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The purpose of the study is to characterize the chemical diversity in Rice bran (RB) lipidome and determine whether daily RB consumption for 4 weeks may modulate plasma lipid profiles in children.Untargeted and targeted lipidomics via ultra-performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UPLC-MS/MS) were applied to identify bioactive RB lipids from a collection of 17 rice varieties. To determine the impact of RB (Calrose-USA variety) supplementation on plasma lipid profile, a secondary analysis of plasma lipidome was conducted on data recorded in a clinical study (NCT01911390, n = 18 moderately hypercholesterolemic children) before and after 4 weeks of dietary intervention (15 g/d) with a control or RB supplemented snack. Untargeted lipidomic revealed 118 lipids as the core of lipidome across all 17 varieties among which phospholipids were abundant and oxylipins present. Phytoprostanes and phytofurans were quantified and characterized. Lipidome analysis of the children plasma following RB consumption revealed the presence of novel polar lipids and oxylipins alongside putative modulations in endocannabinoids associated with RB consumption.The investigation of novel polar lipids, oxylipins, phytoprostanes, and phytofurans in RB extracts provides support for new health-promoting properties especially interesting for people at risk for cardiometabolic disease. This article is protected by copyright. All rights reserved.

Natural Deep Eutectic solvents (NaDES) was used to produce, after sequential one-pot extraction and biotransformation of naturally pigmented rice bran (RB), ready-to-use extracts that improve the oxidative stability of lipids in an oil-in-water emulsion. Two NaDES-based strategies were implemented. Extraction of phenolics content varied according to the NaDES. The shiftable NaDES (obtained from the acidic-NaDES based on ChCl and xylitol) stands out by showing content of 1525 mg eq gallic acid/100 g RB. The sequential one-pot biotransformation with immobilized Candida antarctica lipase B after increasing pH, was marked by a decrease in phenolics content and a lipids profile variation. These enriched extracts could be used as natural additives or ready-to-use extracts, as confirmed by the encouraging antioxidant results observed in emulsion. Omics tools should be applied to elucidate the structural rearrangement between compounds and the pool of extracted antioxidant molecules that may explain the protection against lipid oxidation.

International audience; Phenolic compounds (PC) strongly contribute to the beneficial health effects of wheat, but their interactions can affect the quality of end-use wheat products. Free and bound PC were comprehensively characterized in 14 wheat flours (Triticum aestivum) from different Brazilian genotypes and technological qualities by using a metabolomics approach (UPLC-ESI-QTOF-MSE) combined with classical characterizations: colorimetry, ash, protein, starch and total phenolic content (TPC). Globally, 43 PC were identified: 33 (bound, 28 (free) and 15 in all flours, regardless of extract. Ferulic acid isomers were the most abundant PC, representing 25–50% of ion abundance depending on genotype. Campeiro, Sossego and Topázio genotypes showed a distinguished profile, with the highest total relative abundance of PC. TPC was significantly higher in flours with higher gluten strength (66.5–58.0 mg GAE/100 g flour). The ratio free-to-bound of PC averaged 1.15 between the flours of different technological qualities. Although PCA highlighted specific PC related to technological qualities, the genotype effect was very pronounced. This study correlates the phenolic profile and technological quality of wheat flours and provides the most recent data on the secondary metabolites profile, especially PC in refined flour, attesting to its significant nutritional importance due to its large consumption in refined forms.

International audience; Severe Acute Malnutrition (SAM) is still a public health issue in many low-income and middle-income countries. Its management has changed with the development of Ready-to-Use Therapeutic Foods (RUTF) that are energy-dense, lipid-based, micronutrient-enriched foods. The purpose of the present study was to define some aspects of the nutritional profile (in particular, lipid content, fatty acids profile, lipophilic vitamin content), oxidative status, and mycotoxin content of three RUTF products (of which two manufactured in Asia and one in Europe), at different time points during their storage. All RUTF displayed good lipid stability, with peroxide values

