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While million people lack access to food or some nutrients, up to one-third of food is never consumed, especially fruit and vegetables, naturally rich in phytonutrients. Fruit and vegetables waste and loss arise at all steps of the food chain from production to consumption. The access to phytonutrients is also threatened with climate changes that impact both yields and the composition of harvested organs. Finding trade-offs between yield and quality along the food chain appears necessary to improve crop sustainability and to limit losses. Processing tomato is a good target to address these challenges: it is a major crop and an important source of phytonutrients notably phenolic compounds and carotenoids, and it represents an intensive production in terms of water use. Two examples of integrated analyses will be given. First, we will focus on pre-postharvest relationships and the ability of tomatoes to be processed into purees. We investigated fruit quality in response to water supply, genotypes and ripening stage, and we assessed their impact on puree obtained from hot break and cold break processes. We found that fruit growth and quality were weakly impacted by moderate water insufficiency during growth. A reduction of water supply from 100% to 60% of the evapotranspiration strongly impacted plant growth but had little impact on fresh fruit yield and increased the water use efficiency by 20%. Second, we address the accumulation of carotenoids in ripe tomato in response to water insufficiency in two genotypes. A medium water deficit (-0.5 MPa soil water potential while permanent wilting point is estimated at-1,5 MPa) at the beginning of fruit development impacted the fruit composition at maturity. The dry matter contents increased up to 23% while an interaction between genotype and water regime was found for carotenoid contents which may affect tomato health value.

The dairy platform of the STLO, Rennes, developed an innovative technology and more sustainable cheese making process (INRAE patent, From’Innov, WO2016108024). This technology consists of mixing a texture matrix obtained by ultrafiltration with one or more aromatic matrix. The latter is innovative: it allows obtaining a maximum of aroma in a short time, less than a few days. The principle is to grow each of microorganisms in an optimized middle with essential nutrients, optimal pH and temperature, and O2 if necessary. After adjusting the pH and temperature of the mix, we proceed with the coagulation then the molding, and the next day the demolding. The cheese is ready and contains the expected aromas. It needs five days to obtaining a soft-cheese with surface flora such as Penicillium and/or Geotrichum.We used this vector to define the consumer’s level of acceptability in view of a breakthrough technology.In this study, a commercial cheese (control product), representative of solubilized soft-cheeses, and two From'Innov cheeses (one close to control and the other more with more character) were studied. The acceptability and the main sensory properties of these three cheeses were evaluated by a panel of 142 consumers. The objective was to determine the hedonic appreciation of From'Innov cheeses, compared to that of commercial cheese, and to determine the sensory properties enhancing or penalizing the appreciation of different cheeses.The results showed that the hedonic appreciation of From’Innov cheese with character, although lower than that of commercial cheese, is satisfactory (5.6/10), despite a ripening time four times shorter. In addition, the intensity of the fruity notes and the character of this From’Innov cheese were judged to be close to ideal, whereas these two characteristics were judged to be insufficiently intense in commercial cheese. Finally, despite a lower salt (-20%) and fat (10%) content, the intensity of saltiness and fat of From’Innov cheese with character was judged to be close to ideal, very close to that of commercial cheese. The perspective of this study is to know whether our innovative technology will have a place in the current market and for which products, for whom?

International audience; La modélisation et l’optimisation des procédés agroalimentaires est une tâche difficile dû à la complexité des produits agroalimentaires, le manque de connaissances sur les mécanismes limitant les performances [1] et l’hétérogénéité des variables impliquées. C’est le cas pour la microfiltration tangentielle 0.1 μm de lait écrémé (MF 0.1 μm). Cette opération est généralement utilisée dans l’industrie laitière pour séparer les protéines : micelles de caséines natives (rétentat) utilisées dans les fromages et les protéines de lactosérum (perméat) principalement utilisées dans les formulations alimentaires à destination des populations spécifiques (personnes âgées, nourrissons, sportifs). En dépit du fort intérêt porté à la MF 0.1 μm dans le secteur de l’industrie agroalimentaire, ce procédé de transformation n’a pas été intégralement optimisé au regard des objectifs des utilisateurs. Les choix de conception, dimensionnement et conditions opératoires sont principalement basées sur le savoir-faire des équipementiers et des connaissances expertes disponibles. Dans la littérature, l’optimisation de la MF 0.1 μm de lait écrémé est abordée en mono-objectif sur un problème posé empiriquement [2] ou sur l’influence spécifique d’une variable d’intérêt sur un groupe de variables choisies [3]. Ce travail vise à optimiser la microfiltration tangentielle 0.1 μm de lait écrémé depuis la conception jusqu’aux performances des produits avec des objectifs d’optimisation contradictoires en intégrant des connaissances expertes et scientifiques dans la formulation d’un problème multiobjectif. La méthodologie, basée sur « l'intégration des connaissances » se compose de quatre étapes : 1) l'acquisition de connaissances scientifiques et expertes sur les objectifs à optimiser ; 2) la modélisation des objectifs sous forme de fonctions calculables ; 3) la résolution du problème multiobjectif en utilisant un algorithme d'optimisation métaheuristique adapté ; 4) l'aide à la décision multicritère. Les objectifs considérés sont de maximiser la composition des fractions rétentat et perméat, de maximiser le rendement de récupération des protéines dans la fraction perméat et de minimiser les coûts économiques. Environ 1000 solutions Pareto-optimales ont été trouvées, dont des solutions proches de celles utilisées dans l'industrie et à moindre coût. L'optimisation multiobjectif de la MF a ouvert de nouvelles réflexions sur la conception des installations et les combinaisons de conditions opératoires en améliorant les caractéristiques du produit tout en maintenant constants les coûts d'investissement et de production. Le résultat de l'optimisation est une preuve de concept dont la faisabilité et la viabilité à l'échelle industrielle doivent être validées. Ces travaux ouvrent de nouvelles perspectives pour l'optimisation multiobjectif des procédés alimentaires.

We show that a simple model with a maintenance term can satisfactorily reproduce the simulations of several existing models of wine fermentation from the literature, as well as experimental data. The maintenance describes a consumption of the nitrogen that is not entirely converted into biomass. We show also that considering a maintenance term in the model is equivalent to writing a model with a variable yield that can be estimated from data.

The present work aimed at reinforcing the mechanical results obtained using a home-made and small-sizedbubble inflation device which makes the inflation of thin dough films possible under controlled temperature andatmosphere in a wide range of constant strain rates. The analysis of the experimental biases associated to thatnew small-sized bubble inflation device was carried out. Without inflating bubble, a first part of the work wasdevoted to the analysis of gas tightness of the device at 20°C and 70°C and to the uniformity in temperatureafter stabilization at 70°C. In a second part, bubble inflation experiments were carried out and an experimentalstress-strain sensitivity analysis to the time left for the dough film to relax its stress before bubble inflation aswell as to the initial geometry of the dough disk (diameter and thickness) was conducted. Finally, a numericalsensitivity analysis was performed on the basis of the set of the analytical equations available for the calculationof the height and the radius of the bubble during inflation, as well as for the calculation of the thickness of thedough film, strain and stress at the top of the bubble. The equations developed by Bloksma (1957) and revisedby Charalambides et al. (2006) were adapted to reach constant strain rate at the top of the bubble.

