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International audience; Infant formula (IF) is the adequate Human milk (HM) substitute despite of still remaining differences in fine composition and structure.✓ HM and IF are assumed to have different digestion kinetics although they are rarely directly compared either in vivo or in vitro.➔ The present study aimed to evaluate the digestion kinetics and the structure evolution using the DIDGI® dynamic digestion system at the infant stage

International audience; Infant formulas (IFs), the only adequate substitute to human milk, are complex matrices that require numerous ingredients and processing steps. The objective was to understand how protein structure and quality within IFs impact plasma amino acid (AA) kinetics, gut physiology and microbiota.Four IFs containing whey proteins (WPs) with different origins and denaturation rates (IFs-A/-B/-C) or caseins with different organizations (IFs-C/-D) were produced as isonitrogenous despite slight differences of protein profile and AA concentrations. Both structure and in vitro digestion kinetics differed among IFs. Ten Yucatan mini-piglets (12- to 27-day-old) used as an infant model, received each IF during three days according to a Williams Latin square, followed by a two days wash-out period. Jugular plasma was regularly sampled from 10 min pre-prandial to 4 hours post-prandial on the third experimental day to measure free AA, urea, insulin and glucose concentrations. Data were analysed using a linear mixed model for repeated measures.IFs-A and -B, with higher WP denaturation rates, had significantly higher plasma total and essential AAs concentrations compared to IFs-C and -D, regardless of the time. Plasma threonine concentration was significantly different regardless of the time (A>B>C=D), probably resulting from glycomacropeptides presence in IFs-A and -B, known to cause increased threoninemia in infants. WP denaturation (IF-A) and casein supramolecular organization (IF-D) seemed to reduce AA catabolism. All these differences were present before meal ingestion indicating that a metabolic adjustment occurred during the dietary adaptation. Overall, this highlights the importance of the protein ingredient quality (WPs and caseins) within IFs on the plasma AA delivery, which can further impact protein metabolism, including the anabolic pathway of high importance at the infant stage. Whether it has consequences on the gut maturation and on the microbiota, an important actor within the microbiota-gut-brain axis is currently being investigated.

International audience; Docosahexaenoic acid (DHA) is the most important n-3 polyunsaturated fatty acid (PUFA),mainly known for its health benefits on cognitive development and cardiovascular functions.However, the current intake of DHA and EPA in the Western diet averages 150 mg per day,whereas the recommended daily consumption from The French Food Safety Authority is 500mg. Therefore, enrichment of food with DHA is considered as an efficient strategy to meet therecommended intake threshold. The main challenge is to preserve DHA oil from oxidationleading to undesirable flavors and reduced bioactive functions. Encapsulation techniques seekto enhance the stability and bioavailability of bioactive food ingredients. In thisstudy, DHAoilcomposedofDHA-enrichedtriacylglycerols(TAG)waspreparedasPickeringemulsionbyencapsulationwithheat-denaturedwheyproteins.Pureoiloremulsionwerethenincorporated in eggs and cooked in an omelet. The effect of encapsulation of DHA oil wasdetermined by using the static in vitro digestion model of an adult. The FA profile wasfollowed by gas chromatography coupled with mass spectrometry, from the lipid speciesformed during the digestion and separated by thin layer chromatography. Firstly, resultsshowed that the DHA concentration in omelets with unencapsulated DHA oil (UN-DHA-O)waslower than inomeletswithencapsulated DHA oil(EN-DHA-O)due tothe loss ofunencapsulated DHA oil during the food preparation. However, the food preparation did notshow any degradation of DHA in any DHA-rich omelets. Secondly, during digestion in thegastric phase, DHA-enriched TAG was not hydrolyzed in UN-DHA-O nor in EN-DHA-O. Incontrast, digestion during the intestinal phase released freeDHA from TAG and also from1,2-diacylglycerols and 2-monoacylglycerols. Release of free DHA was significantly higherwith EN-DHA-O than with UN-DHA-O after 2 hours (52.2% and 40.4% of total DHA,respectively). These results suggest that encapsulation through Pickering emulsion can reducethe loss of DHA oil during the food preparation and can also improve the DHA release duringtheintestinal phase.

International audience; Protein digestibility, a key indicator of dietary protein quality, can be estimated in vitro. The objectivewasto determinethe contribution of endogenous N, released by the enzyme autolysis, to in vitro protein digestibilityusing 15N-labelled proteins. Methods:15N-labelled gluten and caseins (4, 8 and 16% of the meal) were digested using the INFOGEST static in vitromodel.The endogenous N was measured after centrifugation and 10-kDa ultrafiltration, allowing the true N digestibilitydetermination. The proteolysis degree, based on the primary amine content, was determined. Results: Alarge proportion (93±11%) of the endogenous N < 10 kDa within digesta was present before digestion, with somecontribution, although limited(20-30%),of the enzyme autolysis. For both proteins, true N digestibility was not significantly different between 30and120 min of intestinal digestion,but significantly higher for the lowest protein content (4%). The proteolysis degree was more correlated to theapparentdigestibility, i.e.withno endogenous N correction, than to the true digestibility, showing that further endogenous correction is needed for more accuracy.Conclusion: In vitro protein digestibility, as well as proteolysis degree, needs to be corrected for the endogenous N contribution, although to a different extent.

National audience; Introduction et But de l’étude. – Une consommation chronique de produits de glycation alimentaires est associée à l’apparition de certains troubles métaboliques tels que l’insulinorésistance au cours du vieillissement et du diabète. L’exposition de cellules L6 de muscle squelettique à de l’hémoglobine glyquée humaine induit des perturbations de la voie de signalisation de l’insuline. Nous émettons l’hypothèse que l’administration unique de protéines alimentaires glyquées (PAG) peuvent influer la voie de signalisation de l’insuline dans le muscle squelettique. Matériel et Méthodes. – Un régime semi-liquide contenant soit de la caséine chauffée (PAG élevée), soit de la caséine non chauffée (PAG faible) a été administré en une fois à des rats âgés de 7 mois. Les concentrations en insuline plasmatique ont été mesurées par ELISA. La phosphorylation d’Akt, de p70S6K et l’expression du récepteur aux produits avancés de glycation (RAGE) ont été mesurées par Western-blot dans le soleus (type I) et le tibialis (type II) à 0, 1, 2, 4 heures après l’administration du régime alimentaire. Résultats. – Les concentrations plasmatiques d’insuline sont augmentées de façon similaire après l’administration des régimes. Après l’administration du régime PAG faible, les phosphorylations d’Akt et de p70S6K sont significativement augmentées dans le tibialis (+ 26,4 ± 4,5 unités arbitraires (UA), + 26,2 ± 3,7 UA par rapport au temps 0, P < 0,05) mais pas dans le soleus. La phosphorylation d’Akt augmente significativement dans le soleus 1 heure après l’administration de PAG élevée (+ 3,1 ± 0,7 UA par rapport à 0 heure, P < 0,05). Le régime PAG élevée n’a pas d’effet sur la phosphorylation de p70S6K. L’expression de RAGE n’est pas modifiée quelle que soit l’heure d’administration de PAG élevée dans les deux types de muscle. Conclusion. – L’administration unique de protéines alimentaires glyquées n’affecte pas l’activation des voies de signalisation à l’insuline dans les muscles squelettiques de type I et II chez le rat adulte. Par conséquent, ces données suggèrent que la réponse anabolique postprandiale du muscle squelettique n’est pas modifiée après une seule administration orale de protéines alimentaires glyquées.