International audience; The residual biomass of cold-pressed green coffee oil (GCO), rich in chlorogenic acids (CGA), was reused by incorporating the press cake (CE) and sediment (SE) extracts into carboxymethyl cellulose (CMC) films. The effect of these extracts combined with GCO was investigated on the physicochemical, barrier, and antioxidant properties, and on the ability of the active films to delay fish oil oxidation. The films with added CE and GCO (C-CE) or SE and GCO (C-SE) showed high antioxidant activity, 3.61 ± 0.01 and 2.03 ± 0.01 mmol Trolox eq/g dry film, respectively. These findings are in line with the CGA content in CE and SE (9.8 and 9.0% w/w, respectively), as determined by HPLC. The addition of SE and GCO slightly affects the oxygen barrier of CMC films, while providing them with high Ultraviolet–Visible (UV–Vis) absorption. The evolution of peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) in fish oil samples covered by C-CE and C-SE films and inert headspace was significantly lower than those of controls (storage at 40 °C for 16 days). The antioxidant release from films with added CE and SE showed an antagonistic behaviour into the food simulants. Although both active films are promising for active packaging, the C-SE film appeared as more advantageous for oil-rich food protection.

International audience; Lipid oxidation is a major cause of quality deterioration in food products. In these foods, lipids are often present in a bulk or in emulsified forms. In both systems, the rate, extent and pathway of oxidation are highly dependent on the presence of colloidal structures and interfaces because these are the locations where oxidation normally occurs. In bulk oils, reverse micelles (association colloids) are present and are believed to play a crucial role on lipid oxidation. Conversely, in emulsions, surfactant micelles are present that also play a major role in lipid oxidation pathways. After a brief description of lipid oxidation and antioxidants mechanisms, this review discusses the current understanding of the influence of micellar structures on lipid oxidation. In particular, is discussed the major impact of the presence of micelles in emulsions, or reverse micelles (association colloids) in bulk oil on the oxidative stability of both systems. Indeed, both micelles in emulsions and associate colloids in bulk oils are discussed in this review as nanoscale structures that can serve as reservoirs of antioxidants and pro-oxidants and are involved in their transport within the concerned system. Their role as nanoreactors where lipid oxidation reactions occur is also commented.

International audience; The postnatal period is characterized by rapid growth and development. Lipids, especially long-chain polyunsaturated fatty acids (LC-PUFA) such as docosahexaenoic (DHA) and arachidonic (ARA) acids, play an essential role during this period. The main objective of infant formulas is to be biomimetic of the “golden standard” i.e. breast milk, both in terms of composition and structure, thus offering the best possible alternative to breastfeeding when it has failed and/or is not possible. In this context, European regulations have evolved and now require DHA supplementation of formulas. Formulas are also fortified with ARA, another PUFA essential for child development, although there is no requirement for a minimum content. Their high degree of unsaturation makes these fatty acids particularly sensitive to lipid oxidation, making their inclusion in infant formulas more difficult. The objective of this review is therefore to provide a state of the art on the various key parameters that allow better control of LC-PUFA supplementation in infant formulas.; La période postnatale est caractérisée par une croissance et un développement rapide. Les lipides, et plus particulièrement les acides gras polyinsaturés à longues chaînes (AGPI-LC), tels que les acides docosahexaénoïque (DHA) et arachidonique (ARA), jouent un rôle essentiel durant cette période. L’objectif principal des formules infantiles est d’être biomimétique de « l’étalon d’or » : le lait maternel, aussi bien en termes de composition que de structure, pour ainsi offrir la meilleure alternative possible à l’allaitement lorsqu’il a échoué et/ou n’est pas possible. Dans ce contexte, la réglementation européenne a évolué et impose désormais la supplémentation des formules en DHA. Elles sont également fortifiées en ARA, autre AGPI indispensable pour le développement de l’enfant, bien qu’aucune obligation ne soit établie quant à sa teneur minimale. Leur important degré d’insaturation rend ces acides gras particulièrement sensibles à l’oxydation lipidique, complexifiant ainsi leur introduction dans les formules infantiles. L’objectif de cette revue est donc de faire un état de l’art sur les différents paramètres clés permettant de mieux maîtriser la supplémentation des formules infantiles en AGPI-LC.

International audience; Lipid oxidation is a well-recognized issue in dried food emulsions, such as infant milk formula. Antioxidants can be used to mitigate this issue; however, their efficiency in such complex systems is far from understood. In this study, antioxidant polarity is varied through the alkyl chain length of gallic acid esters (0–16 carbon atoms) incorporated to O/W emulsions that are subsequently spray-dried. During processing and subsequent storage of the samples, antioxidants with more than eight carbon atoms are effective. Both for encapsulated fat and surface free fat, we observe a slight cut-off effect, meaning that beyond eight alkyl groups, a more nonpolar antioxidant is slightly less effective. Depending on the antioxidant polarity, lipid oxidation is faster either in the encapsulated or in the surface free fat. The insights obtained contribute to understanding lipid oxidation in low moisture food emulsions, and thus lead to effective antioxidant strategies.