International audience; Decentralized food production, usage of high-quality, local raw material, compliance with traditional processing methods, and preservation of nutritional value are attributes of Intermediate Food Value Chains (ivc) and may significantly contribute to the agri-food sustainability transformation. As these practices typically come with an extra cost, the consumer should be aware and convinced of them so that a premium price can be paid. But the food chain is complex and such a proof is challenging: Raw material come from multiple sources, it undergoes complex processing,while the package-imprinted attributes presently display mainly nutritional attributes. The large number of intermediates in the food supply chain adds to the complexity and fraud possibilities, while each production line has its own characteristics. This creates a challenge in terms of transparency and trust, from the consumer perspective. Blockchain as an open, distributed ledger can record transactions in a verifiable and permanent way and it promises transparency in food chains [1]. In this work, we investigate whether Blockchain can be sustainably applied in the dairy ivc of H2020 FAIRCHAIN project, identifying four challenges and our working practices. The ivc focuses on Feta cheese production; Feta is the most known, traditional Greek product of designated origin (PDO). It is based only on sheep and goat milk, under defined percentages, processed in specific regions, with requirements of minimum maturation periods. The information offered to the consumer covers the nutritional aspects and is difficult to verify. Challenge #1, which data to register, so that they are quantitative and meaningful? Through the FAIRCHAIN co-creation process we have identified a set of high-level attributes (taste, origin, integrity) and associated them with quantitative operational parameters in the end-to-end process, such as milk temperatures and pH, microbiological checks, milk mixing and percentages, maturation duration, IoT readings. These carefully selected attributes create the ‘digital product passport’. Challenge #2, how to guarantee the correctness of the data? If erroneous data are inserted at the edge, the Blockchain cannot correct them. While this risk cannot be eliminated, it can be mitigated with data verification rules (such as acceptable data ranges of input data), regular checks, and anomaly detection [2-4]. Challenge #3, how to rationalize Blockchain transaction fees and allow for verification on behalf of the consumer? Not all info can be registered in the Blockchain due to the need for performance and the transaction fees. While technological choices (such as the consensus algorithms) can affect the performance, the data granularity is an open question. Anchoring mechanisms (from private to public Blockchains). Data verification is based on (Ethereum) smart contracts and visualized through simple mobile app (confronting digital divide aspects as presented in [5]).Challenge #4, how to facilitate the involvement of stakeholders and build an application ecosystem? The offering of open APIs (Application Programming Interfaces) paves the way for an ecosystem of applications involving externalstakeholders (such as public authorities for food certifications). The platform is currently reaching a stable version and it is undergoing evaluation for identifying adoption challenges and quantifying the operational overhead

International audience; In human milk banks (HMBs), donor milk (DM) is commonly sterilized by Holder pasteurization (HoP). High hydrostatic pressure (HHP) processing is an innovative, alternative method for DM sterilization. We evaluated the impact of HHP processing on the concentration of seven metabolic milk hormones. Eight samples of raw DM were aliquoted. One aliquot was sterilized by HoP (62 • C for 30 min), and another was processed by HHP (350 MPa at 38 • C). Compared with raw DM, HoP milk displayed reduced concentrations of insulin, nesfatin-1, cortisol, leptin, apelin and GLP-1, though adiponectin levels were unchanged. HHP processing maintained the levels of insulin, nesfatin-1, cortisol and leptin at their initial levels in raw DM, reduced apelin and adiponectin levels, but increased GLP-1 level. Sterilization of DM by HHP thus preserves the main metabolic hormones in human milk, underlining the interest of this method for use in HMBs.

International audience; In the food industry, the control of surface hygiene is a major issue. It is therefore essential to identify those parameters that can affect the bacterial contamination of surfaces and the effectiveness of hygiene procedures. Numerous studies have focused on the role of bacteria, flow arrangements or materials, but almost nothing has been reported on the possible impact of vertical or horizontal positioning of surfaces on bacterial contamination. The aim of the current study was firstly to determine the ability of bacterial species usually found in food processing lines to form biofilms on surfaces positioned vertically or horizontally and then to assess the resistance of these biofilms to detachment. The experiments were carried out using three bacterial strains (Escherichia coli SS2, Bacillus cereus 98/4, and Pseudomonas fluorescens Pf1) that produced biofilms on glass, polypropylene and stainless steel (surface finishes 2B and 2R). We first observed that not only did the bacterial strain type impacts its ability to form biofilms (Ec-SS2 > Pf1 > Bc-98/4), but that the vertical vs horizontal position of the surface would also affect biofilm formation, probably due to the accumulation through sedimentation of bacteria on horizontal surfaces. However, the horizontally formed Pf1 biofilms were very fragile and could be partially removed by a gentle rinsing step. Lastly, no significant differences could be found in the ability to form biofilms on the different materials. The resistance to detachment to a standard rinsing process in a pilot rig was also investigated. While both strains and materials significantly affected the amount of biofilm detached, only Bc-98/4 biofilms were impacted by the surface position, with horizontal biofilms showing extreme resistance to shear forces. In conclusion, this study shows that horizontal surfaces in food environments probably represent an increased risk of contamination by bacteria frequently isolated from these environments and should be subjected to increased monitoring.

Correction: Chemical Senses, Volume 46, 2021, bjab050, https://doi.org/10.1093/chemse/bjab050 Published: 08 December 2021 Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19-79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change +/- 100) revealed a mean reduction of smell (-79.7 +/- 28.7, mean +/- standard deviation), taste (-69.0 +/- 32.6), and chemesthetic (-37.3 +/- 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis.The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms.

compréhension des interactions entre protéines végétales et protéines de blanc d’œuf pour permettre l’amélioration de la « techno-fonctionnalité » des mélanges, notamment pour la stabilisation des mousses et émulsions, l’optimisation de ces fonctionnalités et l’identification des conditions permettant de limiter leur sensibilité aux traitements thermiques.

The European candidate Partnership Sustainable Food Systems [1] focuses on the needed transition towards sustainable food systems (SFS) via system approaches [2]. However, this makes only sense if we understand what sustainable food systems are and how they function. Sustainability is defined as ‘whatever we do, we should not compromise future generations’ (Brundtland report, 1987). Hence, SFS are systems that have the capacity to endlessly evolve, continuously providing affordable, safe, healthy, delicious, functional foods for all people in their various cultural settings, and produced in an environmental-friendly manner. This is what the Partnership SFS strives for in all Europe regions, by changing the way (what) we eat, how we process and supply, how we connect ourselves to food systems, and how we govern them [1]. The implications for new developments in Food Science and Technology (FST) are numerous. First, these target an efficient usage and reusage of biomass in time (in our open thermodynamic planetary system fuelled by solar energy). Secondly, the handling of all diverse resources and food products respects both upper and lower limits for all environmental, social, economic and health indicators. Third, food process-structure-function relationships are considered in robust and performing food systems from a broader perspective. This includes playing fields (context), players (food actors), pieces (resources, products, waste, services), moves (food chain activities), rules (food laws, incentives…), duration (e.g. in terms of renewing resources) and outcomes (win/lose); i.e. the seven building blocks of a game [3]. Several case studies are presented that provide new research questions for the future Partnership and serve to exchange insights in FST with Central and Eastern European Countries.

