Scientific publications

Our scientific publications

You can find all publications from the STLO unit on the website Hal-INRAE

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HAL : Dernières publications

  • [hal-04573021] Plant and animal protein mixed systems as wall material for microencapsulation of Mānuka essential Oil: Characterization and in vitro release kinetics

    Combination of plant and animal protein diet is becoming a valuable source of nutrition in the modern diet due to the synergistic functional properties inherent in these protein complexes. Moreover, the synergy between animal and plant proteins can contribute to the high stability and improved solubility of the encapsulated bioactive ingredients (e.g., essential oils). Therefore, the study was designed to evaluate the plant (pea protein (PP) and lupine protein (LP)) and animal protein (whey protein, WP) mixed systems as a wall material for microencapsulation of mānuka essential oil, as an example of bioactive compound. Moreover, physicochemical properties and in vitro release profile of encapsulated mānuka essential oil were studied. Mānuka essential oil microcapsules exhibited low moisture content (5.3–7.1 %) and low water activity (0.33–0.37) with a solubility of 53.7–68.1 %. Change in wall material ratio significantly affected the color of microcapsules, while microcapsules prepared with 1:1 protein/oil ratio demonstrated a high encapsulation efficiency (90.4 % and 89.4 %) for protein mixed systems (PP + WP and LP + WP), respectively. Microcapsules further showed low values for lipid oxidation with a high oxidative stability and antioxidant activity (62.1–87.0 %). The zero order and Korsmeyer–Peppas models clearly explained the release mechanism of encapsulated oil, which was dependent on the type and concentration of the protein mixed used. The findings demonstrated that the protein mixed systems successfully encapsulated the mānuka essential oil with controlled release and high oxidative stability, indicating the suitability of the protein mixed systems as a carrier in encapsulation and application potential in development of encapsulated functional foods.

    ano.nymous@ccsd.cnrs.fr.invalid (Kandi Sridhar) 13 May 2024

    https://hal.inrae.fr/hal-04573021
  • [hal-04615988] Production de boissons fermentées à partir de lactosérum de fromage Francs-Comtois : une plus-value pour la filière, un défi pour la recherche

    Comté et Morbier sont deux fromages emblématiques de la région Bourgogne Franche-Comté. Lors de leur fabrication, une quantité importante de lactosérum (LS) est produite, jusqu’à 350 L pour une meule de Comté. Une partie de ce LS est peu voire pas valorisée. L’objectif de ce travail, dans le cadre du projet FAIRCHAIN[1], était de produire des boissons fermentées originales et attractives, afin de proposer aux producteurs une nouvelle source de valorisation du LS. Le défi à relever était, grâce à la fermentation et à une aromatisation adéquate, d’atténuer le goût et l’odeur particulière du LS. Dans cet objectif, nous avons travaillé avec des LS de comté et de morbier, natifs, doux ou acides, et issus directement de fromagerie. Plusieurs étapes ont été mises en œuvre, combinant procédé (traitement du LS & fermentation), études marché et consommateurs et transfert à l’échelle semi-industrielle. - Test de 160 souches de bactéries lactiques issues des collections CIRM-BIA[2] (n=120) et Standa[3] (n=40) et de 8 ferments de kéfir (Standa) pour leurs capacités à fermenter des LS (acidification, propriétés organoleptiques) & choix de solutions aromatisantes (jus de fruit, sirop et herbes aromatiques). Sur 600 combinaisons testées, 69 ont été jugées satisfaisantes (1 combinaison = 1 type de LS / 1 ferment / 1 aromatisation). - Études qualitatives exploratoires : tendances, marché (4 pays européens) et 8 focus groups (> 50 consommateurs) permettant de définir 12 concepts de boissons susceptibles de plaire. - Sélection de 10 boissons répondant à certains de ces concepts parmi les 69 mises au point. - Dégustation par un jury interne (20 personnes) permettant de sélectionner 7 boissons correspondant à 2 concepts phares (3 boissons pétillantes & 4 boissons au jus de fruit). - Définition des paramètres de production à l’échelle pré-industrielle, puis production des 7 boissons, mise en bouteille et vérification des qualités sanitaires. -Test hédonique sur les 7 boissons (60 consommateurs) : sélection des 2 boissons les plus appréciées.

    ano.nymous@ccsd.cnrs.fr.invalid (Marine Penland) 18 Jun 2024

    https://hal.inrae.fr/hal-04615988
  • [hal-04619674] Caractérisation d' un mécanisme de défense chez Propionibacterium freudenreichii pour résister à l'infection de phages filamenteux

    Les bactériophages (ou phages) sont des virus qui infectent les bactéries. Parmi les phages décrits, les phages filamenteux se caractérisent par une forme allongée, et sont constitués d’ADN simple brin. Le phage M13 infectant Escherichia coli en est le modèle. Depuis plusieurs années, notre laboratoire étudie les phages filamenteux infectant les bactéries propioniques laitières (BPL). Ces bactéries sont utilisées dans l’affinage des fromages à pâte pressée cuite, comme l’emmental. Les phages filamenteux des BPL ont la particularité d’être les seuls phages filamenteux connus et cultivables capables d’infecter des bactéries Gram positif. Dans ce travail, nous nous sommes intéressés au phage filamenteux B5 [1], capable d’infecter Propionibacterium freudenreichii, en particulier la souche sensible CIRM-BIA15 (CIRM-BIA, INRAE, Institut Agro, Rennes, France). Nous avons étudié le mécanisme de résistance mis en place par un variant M isogénique de la souche CIRM-BIA 15 présentant une résistance au phage B5. Dans un premier temps des tests d’adsorption entre le phage B5 et la souche sauvage sensible ou son variant M ont été réalisés. Puis des tests de transformation par électroporation de la forme replicative double brin du phage B5 ont été réalisés dans la souche sensible et le variant M. Finalement, après séquençage, les génomes des deux souches ont été comparés pour mettre en évidence une ou des mutations éventuellement responsables de cette résistance. Les résultats ont montré que le phage B5 parvient toujours à s’adsorber à la surface du variant M. De plus, la transformation de la forme réplicative de ce phage dans le variant M restaure sa capacité à former des plages de lyse. Ces résultats indiquent que la résistance se situe vraisemblablement au niveau de la paroi du variant M et plus précisément au niveau de l’étape d’injection de l’ADN. L’analyse des séquences du génome de la souche sensible et du variant M a montré une mutation d’un nucléotide au niveau d’un gène codant pour une hypothétique protéine transmembranaire pouvant lier l’ADN. L’insertion de ce gène muté sur un plasmide réplicatif dans la souche sauvage sensible a permis de démontrer son implication dans la résistance de P. freudenreichii au phage B5. Ce mécanisme de défense répondant à une infection phagique d’un phage filamenteux, peu connu chez les bactéries et caractérisé chez la bactérie Gram positif P. freudenrenchii, fera l’objet de cette communication.

    ano.nymous@ccsd.cnrs.fr.invalid (Noël Grosset) 21 Jun 2024

    https://hal.inrae.fr/hal-04619674
  • [hal-04615833] Lactiplantibacillus plantarum et Lactobacillus helveticus :des espèces efficaces pour dégrader l’acide phytique présent dans les légumineuses, céréales et pseudo-céréales

    L'acide phytique (AP), ou inositol-hexaphosphate, est un composé présent dans les graines de légumineuses, fruits à coque, céréales et pseudo-céréales, où il constitue la principale forme de stockage du phosphore. L’AP est considéré comme un composé anti-nutritionnel, en raison de sa capacité à se lier à certains minéraux (Ca2+, Fe2+, Mg2+, et Zn2+). Dans l'alimentation, l'AP peut limiter l'absorption de ces minéraux au niveau de l’intestin, provoquant des carences nutritionnelles. La fermentation lactique peut permettre de réduire la teneur en AP par la production de phytase bactérienne. Dans cette étude, nous avons étudié la capacité de 64 souches de bactéries lactiques (BL) à dégrader l’AP in vitro avec un test qualitatif sur boite de Pétri. Neuf souches (8 phytase+ et 1 phytase -) ont été sélectionnées à l’issue de ce crible. Leur capacité à dégrader l’AP a été évaluée en fermentation, sur un milieu de culture liquide, supplémenté en AP, avec dosage biochimique d’AP avant et après fermentation. Ces neuf souches ont aussi été testées pour leur capacité à dégrader l’AP naturellement présent dans du jus de soja commercial, et dans des bouillies préparées à base de farines de lupin ou d’avoine. La quantité d’AP en fin de fermentation était là aussi comparée à la quantité d’AP initiale. Le test sur boite de Pétri s’est montré efficace pour identifier des souches phytases+. Sur les 64 souches de BL testées (=24 espèces), 33 souches provenant de 12 espèces, se sont révélées positives. C’est au sein des espèces L. plantarum et L. helveticus qu’a été identifiée la plus grande proportion de souches positives. Pour les 9 souches sélectionnées (8 phytase+ et 1 phytase -) le test de fermentation du milieu de culture supplémenté en AP s’est révélé peu discriminant, et de très faibles diminutions de la teneur en AP ont été observées, quelle que soit la souche. En revanche, en condition jus de soja ou bouillies, la fermentation par les 8 souches phytases+ a permis de réduire la quantité d’AP : jusqu’à 33 % dans le jus de soja commercial ([APinitiale]= 94 mg/L), et jusqu’à 40 % dans les bouillies ([APinitiale]= entre 103 et 165 mg/L). En conclusion, cette étude a permis de montrer que le test sur boite de pétri est un bon indicateur pour identifier des BL aptes à dégrader l’AP. Par ailleurs, certaines souches sont efficaces dans tous les types de matières premières testées (soja, lupin, avoine).

    ano.nymous@ccsd.cnrs.fr.invalid (Sandrine Parayre) 18 Jun 2024

    https://hal.inrae.fr/hal-04615833
  • [hal-04606603] Les mixtes animal-végétal : un levier d’innovation pour végétaliser l’alimentation

    Transition alimentaire et innovation : Quelles innovations et comment accompagner les consommateurs dans la transition alimentaire ? Qu'entend-on par "Transition alimentaire" ? C’est un mouvement vers une alimentation plus saine & plus durable. La transition alimentaire vise à répondre aux enjeux de santé, d'environnement et économiques dans un contexte de croissance démographique. Elle implique une modification importante de nos manières de produire et consommer les aliments afin de : réduire la pression environnementale, préserver les ressources naturelles et la biodiversité, lutter contre le dérèglement climatique, lutter contre le gaspillage alimentaire, lutter contre la malnutrition, permettre aux producteurs de vivre de leurs productions tout en garantissant des prix accessibles aux consommateurs... Elle concerne tous les acteurs/actrices du système alimentaire "de la semence à l’assiette et au verre". L’innovation est clef pour réussir dans la transition alimentaire.

    ano.nymous@ccsd.cnrs.fr.invalid (Fanny Guyomarc'H) 10 Jun 2024

    https://hal.inrae.fr/hal-04606603
  • [hal-04606558] Des bactéries et des produits laitiers : qu’est-ce que Prolific, ce projet scientifique rennais à 14 millions d’euros ?

