Hypothalamus-olfactory system crosstalk: orexin a immunostaining in mice.

Short title: Orexin in miceInternational audienceIt is well known that olfaction influences food intake, and conversely, that an individual's nutritional status modulates olfactory sensitivity. However, what is still poorly understood is the neuronal correlate of this relationship, as well as the connections between the olfactory bulb and the hypothalamus. The goal of this report is to analyze the relationship between the olfactory bulb and hypothalamus, focusing on orexin A immunostaining, a hypothalamic neuropeptide that is thought to play a role in states of sleep/wakefulness. Interestingly, orexin A has also been described as a food intake stimulator. Such an effect may be due in part to the stimulation of the olfactory bulbar pathway. In rats, orexin positive cells are concentrated strictly in the lateral hypothalamus, while their projections invade nearly the entire brain including the olfactory system. Therefore, orexin appears to be a good candidate to play a pivotal role in connecting olfactory and hypothalamic pathways. So far, orexin has been described in rats, however, there is still a lack of information concerning its expression in the brains of adult and developing mice. In this context, we revisited the orexin A pattern in adult and developing mice using immunohistological methods and confocal microscopy. Besides minor differences, orexin A immunostaining in mice shares many features with those observed in rats. In the olfactory bulb, even though there are few orexin projections, they reach all the different layers of the olfactory bulb. In contrast to the presence of orexin projections in the main olfactory bulb, almost none have been found in the accessory olfactory bulb. The developmental expression of orexin A supports the hypothesis that orexin expression only appears post-natally

Les ateliers agrifood : Reconnecter la recherche sur la production agricole et la transformation alimentaire

Rapport IDEAS-INRA-AgroParisTechLes ateliers agrifood : Conception d’un agenda de recherche partagé pour des systèmes agri-alimentaires plus sains et plus durable

Lack of Hypothalamus Polysialylation Inducibility Correlates With Maladaptive Eating Behaviors and Predisposition to Obesity

High variability exists in individual susceptibility to develop overweight in an obesogenic environment and the biological underpinnings of this heterogeneity are poorly understood. In this brief report, we show in mice that the vulnerability to diet-induced obesity is associated with low level of polysialic acid-neural cell adhesion molecule (PSA-NCAM), a factor of neural plasticity, in the hypothalamus. As we previously shown that reduction of hypothalamic PSA-NCAM is sufficient to alter energy homeostasis and promote fat storage under hypercaloric pressure, inter-individual variability in hypothalamic PSA-NCAM might account for the vulnerability to diet-induced obesity. These data support the concept that reduced plasticity in brain circuits that control appetite, metabolism and body weight confers risk for eating disorders and obesity

Ecoconception des aliments et bioproduits : de l’intégration des qualités des produits à l’éco-innovation pour des systèmes alimentaires plus durables

This thesis presents ecodesign and ecoinnovation approaches in the field of agricultural product transformation into food and bioproducts. A central topic of the work is the environmental assessment of products and systems, mainly performed by Life Cycle Assessment (LCA), and its integration into the design process. To be successful, this integration must be done in conjunction with the intrinsic qualities of the products (nutritional, sensory, functional). In a first step, the intrinsic qualities of food and bioproducts and their evolution during processing operations were studied, through experimental and modeling approaches. In a second step, the environment was retained as a priority objective, by adopting an ecodesign approach which consists in articulating diagnosis, proposal and evaluation of solutions in an iterative process with LCA as the method of choice to support ecodesign.The research perspectives concern the environmental assessment in innovation processes. A first research axis aims at proposing appropriate LCA approaches to assess and support eco-innovation. A second axis seeks to operationalize evaluation to support transitions towards greater sustainability, in particular by confronting theoretical frameworks for assessment with participatory approaches. A third axis focuses on formalizing and sharing knowledge on environmental issues and impacts to stimulate eco-innovation. These axes are addressed through projects dealing with (i) the production of innovative legume-based foods to support the dietary transition, (ii) coupled innovation between agricultural production and food in the case of collective catering to support the agro-ecological transition and (iii) small-scale processing to support the reterritorialization of food systems.Ce mémoire présente des approches d’écoconception et d’éco-innovation dans le domaine de la transformation des productions agricoles en aliments et bioproduits. Un sujet central des travaux est l’évaluation environnementale des produits et systèmes, principalement réalisée par Analyse du Cycle de Vie (ACV), et son intégration dans les processus de conception. Pour qu’elle soit réussie, cette intégration doit se faire conjointement avec les qualités intrinsèques des produits (nutritionnelles, sensorielles, fonctionnelles). Dans un premier temps, ce sont les qualités intrinsèques des aliments et bioproduits et leur évolution au cours des opérations de transformation qui ont été étudiées, par des approches expérimentales et de modélisation. Dans un deuxième temps, l’environnement a été retenu comme objectif prioritaire, en adoptant une démarche d’écoconception qui consiste à articuler diagnostic, proposition et évaluation de solutions dans un processus itératif avec et l’ACV comme méthode de choix pour soutenir l’écoconception. Les perspectives de recherche portent sur l’évaluation environnementale dans les processus d’innovation. Un premier axe de recherche vise à proposer des démarches ACV appropriées pour évaluer et accompagner l’éco-innovation. Un deuxième axe cherche à opérationnaliser l’évaluation pour soutenir les transitions vers plus de durabilité, notamment en confrontant des cadres théoriques d’évaluation à des approches participatives. Un troisième axe se focalise sur la formalisation et le partage des connaissances sur les enjeux et impacts environnementaux pour stimuler l’éco-innovation. Ces axes sont abordés via des projets traitant de (i) la production d’aliments innovants à base de légumineuses pour soutenir la transition alimentaire, (ii) l’innovation couplée entre production agricole et alimentation dans le cas de la restauration collective pour soutenir la transition agro-écologique et (iii) la transformation à petite échelle pour soutenir la reterritorialisation des systèmes alimentaires

