IThe potato starch industry in the European Union alone generates close to 6 million tons of potato fruit juice(PFJ), a highly polluting waste product that is only marginally profitable as fertilizer or animal feed. PFJ containsup to 2% of crude proteins that are essentially wasted nutrients, and though their extraction and isolation havebeen exhaustively studied, their properties and applications in the food industry remain insufficiently documented.Patatin is a globular protein that makes up 35 to 40% of the total soluble proteins found in potatoes, and hassuccessfully been extracted from PFJ in its quasi-native form and commercialized as a nutritious isolate with ahigh degree of purity and numerous associated functionalities like gelling, emulsifying and foaming properties.The aim of this work is twofold: (1) to study and compare the aggregation pathways of a patatin-rich isolate viatwo processes: heat treatment and high hydrostatic pressure and (2) to characterize the obtained aggregatesfrom a physico-chemical and functional point of view in order to select promising structures for the encapsulationof a bioactive molecule. For that, patatin dispersions (1 and 4% w/w) at pH 6 and 7 were subjected to varyingtemperatures (45, 50, 55°C) or pressure levels (400,600 MPa) for time intervals going from 30 minutes up to 48hours. The characteristics of the formed assemblies were studied at the micro, meso and macroscopic scalesusing dynamic light scattering, differential scanning calorimetry, dynamic rheology, fluorescence spectroscopy (in-situ, under high pressure), circular dichroism, size exclusion chromatography, and electrophoresis. The resultsindicated the pH dependency of the aggregation kinetics and the final sizes of the structures formed for eachprocess, with aggregates twice as large at pH closer to the isoelectric point. At moderate temperatures,micrometric aggregates were obtained within minutes, while high pressure generated smaller aggregates aftermuch longer treatment durations. Insights on protein denaturation, unfolding, protein-protein and protein-bioactivemolecule interactions were also acquired. This work shows that the functionality of this plant-based protein can beimproved and that this by-product can be valorized as a nano-vector for hydrophobic bioactive molecules in thefield of functional ingredients.

Chromophore are encapsulated into host single-walled carbon nanotubes to create hybrid nano-systems with tunable optical and electronic properties. The interplay between the confined molecules and the host nanotube is a key factor1,2.From Raman spectroscopy and G-band shift measurements, a significant charge transfer from the confined dye to the nanotube is evidenced. A photo-activated electron transfer is also inferred for small diameter (~9 Å) semiconducting and metallic tubes.3 The key parameters that govern the charge transfer are the nanotube diameter and the electron donor or acceptor character of the molecules. The resonance Raman intensities of the confined molecules are strongly affected by applying an external pressure.4Furthermore, photoluminescence intensities of nanotubes are either significantly enhanced or quenched depending on the electron donor or acceptor character of the molecules.5 Indeed, the electron (hole) transfer up (down)-shifts the Fermi level of the nanotubes, modulating the radiative de-excitation efficiency.Therefore, molecule confinement into nanotubes is an interesting strategy for the engineering of new opto-electronic devices.[1] L. Alvarez et al, J. Phys. Chem. C, 119, (2015), 5203−5210[2] Y. Almadori et al, J. Phys. Chem. C; 118, (2014), 19462−19468[3] Y. Almadori et al, Carbon 149, (2019), pp. 772-780 [4] R.S. Alencar et al, Carbon 173 (2021) 163-173[5] R. Chambard et al, Carbon, 186, (2022), 423-430

Dyes are encapsulated into single-walled carbon nanotubes to elaborate hy-brid nano-systems with tunable optical and electronic properties. The physical interaction be-tween the confined molecules and the host nanotube is a key factor1,2.From Raman spectroscopy and G-band shift measurements, a significant charge transfer from the confined dye to the nanotube is evidenced. A photo-activated electron transfer is also inferred for small diameter (~9 Å) semiconducting and metallic tubes.3 The key parameters that govern the charge transfer are the nanotube diameter and the electron donor or acceptor character of the molecules. Furthermore, photoluminescence intensities of nanotubes are either significantly en-hanced or quenched depending on the electron donor or acceptor character of the molecules.5The resonance Raman intensities of the confined molecules are strongly affected by applying an external pressure.4 DFT Calculations clearly allow to account for this effect.Therefore, molecule confinement into nanotubes is an efficient strategy for the engineering of new opto-electronic devices.

L’intervention évoquera les éléments de formation interdisciplinaire pour initier une réflexion pédagogique sur l’anthropocène, cette nouvelle ère géologique qui débuterait lorsque les activités humaines ont radicalement changé notre relation à la planète avec un impact profond et durable sur les écosystèmes. Ce concept sera traité au travers d’une approche historique, scientifique et sociotechnique et interrogera le notion de limite planétaire.

Le terme de transition écologique s’est imposé pour remplacer la notion de développement durable (« sustainabledevelopment », rapport Brutland 1987) devant l’incapacité de la dynamique initiée à l’époque à répondre aux enjeux sociétaux liés au modèle économique linéaire dominant. Sur ce sujet, le rôle des scientifiques pour sensibiliser la société aux défis environnementaux a été déterminant depuis les travaux du groupe Meadows du MIT sur les limites de la croissance (1972), en passant par les mises en place du Groupe d’experts intergouvernemental sur l’évolution du climat (GIEC 1988) , la création La plateforme intergouvernementale scientifique et politique sur la biodiversité et les services écosystémiques (IPBES 2012), et enfin concernant l’impact des déclarations de scientifiques comme le colauréat du prix Nobel de chimie P. Grutzen, suite à ses travaux sur la chimie de l’atmosphère (1995), sur l’émergence de l’anthropocène (2000), entre autres… Aujourd’hui on parle de transition au singulier, ou au pluriel (énergétique, numérique…). L’irréversibilité de la transition, la temporalité du régime transitoire, sont questionnées. La compréhension de la dynamique du système global en lien avec les évolutions scientifiques et technologiques interroge les communautés scientifiques et de l’enseignement supérieur sur les actions à mettre en œuvre. Je ferai un point d’étape sur la base d’une expérience initiée par l’enseignement.