    Depuis 2020, un projet scientifique de 14 millions d’euros mobilise plusieurs équipes de recherche. Son nom ? Prolific. Le thème ? Les (bonnes) bactéries. « Il s’agit d’explorer les avantages de la fermentation des produits laitiers en termes de bénéfices sur la santé des jeunes enfants et des seniors », explique le coordinateur des travaux, Yves Le Loir, par ailleurs directeur du laboratoire rennais STLO.

    ano.nymous@ccsd.cnrs.fr.invalid (Guillaume Bietry) 10 Jun 2024

    https://hal.inrae.fr/hal-04606558
  • [hal-04618243] In vitro gastrointestinal digestion of cow’s and sheep’s dairy products: Impact of species and structure

    Sheep’s milk (SM) is known to differ from cow’s milk (CM) in nutritional composition and physicochemical properties, which may lead to different digestion behaviours. This work aimed to investigate the impact of the species (cow vs sheep) and the structure (milk vs yogurt) on the digestion of dairy products. Using an in vitro static gastrointestinal digestion model, CM, SM, cow’s milk yogurt (CY) and sheep’s milk yogurt (SY) werecompared on particle size evolution, microscopic observations, degree of lipolysis, degree of proteolysis, specific protein degradation and calcium bioaccessibility. Species and structure affected particle size evolution during the gastric phase resulting in smaller particles for yogurts compared to milks as well as for CM products compared to SM products. Species impacted lipid composition and lipolysis, with SM products presenting higher short/medium-chain fatty acids content and higher intestinal degree of lipolysis. Proteolysis was influenced by structure, with milks showing higher intestinal degree of proteolysis compared to yogurts. Caseins were digested faster in CM, ⍺-lactalbumin was digested faster in SM despite its higher concentration, and during gastric digestion β-lactoglobulin was more degraded in CM products compared to SM products and more in yogurts compared to milks. Lastly, SM products released more bioaccessible calcium than CM products. In conclusion, species (cow vs sheep) impacted more the digestion compared to the structure (milk vs yogurt). In fact, SM was different from CM mainly due to a denser protein network that might slow down the accessibility of the enzyme to its substrate which induce a delay of gastric disaggregation and thus lead to slower the digestion of the nutrients.

    ano.nymous@ccsd.cnrs.fr.invalid (Tanguy Saviard) 20 Jun 2024

    https://hal.inrae.fr/hal-04618243
  • [hal-04607922] Machine Learning to better understand and optimize cheese production

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    ano.nymous@ccsd.cnrs.fr.invalid (Manon Perrignon) 11 Jun 2024

    https://hal.inrae.fr/hal-04607922
  • [hal-04607887] Safety assessment of post-milking application of a Lacticaseibacillus paracasei strain on the bovine teat skin regarding downstream dairy processes

    Bovine mastitis (BM) is a major disease in the dairy industry, which negatively impacts the milk quality. In a previous study, we highlighted that a post-milking application of a Lacticaseibacillus paracasei (Lp1542) strain on the bovine teat skin is safe with regard to mammary gland functionality and integrity while having an impact on its microbiota. The present study aims to further evaluate the safety of such strategy by assessing how the presence of this strain in milk can impact the downstream dairy processes. Firstly, the heat sensitivity of Lp1542 was demonstrated for representative milk heat treatment conditions. Secondly, Lp1542 does not interfere with the acidification capabilities of a commercial starter culture nor its proteolytic activities. In conclusion, the combined results highlighted that a topical treatment with Lp1542 is safe with regard to animal health as well as downstream dairy processes inviting us to further explore its effectiveness for BM prevention.

    ano.nymous@ccsd.cnrs.fr.invalid (Coralie Goetz) 11 Jun 2024

    https://hal.inrae.fr/hal-04607887
  • [hal-04608094] Drainage of acid-rennet gels from preheated milk

    In France, Fresh cheese production from cow's and goat's milk accounts for 600,000 tonnes a year (source: L'économie laitière en chiffres, 2019). ✓ There is very few published work on the drainability of acid-rennet curds. Little data is available on the effect of technological factors on the draining capacity of the latter gels. Some studies on the effect of milk preheating, but virtually none on its effect on gel drainage ✓ The main aim of this work was to study the effect of 2 preheating treatments of milk on acid-rennet induced gelation and drainage

    ano.nymous@ccsd.cnrs.fr.invalid (Marie-Hélène Famelart) 11 Jun 2024

    https://hal.inrae.fr/hal-04608094
  • [hal-04608382] The structure of dairy products at different length scales drives the bioavailability bioavailability of nutrients

    The structure of the food matrix is one of the key factors controlling the fate of food in the digestive tract and consequently the kinetics of nutrient release. Using a wide range of static and dynamic in vitro digestion models and animal models (pigs), we have shown that differences in the macrostructure of dairy products (liquid vs. gel vs. solid) can lead to differences in gastric emptying, kinetics of protein hydrolysis in the gut and amino acid bioavailability, when the composition is identical. These differences in digestion kinetics have been attributed to the ability of casein micelles to coagulate under gastric conditions, resulting in the formation of a firm curd that is slowly broken down by digestive enzymes into particles small enough to be transferred in the small intestine. Among the milk matrices, cheese has a different behaviour under gastric conditions because it is already a solid food. Regarding cheese digestion, our research efforts have focused on determining whether cheese microbiota can contribute to the digestion of milk proteins. We have also developed whey protein-based cheeses for the older adult population. These cheeses have higher leucine concentrations than their casein-based counterparts and may be ideal tools for restoring muscle protein synthesis in older people suffering from sarcopenia. The presentation will demonstrate that the structure of dairy products at different length scales can be considered as a lever to control the kinetics of nutrient release during digestion to meet the nutritional needs of specific populations (elderly, obese, athletes).

    ano.nymous@ccsd.cnrs.fr.invalid (Didier Dupont) 11 Jun 2024

    https://hal.inrae.fr/hal-04608382
  • [hal-04465924] Correlating structure and activity of pepsin enzyme in H2O and D2O for the study of gastric digestion

    D2O, an isotope of H2O, is commonly used as a solvent in neutron scattering; the large difference in scattering length density between H and D can provide better contrast between the sample and the solvent. However, this is of concern for studies using enzymes as the use of D2O can influence protein interactions (due to differences in hydrogen bonding) and is therefore expected to affect the function, activity and solubility of enzymes. Neutron-based in vitro digestion assays on proteins, including those found in food or as oral protein and peptide drugs, often involve different solvents or pH conditions where the activity of the digestive enzyme may not be optimal. Herein, we investigate the structure and activity of the main gastric protease, porcine pepsin, in both H2O and D2O at pH values in the range 1 – 8. We showed that the activity of pepsin was lower in D2O, although the relative change in activity with pH was similar for both solvents. We demonstrated using a combination of SAXS and CD that this relative change in activity was not related to any structural change within the protein but was, rather, linked to relative changes in solubility of the protein.

    ano.nymous@ccsd.cnrs.fr.invalid (Meltem Bayrak) 21 Feb 2024

    https://hal.science/hal-04465924
  • [hal-04611850] Current advances for in vitro protein digestibility

    Protein is an essential macronutrient in our diet, source of nitrogen and essential amino acids, but the biological utilization of dietary protein depends on its digestibility and the absorption of amino acids and peptides in the gastrointestinal tract. The methods to define the amount and the quality of protein to meet human nutritional needs, such as the Digestible Indispensable Amino Acid Score (DIAAS), require the use of animal models or human studies. These in vivo methods are the reference in protein quality evaluation, but they are expensive and long-lasting procedures with significant ethical restrictions. Therefore, the development of rapid, reproducible and in vitro digestion methods validated with in vivo data is an old demand. This review describes the challenges of the in vitro digestion methods in the evaluation of the protein nutritional quality. In addition to the technical difficulties to simulate the complex and adaptable processes of digestion and absorption, these methods are affected by similar limitations as the in vivo procedures, i.e., analytical techniques to accurately determine bioavailable amino acids and the contribution of the endogenous nitrogen. The in vitro methods used for the evaluation of protein digestibility, with special attention on those showing comparative data, are revised, emphasizing their pros and cons. The internationally harmonized digestion protocol proposed by the INFOGEST network is being adapted to evaluate protein and amino acid digestibility. The inter-laboratory reproducibility of this protocol was demonstrated for dairy products. The in vivo/in vitro comparability results obtained to date with this protocol for several plant and animal sources are promising, but it requires an extensive validation with a wider range of foods and substrates with known in vivo digestibility. These in vitro methods will probably not be applicable to all foods, and therefore, it is important to identify their limitations, not to elude their use, but to apply them within the limits, by using the appropriate standards and references, and always as a complementary tool to in vivo tests to reduce their number.

    ano.nymous@ccsd.cnrs.fr.invalid (Guillermo Santos-Sánchez) 14 Jun 2024

    https://hal.inrae.fr/hal-04611850
  • [hal-04615159] Protein Ingredient Quality within Infant Formulas Impacts Plasma Amino Acid Concentrations in Neonatal Minipiglets

    Background: Infant formulas (IFs), the only adequate substitute to human milk, are complex matrices that require numerous ingredients and processing steps that may impact protein digestion and subsequent amino acid (AA) absorption. Objectives: The objective was to understand the impact of the protein ingredient quality within IFs on postprandial plasma AA profiles. Methods: Four isonitrogenous and isocaloric IFs were produced at a semi-industrial scale using whey proteins from different origins (cheese compared with ideal whey) and denaturation levels (IF-A, -B, -C), and caseins with different supramolecular organizations (IF-C, -D). Ten Yucatan minipiglets (12- to 27-d-old) were used as a human infant model and received each IF for 3 d according to a Williams Latin square followed by a 2-d wash-out period. Jugular plasma was regularly sampled from 10 min preprandial to 4 h postprandial on the third day to measure free AAs, urea, insulin, and glucose concentrations. Data were statistically analyzed using a mixed linear model with diet (IFs), time, and sex as fixed factors and piglet as random factor. Results: IFs made with cheese whey (IF-A and -B) elicited significantly higher plasma total and essential AA concentrations than IFs made with ideal whey (IF-C and -D), regardless of the pre- and postprandial times. Most of the differences observed postprandially were explained by AA homeostasis modifications. IFs based on cheese whey induced an increased plasma concentration of Thr due to both a higher Thr content in these IFs and a Thr-limiting degrading capability in piglets. The use of a nonmicellar casein ingredient led to reduced plasma content of AA catabolism markers (IF-D compared with IF-C). Conclusions: Overall, our results highlight the importance of the protein ingredient quality (composition and structure) within IFs on neonatal plasma AA profiles, which may further impact infant protein metabolism.

    ano.nymous@ccsd.cnrs.fr.invalid (Lucile Chauvet) 18 Jun 2024

    https://hal.inrae.fr/hal-04615159
  • [hal-04590151] Life cycle assessment to quantify the environmental performance of multi-products food processing systems such as milk fractionation: Importance of subdivision and allocation

    Many industrial food processes are multi-steps, multi-products systems, and sharing the environmental impacts produced by each step to each product is critical when implementing life cycle assessment (LCA) method. The objective of the study was therefore to investigate subdivision and different allocation rules as means of accounting for branched process itineraries such as the fractionation of milk into cream, casein, whey proteins and lactose as a case study. Depending on the mass, dry matter, protein or economic allocation, single products may or may not bear significant environmental impacts, thereby stressing the need for equally detailed inventories for all co-products. Aggregating the results by step or by input further helps identifying hotspots. Methodological choices in LCA of multifunctional systems are therefore strategic decisions that ultimately affect the eco-design of products, processes and food chains

    ano.nymous@ccsd.cnrs.fr.invalid (Fanny Guyomarc’h) 28 May 2024

    https://hal.inrae.fr/hal-04590151
  • [hal-04586551] Quels besoins de recherche pour améliorer conjointement la santé et le bien-être des animaux dans la transition agroécologique de l’élevage ?