Lipid oxidation is a major concern in the food, cosmetic, and pharmaceutical sectors. The degradation of unsaturated lipids affects the nutritional, physicochemical, and organoleptic properties of products and can lead to off-flavors and to the formation of potentially harmful oxidation compounds. To prevent or slow down lipid oxidation, different antioxidant additives are used alone or in combination to achieve the best possible efficiency with the minimum possible quantities. In manufactured products, that is, heterogeneous systems containing lipids as emulsions or bulk phase, the efficiency of an antioxidant is determined not only by its chemical reactivity, but also by its physical properties and its interaction with other compounds present in the products. The antioxidants most widely used on the industrial scale are probably tocopherols, either as natural extracts or pure synthetic molecules. Considerable research has been conducted on their antioxidant activity, but results regarding their efficiency are contradictory. Here, we review the known mechanisms behind the antioxidant activity of tocopherols and discuss the chemical and physical features that determine their efficacy. We first describe their chemical reactivity linked with the main factors that modulate it between efficient antioxidant capacity and potential prooxidant effects. We then describe their chemical interactions with other molecules (phenolic compounds, metals, vitamin C, carotenes, proteins, and phospholipids) that have potential additive, synergistic, or antagonist effects. Finally, we discuss other physical parameters that influence their activity in complex systems including their specific interactions with surfactants in emulsions and their behavior in the presence of association colloids in bulk oils.

International audience; The involvement of natural deep eutectic solvents (NaDES) in biological processes has been speculated but experimental evidence based on their observation in cells and biochemical reactions is still largely missing. Nevertheless, a sum of observations and analogies between NaDES physical-chemical properties and those of peculiar cellular environments allows raising interesting hypothesis on the role they could play. To contribute to the current thinking on NaDES in biological systems, an overview of these unusual liquid media is first presented with a special focus on how their occurrence in Nature (animal and plant) and hypothetical roles in cell metabolism were supported by experimental approaches. Then, a discussion pointing out the diversity of membranes formation and structures, describes, while challenging the readers, how NaDES may be related with membrane systems. The occurrence of NaDES in the cell and their possible interaction with highly organized intracellular structures and membrane-less organelles is also discussed. Observations already made with NaDES metabolites in cells allow discussing the possible roles and effects of NaDES on cell metabolism in connection with membranes or subcellular assemblies. Finally, suggestions for further investigations regarding the occurrence and the contribution of NaDES in the regulation of cellular functions are proposed.

International audience; The effect of the presence of surfactant micelles and of the mode of incorporation (pre-homogenization or post-homogenization) on the antioxidant efficiency of a homologous series of n-alkyl gallates phenolipids (G0, G3, G8, G12 or G16) was investigated in oil-in-water nanoemulsions. In both absence and presence of surfactant micelles, G12 and G16 were the best antioxidants. The effect of the mode of incorporation was modulated by the presence of surfactant micelles. In absence of surfactant micelles, G8 and G16 had higher efficiency when incorporated pre-homogenization, suggesting that the mode of incorporation promoted a distinct initial distribution of these compounds. In contrast, in presence of surfactant micelles, the antioxidants could be incorporated in any phases without efficiency loss. These results demonstrate the important role of surfactant micelles in modulating the antioxidant efficiency and could be used by the food industry to optimize emulsion formulations.

International audience; This work describes a low-cost biophotonic sensor shaped by way of cheap processes as hybrid silicon/silica/polymer resonators able to detect biological molecule gel/fluid phase transition as lipids at very low concentration (sphingomyelin). The photonic structure is composed of specific amplified deep UV photoresist-polymer waveguides coupled by a sub-wavelength gap with racetrack microresonators allowing a low temperature-dependent operation ranging from 16 to 42 °C. The temperature dependent wavelength shift and the thermo-optic coefficient characterizing the quantified resonances and opto-geometric properties of the device have been evaluated, highlighting an enough low thermal features of the whole system for such application. With an appropriate vesicle lipid deposition process specific in biology associated to an apt experimental bio-thermo-photonic protocol (made of serial optical resonance spectra acquisitions with statistical treatments), the dynamic evolution of the sphingomyelin lipid phase transition was assessed: then, the ability to detect their own gel/fluid transition phase and melting temperature has been demonstrated with a mass product factor 10 power 7 lower than that of more conventional methods. The equilibrium of the regime of the resonators was highlighted as being broken by the dynamic of the sphingomyelin and its own phase transition prior relevant detection.