Écoconception des aliments, bioproduits, bioprocédés et procédés alimentaires

International audienc

Structuration, gestion et réutilisation des données autour des aliments / bioproduits / procédés: Evaluation environnementale de produits et procédés de transformation dans le secteur agri-alimentaire Apport de l’interopérabilité entre la base de données PO2-BaGaTel et la Plateforme Means

International audienceLes systèmes alimentaires sont les principaux responsables des impacts environnementaux à l’échelle mondiale. Par ailleurs, la moitié de l'humanité souffre d'un régime alimentaire insuffisant ou de mauvaise qualité. Des données environnementales sur l'alimentation sont nécessaires pour accompagner les nécessaires changements drastiques des systèmes alimentaires vers plus de durabilité. La base de données PO²-BaGaTel, structurée par l'ontologie PO², et MEANS-InOut sont deux outils complémentaires qui permettent de créer, structurer et partager de telles données. Ce webinaire présentera l’application MEANS-InOut qui permet l’étude par analyse du cycle de vie (ACV) des procédés de transformation des produits issus de l’agriculture. Après une introduction à l’ACV, une première partie montrera les enjeux de l’évaluation environnementale des procédés et des produits alimentaires à travers deux exemples. Une deuxième partie s’attachera à la présentation de MEANS-InOut, de ses possibilités et de son articulation avec PO²-BaGaTel

A mechanistic model of heat and mass transfer used as a tool to bring insight into chemical reactivity during baking of sponge-cake products

National audienceDuring cooking of bakery products, heat and mass transfer phenomena occur as well as many chemical reactions including Maillard reaction. All these physico-chemical phenomena are strongly inter-related and a modeling approach can help to bring insight into these interactions. This paper presents a mechanistic heat and mass transfer model able to predict the nature and level of the transfer phenomena occurring within the product and between the product and its environment during baking of a sponge cake. The developed model takes into account internal moisture evaporation and vapour migration within the open porosity of the product during heating as well as apparent liquid moisture migration described by pseudo-Fick’s law. Internal heat transfer phenomena were described using Fourier’s law and apparent thermal heat conductivity. External heat and mass transfer phenomena taken into account were convective drying, convective and radiative heat transfer for both heated product and baking tray. Measurements of product core and surface temperatures variations as well as product moisture content and air hygrometry were acquired using an instrumented baking oven specifically designed for the project. Baking trials were performed in order to identify the unknown product properties of the model and to validate the assumptions made. The state variables predicted by the model such as local temperature and moisture content could become the input variables of a stoechio-kinetic model of the Maillard reaction, allowing a better understanding of the interactions between transfer and reaction phenomena as well as a better control of the physico-chemical processes involved during baking

Environmental performance of new processes for the production of fructo- and galacto-oligosaccharides (FOS and GOS)

International audienceThe prebiotics like FOS and GOS are receiving special attention in the food industry due to their health benefits.They can be produced by enzymatic synthesis by using disaccharides or other substrates as raw materials orby extraction and hydrolysis from different natural sources (roots, legumes). The environmental footprints ofthese different production schemes are lacking to provide guidance for the ecodesign of such new productionprocesses.In this work, Life Cycle Assessment (LCA) was undertaken to analyze and compare the production of FOSand GOS by enzymatic synthesis from glucose (to get FOS) or lactose (to get GOS) and hydrolytic productionfrom extraction of yacon potato (to get FOS) or chickpea (to get GOS).A cradle-to-gate approach was considered in the two scenarios under assessment (the phases of use and/or finaldisposal of FOS/GOS were not considered). The functional unit was defined as 100 g of FOS/GOS produced.LCAs were performed using data collected at the laboratory scale, supplemented with data from Ecoinventdatabase. SimaPro was used for the LCA modeling with the midpoint impact EF2.0 characterization method.Results showed that the main environmental hotspot was the production of yacon potato or chickpea used inthe hydrolysis process. For this reason, the hydrolytic process caused higher environmental burdens than theenzymatic synthesis process. Chickpea production causing more impacts than yacon potato production, GOSproduction generated more environmental impacts than FOS production. When produced by enzymaticsynthesis, FOS and GOS were the sources of similar environmental impacts.From a process point of view, special attention must be paid on three specific stages of production: time ofsynthesis, freeze-drying and purification of the final product. The environmental load of these stages wasassociated to high energy consumption and huge amount of ethanol requirement.The results from this study helped to identify the stages requiring special efforts to ecodesign the productionof FOS and GOS at pilot scale in the future. Further research should primarily be focused in the reduction ofthe biomass used and corresponding solid waste generated during the hydrolytic production. Furthermore,environmental assessment should be included at each development of the process to ensure its efficient ecodesign

Developing a food requirement approach for designing food packaging and edible coating to extent food shelf-life

International audienc