    Cet article présente les recherches nécessaires pour placer la santé et le bien-être au cœur de la transition agroécologique des systèmes d’élevage. Il souligne la nécessité de considérer la santé dans une perspective plus large qu’aujourd’hui et la question des expériences émotionnelles positives en matière de bien-être. Les interactions positives entre santé et bien-être mais aussi les tensions possibles entre ces deux dimensions sont discutées. L'amélioration conjointe de la santé et du bien-être des animaux pose des questions à différentes échelles. Au niveau de l'animal, sont à explorer le rôle du microbiote, les mécanismes psycho-neuro-endocriniens qui relient l'état mental positif et la santé, et les compromis entre les fonctions physiologiques de production, de reproduction et d'immunité. Au niveau de l'exploitation, il conviendrait de considérer l’expertise des éleveurs et d’évaluer l’effet des changements de pratiques sur leur bien-être au travail ; au niveau de la filière de production ou du territoire, étudier les stratégies pour améliorer la santé et le bien-être des animaux tout en préservant la viabilité économique, la possibilité d’étiquetage et de labellisation des produits, le consentement à payer des consommateurs, les conséquences de l'hétérogénéité phénotypique des animaux pour la transformation des produits et la répartition spatiale des exploitations. Au niveau des citoyens, un défi consiste à mieux relier leurs préoccupations en matière de bien-être des animaux et de santé globale. Ces nombreuses questions plaident en faveur d'une approche interdisciplinaire et transdisciplinaire, associant l’ensemble des acteurs, y compris les décideurs publics, dans une démarche de recherche participative.

    ano.nymous@ccsd.cnrs.fr.invalid (Christian Ducrot) 24 May 2024

    https://hal.inrae.fr/hal-04586551
  • [hal-04584647] Isolation, Identification, and Characterization of Bacillus cereus Group Bacteria Isolated from the Dairy Farm Environment and Raw Milk in Tunisia

    Members of the Bacillus cereus group are well-known opportunistic foodborne pathogens. In this study, the prevalence, hemolytic activity, antimicrobial resistance profile, virulence factor genes, genetic diversity by enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction (PCR) genotyping, and adhesion potential were investigated in isolates from a Tunisian dairy farm environment and raw milk. A total of 200 samples, including bedding, feces, feed, liquid manure, and raw bovine milk, were examined. Based on PCR test targeting sspE gene, 59 isolates were detected. The prevalence of B. cereus group isolates in bedding, feces, liquid manure, feed, and raw milk was 48%, 37.8%, 20%, 17.1%, and 12.5%, respectively. Out of the tested strains, 81.4% showed β-hemolytic on blood agar plates. An antimicrobial resistance test against 11 antibiotics showed that more than 50% of the isolates were resistant to ampicillin and novobiocin, while a high sensitivity to other antibiotics tested was observed in most isolates. The distribution of enterotoxigenic genes showed that 8.5% and 67.8% of isolates carried hblABCD and nheABC, respectively. In addition, the detection rate of cytotoxin K (cytk), enterotoxin T (bceT), and ces genes was 72.9%, 64.4%, and 5.1%, respectively. ERIC-PCR fingerprinting genotype analysis allowed discriminating 40 different profiles. The adhesion potential of B. cereus group on stainless steel showed that all isolates were able to adhere at various levels, from 1.5 ± 0.3 to 5.1 ± 0.1 log colony-forming unit (CFU)/cm2 for vegetative cells and from 2.6 ± 0.4 to 5.7 ± 0.3 log CFU/cm2 for spores. An important finding of the study is useful for updating the knowledge of the contamination status of B. cereus group in Tunisia, at the dairy farm level.

    ano.nymous@ccsd.cnrs.fr.invalid (Randa Ben Akacha) 23 May 2024

    https://hal.inrae.fr/hal-04584647
  • [hal-04593517] Déterminants mécanistiques de l'évolution de la structure et des propriétés viscoélastiques des gels laitiers enzymatiques

    Une des premières étapes de la transformation fromagère consiste à supprimer la stabilité colloïdale des micelles de caséine par ajout d’un enzyme coagulant afin d’initier la transition de phase liquide-gel du lait. Sous dépendance des conditions physicochimiques du lait, le gel laitier enzymatique évolue dans ses propriétés viscoélastiques et sa structure jusqu’à atteindre un état « pseudo »-stationnaire. En pratique, le gel est tranché pour favoriser l’expulsion du lactosérum avant d’atteindre cet état « pseudo »-stationnaire. Les pertes de protéines et de matière grasse dans le sérum et en conséquence la composition du caillé après égouttage, dépendent de l’instant du tranchage du gel laitier enzymatique. Comprendre les mécanismes à l’origine des cinétiques d’évolutions des propriétés et de la structure des gels laitiers enzymatiques en fonction des conditions physicochimiques du lait est essentiel pour optimiser les transformations fromagères car le gel est tranché alors que sa structure et ses propriétés changent. Pour étudier ces mécanismes, nous avons combiné d’une part, l’étude les propriétés linéaires et non-linéaires par rhéologie oscillatoire aux faibles et fortes déformations de gels laitiers enzymatiques en fonction des conditions physicochimiques du milieu et d’autre part, l’analyse des répartitions minérales au sein des micelles de caséines, ainsi que l’observation de la structure des micelles de caséines et des gels par des techniques microscopiques (microscopie à force atomique, microscopie électronique à balayage, microscopie confocale à balayage laser) et diffusion des rayons X afin de sonder différentes échelles de taille et de temps. Nous avons pu montrer que la prise en compte du rôle de 2 formes de cations au sein des micelles de caséines, i.e. le calcium précipité sous forme CaHPO4 et les cations calcium et magnésium directement associés aux caséines permettait d’expliquer l’évolution de la structure et les propriétés rhéologiques dans le domaine linéaire des gels laitiers enzymatiques. En modifiant la charge des micelles de caséines, la teneur en cations associés aux caséines affecte la fermeté des gels laitiers enzymatiques alors que la teneur en calcium précipité affecte la rigidité des micelles de caséines et les propriétés viscoélastiques macroscopiques des gels laitiers enzymatiques (G’ et G’’). Lorsqu’une contrainte d’amplitude croissante est imposée à un gel enzymatique laitier, celui-ci présente, au-delà du domaine linéaire, une phase d’adaptation à la contrainte imposée, traduisant un ramollissement du gel, suivie d’une phase de raffermissement qui précède une facture irréversible. L’amplitude de ces deux phases dépend de la fraction volumique du gel et de son stade d’évolution. Contrairement à la phase de raffermissement du gel avant fracture, la phase d’adaptation du gel à la contrainte imposée semble indépendante de la structure du réseau de micelle de caséines à l’échelle mésoscopique. La phase d’adaptation du gel à la contrainte imposée s’expliquerait par l’existence de liaisons à courte durée de vie permettant des réarrangements locaux plastiques, vraisemblablement entre micelles de caséines, c’est-à-dire à l’échelle nanoscopique, car la structure interne de ces dernières ne semble pas impactée au cours de la gélification.

    ano.nymous@ccsd.cnrs.fr.invalid (Julien Bauland) 30 May 2024

    https://hal.science/hal-04593517
  • [hal-04586285] Fairchain project to test business plans for small fruit & vegetable producers

    To shift from long and short food value chains and integrate innovations into the new economic system of intermediate food value chains (IFVC), innovative business models are required. These models are based on new collaborations and value creation within existing supply chains. The FAIRCHAIN project develops technological, organisational, and social solutions to offer additional business model opportunities for small to medium scale fruit and vegetable (and dairy) producers. Three organisational innovations, two social, and eleven technological are tested by FAIRCHAIN in six European cases in six countries. The FAIRCHAIN approach involves definition of IFVC and identification of barriers and drivers. Then, development of sustainable IFVC business models by structured co-creation to (i) agree on common goals, (ii) define a plan for implementation, and (iii) assess and valorise outcomes from various perspectives (technical-economic, social, environmental, legal). In Business Model Generation Workshops, case participants use these outcomes to maximize impact and reach regional business concepts, often with new players and governance models. Several possible business models are envisioned by type of innovation and the most relevant and sustainable regional business concept is developed with the core stakeholders. The co-creation process guarantees a win-win approach that is multidisciplinary and systemic and considers all 4 pillars of sustainability. Four of the six FAIRCHAIN cases address fruit and vegetable chains and these are applying business models for IFVC as follows: the development of an Information and Communication Technology tool for local people to locate wild berries and re-establish local business in wild berry processing and sales (Sweden), a flexible packaging machine to be shared by small scale fruit and vegetable producers to reduce equipment costs and allow more efficient packaging and longer shelf life for local products (Belgium), a “Food Incubator” provides market insights, networking and facilities for innovations to meet market demand for local producers to valorise their products (Austria), co-product recycling gives multiple sources of revenues (renewable energy, biochar, and carbon credits) by creating a recycling scheme with several value-added loops as close as possible to the farmers (Switzerland). The development of business models in the FAIRCHAIN case studies can inspire and be a core component of business model generation for many small fruit and vegetable producers. However, challenges remain, such as integrating businesses into an existing and representative local European ecosystem.

    ano.nymous@ccsd.cnrs.fr.invalid (Katherine Flynn) 24 May 2024

    https://hal.inrae.fr/hal-04586285
  • [hal-04578688] FAIRCHAIN, favoriser des chaines de valeur intermédiaires pour répondre aux défis écologiques, climatiques et de santé