The adage “in unity is strength” also applies to fermented foods: the association of lactic acid bacteria (LAB) strains brings benefits to their organoleptic properties and potential health benefits. Such functionalities can depend on positive interactions, as observed between LAB in yogurt. Finding waysto create new functional associations of LAB strains is challenging, especially in the context of the food transition where new resources, notably proteins, are increasingly used. The objective of this PhD work was to understand how to promote positive interactions between LAB, on the basis of their nitrogen metabolism, to conceive new food applications. The interactions were studied in cocultures that associated a proteolytic (prot+) and a non-proteolytic (prot-) strain. These prot+/prot- pairs were first grown in a model medium containing milk and lupin proteins as sole nitrogen nutriments, in which the growth of prot- strain thus depended on the peptides and amino acids released by the prot+ strain. Strong,weak, or no positive interactions were observed between prot+ and prot- strains. Peptidomics results showed that the release of branched-chain amino acids either free or within peptides was important in the positive interactions observed. We then studied the impact of these interactions in alternative yogurts made from milk and lupin, characterized for their physical and sensory properties. Positive interactionsbetween LAB led to diversified functionalities of alternative yogurts, such as flavour compound and organic acid formation, and texture improvement. This work brings new knowledge on the interactions between LAB, which is useful in designing future fermented foods.

Kombucha is a non-alcoholic beverage made of sugared tea that is transformed by a symbiotic consortium of yeasts and bacteria. This beverage is increasingly produced at industrial scale, but its quality standards remain to be defined. Metabolomics analysis was carried out using FT-ICR-MS (Fourier Transform-Ion Cyclotron Resonance-Mass Spectrometry) to understand the chemical transformations induced by the production phases and the type of tea on the non-volatile compounds of kombucha.

Food packaging facilitates its handling, preservation, and distribution. Most food is consumed far away from its production sites and at times which are not necessarily correlated with the seasonal harvesting of crops. Recycling is one of the main strategies to reduce plastics environmental impact, but it requires an important investment in the waste treatment infrastructure. Moreover, the use of recycled materials to produce new food packaging presents challenges concerning food safety, because open recycling streams can be a source of contamination of the packed products. Under this perspective, the use of biodegradable materials for food packaging represents a promising alternative to reduce the societal waste disposal problem, while requiring less investment. Furthermore, innovation using new polymer resins is also an opportunity to include by-products of food industry and agriculture in the production of packaging materials, offering the possibility to increase the part of renewable materials in the sector and to decrease the waste generation. Active biodegradable packaging materials are with this respect of particular interest for food manufacturers eager to improve the sustainability and environmental impact of their products, because they contribute maintaining food quality and safety. Here, we used bixin, a carotenoid with colouring and antioxidant properties and plasticized polylactide (PLA) as polymer matrix. Typical melt processes of PLA are carried out between 160 and 220 °C involving heat and shear, which can cause thermal degradation of the antioxidant. The aim of the study was to measure the thermal degradation of bixin, analyse degradation products, and evaluate its impact on the performance of the active packaging in the protection of oxidation sensitive foods.

Dans l'ensemble de la chaîne de production alimentaire, de la ferme à la fourchette, les étapes de transformation des aliments ont un impact environnemental important. Pour accompagner les nécessaires changements drastiques des systèmes alimentaires vers plus de durabilité, il est nécessaire d’apporter des données environnementales sur les produits transformés et de réfléchir à l’amélioration et l’éco-conception des procédés.L’Analyse de Cycle de Vie, ACV est une méthode standardisée par les normes ISO, de plus en plus utilisée, qui traite des aspects et des impacts environnementaux potentiels tout au long du cycle de vie d’un produit. Cette présentation abordera l’apport de l’ACV dans l’évaluation environnementale des procédés laitiers et des produits transformés qui en sont issus. Les potentialités de l’ACV (identification d’opérations à fort impact environnemental, évaluation de propositions alternatives innovantes, ...) seront illustrées au travers d’exemples du secteur laitier. La présentation abordera également les approches émergentes et prometteuses de conception environnementale des procédés incluant l’ACV et les challenges et travaux ultérieurs qui en découlent (collecte et structuration des données, modélisation des procédés, intégration des autres dimensions de la durabilité, intégration des approches dans la filière, ...).

The packaging industry as one of the biggest target market for plastics, is obviously affected by the recent environmental concerns and there has been a huge investment on the domain of research and development in order to find more sustainable solutions for plastic material production. Polylactide (PLA) is the most used rigid biodegradable and biobased packaging (1). There are strict regulations by the European Union for new packaging materials to be respected, since they come in contact with food products (2). In this project, the chemical and microbiological safety aspects of PLA packaging material were analyzed. As an application, a real life conditioning experiment of ham inside PLA trays compared to commonly used poly(ethylene terephthalate) (PET) trays under modified atmosphere was carried out.

International audience; Les activités spécifiques des lipases gastriques et pancréatiques ont été mesurées à l'aide de triacylglycérols (TAG) issus d'huile de colza, de 1,3-sn-DAG et de 1,2(2,3)-sn-DAG purifiés produits à partir de cette huile, ainsi que d'une huile de colza huile enrichie à 40% w/w DAG (DAGOIL). La lipase gastrique était plus active sur le 1,3 --DAG et le TAG, tandis que la lipase pancréatique présentait une sélectivité inverse avec une activité plus élevée sur le TAG que sur le DAG pris comme substrats initiaux. Cependant, dans les deux cas, les activités les plus élevées étaient affichées sur DAGOIL. Ces résultats montrent que le DAG mélangé au TAG, comme au cours de la digestion, est un meilleur substrat pour les lipases que le TAG. Les mêmes acylglycérols d'huile de colza ont été utilisés pour étudier l' absorption des graisses intestinales - sn -DAG que sur 1,2(2,3) -snchez le rat avec canulation du canal lymphatique mésentérique. Les taux de TAG synthétisés dans l'intestin et la concentration en acides gras totaux dans la lymphe n'étaient pas différents lorsque les rats recevaient des quantités identiques d'huile de colza TAG, de 1,2(2,3)-- DAG ou de DAGOIL. Depuis la lipolyse du 1,3- sn -DAG, 1,3- sn sn-DAG par les lipases digestives conduit au glycérol et non au 2-sn-monoacylglycérol (2- sn - MAG) comme la lipolyse des TAG, ces résultats suggèrent que la re-synthèse des TAG dans les entérocytes peut se faire entièrement via le « glycérol-3-phosphate ». (G3P) », avec la même efficacité que la voie 2- sn -MAG majoritairement impliquée dans l'absorption des graisses intestinales. Ces découvertes apportent un nouvel éclairage sur le rôle joué par les DAG en tant que produits intermédiaires de lipolyse. Selon leur structure, 1,2(2,3) -sn - DAG versus 1,3 - sn -DAG, les DAG peuvent contrôler la voie (2- sn -MAG ou G3P) par laquelle les TAG sont resynthétisés dans les entérocytes .