Current Status and Future Prospects of Biocatalysis in Deep Eutectic Solvents. 17. Euro Fed Lipid Congress

WOS: 000462482100001, PubMed ID: 30886367, Developing a mechanistic understanding of the impact of food structure and composition on human health has increasingly involved simulating digestion in the upper gastrointestinal tract. These simulations have used a wide range of different conditions that often have very little physiological relevance, and this impedes the meaningful comparison of results. The standardized protocol presented here is based on an international consensus developed by the COST INFOGEST network. The method is designed to be used with standard laboratory equipment and requires limited experience to encourage a wide range of researchers to adopt it. It is a static digestion method that uses constant ratios of meal to digestive fluids and a constant pH for each step of digestion. This makes the method simple to use but not suitable for simulating digestion kinetics. Using this method, food samples are subjected to sequential oral, gastric and intestinal digestion while parameters such as electrolytes, enzymes, bile, dilution, pH and time of digestion are based on available physiological data. This amended and improved digestion method (INFOGEST 2.0) avoids challenges associated with the original method, such as the inclusion of the oral phase and the use of gastric lipase. The method can be used to assess the endpoints resulting from digestion of foods by analyzing the digestion products (e.g., peptides/amino acids, fatty acids, simple sugars) and evaluating the release of micronutrients from the food matrix. The whole protocol can be completed in similar to 7 d, including similar to 5 d required for the determination of enzyme activities., COST actionEuropean Cooperation in Science and Technology (COST) [FA1005 INFOGEST26]; French National Institute for Agricultural Research (INRA)Institut National de la Recherche Agronomique (INRA), We acknowledge COST action FA1005 INFOGEST26 (http://www.cost-infogest.eu/) for providing funding for travel, meetings and conferences (2011-2015). We acknowledge the French National Institute for Agricultural Research (INRA, http://www.inra.fr) for its continuous support of the INFOGEST network by organizing and co-funding the International Conference on Food Digestion and workgroup meetings. We thank A.G.F. Lopes (Universidade de Lisboa, Portugal) and V.S.N. Mishra (Teagasc Food Research Centre, Moorepark, Ireland) for their help in the final preparation of the videos. We also acknowledge the many other researchers, mostly associated with the above COST action and subsequent events, who have contributed to the discussion of digestion parameters.