    De plus en plus de consommateurs souhaitent adopter des pratiques alimentaires plus durables. Le projet européen H2020-FAIRCHAIN (https://www.fairchain-h2020.eu/; convention de subvention n° 101000723) répond à cette demande croissante d'une transformation significative des systèmes alimentaires actuels. L’enjeu du projet est d’aider les petits et moyens agriculteurs et producteurs de produits alimentaires à élargir leur gamme et augmenter le volume d’aliments de qualité, en augmentant les revenus agricoles et développant de nouveaux marchés, le tout de manière durable. Les procédés fermentaires constituent en ce sens un levier intéressant dans la mesure où ils permettent de valoriser certains co-produits de manière robuste et efficiente. Le projet FAIRCHAIN a montré qu’il était possible de produire de nouvelles boissons appréciées des consommateurs à partir d’un co-produit de la transformation fromagère (lactosérum), non valorisé par les fromageries isolées géographiquement. Les nouvelles boissons fermentées sont stabilisées et se conservent à température ambiante. Le procédé proposé n’implique pas d’équipements lourds, ni de compétences complexes. Les modèles d’affaires les plus pertinents sont en cours de définition. Cette solution opérationnelle, co-construite avec les acteurs de la chaine de valeur, participe, comme l’ensemble des innovations développées et testées dans le projet FAIRCHAIN, à améliorer la compétitivité et la durabilité des systèmes agro-alimentaires de l’Union Européenne.

    ano.nymous@ccsd.cnrs.fr.invalid (Geneviève Gésan-Guiziou) 17 May 2024

    https://hal.inrae.fr/hal-04578688
  • [hal-04581000] Integration of metataxonomic data sets into microbial association networks highlights shared bacterial community dynamics in fermented vegetables

    The management of food fermentation is still largely based on empirical knowledge, as the dynamics of microbial communities and the underlying metabolic networks that produce safe and nutritious products remain beyond our understanding. Although these closed ecosystems contain relatively few taxa, they have not yet been thoroughly characterized with respect to how their microbial communities interact and dynamically evolve. However, with the increased availability of metataxonomic data sets on different fermented vegetables, it is now possible to gain a comprehensive understanding of the microbial relationships that structure plant fermentation. In this study, we applied a network-based approach to the integration of public metataxonomic 16S data sets targeting different fermented vegetables throughout time. Specifically, we aimed to explore, compare, and combine public 16S data sets to identify shared associations between amplicon sequence variants (ASVs) obtained from independent studies. The workflow includes steps for searching and selecting public time-series data sets and constructing association networks of ASVs based on co-abundance metrics. Networks for individual data sets are then integrated into a core network, highlighting significant associations. Microbial communities are identified based on the comparison and clustering of ASV networks using the “stochastic block model” method. When we applied this method to 10 public data sets (including a total of 931 samples) targeting five varieties of vegetables with different sampling times, we found that it was able to shed light on the dynamics of vegetable fermentation by characterizing the processes ofcommunity succession among different bacterial assemblages. IMPORTANCE Within the growing body of research on the bacterial communities involved in the fermentation of vegetables, there is particular interest in discovering the species or consortia that drive different fermentation steps. This integrative analysis demonstrates that the reuse and integration of public microbiome data sets can provide new insights into a little-known biotope. Our most important finding is the recurrent but transient appearance, at the beginning of vegetable fermentation, of amplicon sequence variants (ASVs) belonging to Enterobacterales and their associations with ASVs belonging to Lactobacillales. These findings could be applied to the design of new fermented products.

    ano.nymous@ccsd.cnrs.fr.invalid (Romane Junker) 21 May 2024

    https://hal.inrae.fr/hal-04581000
  • [hal-04582085] Peptidomic profile of human milk as influenced by fortification with different protein sources : An in vitro dynamic digestion simulation

    Objectives and Study Supplementing human milk (HM) is often necessary to fulfill the nutritional needs of premature infants. This study aimed to determine if enriching HM with either an experimental donkey milk-derived fortifier (DMF), containing whole DM proteins, or a commercial bovine milk-derived fortifier (BMF), containing hydrolyzed BM whey proteins, affects the release of peptides during digestion. Methods Milk samples were collected, fortified and digested by means of DIDGI® bi-compartmental in vitro dynamic system to simulate the digestion of a preterm newborn at a postnatal age of four weeks. Identification and quantification of the peptides in undigested and digested samples was performed by HPLC-HRMS. Each identified peptide was quantified by means of label-free MS, using MassChroQ software. Data were elaborated by Multivariate analyses of variance (Principal Component Analysis - PCA). Results Results indicated that the different fortifiers did not significantly alter the overall intensity of HM peptides. However, fortification led to distinct impacts on the release of specific bioactive peptides. Additionally, when HM was supplemented with DMF, there was a minor delay in the release of peptides from lactoferrin and ?-lactalbumin. Conclusions Lactoferrin from human milk (HM) exhibited less peptide release during intestinal digestion when fortified with the DM-derived fortifier. This prolonged presence of intact lactoferrin holds promise for bolstering gut protection against infections and inflammation. Another benefit of fortifying HM with the DM-derived fortifier is the generation of extra anti-inflammatory peptides from DM during digestion. These discoveries carry significant implications for the clinical nutrition of premature infants, who frequently face challenges related to intestinal health issues and inflammation

    ano.nymous@ccsd.cnrs.fr.invalid (Marzia Giribaldi) 21 May 2024

    https://hal.inrae.fr/hal-04582085
  • [hal-04582804] Protein ingredient quality of infant formulas impacts gut physiology and microbiota in mini-piglets used as a human infant model.

    Infant formulas (IFs), the only adequate substitute to human milk, are complex matrices that require numerous ingredients and processing steps. Previously, we showed that the quality of the dairy protein ingredients within IFs modulated protein microstructure and in vitro and in vivo digestive kinetics. Therefore, the aim was to assess the impact of protein ingredient quality (composition and structure) on gut physiology and microbiota. Three isonitrogenous IFs were formulated with whey proteins from different origins (cheese whey: IF-A, vs. ideal whey: IFs-B/C) and casein with different organizations (micellar: IFs-A/B, vs. non-micellar: IF-C). Twenty-four Yucatan mini-piglets (2- to 21-day-old), used as an infant model, received one of the three IFs. Digestive contents, faeces, and tissues were analysed using metagenomic, histological, ex vivo permeability and gene expression approaches and a metabolomic analysis was done on serum. Univariate and multivariate statistical analyses were performed. The increase of colonic paracellular permeability associated with a slight immune boost, and the changes in colonic amino acid transporter expression in IF-C compared with IF-A fed piglets, suggested a combined effect of whey origin and casein supramolecular organization on intestinal physiology in favour of IF-C, whose parameters were closer to those recently reported for human milk-fed piglets (Charton et al., 2022). Gut microbiota composition was moderately changed between diets, whereas faecal short-chain fatty acid composition differed according to whey protein origin. Differences in microbiota fermentative activity may result from differences in digestive kinetics previously observed in vitro between cheese whey-based IF (A) and ideal whey-based IFs (B and C), which could modulate the colonic substrate available for the microbiota. Serum metabolomic data are currently being analysed and may provide a better understanding of the mechanisms involved. The use of ideal whey and the modulation of casein organization appear to be possible avenues for improving IFs.

    ano.nymous@ccsd.cnrs.fr.invalid (Lucile Chauvet) 22 May 2024

    https://hal.inrae.fr/hal-04582804
  • [hal-04581102] Post-milking application of a Lacticaseibacillus paracasei strain impacts bovine teat microbiota while preserving the mammary gland physiology and immunity

    Bovine mastitis (BM) is a major disease in dairy industry. The current approaches – mainly antibiotic treatments are not entirely effective and may contribute to antimicrobial resistance dissemination, rising the need for alternative treatment. The present study aims to evaluate the impact of post-milking application of Lacticaseibacillus paracasei CIRM BIA 1542 (Lp1542) on the teat skin (TS) of 20 Holstein cows in mid lactation, in order to reinforce the barrier effect of the microbiota naturally present on the teat. Treatment (Lp1542, iodine or no treatment) was applied post-milking twice a day on the 4 teats of healthy animals for 15 days. Blood and milk samples, and TS swabs were collected at day (D)1, D8, D15 and D26 before morning milking and at D15 before evening milking (D15E) to evaluate Lp1542 impact at the microbial, immune and physiological levels. Lp1542 treatment resulted in a higher lactic acid bacteria and total microbial populations on TS and in foremilk (FM) at D15(E) compared with iodine treatment. Metabarcoding analysis revealed changes in the composition of TS and FM microbiota, beyond a higher Lacticaseibacillus abundance. This included a higher abundance of Actinobacteriota, including Bifidobacterium, and a lower abundance of Pseudomonadota on TS of Lp1542 compared with iodine- treated quarters. In addition, Lp1542 treatment did not trigger any major inflammatory response in the mammary gland, except interleukin 8 production and expression which tended to be slightly higher in Lp1542-treated cows compared with the others. Finally, Lp1542 treatment had no impact on the mammary epithelium functionality (milk yield and composition) and integrity (epithelial cell exfoliation into milk and milk Na + /K + ratio). Altogether, these results indicate that a topical treatment with Lp1542 is safe with regard to mammary gland physiology and immune system, while impacting its microbiota, inviting us to further explore its effectiveness for mastitis prevention.

    ano.nymous@ccsd.cnrs.fr.invalid (C Goetz) 21 May 2024

    https://hal.inrae.fr/hal-04581102
  • [hal-04574506] Effect of a pre-hydrolysis on the in vitro digestibility of Arthrospira platensis

    Spirulina, a cyanobacteria that is 60% protein, could provide an alternative to animal proteins, the production of which is a major contributor to greenhouse gas emissions. Protein from this organism, which is also rich in vitamins and minerals, has good amino acid profile and contains bioactive activities. However, its digestibility has been poorly assessed and varies greatly from one study to another. Moreover, spirulina protein digestibility remains lower than that of animal proteins. One possibility to improve spirulina digestibility is to pre-hydrolyze the proteins into peptides using various proteases. Additionally, pre-hydrolysis of Spirulina by various enzymes could significantly increase spirulina protein digestibility. In this study, alcalase and bromelain were used at different concentrations (0.25% and 1%) to pre-hydrolyze dry or frozen spirulina. Samples were analyzed by size exclusion chromatography and mass spectrometry before digestion. Then, the INFOGEST in vitro static digestion model was used to assess spirulina digestibility and free amino acids were assayed after digestion. Pre-hydrolysing spirulina did not improve significantly protein digestibility, which stands at around 81%. However, qualitative differences were observed in the pre-hydrolyzed solutions before and after digestion. In particular, peptide size varied according to the enzyme used (alcalase vs bromelain), its concentration (0.25% vs 1%), and the storage method (dry or frozen spirulina). Additionally, at the end of the gastric phase, bioactive peptides could be identified although they were still encrypted in longer sequences

    ano.nymous@ccsd.cnrs.fr.invalid (Alizé Mouchard) 14 May 2024

    https://hal.inrae.fr/hal-04574506
  • [hal-04572984] From taste to purchase: Understanding the influence of sensory perceptions and informed tasting on plant-based product purchases - An extension of the theory of planned behavior