La microfiltration tangentielle de lait écrémé, MF 0.1 μm, équipée de membranes céramiques, est apparue à l’échelle industrielle au milieu des années 90s pour la séparation des micelles de caséines (CN) et des protéines sériques (PS). Face aux enjeux grandissants des ingrédients laitiers et l’importance que revêt la MF 0.1 μm dans la production de ces ingrédients, notamment en nutrition infantile, il devient important d’optimiser la MF 0.1 μm de lait écrémé, que ce soit au niveau de la conception de l’installation que de sa conduite. Le développement industriel a été rendu possible grâce à la mise en œuvre du système Uniform Transmembrane Pressure (UTP) qui permet de limiter l’accumulation de la matière à la membrane et donc de maintenir de très bonnes performances en termes de flux de perméation et de transmission de protéines sériques au cours du temps de production [1]. Néanmoins, les coûts énergétiques et économiques (investissement et maintenance) de cette opération sont très élevés puisque la mise en circulation du perméat à co-courant du rétentat nécessite une pompe supplémentaire côté perméat. Au début des années 2000, le concept à Gradient de Perméabilité (GP) a été proposé par Pall pour rendre la MF 0.1 μm plus économiquement attractive. Ce concept offre des propriétés de perméabilité (et de résistance hydraulique) du support macroporeux variables entre l’entrée et la sortie de la membrane, de manière à compenser les gradients de pression transmembranaire et ainsi offrir des performances acceptables sans ajout de pompe côté perméat et avec une couche filtrante de 0.1μm identique à la membrane UTP. A l’heure actuelle, les membranes UTP et GP cohabitent industriellement pour la mise en œuvre de la MF 0.1 μm. Pour des raisons principalement économiques, la membrane GP remplace peu à peu la membrane UTP. Elle est proposée depuis une quinzaine d’années par les équipementiers qui se basent principalement sur leur expérience, savoir-faire et connaissances empiriques pour proposer le dimensionnement et les modes de conduites de ces installations. Pourtant peu d’études sont publiées sur les performances de la membrane GP (une dizaine d’articles seulement dont [2]) et l’analyse de ces articles montre le manque de connaissances sur les performances de cette membrane. La conception des installations est donc réalisée sans une réelle analyse comparative critique. L’objectif de ce travail est d’apporter des connaissances sur les performances de la membrane GP 0.1μm pour la séparation CN-PS de lait écrémé thermisé de vache à 50°C et de comparer ces performances à celles de la membrane UTP, qui fait référence. Les performances des membranes Pall 0.1 μm UTP et GP ont été étudiées à 3 niveaux de Facteur de Réduction Volumique (FRV1 ; 2 ; 3). La membrane GP a été mise en œuvre dans les conditions d’écoulement tangentiel pour lesquelles elle est conçue, c’est à dire une Perte de Charge Rétentat (PCR) de 2 bar, conduisant à des vitesses d’écoulement tangentiel de l’ordre de 7.0 m/s. Pour chaque facteur de réduction volumique (FRV), les membranes GP et UTP ont été comparées à la même perte de charge (2 bar). Pour la membrane GP, les plages de pression transmembranaire (PTM) préconisées sont supérieures à 1.0 bar pour éviter la rétroperméation. Pour la membrane UTP, les plages de PTM préconisées sont inférieures à 0.6 bar pour limiter le colmatage. D’un point de vue hydrodynamique, le flux de perméation Jp (l/h/m²) a été suivi en fonction de la PTM appliquée par palier de 15 à 30 min à des valeurs comprises entre 0.4 et 0.8 bar pour la membrane UTP et entre 0.8 et 2.0 bar pour la membrane GP. D’un point de vue sélectivité, la transmission des PS (TrPS) a été calculée à partir des concentrations en protéines sériques des fractions rétentat (CrPS) et perméat (CpPS) déterminées par la méthode Kjeldahl. TrPS (%) = (CpPS / CrPS) x100. Les fuites de micelles de caséines dans les perméats ont été évaluées par mesure de colmatage. ✓ Pour chaque FRV, les valeurs de Jp limite sont similaires pour les 2 membranes : 180 l/h/m² à FRV1 ; 110 l/h/m² à FRV2 (Fig 1a). A FRV1, Jp limite est atteint à une PTM respectivement de 2.0 bar pour la membrane GP et 0.4 bar pour la membrane UTP. ✓ Pour la membrane UTP, TrPS (%) diminue de 80 à 68 % sur la plage de PTM de 0.4 à 0.8 bar, et cela indifféremment pour FRV 1 et 2. En revanche, pour la membrane GP, TrPS est stable et élevée (80%) de 0.8 à 1.8 bar à FRV 1 mais elle est faible et diminue de 65% à 55% sur la même plage de PTM, à FRV 2 (Fig 1b). ✓ A la différence des perméats obtenus avec la membrane UTP qui sont limpides (turbidité = 0 NTU), les perméats obtenus avec la membrane GP sont troubles (turbidité ≈ 100 NTU) et indiquent des fuites de micelles de caséines estimées à 0.2 g/kg de caséine. Fig 1 - Performances des membranes GP (triangle) et UTP (rond) en fonction de la pression transmembranaire (PTM) à FRV1 (en vert) et FRV2 (en orange) pour une PCR 2 bar, à 50°C Fig1a : Flux de perméation Jp ; Fig1b : Transmission de protéines sériques, TrPS Ces résultats montrent que le choix de la membrane GP (et de son mode de conduite à PCR = 2bar) a un impact sur les performances de la séparation CN-PS. A FRV élevé comme recherché industriellement (FRV 2), les flux sont plus élevés avec la membrane UTP dans les conditions de PTM préconisées (1.0 +/-0.2 bar pour GP et 0.6 +/-0.2 bar pour UTP). Les performances en termes de transmission de PS sont semblables (68±5 %) à FRV 2, mais la fuite de micelles est plus élevée, ce qui pénalise la valorisation du perméat. Ces différences s’expliquent par la conception même de la membrane GP. Ces connaissances permettent d’apporter des informations indispensables pour envisager la conception raisonnée et optimisée des installations de MF mettant en œuvre des membranes céramiques [3]

Kombucha is a non-alcoholic beverage made of sugared tea that is transformed by a symbiotic consortium of yeasts and bacteria. Polyphenols are expected to be responsible of several health benefits attributed to kombucha consumption, among other metabolites. Evidence point at an enhancement of tea polyphenol bioactivity during kombucha elaboration. This study investigated the impact of tea infusion time and of kombucha "fermentation", on the tea polyphenols and the color. Most of the present experiments have been carried out during a 3 rd year Bachelor training by Shane Fennell from Carlow Institute of Technology (Ireland).