Lipids of human milk or infant formula convey most of the energy necessary to support thenewborn growth. Until recently, infant formula chemical composition had been optimized but not theirstructure. And yet, more and more proofs of evidence have shown that lipids structure in human milkmodulates digestion kinetics and is involved in metabolic programming. Indeed there is a striking differenceof structure between human milk which is an emulsion based on dispersed milk fat globules (4 mm) secretedby the mammary gland and submicronic neoformed lipid droplets (0.5mm) found in infant formula. Thesedroplets result from a series of operation units. This difference of structure modifies digestion kinetics andemulsion disintegration in the intestinal tract of the newborn. This difference persists along gastric phasewhich is mainly dominated by acid and enzyme-induced aggregation. Lipid droplets size is thus the keyparameter to control gastric lipolysis and emptying and intestinal lipolysis. This parameter also controlsproteolysis since adsorbed proteins are more rapidly hydrolyzed than when in solution. In animal models,these differences of lipid structure would also impact digestive and immune systems’ maturation andmicrobiota. Lipid structure during neonatal period would also be involved in the early programming ofadipose tissues and metabolism. The supplementation of infant formulas with bovine milk fractions (milk fatglobule membrane extracts, triacylglycerol) or recent development of large droplets infant formula, alongwith new fields of innovation in neonatal nutrition, are here reviewed.; Vers des formules infantiles mimant la structure et le profil de digestion du lait maternel.Les lipides laitiers du lait maternel ou de formules infantiles fournissent la plupart de l’énergie disponiblepour la croissance du nouveau-né. Jusqu’alors, la composition chimique des formules infantiles a étéoptimisée mais pas leur structure. Or il est de plus en plus démontré que la structure des lipides dans le laitmaternel module les cinétiques de digestion et participe à la pré-programmation métabolique. Il existe eneffet une différence majeure entre les émulsions natives de globules gras laitiers (4mm) sécrétées par laglande mammaire et la structure des lipides dans les formules infantiles qui résultent d’une successiond’opérations unitaires de transformation et sont constituées de gouttelettes submicroniques (0.5 mm) avecdes interfaces néoformées. Cette différence de structure modifie les cinétiques de digestion et dedéstructuration des émulsions dans le tractus digestif des nouveau-nés. De façon générale, la différence destructure initiale entre lait maternel et formules infantiles se maintient pendant toute la phase gastrique, quiest surtout dominée par des mécanismes d’agrégation acide et enzymatique. La taille des gouttelettes est leparamètre clé pour contrôler les lipolyses gastrique et intestinale et module également la vitesse de vidangegastrique néonatale. Ce paramètre contrôle également les cinétiques de protéolyse puisque les protéinesadsorbées sont hydrolysées plus rapidement que les protéines solubilisées. Ces différences de structureimpacteraient également chez l’animal le développement des systèmes digestif, immunitaire et la mise enplace du microbiote. La structure des lipides ingérés pendant la période néonatale pourrait également participer à la pré-programmation des tissus adipeux et du métabolisme chez l’adulte. La réintroductiond’extraits membranaires et de triacylglycérols issus de lait bovin dans les formules, le développement deformules nouvelles basées sur des émulsions moins fines ainsi que les dernières tendances de développement de formules infantiles biomimétiques sont reportées et discutées dans cette synthèse.

Numerous compounds exist in nature that can scavenge free radicals and thus have the potential to act as antioxidants in foods. Interest in natural free radical scavengers has resulted in tens of thousands of publications on various molecules and extracts but only an extremely small number have actually been used in commercial applications. The gap between research interest and commercial application is mainly due to the lack of bench top methods that can predict the efficacy of antioxidants in complex food matrices. This disconnection seems to be due to the extremely complex nature of lipid oxidation and antioxidant activity in even relatively simple food systems such as oil-in-water emulsions. This review highlights a number of areas where lack of knowledge is currently holding back our ability to predict which free radical scavengers will be good antioxidants in emulsions: non-free radical scavenging reactions of antioxidants; the existence of different types of oil-water interfaces; difficulties in characterizing lipid droplet surfaces; and differences in oxidation kinetics in different lipid droplets. Further research is needed to identify the key factors that determine antioxidant efficacy in complex heterogeneous systems. This knowledge would then increase our ability to predict how antioxidant structure and properties relate to their activity in food emulsions.