    [...]

    ano.nymous@ccsd.cnrs.fr.invalid (Muhammad Adzran Che Mustapa) 13 May 2024

    https://hal.inrae.fr/hal-04572984
  • [hal-04509395] Revealing the dynamics and mechanisms of bacterial interactions in cheese production with metabolic modelling

    Cheese taste and flavour properties result from complex metabolic processes occurring in microbial communities. A deeper understanding of such mechanisms makes it possible to improve both industrial production processes and end-product quality through the design of microbial consortia. In this work, we caracterise the metabolism of a three-species community consisting of Lactococcus lactis, Lactobacillus plantarum and Propionibacterium freudenreichii during a seven-week cheese production process. Using genome-scale metabolic models and omics data integration, we modeled and calibrated individual dynamics using monoculture experiments, and coupled these models to capture the metabolism of the community. This model accurately predicts the dynamics of the community, enlightening the contribution of each microbial species to organoleptic compound production. Further metabolic exploration revealed additional possible interactions between the bacterial species. This work provides a methodological framework for the prediction of community-wide metabolism and highlights the added value of dynamic metabolic modeling for the comprehension of fermented food processes

    ano.nymous@ccsd.cnrs.fr.invalid (Maxime Lecomte) 18 Mar 2024

    https://hal.inrae.fr/hal-04509395
  • [hal-04551059] Ferments, Ils vont révolutionner la nourriture du futur

    En consommation croissante, les produits fermentés constituent désormais une sérieuse solution de transition vers une alimentation moins carnée et moins sucrée. Un nouveau centre de recherche en région parisienne va explorer ce monde encore méconnu des bactéries, levures et champignons.

    ano.nymous@ccsd.cnrs.fr.invalid (Romain Jeantet) 18 Apr 2024

    https://hal.inrae.fr/hal-04551059
  • [hal-04573534] Impact of sensory properties and their appreciation on willingness to pay for innovative cheeses with health benefits

    [...]

    ano.nymous@ccsd.cnrs.fr.invalid (Christophe Martin) 13 May 2024

    https://hal.inrae.fr/hal-04573534
  • [tel-04583312] Approche hybride de modélisation explicable du métabolisme des écosystèmes microbiens

    Les communautés microbiennes sont des systèmes complexes composés de diverses espèces de micro-organismes interagissant entre elles et avec leur environnement. La biologie des systèmes offre un cadre pour leur étude, alliant expérimentation, génération de données à haut-débit et leur intégration dans des modèles informatiques. La compréhension de ces communautés passe notamment par celle de leur métabolisme et des échanges de molécules entre espèces susceptibles d’impacter positivement ou négativement chacun des membres. Le métabolisme est un ensemble de réactions biochimiques et peut s’abstraire à l’échelle d’un génome par des réseaux faisant le lien entre les gènes et les réactions d’un organisme. Ces réseaux permettent de construire des modèles métaboliques, représentations informatiques ou mathématiques du comportement des organismes dans des conditions expérimentales. Le passage de l’individu à la communauté, composée de quelques espèces en conditions contrôlées, ou de plusieurs centaines en conditions environnementales, soulève des difficultés méthodologiques dans la construction des modèles. Ce manuscrit de thèse traite de la modélisation du métabolisme et des interactions métaboliques au sein des écosystèmes microbiens en mettant l’emphase sur l’explication des mécanismes cellulaires qui justifient les interactions bactériennes. Des solutions numériques sont majoritairement utilisées - assurant la précision des résultats - mais sont confrontées à l’importante combinatoire engendrée par les interactions bactériennes pour des communautés de grande taille. Les réponses apportées par les approches discrètes surmontent la problématique du passage à l’échelle mais sont limitées à une analyse par paire d’organismes. Afin d’identifier un potentiel ajustement méthodologique - conciliant les avantages des deux démarches, i.e. trouver une approche hybride - une première contribution se focalise sur le développement d’un modèle numérique dynamique et précis d’une communauté fromagère composée de trois souches. Notre stratégie itérative a permis l’intégration de données hétérogènes au moyen d’étapes de raffinement et de calibration dynamique. Ces allers-retours entre la connaissance et le modèle ont assuré la bonne prédiction des concentrations des métabolites dosés en métabolomique ainsi que des densités bactériennes au cours de la cinétique de fabrication du fromage. Dans une seconde contribution, nous proposons un modèle par raisonnement permettant de cibler des potentiels de coopération et de compétition dans des communautés bactériennes. Ce modèle repose sur l’inférence de règles logiques inférées de la biologie pour évaluer et comparer les potentiels d’interaction de communautés. Des potentiels d’interaction spécifiques à des écosystèmes ont été révélés ainsi que la pertinence de son utilisation grâce à sa rapidité d’exécution. Enfin, la troisième contribution est une réflexion portant sur l’enrichissement du modèle logique. Nous proposons un prototype s’appuyant sur l’inférence de règles logiques et permettant de (i) sélectionner la meilleure communauté à partir de contraintes biologiques et (ii) d’apporter une notion temporelle, pouvant influencer les potentiels d’interactions. Par cette thèse, nous avons montré que la construction d’un modèle de modélisation hybride du métabolisme n’est pas nécessaire, mais qu’une approche hybride, utilisant des modèles numériques, pour des communautés de petite taille et des modèles discrets, pour analyser rapidement les communautés de taille réelle semble être pertinente.

    ano.nymous@ccsd.cnrs.fr.invalid (Maxime Lecomte) 22 May 2024

    https://theses.hal.science/tel-04583312
  • [hal-04555868] Viscoelastic systems from glycolipid biosurfactants

    Biosurfactants offer significant advantages over their chemical counterparts due to their environmentally friendly nature. Among them, glycolipids are one of the most studied classes and possess the ability to self-assemble into various structures. The ability of glycolipid bioamphiphiles to impart viscoelasticity and immobilize the solvent underscores their potential use beyond their surface-active properties, posi- tioning them as efficient low-molecular-weight gelators for the development of functional soft materials. Herein, we review the viscoelastic properties of self-assembled glycolipid systems, namely worm-like micelles, fibrillar, and lamellar hydrogels. Next, recent trends in the development of multicomponent systems from the orthogonal self-assembly of glycolipids and biopolymer gels are highlighted.

    ano.nymous@ccsd.cnrs.fr.invalid (Ghazi Ben Messaoud) 23 Apr 2024

    https://hal.inrae.fr/hal-04555868
  • [hal-04572934] Macronutrient digestion and nutritional quality: how to measure it and what matters?

    Food digestion and nutrient absorption efficiency and kinetics are important parameters for futher metabolic use. They can be influenced by different food properties, such as the structure and the fine composition, but also by the host digestion capacity. The present talk will illustrate these concepts through results from our research group obtained either through in vivo models (pig or human) or in vitro models (static and dynamic conditions). For instance, we have demonstrated that, at identical composition, differences in dairy product macrostructure lead to differences in gastric emptying and protein digestion. For similar macrostructure, differences at the microscopic scale can also impact food digestion kinetics, as shown for egg white gels and protein hydrolysis kinetics but also for infant milk and lipid and protein hydrolysis kinetics. Other examples of how lipid structuration can impact on the bioaccessibility/bioavailability of essential fatty acids such as DHA will be given. Besides food structure, the composition of the food or the meal can influence the digestion mechanisms, particularly for plant-based foods containing fibers, anti-nutritional factors, polyphenols, …. Finally, the host is also an important modulating factor, especially when considering the physiological stage, from infant to senior, such as demonstrated through in vitro approaches. Overall, beyond food composition, the structure of food at different length scales can be considered as an important lever to control the kinetics of nutrients release during digestion and fulfil the nutritional needs of specific populations (elderly, infant, …) .

    ano.nymous@ccsd.cnrs.fr.invalid (Amélie Deglaire) 13 May 2024

    https://hal.inrae.fr/hal-04572934
  • [hal-04554902] Variations in Chlorella lipid content in commercial and in-lab produced biomass ☆

    Microalgae appear as a sustainable source of biomass with relevant nutritional qualities. Still, regulatory restrictions currently limit the use of eukaryotic microalgae for human consumption to a short list of species dominated by Chlorella spp. Chlorella biomass contains valuable proteins but also interesting lipids, including polyunsaturated fatty acids (PUFA) v3 and v6. The amount of PUFA and the v6/v3 ratio vary significantly depending on the species and cultivation trophic mode. While the lipid profiles of in-lab produced Chlorella has been widely studied, the variability of lipid content in commercial biomasses is barely described. Here, lipid classes and fatty acid profiles of six commercial biomasses of Chlorella spp. as well as those of lab-produced C. sorokiniana grown in photo-autotrophy and in four mixotrophy conditions were characterized. Results showed significant lipid composition variations between the biomasses, such as the triacylglycerols/glycolipids and v6/v3 contents. The v6/v3 ratios were lower in photo-autotrophic mode (2.5) while they ranged between 1.3 and 8.9 in commercial biomasses. The free fatty acids level was also variable (1.4% to 17.9% of total lipids). As a consequence, Chlorella lipid content and quality differed significantly, impacting the potential nutritional benefits of the consumption of commercial biomass. Processing and post-processing conditions should therefore be carefully controlled to optimize lipid profiles

    ano.nymous@ccsd.cnrs.fr.invalid (Nathalie Barouh) 22 Apr 2024

    https://hal.inrae.fr/hal-04554902
  • [hal-04554465] Solutions technologiques, organisationnelles et sociales innovantes pour des chaînes de valeur plus équitables dans les secteurs des produits laitiers et des fruits et légumes

    Projet FAIRCHAIN: Permettre aux petits et moyens agriculteurs et producteurs de produits alimentaires d'augmenter et de développer la production d'aliments nutritionnels par le biais de chaînes de valeur intermédiaires compétitives au niveau régional

    ano.nymous@ccsd.cnrs.fr.invalid (Geneviève Gésan-Guiziou) 22 Apr 2024

    https://hal.inrae.fr/hal-04554465
  • [hal-04554749] Projet Fairchain: Le cas d’étude français : approches et enseignements

    [...]

    ano.nymous@ccsd.cnrs.fr.invalid (Geneviève Gésan-Guiziou) 22 Apr 2024

    https://hal.inrae.fr/hal-04554749
  • [hal-04555831] Liquid-liquid phase separation in heteroprotein systems: recent advances