This poster serves to underline the following: • we use synchrotron radiation to measure local solids concentration in the membrane fouling layer (concentration vs. distance to the membrane with the spatial resolution of 20 µm); this measurement requires less than a minute; • our method of fouling analysis is particular, but our conclusions are general; • fouling is sensitive to all operating conditionsnot only that that applied during the fouling formation, but also that applied during the fouling analysis; • the fouling layer may change during the fouling analysis; this change is not immediate; this fact must be accounted in the fouling analysis (whatever is the method of analysis); • all experiment conditions should be described properly at every stage of experiment (e.g. no such thing as "simple rinsing")

International audience; The formation of deposits by evaporation of droplets contaminated by Bacillus spores was investigated, focusing on the role of spore and material properties. Droplets containing hydrophilic to hydrophobic spores were deposited on materials (stainless steels, polypropylene, glass). The presence of spores within the droplets, as well as material hydrophobicity plays a major role in the kinetics of the droplet shape during drying while the pattern of the dried deposit was affected by both material and spore properties. The resistance to detachment of the different deposits was then investigated. After a single rinsing procedure, a very high resistance to detachment of adherent spores was observed (up to 90% of residual spores). The hydrophilic Bs PY79 spores were the least resistant to removal, while the differences between materials were not pronounced. The ease of cleaning of the dried deposits was much greater. The least resistant spores were still the Bs PY79 ones, while the detachment was 3–100 times more effective on glass than on other materials.These results highlight the predominant role of hydrophilic/hydrophobic properties of particles and materials on the structure of deposits and their further resistance to rinsing and cleaning procedures.

Consumption of energy during wine fermentation process is directly linked to the temperature profile, which has also proven to have a major impact on the aromatic composition of the end product. This paper studies the impact of the temperature profile in wine fermentation, and the trade-off between the synthesis of aroma compounds and the energy required to regulate the temperature during the process. To this end, we consider a mathematical model representing the main chemical reactions of the wine fermentation including the synthesis of aromas, and a thermal model able to compute the power required to follow the temperature profile in the fermenter. The objective is to maximize the aroma concentration in the final product while minimizing the energy required to refrigerate the fermenter. The compromise between the two optimization objectives forms Pareto-optimal front solutions, and different solutions are shown in order to better understand the impact of temperature on the process. The approach intends to highlight the potential of control theory techniques and optimization to tackle the inherent cost/quality trade-offs in wine fermentation process, towards a more sustainable energy-efficient winemaking industry.

Color is essential for perception of rosé wine quality and is a key element in the consumer's purchasing act, due to their packaging in clear glass bottles. This project aims at understanding the pigments responsible for the diversity of rosé wine color and the mechanisms involved in color and pigment evolution during wine-making, in order to better control them. This thesis focuses on alcoholic fermentation, which is a major stage of the wine-making process, known to have a strong influence on color.The first results were obtained on 268 commercial rosé wines, using an approach combining color analysis by UV-visible spectrophotometry, polyphenol analysis by a targeted metabolomics approach based on high performance liquid chromatography hyphenated with tandem mass spectrometry in the MRM (mutiple reaction monitoring) mode and chemometrics treatment of the data. They revealed a great diversity in the color of rosé wines, which can be explained by their very different phenolic compositions. The color of light rosé wines is mainly due to pigments derived from the reactions of anthocyanins with hydroxycinnamic acids and with pyruvic acid, a yeast metabolite. In contrast, the color of dark rosé wines is due to anthocyanins and flavanols for the red component a*, in connection with extraction, and, for the yellow component b*, to oxidation products resulting from the reactivity of anthocyanins and ethanal. This first approach allowed to identify the pigments involved in the color of rosé wines in order to study them during the alcoholic fermentation. The same analytical strategy was applied to investigate the impact of alcoholic fermentation on color and pigment composition of wines made from three varieties commonly used in Provence for rosé wine-making, with two levels of maceration. The influence of three parameters, namely pH, sulfite content, and fermentation temperature, were analyzed simultaneously using experimental designs. Except for the well-established impact of pH and sulfites on anthocyanin color, these three parameters had no significant impact on the final characteristics of wines fermented at laboratory scale, under the selected experimental conditions. Analysis of the replicated central points of the experimental designs highlighted polyphenol compositions specific of each variety, responsible for the observed color differences. Size exclusion chromatography analysis revealed the presence of higher molecular weight compounds that were not analyzed by the targeted MRM method but contributed absorbance in the UV-visible range, with spectra suggesting structural differences between the three varieties. Moreover, selective adsorption of some pigments on the lees during fermentation was demonstrated enhancing this varietal effect. Indeed, a significant part of the color of the rosé wines was adsorbed on the yeast walls, highlighting the importance of this phenomenon in rosé wine–making. A non-targeted metabolomics approach using high resolution mass spectrometry coupled to high performance liquid chromatography provided confirmation of these results and allowed us to validate the protocol for alcoholic fermentation at laboratory scale. It also established lists of markers of the must and/or wine of each variety and, in particular, revealed a specific composition of Cinsault wines, characterized by higher molecular weight polyphenols presumably resulting from enzymatic oxidation at must stage;These results shed light on the color diversity of rosé wines and allowed progress in the understanding of the reaction and interaction mechanisms involving phenolic compounds during alcoholic fermentation., La couleur est essentielle pour la perception de la qualité des vins rosés et constitue un élément clé de l’acte d’achat des consommateurs, du fait de leur conditionnement en bouteilles de verre transparent. Ce projet vise à caractériser les pigments responsables de la couleur des vins rosés et plus particulièrement à comprendre les mécanismes impliqués dans leur évolution au cours de la fermentation, étape primordiale de la vinification réputée pour avoir un impact fort sur la couleur, afin de mieux les maîtriser. Les premiers résultats ont été obtenus sur un échantillon de 268 vins rosés commerciaux, par une approche combinant l’analyse de la couleur par spectrophotométrie UV-visible, l’analyse de la composition phénolique par une analyse ciblée reposant sur le couplage chromatographie liquide avec la spectrométrie de masse en mode MRM (multiple reaction monitoring) et le traitement de ces données par chimiométrie. Ils ont révélé une grande diversité de couleur des vins rosés qui s’explique par leurs compositions phénoliques très différentes. La couleur des vins rosés clairs est principalement due à des pigments dérivés résultant des réactions des anthocyanes avec les acides phénols et l'acide pyruvique, un métabolite de la levure. Au contraire, la couleur des vins rosés foncés est due, d’une part, aux anthocyanes et aux flavanols pour la composante rouge a*, en lien avec l’extraction, d’autre part, pour la composante jaune b *, à des produits d’oxydation découlant de la réactivité des anthocyanes et de l’éthanal. La même stratégie analytique a été mise en œuvre pour étudier l’impact de la fermentation alcoolique sur les pigments et la couleur des vins élaborés à partir de cépages emblématiques des rosés de Provence, Cinsault, Grenache et Syrah, avec deux niveaux de macération. Les travaux réalisés à l’aide de plans d’expérience faisant varier 3 paramètres (pH, teneur en sulfites et température) au cours de la fermentation, ont montré qu’hormis l’impact bien connu du pH et des sulfites sur la couleur des anthocyanes, ces paramètres, dans les conditions expérimentales choisies, n’ont pas affecté les caractéristiques des vins fermentés en laboratoire. L’analyse approfondie des points centraux des plans d’expérience a permis de mettre en évidence des compositions spécifiques de chaque cépage, à l’origine de leurs différences de couleur. Les analyses par chromatographie d’exclusion stérique ont révélé la présence de composés de haut poids moléculaire, non analysés par la méthode MRM ciblée, qui semblent structurellement différents en fonction des cépages. Une adsorption sélective de certains pigments sur les lies au cours de la fermentation, renforçant cet effet cépage, a également été démontrée, mettant en lumière l’importance de ce phénomène dans la vinification des vins rosés. Une dernière approche métabolomique non ciblée par spectrométrie de masse haute résolution a permis de confirmer ces résultats, de valider le protocole de fermentation alcoolique en laboratoire et d’établir des listes de marqueurs des différents cépages au stade moût et /ou vin. Elle a notamment révélé une composition particulière du Cinsault avec la présence de composés de haut poids moléculaire résultant probablement de l’oxydation enzymatique des moûts.