Introduction et But de l’étude Une meilleure compréhension de la digestion du lait maternel chez le nouveau-né est nécessaire pour améliorer les formules infantiles et les rendre plus biomimétiques. Pour des raisons éthiques, il est difficile de conduire de telles études chez le nouveau-né. Il est donc nécessaire de développer des modèles pertinents de digestion in vitro. L’objectif de notre étude était de comparer un modèle de digestion dynamique in vitro avec des données obtenues chez le nouveau-né.Matériel et Méthodes Un digesteur in vitro dynamique (i.e. avec, en continu, une régulation du pH, une sécrétion enzymatique et une vidange) comportant une phase gastrique et une phase intestinale (DIDGI®, INRA) a été utiliséa. Les paramètres du modèle de digestion au stade nouveau-né prématuré ont été fixés grâce à une revue exhaustive de la littératureb en termes de types et quantités d’enzymes, de flux de sécrétions, de descente en pH et de vitesse de vidange. Un pool de lait maternel cru ou pasteurisé (62,5°C, 30 min) issu de mères d’enfants prématurés (n = 5) a été digéré in vitro. Les digestas gastriques étaient prélevés à intervalle régulier. En parallèle, la digestion de lait maternel cru ou pasteurisé a été suivie chez des nouveau-nés prématurés au Centre Hospitalo-Universitaire de Rennes (NCT02112331, n=12). Des prélèvements postprandiaux étaient réalisés à 35, 60 ou 90 minutes après le début du repas par la sonde d’alimentation de ces enfants. La structure des digestas (in vitro et in vivo) a été analysée par granulométrie laser et microscopie confocale, la protéolyse par électrophorèse (SDS-PAGE) et la lipolyse par chromatographies en couche mince et gazeuse. Le pH et les volumes des digestas étaient également suivis.Résultats et Analyse statistique Au cours des digestions in vitro et in vivo, une hydrolyse rapide des caséines et une résistance de l’alpha-lactalbumine ont été observées. Un faible degré de lipolyse gastrique (7-19% à 90 min) a été confirmé in vitro et in vivo. Dans les deux types de digestion, la pasteurisation n’affectait pas les cinétiques ni le degré final de lipolyse et protéolyse, mais impactait l’évolution structurale des digestas, en particulier la désintégration de l’émulsion et l’agrégation protéique. Les données de descente en pH et de vidange gastrique paramétrées dans le digesteur sont à améliorer pour s’approcher au mieux de la physiologie du nouveau-né prématuré.ConclusionNotre étude a permis de mettre en évidence des conclusions similaires in vitro et in vivo quant à l’impact de la pasteurisation sur la digestion du lait maternel, en termes d’hydrolyse digestive mais aussi en termes d’évolution structurale. Les données in vivo vont permettre d’ajuster au plus près les paramétrages concernant la descente en pH et la vidange gastrique. Notre modèle sera utile à la fois pour la communauté scientifique et pour les industriels qui s’intéressent à la digestion néonatale et l’optimisation de formules infantiles.Références:a Bourlieu C., et al. (2015). Crit Rev Food Sci Nutr, 54(11), 1427-57.b Ménard O., et al. (2014). Food Chem, 145, 1039-45.

Incorporation of milk fat and milk fat globule membrane fragments in infant formulas could be an interesting way to get closer to the composition and structure of human milk and its physiological impacts.Two adapted formulas were processed containing either vegetable fat (STD) or a combination of milk and vegetable fats stabilized by a mixture of proteins and milk fat globule membrane fragments (EXP). The formulas were distributed with an automatic milk feeder to piglets until slaughter at 28 days. Intestinal contents and tissues (proximal jejunum and ileum) as well as mesenteric lymph nodes (MLN) were collected. The residual immunoreactivity of β-lactoglobulin (β-lg) and caseins (Cns) present in the digestive compartments was determined by ELISA. Mononuclear cells isolated from MLN were cultured in vitro to evaluate their cytokine secretory profiles. Microbiota diversity and composition was assessed using DHPLC and metasequencing analysis. Finally the immunomodulatory capacity of peptide and lipid fractions extracted from the jejunal contents of STD and EXP piglets were tested in vitro on MLN cells from sow’s suckling piglets. The immunoreactivity of β-lg and Cns was higher in EXP than in STD intestinal contents. The secretory activity of MLN cells was modified by the formula composition, the highest IFNγ secretion was obtained in EXP piglets. A major immunosuppressor effect of lipid fractions was evidenced with both formulas. Microbiota clustering successfully discriminated infant formulas according to the presence of exclusive vegetable vs. a combination of milk and vegetable lipids. Differences in proteobacteria and firmicutes phyla were observed. In conclusion we evidenced that lipid composition of formulas had influence on gut physiology through the release of immunomodulatory lipids in contact with the mucosa, modulation of the dynamic of proteolysis and microbiota composition.