    Liquid–liquid phase separation (LLPS) has emerged as a new paradigm in the fields of soft matter, colloid chemistry, food science and cell biology. Research in this area constitutes a fine example where physics and biology intertwine harmoniously. LLPS is a dynamic assembly process that leads, in solution or in vivo, to the formation of micrometer-sized droplets, which are referred as biomolecular condensates, membrane less organelles, liquid droplets or complex coacervates, depending on the scientific community concerned [1,2]. In this presentation, I focus on LLPS that occurs in binary cationic and anionic protein mixtures (heteroprotein systems, HPCC). I briefly review aspects that are of particular interest: formation dynamics; main driving forces; physical and chemical properties; functions and applications. Throughout studied binary protein systems, the route to complex coacervation involves the formation of intermediate hetero-oligomers specific for each binary system. Dimers, tetramers, or pentamers were identified (Fig. 1). While the mechanism behind the association of these primary units into building blocks and their growth to form complex coacervates remain elusive, I will present and discuss the main relevant structural and physicochemical parameters for HPCC. Finally, the challenges and future research directions in particular how HPCC can be explored in the food sector for the encapsulation and protection of bioactives or to modify the viscosity of the food matrices will be discussed.

    ano.nymous@ccsd.cnrs.fr.invalid (Said Bouhallab) 23 Apr 2024

    https://hal.inrae.fr/hal-04555831
  • [hal-04555804] On the (Micro)Rheology of Lactoferrin/β-Lactoglobulin Coacervates

    Heteroprotein complex coacervates (HPCC) has great potential in many food applications. However, understanding the rheology-coacervate structure relationship, as well as their sensitivity to slight changes in the physicochemical environment, is still an active research topic. Herein, HPCC between two oppositely charged proteins, lactoferrin (LF) and β-lactoglobulin (βLG) was investigated. The influence of ionic strength and temperature on the rheological properties of LF/βLG coacervates was examined using oscillatory shear rheology and microrheology from dynamic light scattering. LF/βLG HPCC exhibited a liquid-like character with G’(ω) < G’’(ω) and an increase of both moduli with decreased temperature but a softening effect with increased ionic strength. The dependency of G’ and G’’ on angular frequency (ω) demonstrated a scaling of G” ∝ ω1 and a lack of terminal behavior with G’ ∝ ω1.4. The application of time-temperature superposition (TTS) nd time-salt superposition (TSS) principles allowed the prediction of the rheological properties over a wide range of timescales and temperatures below the denaturation temperature of βLG and LF. The two principles suggested that increasing temperature or ionic strength accelerates coacervates dynamics but does not affect larger-scale physics. Microrheology experiments using polystyrene-coated microspheres as tracers, allowed access to a frequency range up to (ω ~ 106 rad/s) and revealed a variable scaling of G’= G” ∝ ω1/2 or ∝ ω3/4 at the high-frequency terminal regime and approaching theoretical predictions of Rouse regime and Worm-Like Chain model for polymers. In the present case, it reflected a freely draining system where hydrodynamic interactions are neglected at these timescales. By combining rheology and microrheology, we provide a comprehensive study that underscores the influence of ionic strength and temperature on LF/βLG coacervates. This study highlights the similarities and differences between protein coacervates and polymer systems and offers new insights into the microstructure of HPCC relevant to various applications.

    ano.nymous@ccsd.cnrs.fr.invalid (Ghazi Ben Messaoud) 23 Apr 2024

    https://hal.inrae.fr/hal-04555804
  • [hal-04557683] Interactions between Salivary Proteins and Apple Polyphenols and the Fate of Complexes during Gastric Digestion

    Beneficial polyphenols in apples can reach the stomach as complexes formed with salivary proteins. The present study aimed at documenting the interactions between salivary proteins and cider apple polyphenols and the fate of complexes during gastric digestion. A polyphenolic extract was mixed with human saliva, and interactions were characterized by analyzing proteins and polyphenols in the insoluble and soluble fractions of the mixtures, before and after in vitro gastric digestion. Results confirmed that proline-rich proteins can efficiently precipitate polyphenols and suggested that two zinc-binding proteins can also form insoluble complexes with polyphenols. The classes of polyphenols involved in such complexes depended on the polyphenol-to-protein ratio. In vitro gastric digestion led to extensive proteolysis of salivary proteins, and we formulate the hypothesis that the resulting peptides can interact with and precipitate some procyanidins. Saliva may therefore partly modulate the bioaccessibility of at least procyanidins in the gastric compartment.

    ano.nymous@ccsd.cnrs.fr.invalid (Müzeyyen Berkel Kasikci) 24 Apr 2024

    https://hal.inrae.fr/hal-04557683
  • [hal-04546199] The in vitro dynamic digestion : a suitable model to mimic the in vivo digestion of infant foods in terms of food deconstruction and protein hydrolysis

    Human infants are preferably fed human milk (HM), but a majority still receive infant formula (IF) as a HM substitute. Optimization of IF is still required to improve HM biomimetics, including digestion behavior biomimetics. While this can be studied in vivo, such experiments have to be reduced and appropriate in vitro models are needed. The present study aimed to compare food deconstruction and protein digestion of HM vs. IF using two infant digestion models, the mini-piglet and the in vitro dynamic gastrointestinal system (DIDGI®). Mini-piglets (Yucatan) were fed either a mature HM (n=9) or a standard IF (n=9) during 6 days. Piglet digesta were collected along the digestive tract 30 min after the last meal. The same foods were digested in triplicate using a term infant in vitro dynamic model with regular digesta sampling along time. Microstructure (confocal microscopy and laser diffraction) and protein digestion (SDS-PAGE, hydrolysis degree, peptidomics) were investigated in both digestion models. Data were statistically analyzed thanks to ANOVA and multidimensional analyses (hierarchical classification and multiple factor analyses). The microstructure of the digesta differed between HM and IF in a similar manner in vitro and in vivo along digestion. The meal dilution and emptying were similar between both digestion models, with a faster emptying for HM. Proteolysis, as investigated by SDS-PAGE, were similar between digestion models, with a lower hydrolysis level for HM caseins. Peptide mapping along the sequence of the major proteins was well correlated between models, particularly in the stomach and the proximal jejunum (r > 0.6). Similar result was found for bioactive peptide release. The ratio between bioaccessibility (in vitro) and bioavailability (in vivo) of amino acids was high (50-80%) at the cleavage sites of the pancreatic enzymes, more precisely for Arg, Tyr, Lys, Phe and Leu, but was much lower for the other amino acids (<30%). In overall, the in vitro dynamic gastrointestinal digestion model well predicted the in vivo digestion of HM and IF, particularly for protein hydrolysis, peptidomics and food deconstruction, while further improvement is needed to better correlate bioaccessibility and bioavailability.

    ano.nymous@ccsd.cnrs.fr.invalid (Elise Charton) 15 Apr 2024

    https://hal.inrae.fr/hal-04546199
  • [hal-04547092] An original, remotely controlled set-up for studying in vitro digestion by MRI – application to bread

    Magnetic Resonance Imaging (MRI) has demonstrated its efficacy in characterizing food properties, offering great potential for quantitatively monitoring digestion. If MRI is a technique of choice for monitoring in vivo digestion, we believe in its great potential for in vitro exploration to provide insights into the composition and multi-scale structure of ingested foods; we are also expecting contributions to the in vivo approach, in terms of signal interpretation and proposals for innovative acquisition sequences. The objectives of this study were to develop a set-up compatible with a whole body MRI scanner to investigate oral-gastric-intestinal food digestion without human intervention in the MRI room, and to use this set-up to gain spatial insights via high-resolution MRI scans into the digestion mechanism of bread structure. The set-up comprises a compartment (referred to as 'cell') that can suit a wrist radiofrequency receive coil for MRI measurements and contain a ~ 1.5 cm wide food piece to be digested. Connected to the cell, another compartment, 'vessel’, is positioned outside the MRI room, linked through a circulating loop controlled by a peristaltic pump (flow rate: 8.4 mL/min). All the manipulations occurred in the vessel. Both the cell and vessel were equipped with water jackets to maintain temperature at 37 °C. The set-up underwent examination for temperature regulation and mixing, in particular for composition homogeneity between compartments. Subsequently, oral-gastric-intestinal digestion of a piece of bread crumb was conducted, with the bread installed in the cell. Manual control and sampling took place in the vessel, while MRI acquisitions, including Multi Spin-Echo and Ultra Short TE (UTE) sequences (for T2 mapping and morphology), were performed. Results demonstrated the set-up enabled the successful execution of digestion, with rapid mass transfer and mixing (complete renewal of the fluid in the cell in 4 min; pH and hydrolysed starch concentrations matching in the cell and vessel) and effective temperature regulation. MRI scans provided internal insights, quantitatively measuring bread piece erosion, pore changes, and local composition during digestion. The degradation level obtained from MRI aligned with the degree of digestion determined through analysis of peptides and hydrolysed starch in the digesta. The present study demonstrated the feasibility of monitoring real-time digestion in a set-up with two separate, potentially distant compartments, facilitated by the circulation of the digestion fluid, which ensures the continuous renewal of the fluid around the food cube. High-resolution MRI images acquired using this set-up offer spatial visualization of bread degradation. The developed setup holds promise for various applications on other foods, providing comprehensive insights into structure changes during digestion.

    ano.nymous@ccsd.cnrs.fr.invalid (Ruoxuan Deng) 15 Apr 2024

    https://hal.inrae.fr/hal-04547092
  • [hal-04547163] A semi-dynamic gastric digestion protocol adapted to the population under proton pump inhibitors (PPI): Impact on the release of macro- and micro-nutrients of a mixed meal

    There are widespread concerns regarding gastric diseases and discomfort, such as heartburn and reflux. The common medicinal solution prescribed is the use of proton pump inhibitors (PPIs). PPIs function by blocking the gastric HK-ATPase, inhibiting gastric acid secretion and leading to a significantly higher pH in the stomach throughout digestion. However, the importance of a gastric acidic environment for food digestion, erosion, and enzyme activity cannot be overlooked, and the impact of PPIs on food digestion and nutrient release remains relatively unexplored. To address this knowledge gap, our study aims to propose an in vitro semi-dynamic digestion protocol under PPI mediation and investigate the effect of PPIs on the digestion of a mixed meal consisting of bread, cheese, and tomato. The PPI digestion protocol was developed based on the INFOGEST semi-dynamic digestion protocol and the reported influence of PPIs on the acidity and rate of gastric secretions in humans. Gastric fluid and rabbit gastric extract (RGE) were added continuously, and five gastric emptying steps were conducted. Consistently with the in vivo literature, a final targeted gastric pH of 4.2 could be obtained by reducing by half the concentration of gastric acid and its secretion rate compared to healthy conditions. The emptied digesta was analysed for the digestion of carbohydrates, proteins, lipids, and minerals using ion chromatography, OPA, thin-layer chromatography, and ICP, respectively. Results revealed that under PPI conditions, less arabinose, peptides, and minerals (Ca, Mg, P) were released during digestion, while other compounds showed similar patterns with the healthy condition. The observed effects on nutrient digestion are likely due to the higher gastric pH, resulting in less acidic erosion and modified enzymatic activities. These results are consistent with some of the well-known adverse effects of PPIs such as infections, hypomagnesemia, fractures, etc. In conclusion, this study presents a detailed semi-dynamic digestion protocol under PPI medication, shedding light on the effects of PPIs on macro- and micro-nutrients during gastric digestion. This protocol can serve as a valuable resource for researchers studying food digestion, contributing to a better understanding of the association between PPI intake and clinical side effects, ultimately promoting better health.

