de notre planète. Dans le but de réduire la consommation des matières issues du pétrole, et de développer de nouveaux produits et procédés industriels plus propres, l’industrie des fragrances et des arômes cherche aujourd’hui à développer de nouveaux matériaux bio-sourcés pour protéger leurs molécules volatiles odorantes. Dans ce travail de thèse, les maltodextrines ont été choisies comme composé majoritaire, les protéines de pois et un amidon modifié ont été sélectionnés comme additifs compatibilisants pour la composition des matrices d’agromatériaux. L’incorporation des molécules volatiles odorantes, ainsi que l’élaboration des matrices encapsulantes ont été réalisées en une seule étape, grâce à la technologie d’extrusion bi-vis à basse température. Les caractéristiques physicochimiques, thermiques et morphologiques de ces nouvelles matrices enrobantes ont été analysées, de même que la détermination de leur efficacité d’encapsulation et du profil de libération du principe actif. Les différentes investigations menées ont permis de mieux comprendre l’impact des formulations et de l’incorporation des molécules volatiles odorantes sur les paramètres opératoires. Les interactions entre la matrice enrobante et le principe actif ont également été étudiées. Les conditions d’extrusion établies, ainsi que les caractéristiques de ces nouvelles matrices encapsulantes, s’avèrent être pertinentes pour le domaine de la parfumerie.