Health organizations now recommend diversifying and increasing our dietary intake of polyunsaturated fatty acids (PUFA) omega-3, which are essential for the proper functions of our cells. To meet these recommendations, plant membranes, and in particular photosynthetic membranes, represent a real potential, as they contain specific lipids, and in particular galactolipids, whose degradation by enzymatic reactions provides PUFA omega-3. Due to their particular composition, these systems present phase coexistences and thus lateral heterogeneity impacting their digestibility. In order to optimally exploit plant lipid sources, it is necessary to understand their fate in the human gastrointestinal tract. The results obtained in this research work provide an in-depth understanding of the mechanisms of interaction between digestive enzymes and plant membrane assemblies. In particular, this work is the first to investigate the digestion of heterogeneous monolayers of galactolipids and phospholipids by close analogues of the main enzymes responsible for the gastrointestinal degradation of plant lipids in humans. The originality of this study is based on a thorough characterization of the interfacial behavior of plant lipid systems, presenting a chemical heterogeneity inducing a physical heterogeneity. The digestibility of these heterogeneous plant lipid assemblies was studied at the molecular scale, but also at the micronic object scale. This work allowed to report the substrate specificity of the studied lipases and phospholipases (rDGL, sPLA2-IB, gPLRP2) on plant polar lipids. In particular, the galactolipase, but also phospholipase A1 activities of gPLRP2 were observed in heterogeneous galactolipid and phospholipid systems. The genericity of action of these enzymes with respect to the physical state of the membranes has also been demonstrated. We demonstrate here that at the lipid interfaces, a high content of polyunsaturated acyl groups can amplify the local compressibility and be an asset for the insertion of digestive lipases. This physical aspect remains to be confronted with the chemical specificity of the enzyme. Overall, plant lipid assemblies are rich in polar lipids and particularly galactolipids, which concentrate significant quantities of omega-3 PUFA, and are bioaccessible under model conditions under the action of gPLRP2. These assemblies also exhibit surface-active and oxidative stability properties characterized in this work. The galactolipase activity of PLRP2 at the level of modulable model membrane monolayers, but also at the level of natural membrane assemblies, opens the way to the development of plant-based dietary alternatives to vectorize omega-3 PUFA, and contribute to rebalancing human and animal diets.; Les organismes de santé recommandent aujourd’hui de diversifier et d'augmenter nos apports alimentaires en acides gras polyinsaturés (AGPI) oméga-3, essentiels au bon fonctionnement de nos cellules. Pour répondre à ces recommandations, les membranes végétales, et en particulier les membranes photosynthétiques, représentent un réel potentiel, car elles contiennent des lipides spécifiques, et notamment des galactolipides, dont la dégradation par des réactions enzymatiques fournit des AGPI oméga-3. De par leur composition particulière, ces systèmes présentent des coexistences de phases et donc une hétérogénéité latérale influant sur leur digestibilité. Or, afin d’exploiter de façon optimale les sources lipidiques végétales, il est nécessaire de comprendre leur devenir dans le tractus gastro-intestinal humain. Les résultats obtenus dans ce travail de recherche viennent apporter une compréhension approfondie des mécanismes d’interactions entre les enzymes digestives et les assemblages membranaires végétaux. En particulier, ce travail est pionnier sur la digestion des monocouches hétérogènes de galactolipides et de phospholipides par de proches analogues des principales enzymes responsables de la dégradation gastro-intestinale des lipides végétaux chez l’Homme. L’originalité de cette étude repose sur une caractérisation poussée du comportement interfacial de systèmes lipidiques végétaux, présentant une hétérogénéité chimique induisant une hétérogénéité physique. La digestibilité de ces assemblages lipidiques végétaux hétérogènes a été étudiée à l’échelle moléculaire, mais également à l’échelle de l’objet micronique. Ce travail a permis de rendre compte de la spécificité de substrat des lipases et phospholipase étudiées (rDGL, sPLA2-IB, gPLRP2) sur les lipides polaires végétaux. En particulier, les activités galactolipase, mais également phospholipase A1 de la gPLRP2 ont été observées au niveau des systèmes hétérogènes de galactolipides et de phospholipides. La généricité d’action de ces enzymes par rapport à l’état physique des membranes a également été prouvée. Nous démontrons ici qu’au niveau des interfaces lipidiques, une forte teneur en groupements acyls polyinsaturés peut amplifier la compressibilité locale et être un atout pour l’insertion des lipases digestives. Cet aspect physique reste à confronter avec la spécificité chimique de l’enzyme. Globalement, les assemblages lipidiques végétaux sont riches en lipides polaires et particulièrement en galactolipides, qui concentrent des quantités importantes d’AGPI oméga-3, et sont bioaccessibles en conditions modèles sous l’action de la gPLRP2. Ces assemblages présentent en outre des propriétés tensioactives et de stabilité à l’oxydation caractérisées dans ce travail. L’activité galactolipase de la PLRP2 au niveau des monocouches membranaires modèles modulables, mais également au niveau des assemblages membranaires naturels, ouvre la voie vers le développement d’alternatives alimentaires végétales pour vectoriser des AGPI oméga-3, et contribuer à rééquilibrer les régimes alimentaires humains et animaux.