    ano.nymous@ccsd.cnrs.fr.invalid (Ruoxuan Deng) 15 Apr 2024

    https://hal.inrae.fr/hal-04547163
  • [hal-04546723] An INFOGEST international consensus static in vitro digestion model adapted to the general older adult population and its application to dairy products

    Understanding the mechanisms of food digestion is of paramount importance to determine the effect foods have on human health. Significant knowledge on the fate of food during digestion has been generated in healthy adults due to the development of physiologically-relevant in vitro digestion models. However, it appears that the performance of the oro-gastrointestinal tract is affected by ageing and that a model simulating the digestive conditions found in a younger adult (<65 y) is not relevant for an older adult (>65 y). The objectives of this work were: (1) to conduct an exhaustive literature search to find data on the physiological parameters of the older adult oro-gastrointestinal tract, (2) to define the parameters of an in vitro digestion model adapted to the older adult, (3) to apply it to the digestion of dairy products. International experts have discussed all the parameters during a dedicated workshop organized within the INFOGEST network. Data on food bolus properties collected in the older adult were gathered, including food particle size found in older adult boluses. In the stomach and small intestine, data suggest that significant physiological changes are observed between younger and older adults. In the latter, the rate of gastric emptying is slowed down, the pH of the stomach content is higher, the amount of secretions and thus the hydrolytic activities of gastric and intestinal digestive enzymes are reduced and the concentration of bile salts lower. The consensus in vitro digestion model of the older adult was applied to the digestion of 2 fermented dairy products formulated with a ratio of whey proteins to caseins of 80/20 and 20/80. Results showed that the digestion conditions used (young vs. older adult) influenced significantly the kinetics and extent of proteolysis in the gastric phase but not in the intestinal phase.

    ano.nymous@ccsd.cnrs.fr.invalid (Didier Dupont) 15 Apr 2024

    https://hal.inrae.fr/hal-04546723
  • [hal-04557257] Viscoelastic properties of lactoferrin/ β-lactoglobulin coacervates studied by rheology and micro rheology

    Heteroprotein complex coacervates (HPCC) has great potential in many food applications. However, understanding the rheology-coacervate structure relationship, as well as their sensitivity to slight changes in the physicochemical environment, is still an active research topic. Herein, HPCC between two oppositely charged proteins, lactoferrin (LF) and β-lactoglobulin (βLG) was investigated. The influence of ionic strength and temperature on the rheological properties of LF/βLG coacervates was examined using oscillatory shear rheology and microrheology from dynamic light scattering. LF/ßLG HPCC exhibited a liquid-like character with G'(ω) < G''(ω) and an increase of both moduli with decreased temperature but a softening effect with increased ionic strength. The dependency of G' and G'' on angular frequency (ω) demonstrated a scaling of G"∼ω 1 and a lack of terminal behavior with G'∼ω 1.4. The application of time-temperature superposition (TTS) and time-salt superposition (TSS) principles allowed the prediction of the rheological properties over a wide range of timescales and temperatures below the denaturation temperature of βLG and LF. The two principles suggested that increasing temperature or ionic strength accelerates coacervates dynamics but does not affect largerscale physics. Microrheology experiments using polystyrene-coated microspheres as tracers, allowed access to a frequency range up to (ω ∼ 106 rad/s) and revealed a variable scaling of G'= G" ∼ ω 1/2 or ω3/4 at the high-frequency terminal regime and approaching theoretical predictions of Rouse regime and Worm-Like Chain model for polymers. In the present case, it reflected a freely draining system where hydrodynamic interactions are neglected at these timescales. This study offers new insights into the microstructure of HPCC, relevant to various applications, as function of ionic strength and temperature.

    ano.nymous@ccsd.cnrs.fr.invalid (Ghazi Ben Messaoud) 24 Apr 2024

    https://hal.inrae.fr/hal-04557257
  • [hal-04546794] In vivo study combining sensory analysis and ultrasound imaging to investigate food texture perceptions related to tongue biomechanics

    All along food oral processing, the tongue continuously evaluates the mechanical and structural properties of foods, all by guiding them towards the different organs involved in the formation of the bolus. The tongue thus steers the oral strategy, adapting to food type, individual preferences, and physiological constraints, playing an important role in sensory experience and swallowing safety. In the present study, sensory analysis was coupled with ultrasound (US) imaging to better understand the links between tongue motions and texture perceptions. Six commercially available semi-liquid foods (chocolate desserts) were selected for their diverse textures (including mousses, gels and creams). Sensory profile and temporal dominance of sensations were investigated with a trained panel of 16 volunteers. The mechanical interactions between food and an artificial tongue and palate were characterized on a biomimetic test bench embedding multi-axes force sensors, an accelerometer, and a linear US imaging probe. Feasibility US imaging measurements were performed on 10 volunteers, using a convex US probe positioned under the chin. Highly contrasting mechanical and sensory properties could be confirmed across the different food products. Image processing methods were developed on in vitro US imaging datasets to track the evolution of the dorsal surface of the artificial tongue (interface tracking algorithm) and characterize the deformation fields within the artificial tongue (particle image velocimetry). Tongue movement profiles were linked to food rigidity, while shear velocity fields in the bulk of the tongue correlated with friction and adhesion phenomena between the tongue and the palate. High inter-individual variability was reported in the morphology and contrast level of the US images from in vivo experiments. Even though the implementation of image analysis processing methods was challenging, the feasibility of tracking the dorsal surface of the tongue has been demonstrated. The type and number of tongue movements as well as the duration of the oral processing before food swallowing were characterized. The results underscore the potential of US imaging for monitoring and characterizing tongue biomechanics during oral processing, providing valuable insights into the diverse mechanical responses of different food products and their impact on sensory experiences.

    ano.nymous@ccsd.cnrs.fr.invalid (Miodrag Glumac) 15 Apr 2024

    https://hal.inrae.fr/hal-04546794
  • [hal-04546295] Characterization of the mucus lining a co-culture model of Caco-2/HT29-MTX cells

    The Caco-2 cell line is commonly used as a model to study various events occuring at the intestinal level such as the physiological impact of toxins or the absorption of nutriments. More recently, co-cultures integrating enterocyte-like and goblet cells types, namely Caco-2 and HT29-MTX cells, have been reported as promising models of a tunable1 and functional 2 epithelial barrier. One interest of including HT29-MTX cells is their ability to secrete mucins. It is therefore expected that the cell culture will be lined by a mucus layer, with functional consequences on absorption or bacterial adhesion for example. However, the spatial characteristics of this mucus layer (e.g. distribution or volume) is not fully described. The objective of this work was to visualize mucins in a co-culture of Caco-2/HT29-MTX cells, and to set up a method of mucus characterization based on image analysis. Caco-2 and HT29-MTX cells were routinely grown in DMEM medium supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin. Cells were seeded at a density of 2.105 cells/cm2 on transwells in 24-well culture plates, at a ratio of 9:1 (Caco-2:HT29-MTX). Incubation was performed in a humidified atmosphere of 5% CO2 at 37 °C. On day 21, cultures were fixed with 4% PFA and double-stained for F-actin using phalloidin-rhodamine, and for sialic acid using WGA-Alexa488. This aimed at detecting the cytoskeleton (thereby enabling fine contouring of each cell) and mucins, respectively. Images were acquired on a Zeiss-LSM 880 confocal microscope. Two independent culture wells were observed. Five 3-D images (consisting of around 80 stacked images on average) were acquired per well, resulting in a dataset of 10 images. From a qualitative point of view, it was observed that cells at day 21 formed mostly a monolayer. Rather than being flat, cultures showed a clear topographic pattern, with domes that could reach 135 µm in height. Mucins were detected mainly on the apical side of the cells. Brightly-stained mucin clusters were visible in the extracellular apical space in close vicinity of some cells, most likely HT29-MTX cells. In addition, a more diffuse signal was also observed, sometimes lining large parts of the observation sites. This may correspond to secreted mucins spreading on top of the culture to form a typical intestinal mucus. With the objective of eventually study the impact of a treatment (e.g. digested food constituents) on this mucus structure, a method of image analysis was developed. Using the open-source software ilastik3, pixels were classified into three categories corresponding to bright staining mucin clusters, diffuse mucin staining and background. This analysis provides quantitative measurements on average mucin intensity and the volume proportion and average heights of mucin clusters.

    ano.nymous@ccsd.cnrs.fr.invalid (Yann Le Gouar) 15 Apr 2024

    https://hal.inrae.fr/hal-04546295
  • [hal-04574703] Casein structure differently impacts satiety by modulating plasma aminoacid kinetic

    Dietary protein is strong appetite inhibitor as it reduces food intake in following meals by signaling directly or indirectly to the brain, modulating eating behavior. However, the type of protein in snacks or pre-loads differently influences food intake, likely due to differences in dietary protein hydrolysis and amino acid bioavailability. We recently observed striking differences in plasma amino acid kinetics as well as intra-gastric behavior between micellar casein (MC) and sodium caseinate (SC). Gastric distension and plasma amino acid levels, in particular that of leucine, both impact food intake. The objective of the present study was therefore to clarify whether the structure of casein impacts its preload effect on subsequent food intake in the pig model. Overnight fasted pigs (21.5 ± 1.5 kg) equipped with jugular catheters were allowed to consume within 5 min casein drinks differing in casein structure (SC vs. MC, 350 kcal, 10% casein, 1.2% glucose in water) in a cross-over study. Ad libitum intake of their regular feed was assessed during 1hr, either 1 or 4hr after casein drink ingestion. Gastric emptying of the casein drinks radiolabeled with 99Tc- colloïd was followed during 2hr using gamma-scintigraphy. Plasma kinetics of hormones related to eating behavior (ghrelin, GLP-1, insulin) and of free amino acids were evaluated for 2hr following casein drink ingestion. The amount of feed consumed 1hr, but not 4hr, after SC ingestion was lower than the amount of feed consumed after MC ingestion (feed consumed at 1h: SC 1306 ± 138 vs. MC 1513 ± 79 g, P=0.03). Gastric emptying parameters after both types of casein ingestion were not significantly different (t1/2: SC 103 ± 12 vs. MC 116 ± 18 min, β: SC 0.67 ± 0.14 vs. MC 0.52 ± 0.04, P>0.05). Plasma ghrelin, GLP-1 and insulin kinetics were similar after casein drink ingestion (SC vs. MC, P>0.05 for all hormones). Free plasma amino acid concentrations, in particular that of leucine, increased after both SC and MC ingestion but was greater after SC than MC ingestion from 60 to 120 min (plasma leucine at 60 min: SC 87.8 ± 4.8 vs. MC 66.0 ± 3.5 mg/L, P=0.009). In conclusion, ingestion of casein differing in their structure impacts subsequent food intake likely due to difference in amino acid bioavailability. Casein exhibits less anorectic effect when consumed as micellar casein than as sodium caseinate. Such differences might be of importance when designing food dedicated to people with low appetite.

