Electrical stimulation to improve meat quality: Factors at interplay, underlying biochemical mechanisms and a second look into the molecular pathways using proteomics

International audienceEnsuring consistent beef eating quality is paramount for meeting consumer demands and sustaining the meat industry. Electrical stimulation (ES) is a post-slaughter intervention used to accelerate post-mortem glycolysis, to avoid cold shortening, to control the tenderization rate of meat through sophisticated physical, chemical and biochemical mechanisms including proteolysis, to improve beef tenderness and to achieve normal pHu that might lead to positive impact on color. This review comprehensively examines the multifaceted effects of ES on beef quality, encompassing factors and settings influencing its efficacy and the underlying biochemical mechanisms revealed using traditional biochemistry methods. It then delves into the molecular pathways modulated by ES, as unveiled by muscle proteomics, aiming to provide a second look and an unprecedented understanding of the underlying biochemical mechanisms through an integrative proteomics analysis of low-voltage ES (LVES) proteomics studies. The proteins changing as a result of ES were gathered in a compendium of 67 proteins, from which 14 were commonly identified across studies. In-depth bioinformatics of this compendium allowed a comprehensive overview of the molecular signatures and interacting biochemical pathways behind electrically stimulated beef muscles. The proteins belong to interconnected molecular pathways including the ATP metabolic process and glycolysis, muscle structure and contraction, heat shock proteins, oxidative stress, proteolysis and apoptosis. Understanding the intricate interplay of molecular pathways behind ES could improve the efficiency of beef production, ensuring consistent meat quality and meeting consumer expectations. The integrative analysis approach performed in this study holds promise for the meat industry's sustainability and competitiveness

Electrostatic interactions between soft nanoparticles beyond the Derjaguin approximation: effects of finite size of ions and charges, dielectric decrement and ion correlations

International audienceHypothesis. Electrostatic interactions between colloids are governed by the overlap of their electric double layers (EDLs) and the ionic screening of the structural charges distributed at their core surface and/or in their peripheral ion-permeable shell, relevant to soft particles like polymer colloids and microorganisms. Whereas ion size-mediated effects on the organization of isolated EDLs have been analysed, their contribution to the electrostatic energy of interacting soft particles has received less attention. Theory and simulations. Herein, we elaborate a formalism to evaluate the electrostatic interaction energy profile between spherical core/shell particles, building upon a recent Poisson-Boltzmann theory corrected for the sizes of ions and particle structural charges, for ion correlations and dielectric decrement. Interaction energy is derived from pairwise disjoining pressure and exact Surface Element Integration method, beyond the Derjaguin approximation. The theory is sufficiently flexible to tackle homoand hetero-interactions that involve weakly to highly charged hard, porous or core/shell nano-to micro-sized particles in asymmetric multivalent electrolytes. Findings. Results illustrate how ion steric effects, ion correlations and dielectric decrement impact the sign, magnitude and range of the interactions depending on the particle size, the Debye length, and the geometric and electrostatic properties of the particle core and shell components

Are food retailers resilient amid crisis? A cultural resource-based exploration of Lebanese consumers’ engagement with the food retail landscape

International audienceSupermarketization is transforming global food retailing, but research gaps around this transformation include the role of consumers and of crises in informing the supermarketization process, with implications for the resilience of retail structures. This study aims to apply a cultural-resource based theory of the customer and show that retailers need to think more broadly about the value they create for consumers and the meaning they engage in their interactions with consumers. We performed in-depth interviews with Lebanese consumers to understand whether and to what degree COVID-19, economic, and political crises have altered their food purchasing habits and perceptions, and the implications for the developing country context of supermarketization and retail modernization. Findings reveal that multiple factors influence the choice of food shopping destination ranging from those identified in mainstream retail theories (price, product assortment) to the individual-level activation of meaning and identity creation consistent with the cultural resource-based theory of the customer. Recent shifts in retail patronage patterns are linked to specific crisis impacts but do not uniformly favor modern or traditional retailers, suggesting ambiguous impacts on retailers’ resilience and the future trajectory of supermarketization in Lebanon

Quelle(s) Cité(s) idéale(s) ?

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Exil als Palimpsest: der Erinnerungsraum Marseille in Christian Petzolds Adaption von Anna Seghers’ Roman Transit

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Photophysical, cyclic voltammetry, electron paramagnetic resonance, X-ray molecular structure, DFT calculations and molecular docking study of a new Mn(III) metalloporphyrin

International audienceHerein, we have presented a new manganese(III) metalloporphyrin, named, based on the X-ray molecular structure, the bis(4-dimethylaminopyridine)[meso-tetra(para-chlorophenyl)porphyrinato]manganese(III) triflate 1.56 chloroform solvate 0.22 n-hexane solvate 0.22 hydrate with the following formula:[MnIII(TClPP)(DMAP)2] (SO3CF3)and sdot;0.22(C6H14)and sdot;1.56(CHCl3)and sdot;0.22(H2O) (complex I). This coordination compound was characterized by FT-IR and cyclic voltammetry. The dichloromethane solution UV/Vis spectrum of I is typical of a Mn(III) high-spin (S = 2) porphyrin complex with a redshifted Soret band with lambda max value of 487 nm. The single crystal X-diffraction technique was used to determine the molecular structure of our new Mn(III) bis(DMAP) porphyrin complex. Electron paramagnetic resonance (EPR) spectroscopy confirms that this new 3d4 Mn(III) metalloporphyrin (a non-Kramers system) in solid state is high-spin (S = 2). DFT/TD-DFT calculations on complex I were investigated, including (i) the molecular structure optimization using the DFT/B3LYP-D3/LanL2DZ level of theory, (ii) the frontier molecular orbital calculations and the deduction of the global indices of activities, (iii) the molecular electronic potential analysis (MEP), and (iv) the QTAIM and NCI-RDG analyses. Furthermore, complex I was tested against diverse amino acids of the selected Bcl-2 proteins using docking calculations

A la carte dissolution of rare earth elements from lateritic and karstic bauxite residues at mild pH: Toward sustainable extraction processes

International audienceRecovery of rare earth elements from bauxite residues of lateritic versus karstic origin was explored at a pH ranging between 2.7 and 4.5 using a mixture of citric acid and citrate in water. Dissolution yields of up to 82 % for lanthanum and 62 % for yttrium were achieved with excellent selectivity toward iron (a selectivity factor of up to 4200), the main element of bauxite residues. An experimental Box-Behnken statistical design identified the concentration of citric acid/citrate and temperature as key factors controlling the dissolution yield and selectivity of rare earth elements. Observed differences in dissolution yields and selectivity as a function of origin were attributed to differences in the speciation of rare earth elements in the two bauxite residues. It is therefore possible to draw an "à la carte" graph that identified the optimum citric acid/citrate concentrations and dissolution temperatures for dissolution yields and selectivity for the two BRs. This work provides fundamental knowledge for the future development of sustainable processes for the recovery of rare earth elements from bauxite residues derived from bauxites of different origin

Coopérer pour le bien-être ou collaborer pour la croissance ?: Compte-rendu de la conférence introductive d’Eloi Laurent

Numéro coordonné par Lucie Bruis-Gervasone et Anne-Gaëlle BeurierInternational audienc

Few-layered-graphene - Si3N4 composite powders prepared by decomposition of methane onto a Si3N4 powder bed: Control of the average number of layers in the graphene stack

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The difficult conversion of an industrial town nostalgic for its past into a creative city

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