Background: The food industry is a major contributor to greenhouse gas emissions: excessive meat consumption is associated with negative health outcomes and a disproportionately high environmental impact. To achieve more sustainable food consumption, consumers must reduce their meat consumption in favour of plant-based alternatives. In recent years, the steady increase of meat consumption in Sweden has subsided but given the 50 years of unprecedented increase in meat consumption prior, this is not enough. The main objective of IDOSUSCON was to obtain knowledge on how to increase the consumption of meat-free alternatives, with meat substitutes as a case study. Meat substitutes represent one of several plant-based alternatives available to consumers, and the European market for these products has grown dramatically in recent years. However, their role and effectiveness in facilitating meat reduction is not yet fully understood. Using a transdisciplinary approach covering psychology, behavioural economics, and sensory & consumer science we present a more holistic understanding of the obstacles faced by consumers when confronted with reducing their meat consumption and replacing meat with products such as meat substitutes.

Lactococcus lactis is one of the most used species in the dairy industry. This species has the ability to reduce to very negative values the redox potential (Eh) of food matrices, making it one of the most reducing Lactic Acid Bacteria (LAB) [1]. This reducing activity influences oxidation-reduction reactions involved in the organoleptic quality of the product and prevents the undesired microorganisms development [2–4]. The main mechanism involved are exofacial thiol groups, NoxE NADH Oxidase and the Electron Transport Chain mechanism [5-7]. For Eh measurement, the commonly used method consists of a redox probe placed in a liquid medium or food matrix [8]. With this probe, Cachon et al. (2002) proposed an innovative procedure allowing to compare reducing activity of LAB, according to their maximum reduction rate, based on their reduction kinetic vs. time. Despite its accuracy, this method can be complex, time-consuming and expensive for the screening of many strains. Michelon et al. (2013), proposed an agar milk screening using colored oxidation-reduction indicators to quickly categorize, with a reducing power score, a large number of LAB strains. This method was used successfully for screening a large bank of LAB and mutants’ strains. However, while this screening method showed significant inter-species differences, it was difficult to identify intra-species ones [9].In order to differentiate several strains belonging to the same species, we developed a new method combining Cachon et al. (2002) and Michelon et al. (2013) procedures with high throughput screening. This routinely method allows to compare until 30 L. lactis strains simultaneously and can be applied on frozen and freeze-dried mixed starters.1. Brasca et al. 2007. J Appl Microbiol 103,1516–24 2. Caldeo et al. 2016. J Dairy Res 83,479–86 3. Nouaille et al.2014. Appl Environ Microbiol 80,7028–35 4. Abraham et al. 2007. Int Dairy J 17,954–60 5. Michelon et al. 2010. FEBS J 277,2282–906. Tachon et al. 2010. Appl Environ Microbiol 76,1311–9 7. Roussel et al. 2022. Food Res Int 156,1111-548. Cachon et al., 2002. Lait 82,281–8 9. Michelon et al. 2013. J Biosci Bioeng 115,229–32

Complex coacervation is a liquid-liquid phase separation that occurs between two oppositely charged macromolecules and leads to the formation of a concentrated phase called coacervates. The formed coacervates are proposed as efficient encapsulating agents for bioactives. Here, we studied the specific case of heteroprotein complex coacervation (HPCC) between positively charged Lactoferrin (LF) and negatively charged β-lactoglobulin (β-LG). We aimed to determine the sensitivity of LF/β-LG complex coacervation process to ionic strength and subsequent properties of formed coacervates. Dialysis experiments showed the very high sensitivity of LF/β-LG complex coacervation to ionic strength. Complex coacervation only occurred at ionic strength values lower than 30 mM. Furthermore, in an environment of low ionic strengths, there is a small window wherecomplex coacervation between the two proteins is favoured as assessed by ITC measurements. The interaction strengths deduced from the ITC profiles in the range of 3-5 mM NaCl are higher than in the absence of salt. Hence, addiction of a low salt concentration promoted the interaction between the two proteins leading to a higher coacervation yield. These results shed new light on the mechanisms governing the complex coacervation in heteroprotein systems

Human food is responsible for significant environmental impacts. The study of these impacts is therefore essential to better understand their origin and to find ways to reduce them in the design of food products. However, other dimensions of quality are major in food design, such as sensory quality and nutritional quality. In this context, the main objective of the thesis was to explore ways to integrate the environmental dimension in the design of food products in the same way as other quality dimensions. The study of environmental impacts by Life Cycle Assessment (LCA) of different food products of the same category (80 industrial pizzas and 44 artisanal cheeses) revealed a significant variability of these impacts in each of the two categories of products as well as positive correlations to certain nutritional contents within the same food category. Variations in environmental impacts were also found between the same food products (pizzas) produced industrially and at home, related to the variability of consumer practices. All these results, based on mass functional units (FU), present an important limitation since the FU is supposed to be representative of the function of the product studied. The use of different nutritional FUs to rank food products in the same category according to their environmental impacts showed that the ranking of products with a better nutritional value was improved compared to a mass FU. However, although the use of a nutritional FU is a way to take into account the nutritional function of food products during their LCA, its interest is limited. Indeed, its use takes into account only one dimension at a time when qualitative aspects such as sensory quality are not taken into account. However, interviews with professionals in the food industry confirmed that the nutritional and sensory qualities of food were major for them. Thus, a multi-criteria evaluation model based on the DEXi software, which takes into account the nutritional, sensory and environmental qualities of foods, has been developed and makes it possible to discriminate between foods in the same category (pizzas). This approach thus supports the design of foods that are better for the environment while maintaining a good nutritional quality and the sensory pleasure of the consumer., L’alimentation humaine est responsable d’importants impacts environnementaux. L’étude de ces impacts est donc primordiale afin de mieux en comprendre les origines avant d’identifier les solutions permettant de les réduire dès la conception des produits alimentaires. Cependant, d’autres dimensions de la qualité sont majeures dans la conception d’aliments, comme la qualité sensorielle et la qualité nutritionnelle. Dans ce contexte, l’objectif principal de la thèse était d’explorer des moyens permettant d’intégrer la dimension environnementale dans la conception de produits alimentaires au même titre que d’autres dimensions de la qualité. L’étude des impacts environnementaux par Analyse de Cycle de Vie (ACV) de différents produits alimentaires d’une même catégorie (80 pizzas industrielles et 44 fromages artisanaux) a mis en évidence une importante variabilité de ces impacts dans chacune des deux catégories de produits ainsi que des corrélations positives à certaines teneurs nutritionnelles au sein d’une même catégorie d’aliments. Des variations d’impacts environnementaux ont également été mises en évidence entre les mêmes produits alimentaires (pizzas) fabriqués industriellement et à domicile, en lien avec la variabilité des pratiques des consommateurs. Tous ces résultats, basés sur des unités fonctionnelles (UF) massiques, présentent une limite importante puisque l’UF est censée être représentative de la fonction du produit étudié. L’utilisation de différentes UF nutritionnelles pour classer les aliments d’une même catégorie selon leurs impacts environnementaux a montré que le classement des produits ayant un plus grand intérêt nutritionnel était amélioré par rapport à celui obtenu avec une UF massique. Cependant, bien que l’utilisation d’une UF nutritionnelle soit un moyen de prendre en compte la fonction nutritionnelle des aliments lors de leur évaluation par ACV, son intérêt reste limité. En effet, son usage rend compte d’une seule dimension quand d’autres dimensions de la qualité ne sont pas prises en compte. Des entretiens menés auprès de professionnels du secteur de l’agroalimentaire ont cependant confirmé que les qualités nutritionnelle et sensorielle des aliments étaient majeures pour eux. Ainsi, un modèle d’évaluation multicritère, prenant en compte à la fois les qualités nutritionnelle, sensorielle et environnementale des aliments, a été développé sur le logiciel DEXi et permet de discriminer des aliments d’une même catégorie (pizzas). Cette approche constitue ainsi une aide à la conception d’aliments meilleurs pour l’environnement tout en maintenant une bonne qualité nutritionnelle et le plaisir sensoriel du consommateur.