    ano.nymous@ccsd.cnrs.fr.invalid (Sylvie Guerin) 14 May 2024

    https://hal.inrae.fr/hal-04574703
  • [hal-04581043] Adult and older adult in vitro dynamic digestions of α-tocopherol fortified yogurt using DIDGI®

    Age-related losses of physiological functions in older adults are of utmost importance since they directly impact their metabolism, decreasing their ability to digest and adsorb food nutrients. Fortified and functional foods have been regarded as novel alternatives to improve nutraceuticals and bioactive compounds’ delivery extent, increasing foods nutritional properties. the development of tailored foods for older adults aims at providing compounds that are expected to decrease the risk of diet-related diseases., it is critical to understand how these food products interact with other food components, what is their behavior in the gastrointestinal tract and if the formulation modulated, in fact, their bioaccessibility and bioavailability. In vitro gastrointestinal models have become very relevant to evaluate food behavior and must be adapted to the physiological stage targeted. The objectives of this work wera to simulate the digestive conditions of the older adults as mentioned in Menard et al; 2023 by the INFOGEST network using the dynamic system (DIDGI®) and to evaluate the influence of the digestive conditions (adult vs older adult) in the digestibility and on the kinetic release of α-tocopherol from fortified yogurts. Natural fat and sugar free stirred yogurts were supplemented with oil-in-water nanoemulsions containing 15 mg of α-tocopherol. For the adult, the dynamic in vitro digestive parameters were used as described in Menard et al 2018 on yogurt digestions, and for the older adult, parameters were fixed in order to simulate a longer gastric emptying time, a slower gastric acidification profile and a reduction of 30 to 40% of enzymatic level as compared to the adult. During the gastric phase, particle size profiles were measured and in the intestinal phase, the α-tocopherol, either total or soluble, to simulate the bioaccessibility, was analyzed to monitor release kinetics. Despite the lower enzymatic activity and slower acidification profile applied in the gastric phase of the older adult, particle size distribution analysis demonstrated that the initial degradation of the fortified yogurt was similar at earlier stages of digestion, due to longer gastric half-life. Conversely, at the end of the gastric phase, the adult protocol was substantially more effective in degrading and homogenizing the gastric content. The α-tocopherol kinetics reached during the intestinal phase were more important at the adult stage. with 97.3 ± 5.9 % of recovery whereas for the older adult 79.8 ± 5.2 % was obtained. Bioaccessibility was identical in both stages (ranged from 60 to 80 %), being statistically significantly higher at 3 hours in the older adult. Globally, α-tocopherol release kinetics were greatly affected by the physiological stage thus leading to relevant differences in its release extent and profile.

    ano.nymous@ccsd.cnrs.fr.invalid (Jean-Michel Fernandes) 21 May 2024

    https://hal.inrae.fr/hal-04581043
  • [hal-04546844] Quantitative ultrasound to explore tactile perceptions of food elicited by tonguepalate friction: a biomimetic approach

    The tongue has a central role in the sensory experience of texture perception of food. Tongue mechanoreceptors have varied ranges of sensitivity, both in terms of amplitude and frequency of the mechanical stimuli to which they are exposed to. Understanding the behavior of these sensory receptors requires the development of innovative methods, with experimental approaches that integrate both the characteristics of the food and the complex properties of the tongue. In this work, a biomimetic device was composed with artificial tongues (polyvinyl alcohol cryogels) actuated by two translation stages to generate custom sequences of compressional and shearing motions against a rigid plate playing the role of the hard palate. The roughness of the tongues was designed to be reminiscent of the diversity of human tongue papillae height (20–140 µm). Newtonian aqueous solutions of glycerol (1–1400 mPa.s) were deposited on their surface and their frictional behavior was investigated during sequences of shearing motions against the palate. A multi-axes strain gauge sensor and a piezoelectric accelerometer were used to measure forces and vibrations between the tongue and the palate. In addition, non-destructive ultrasound (US) waves were propagated within the tongue with a pulse recurrence frequency of around 1 kHz, using a single-element sensor (5 MHz) positioned under the tongue. Signal processing methods were developed to characterize the evolution of the time of flight (ToF) of the echo corresponding to the reflections of US at tongue-palate interface. The low frequency component of ToF evolution (0–40Hz) was found to correlate both with the normal pressure exerted by the tongue on the palate, and with the thickness of the lubricating film at tongue-palate interface. At higher frequencies (>40 Hz), ToF fluctuations were correlated with vibrations induced by stick-slip phenomena between the tongue and palate, characteristic of the mixed lubrication regime. The study paves the way for the use of US methods (non-invasive and non-destructive) for the continuous monitoring of friction phenomena between the tongue and the palate. Implemented on such a biomimetic system, they make it possible to study the respective contributions of the properties of foods and of the physiological specificities of individuals on the biomechanical phenomena at the origin of texture perceptions.

    ano.nymous@ccsd.cnrs.fr.invalid (Miodrag Glumac) 15 Apr 2024

    https://hal.inrae.fr/hal-04546844
  • [hal-04546162] Protein ingredient quality of infant formulas impacts gut physiology and microbiota in mini-piglets used as a human infant model

    Infant formulas (IFs), the only adequate substitute to human milk, are complex matrices that require numerous ingredients and processing steps. Previously, we showed that the quality of the dairy protein ingredients within IFs modulated protein microstructure and in vitro and in vivo digestive kinetics (protein digestion and amino acids plasma concentration). Therefore, the aim was to assess the consequences on gut maturation and microbiota, an important actor within the microbiota-gut-brain axis. Three isonitrogenous IFs were formulated with whey proteins from different origins (cheese whey: IF-A, vs. ideal whey: IFs-B/C) and casein with different organizations (micellar: IFs-A/B, vs. non-micellar: IF-C). Twenty-four Yucatan mini-piglets (2- to 21-day-old), used as an infant model, received one of the three IFs. Digestive contents, faeces, and tissues were analysed using metagenomic, histological, ex vivo permeability and gene expression approaches and a metabolomic analysis was done on serum. Univariate and multivariate statistical analyses were performed. Piglets fed with IF-C had a significantly higher colonic paracellular permeability than those fed with IF-A, which was also associated with a slight immune boost, potentially as the result of increased antigens passage through the gut barrier stimulating the mucosal immune system. Colonic transcellular amino acid transporters were less expressed in piglets fed with IF-C than with IF-A which could be the result of the increased paracellular permeability with IF-C, favouring paracellular transport. These results suggested a combined effect of whey origin and casein supramolecular organization on intestinal physiology in favour of IF-C, whose parameters were closer to those recently reported for human milk-fed piglets (Charton et al., 2022). Even though gut microbiota composition was moderately changed between diets, faecal short-chain fatty acid composition differed according to the whey protein origin, with higher butyrate concentration for ideal whey than for cheese whey. Differences in microbiota fermentative activity may result from differences in digestive kinetics previously observed in vitro between cheese whey-based IF (A) and ideal whey-based IFs (B and C), which could modulate the colonic substrate available for the microbiota. Serum metabolomic analysis showed that tryptophan metabolic pathway was different between IF-A-fed piglets and IF-C-fed piglets with higher serum concentrations of tryptophan, kynurenine and 3-indole acetic acid in IF-C-fed piglets than IF-A, IF-B being intermediate. Seric polyamines, bacterial metabolites from protein digestion, were also more concentrated in piglets fed with IF-C than IF-A. This study suggests that the use of ideal whey and the modulation of casein supramolecular organization are possible avenues to keep improving IFs towards more human milk biomimetics.

    ano.nymous@ccsd.cnrs.fr.invalid (Lucile Chauvet) 15 Apr 2024

    https://hal.inrae.fr/hal-04546162
  • [hal-04546756] In vitro digestion of protein-rich dairy products adapted to the specific needs of older adults

    Insufficient energy and protein intake can lead to a condition called sarcopenia, characterized by the loss of muscle mass, strength and function. To avoid this condition healthy older adults need to consume nutrient-dense foods and to increase the amount of high-quality proteins in their diet to promote muscle health. However, it is still unclear if changes in nutrients digestibility in old age may affect the anabolic effect of foods [1]. The objective of this study was to investigate in vitro the digestion of two high-protein dairy products similar to cream cheese (containing 24% w/w of proteins, and 20% w/w of lipids). Products were formulated with two different ratios of caseins to whey proteins: 80/20 (= WP20) similar to the ratio found in bovine milk, and 20/80 (WP80) in order to increase the leucine supply. The new static in vitro digestion model adapted to the general older adult population (≥65 y) proposed by INFOGEST [2] was implemented to investigate the digestion of these products, as well as the standard version of the protocol. Kinetics of proteolysis and lipolysis were compared between both models for each product, in the gastric and intestinal phase of digestion. Proteolysis was studied with the OPA method, SDS-PAGE, and amino acids were quantified by HPLC, while lipolysis was investigated through GC-MS, and the structure of the products in gastric conditions was observed by CLSM. In both products, the degree of protein hydrolysis (DHP) was significantly lower in older adults’ conditions than in young at the end of the gastric phase (-19% for WP20, and -44% for WP80), and at the end of the intestinal phase (-16% for WP20, and -20% for WP80). This is most probably due to the reduction in pepsin and pancreatin activities recommended in the older adult model compared to the standard protocol. The degree of lipid hydrolysis (DHL) was also significantly lower in older adults’ conditions than in young at the end of the digestion for WP20 (-30%), but interestingly it was not the case for WP80 (similar DHL were measured). Free fatty acids were also released faster from WP80 than from WP20 in both digestion conditions: after 5 min of intestinal digestion DHL was already ≈ 32% for WP80 against 14% for WP20. This was attributed to the different caseins/whey protein ratios in the products, leading to the formation of different gel structures that may in turn result in different patterns of deconstruction in the gastrointestinal tract.

    ano.nymous@ccsd.cnrs.fr.invalid (Anaïs Lavoisier) 15 Apr 2024

    https://hal.inrae.fr/hal-04546756

-> Books & book chapters

-> Papers in peer-reviewed journals

See also

Modification date: 15 April 2024 | Publication date: 25 October 2022 | By: stlo