Journée SFEL. Etats des lieux des innovations technico-économiques dans le domaine des lipides

Journée SFEL. Etats des lieux des innovations technico-économiques dans le domaine des lipides. Journée SFEL. Etats des lieux des innovations technico-économiques dans le domaine des lipide

Biochemistry, nutrition and technology of lipids. Partie II

Maste

Structure–function relationship of the milk fat globule

Purpose of reviewThe complex biochemical composition and physical structure of the milk fat globule (MFG) are presented asa basis for its paradoxical metabolic fate: MFG is a rapid conveyor of energy through its triacylglycerol(TAG) core but contains some low-digestible bioactive complex lipids and proteins, which influence lipidmetabolism and contribute to intestinal and systemic health.Recent findingsMFG structure modulates gastrointestinal lipolysis, postprandial lipemia and even the postprandial fate ofingested fatty acids. Proof-of-concept of the nutritional programming induced by early consumption of anemulsion biomimetic of MFG compared with a typical infant formula was published in an animal model(mice). The metabolic response to a high-fat diet during adulthood was improved following neonatalexposure to the biomimetic emulsion.SummaryMFG TAG are tailored with a unique regiodistribution delivering in priority short to medium-chain fattyacids in gastric phase, an important amount of quickly metabolizable oleic acid and protecting palmiticacid in sn-2 position. MFG digestion may not only trigger rapid TAG and chylomicron plasma peaks withfast clearance but also the luminal release of nonhydrolysable bioactive compounds (glycosylatedcompounds and sphingomyelin), which contribute to intestinal and systemic health by shaping themicrobiota and modulating the immune system. These bioactive compounds form self-assembled structures,protect specific micronutrients and lower cholesterol absorption. The health benefits of MFG consumption orof some of its fractions (MFGM) under specific structures are steadily being demonstrated with still muchunsolved questions especially for populations with high nutritional needs (e.g. elderly, infants)

ALIMENTATION d’AUJOURD’HUI et de DEMAIN : quelles sources et recommandations nutritionnelles pour les lipides et protéines ?

ALIMENTATION d’AUJOURD’HUI et de DEMAIN : quelles sources et recommandations nutritionnelles pour les lipides et protéines ?. Café scientifique consulat général de France à Rio de Janeir

Stabilité à l’oxydation des aliments fortifiés en vitamines dans les pays du Sud : détermination des leviers d’amélioration via un modèle prédictif

International audienc

Nutritional properties of milk lipids: specific function of the milk fat globule

Beyond fatty acid composition of milk fat that can impact the health of consumers, interest is growing regarding the importance of the supramolecular structure of milk lipids on their nutritional properties. Indeed, milk fat is found naturally under the form of an emulsion of lipid droplets called the milk fat globule (MFG) composed of a triglyceride core stabilized by a complex trilayered membrane called the MFG membrane. Recent researches have highlighted that this unique structure and the presence of bioactive lipids such as sphingomyelin could have a beneficial metabolic impact on lipid metabolism and contribute to intestinal and systemic health. The purpose of this chapter is to provide a focused overview on the composition of milk lipids, their organization as MFG and, their impact on lipid digestion and postprandial lipemia. In addition, the long-term effect on lipid metabolism and related metabolic players such as inflammation and gut microbiota are discussed

Effect of pasteurization on human milk digestion as simulated in an in vitro dynamic system

Human milk is the ideal food for infant nutrition and optimal growth. This is especially true for preterm neonates that are preferentially fed donor milk when their own mother milk is not available. For sanitary reasons, donor milk is pasteurized. This may have structural and biochemical consequences on the maternal milk emulsion and affect digestive kinetics. This has been rarely investigated. Thus that was the aim of our study. Mature human milk was collected over 2 days and stored at +4°C. Half of it was digested as is (fresh milk). The other half was frozen (-20°C, 5 weeks) and pasteurized (62.5°C, 30 min) prior digestion. An in vitro dynamic system was used to simulate the gastric and intestinal digestion phases of a 1-month old newborn. Structural changes of digested samples were evaluated by confocal microscopy and laser light scattering. Proteolysis and lipolysis were monitored over 180 min. Hydrolysis kinetics were followed by SDS-PAGE and Thin-Layer Chromatography methods, followed by densitometry for semi-quantitative estimations. Pasteurization impacted the emulsion structure by increasing the protein susceptibility to acid aggregation especially on the milk fat globule membrane (Fig. 1). In the gastric compartment, we observed a faster hydrolysis of caseins (κ, β) and lactoferrin in pasteurized milk than in fresh milk (X 2 at 30 min). At 120 min, virtually all proteins were digested in pasteurized milk, whereas approximately 55% of proteins were undigested in fresh milk. In the intestinal phase, most proteins were digested during the first 30 min. Lactoferrin was more resistant in fresh milk than in pasteurized milk. Similarly, lipids were digested faster in pasteurized than in fresh milk, but to a lesser extent than proteins. These results demonstrate that pasteurization increases the rate of proteolysis and lipolysis. The physiologic and metabolic impacts remain unknown, especially in newborns exclusively fed pasteurized milk

Edible moisture barriers: materials, shaping techniques and promises in food product stabilization

Edible moisture barriers are effective alternatives to stabilize fresh or processed food products and satisfy consumers’ demand for long shelf-life products that are of good quality and nutritionally acceptable. This chapter deals with traditional and innovative film-forming materials and barrier technologies of edible films reported in scientific literature and patents over the last thirty years. The necessity of adopting an integrated approach in the development of edible moisture barriers to combine regulatory, nutritional, organoleptic andtechnical requirements is highlighted

Observation de lipase gastrique sur systèmes membranaires modèles par microscopie à force atomique

National audienceLe globule gras natif de lait de mammifère constitue un objet biophysique unique se démarquant des autres objets lipoprotéiques (oléosome, lipoprotéines…) notamment par sa membrane tricouche héritée du mécanisme de sécrétion du globule [1,2]. Au niveau de ses fonctions biologiques le globule gras natif est avant tout vecteur d’énergie via son cœur de triglycérides qui fournit 50-60 % des calories nécessaires au développement du nouveau-né de mammifère [3] Afin d’assurer ce rôle énergétique le globule gras est hydrolysé au niveau de la lumière gastro-intestinale. La première phase de cette hydrolyse est catalysée par la lipase gastrique humaine. Les questions qui sont encore aujourd’hui posées concernent d’une part l’organisation structurale de la membrane externe [4] et d’autre part les mécanismes d’action de la lipase sur cet objet. Notre approche est de reconstruire le feuillet externe de la membrane lipidique en utilisant les films de Langmuir comme modèle membranaire et d’utiliser la microscopie à force atomique afin d’obtenir des informations fines d’organisation moléculaire. Ainsi nous avons mis en évidence l’hétérogénéité de la membrane reconstituée à partir des éléments natifs purifiés. Dans la suite de ce travail, l’affinité de la lipase gastrique pour cette membrane a été quantifiée, sur à la fois des systèmes lipides simplifiés (DOPC, DPPC) et sur les systèmes reconstitués ‘naturels’. Pour conclure, au travers de nos résultats nous avons mis en évidence une localisation préférentielle de la lipase sur la membrane avec des taux d’insertion très faibles pour une présence protéique importante. La suite de ce travail est de mettre en évidence des effets des traitements technologiques sur la structuration de la membrane qui seront alors susceptibles d’induire des modifications d’activité de la lipase gastrique