International audience; In the crossflow filtration, analysis of deposit swelling after the transmembrane pressure decrease can shed light on deposit properties and removal mechanism.Recently [1], we proposed a method for the deposit analysis, which is based on a comparison between modeled and experimentally observed deposit swelling curves. The method was applied for the analysis of membrane fouling deposits obtained during the crossflow ultrafiltration of casein micelles dispersions.Special cell was used for the simultaneous measurement of the average filtrate flux and the local deposit structure (i.e. dependency of local casein micelles concentration on the distance to the membrane, c(z)). The deposit structure was measured with the help of a small-angle X-ray scattering (SAXS) method. Fouling deposits with a thickness of about 100µm and 150 µm were obtained under transmembrane pressures of 0.5 bar and 1.1 bar, respectively, and the crossflow velocity of 3.1 cm/s. For both studied transmembrane pressures (both deposits), SAXS data were combined with the average filtrate flux data in order to calculate the local compressibility-permeability of deposit: k·dP/dc vs c, where k is the local hydraulic permeability and P is the local osmotic (or compressive solid) pressure. Despite of the difference in c(z) curves observed for two studied pressures (two studied deposits), two k·dP/dc vs. c curves merged, as it is expected for a function describing a material property.Further, the transmembrane pressure was removed and the c(z) curves were measured via SAXS during the pressure relaxation stage of experiment. The deposit swelling (i.e. decrease of the local micelles concentration) was observed for both studied deposits. Also, the swelling kinetics was modelled numerically using the conventional filtration-consolidation equation with the k·dP/dc-function obtained as described above.For both studied deposits, the model predicted significantly slower swelling, as compared to that measured in experiments. It was concluded that the deposit compression resulted in micelles interaction (attraction), which was partially reversible, since the deposit swelled and re-dispersed in course of time.

Qu’est-ce que l’Infrastructure de Recherche CALIS peut apporter à des projets de recherche pluridisciplinaire ? Exemple du projet FroM’Innov dans le MP SYALSA; International audience; CALIS est une Infrastructure de recherche distribuée s’appuyant sur les compétences « Consommateurs, Alimentation et Santé » des Infrastructures Scientifiques Collectives (ISC) qui la compose. L’ISC Plate-Forme Lait porte un projet dans le méta-programme SYALSA dont l’objectif majeur consiste à tester l’acceptabilité d’une innovation de rupture par le consommateur puis de déterminer précisément l’acceptabilité par le consommateur des principaux paramètres composant la construction de l’axe santé de ce produit ainsi que la construction de l’axe sobriété du procédé.Le présent document explicite l’intérêt que CALIS peut apporter à ce projet via ses composantes : Consommateurs, Alimentation et Santé.

National audience; La cyanobactérie Arthrospira platensis, plus communément appelée spiruline (ou Spirulina platensis), est un microorganisme unicellulaire procaryote qui possède la capacité de photosynthèse oxygénique assimilable à une réduction du CO2 et à une oxydation de l’eau via l’utilisation de l’énergie lumineuse. Utilisée comme source de nourriture humaine et animale, la spiruline a attiré l'attention du monde entier car elle est très intéressante sur le plan nutritionnel : 55 à 70 % de protéines, 6 à 10 % de lipides, 20 % de glucides, et également riche en minéraux (K, Ca, Fe, Mg, Zn) et vitamines (B1, B12, E). Depuis 1980, la production mondiale de spiruline n’a cessé d’augmenter. Environ 19 000 tonnes de spiruline sont produites chaque année dans le monde, essentiellement en Chine, en Inde et aux Etats-Unis, représentant un marché de plus de 348 M$ en 2018. La spiruline est aussi particulièrement connue pour sa teneur élevée en phycocyanine, un piment aux nombreuses propriétés biologiques utilisé dans les secteurs alimentaire, cosmétique et pharmaceutique grâce à son large éventail d'applications (colorant, antioxydant ou marqueur fluorescent). En 2015, le marché annuel de la phycocyanine était d'environ 10 à 50 M$, avec un prix compris entre 130 et 5000 $/kg en fonction de sa qualité. Selon un rapport publié par Future Market Insights, le marché mondial était évalué à 112,3 M$ en 2018 et d'ici la fin de 2025 on estime qu'il atteindra une valeur dépassant les 232,9 M$. Optimiser sa production se révèle donc être un des enjeux majeurs des années à venir.Comme pour les plantes, la photosynthèse est essentielle au bon développement de la spiruline. Dès lors, l’utilisation de sources lumineuses appropriées au cours de sa culture semble être un point clé pour améliorer son rendement photosynthétique. En effet, la spiruline est capable avec de l’eau et du CO2 de convertir l’énergie lumineuse en énergie biochimique grâce à la photosynthèse. Les travaux menés au laboratoire LAPLACE visent à étudier l’impact de différentes longueurs d’ondes sur la croissance et la production de phycocyanine chez la spiruline. La production de biomasse, la production de phycocyanine ainsi que sa pureté ont été analysés sur des cultures éclairées avec une seule longueur d’onde. D’autres essaies ont ensuite été menés avec une association combinée de deux longueurs d’ondes.

International audience; Complex coacervation is a liquid-liquid phase separation that leads to the formation of highly concentrated phase (coacervates). Despite its multiple use, especially in the field of food science, little has been reported on hetero-protein complex coacervation. In our previous work, we reported on the ability of two globular proteins Lactoferrin (LF) and β-lactoglobulin (β-LG) to form coacervates under specific physicochemical conditions [1]. Here, different experiments were conducted in order to characterize the rheological properties of the formed LF/β-LG coacervates. We showed that unlike some polysaccharide/protein systems, LF/β-LG coacervates has a liquid like behavior; the loss modulus G" was 100 times higher than the storage modulus G'. This behavior was confirmed under creep-recovery tests. In addition, the coacervates exhibited a Newtonian viscous flow under low shear rate and a shear thinning behavior above 10 s-1. These results suggest a structural change probably due to the weaknesses of electrostatic interactions inside the protein network at high shear rates. This structural change was proved to be reversible and the rearrangement of the structure was time-dependent. These results allow better understanding of the involved interactions in concentrated protein solutions and open new avenues for the use of coacervates as texturizing agents in food products.

International audience

International audience; Mettre en évidence les propriétés physicochimiques de divers OB  Développer et évaluer le nouveau schéma de raffinerie verte pour l'extraction et la valorisation des OB Objectifs Contexte Les graines oléo-protéagineuses et les grains de céréales renferment de nombreux nutriments et micronutriments minéraux et organiques. In planta, ces nutriments se retrouvent sous forme d'assemblages naturels tels que les oléosomes (OB), qui présentent des propriétés intéressantes (tailles microniques, activité de surface, grande stabilité physico-chimique, ...). Ces assemblages sont généralement extraits par des procédés qui endommagent leurs structures, et de ce fait certaines fonctionnalités. Exploiter la biodiversité des assemblages naturels pour répondre à la demande sociétale d'une alimentation plus naturelle et peu transformée (Green Label), apparaît nécessaire. Le projet du consortium OBTAIN** se propose d'évaluer les potentialités d'un nouveau schéma de raffinerie verte (sans solvant, moins dénaturant).

International audience; A versatile simulator takes into account four major stages: defrosting, warm-up, and convective and boiling drying. This dynamic model considers that a frozen prefried french fries has three compartments: a central compartment (#1) with high water content, a peripheral compartment (#3) corresponding to the prefried dry crust, and an intermediate compartment (#2) appears during frying, filled with water vapour. Convective and boiling drying and freezing are modeled. The predicting model has been identified based on the triplicates of three different modalities. The resulting predictions have been experimentally validated.

International audience

International audience; In this study, we investigated the properties of mitochondria to discriminate fresh from frozen-thawed fish fillets. Mitochondria were isolated from gilthead seabream fillets and the impact of freezing was evaluated by measuring the permeability of mitochondrial membranes. Freezing led to permeabilization of mitochondrial inner membranes to reduced nicotinamide adenine dinucleotide (NADH). The increase in permeability related to freezing shock was compared to the physiological permeabilization of mitochondria isolated from gilthead seabream fillets stored at 4°C. Two approaches were chosen to measure the increase in permeability: a spectrophotometric method to measure the consumption of NADH by complex I, and an oxygraphic method to measure O2 consumption by respiratory chains after exposure of mitochondria to NADH. Mitochondria isolated from frozen-thawed fillets were highly permeable to NADH and were no longer sensitive to a membrane permeabilizing agent: alamethicin. Altogether, our scientific approach allowed us to discriminate mitochondria isolated from fillets that have been exposed or not to a freezing shock (-80°C) and thus to discriminate between fresh and frozen-thawed fish fillets.

Thermophilic spore forming bacteria present in the farm environment are found at low concentrations in raw milk. They are resistant to pasteurization treatments applied in industry and can develop during the manufacturing process of dairy powders and be found in high concentrations. In order to evaluate the contamination of dairy powders produced in France, an enumeration and an evaluation of the species diversity of thermophilic spores was carried out on 61 samples collected from industrials allowed to highlight a great diversity of spore contaminants. It appears that A. flavithermus, G. stearothermophilus and B. licheniformis are the most present thermophilic spore-forming bacterial species in dairy powders. These prevalence depend on the type of dairy powder studied. A phenotypic diversity regarding the enzymatic activity has shown with a spoilage potential for A. flavithermus, G. stearothermophilus and more particularly for B. licheniformis.As a result, contaminated powders used as ingredients in food formulations are possible sources of spoilage. A detailed analysis of the manufacturing process of dairy powders, associated with the growth capacities of thermophilic spore-forming bacteria, allowed to evaluate the steps of the manufacturing process of the powders favouring the development, the formation of biofilms and spores of the studied species. Finally, the estimations of the capacity of biofilm formation by A. flavithermus and G. stearothermophilus on the one hand and of their resistance to the cleaning treatments on the other hand revealed that the A. flavithermus species is the most resistant to the alkaline treatments whereas the resistances to the acid treatments seem to be similar for both species. The results obtained during this thesis have allowed to evaluate the growth capacities of thermophilic spore forming bacteria in the dairy powder industry and to understand the levers allowing to better control their development and their elimination., Les bactéries sporulées thermophiles présentes dans l’environnement de la ferme, se retrouvent en faibles concentrations dans le lait cru. Elles résistent aux traitements de pasteurisation appliqués en industrie et peuvent se développer au cours des procédés de fabrication des poudres laitières pour s’y retrouver en fortes concentrations. Afin d’évaluer la contamination des poudres laitières produites en France, un dénombrement et une évaluation de la diversité des espèces des spores thermophiles mené sur 61 échantillons recueillis auprès d’industriels a permis de mettre en évidence une grande diversité de contaminants sporulés. Il apparait que A. flavithermus, G. stearothermophilus et B. licheniformis sont les espèces bactériennes sporulées thermophiles les plus présentes dans les poudres laitières. Ces prévalences dépendent du type de poudre laitière étudiées. Une diversité phénotypique est observée lors de l’analyse des activités enzymatiques avec un potentiel d’altération observée pour A. flavithermus, G. stearothermophilus et plus particulièrement pour B. licheniformis.Il en résulte que les poudres contaminées utilisées comme ingrédients dans les formulations alimentaires sont de possibles sources d’altération. Une analyse détaillée du procédé de fabrication des poudres laitières, associée aux capacités de croissance des bactéries sporulées thermophiles a permis d’évaluer les étapes du procédé de fabrication des poudres susceptibles de favoriser le développement des espèces étudiées, de la formation de biofilms et de spores. Enfin les estimations d’une part de la capacité de formations de biofilms par A. flavithermus et par G. stearothermophilus et d’autre part de leurs résistances aux traitements de nettoyage en place ont révélé que l’espèce A. flavithermus est la plus résistante aux traitements alcalins alors que les résistances aux traitements acides semblent similaires pour les deux espèces. Les résultats obtenus au cours cette thèse ont permis d’évaluer les capacités de croissance des bactéries sporulées thermophiles dans les industries des poudres laitières et d’appréhender des leviers permettant de mieux maitriser leurs développements et leurs éliminations.

International audience