BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Contr. talk - Understanding gelation of gluten proteins thanks to neutron and X-ray scattering DTSTART;VALUE=DATE-TIME:20210610T080000Z DTEND;VALUE=DATE-TIME:20210610T082000Z DTSTAMP;VALUE=DATE-TIME:20260529T212547Z UID:indico-contribution-178-1110@lindico453.srv.lu.se DESCRIPTION:Speakers: Laurence Ramos ()\nThe origin of the unique rheologi cal properties of wheat gluten\, the water-insoluble protein fraction of w heat grain\, is crucial in bread-making processes and questions scientists since the 18th\ncentury. Gluten is a complex mixture of two families of p roteins\, monomeric gliadins (Gli) and polymeric glutenins (Glu). To bette r understand the respective role of the different classes of proteins in t he supramolecular structure of gluten and its link to the material propert ies\, we have developed model gluten systems comprising controlled amounts of Gli and Glu in food-grade binary solvents [1]. Using contrast variatio n techniques and small-angle neutron scattering\, we have evidenced in\ngl uten gels the presence of distinct regions of typical size several tens of nm\, which arise from the preferential interaction of Glu polymers throug h a tight network of non-exchangeable intermolecular hydrogen bonds\, at t he origin of the gelation of gluten [3]. In addition\, we have used time-r esolved synchrotron ultra-small X-ray scattering to quantitatively probe t he dynamics of liquid-liquid phase separation (LLPS) in gluten protein sus pensions following a temperature quench [4]. Fluid viscoelastic samples de pleted in polymer Glu phase separate\nfollowing a spinodal decomposition p rocess\, with a coarsening resulting from a competition between thermodyna mics and transport. Anomalous phase-separation dynamics is by contrast mea sured for gluten gels rich in Glu\, due to elastic constraints\, illustrat ing the role of viscoelasticity in the dynamics of LLPS in protein dispers ions. Additional experiments conducted by changing the solvent\, from pure water (a bad solvent for gluten proteins) to ethanol/water (60/40 v/v) (a good solvent for gluten proteins) confirm the subtle interplay between ph ase-separation and viscoelasticity in gluten proteins gels [5].\n[1] Dahes h et al. Polymeric assembly of gluten proteins in an aqueous ethanol solve nt. J Phys Chem B 118\, 11065 (2014).\n[2] Banc et al. Small angle neutron scattering contrast variation reveals heterogeneities of interactions in protein gels. Soft Matter 12\, 5340 (2016).\n[3] Dahesh et al. Spontaneous gelation of wheat gluten proteins in a food grade solvent. Food Hydrocoll oids\, 52\, 1 (2016).\n[4] Banc et al. Phase separation dynamics of gluten protein mixtures. Soft Matter 15\, 6160 (2019).\n[5] Costanzo et al. Tail oring the viscoelasticity of polymer gels of gluten proteins through solve nt quality. Submitted (2020)\n\nhttps://lindico453.srv.lu.se/event/159/con tributions/1110/ LOCATION:Online on Zoom URL:https://lindico453.srv.lu.se/event/159/contributions/1110/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. talk - Towards Correlative X-Ray Tomographic Imaging Of Mem branes For Improving Food Processing DTSTART;VALUE=DATE-TIME:20210610T074000Z DTEND;VALUE=DATE-TIME:20210610T080000Z DTSTAMP;VALUE=DATE-TIME:20260529T212547Z UID:indico-contribution-178-1109@lindico453.srv.lu.se DESCRIPTION:Speakers: Emanuel Larsson (Division of Solid Mechanics & LUNAR C\, Faculty of Engineering\, Lund University)\, Gregor Rudolph (Department of Chemical Engineering\, Lund University)\nIn recent years the need for shifting our food system towards more plant-based proteins has become more and more apparent. The key reason for this shift is the economic and sust ainable recovery of plant proteins from valuable\, yet underutilized agric ultural waste streams for use in food\napplications. For highly selective energy and resource-efficient separation processes\, membrane filtration c an play an important role in realizing this shift. \nThe first successful membrane technology in the food industry was the recovery of proteins from whey\, which was until the 1970’s a major disposal challenge for the da iry industry. Using ultrafiltration (UF) membranes\, it was suddenly possi ble to concentrate and desalt whey proteins. Based on this success story\, membrane processes established themselves for the concentration and purif ication of many products in the food industry. However\, clogging of the m embrane during the filtration process\, so-called membrane fouling\, is st ill a major challenge.\nMembrane fouling alters the separation performance during operation. It may be caused by the deposition of suspended and dis solved substances on the membrane surface\, thereby forming a cake or gel layer\, thus blocking the pore openings\, or causing adsorption on the sur face and on the pore walls. Membrane fouling can only be overcome by regul ar chemical cleaning\, which in turn leads to plant down time\, membrane a ging\, consumption of high-quality drinking water and the generation of hu ge amounts of waste water. \nThus\, a comprehensive understanding on membr ane fouling on a fundamental level is needed. One approach to generate in depth knowledge\, is to examine changes due to fouling and cleaning of the inner structure of the membranes on a micrometer to nanometer scale using correlative X-ray tomographic imaging techniques\, including microtomogra phy\, full-field nanotomography\, holographic nanotomography and ptycho-to mography. This presentation will give an overview\nof the possibilities of X-ray tomographic imaging methods for membrane technology to improve the operation of membrane processes in the food industry More specifically an example of UF for the separation of rapeseed proteins from the press cake of the rapeseed oil production will be presented\, including the need for sample preparation by Focused Ion Beam (FIB).\n\nhttps://lindico453.srv.lu .se/event/159/contributions/1109/ LOCATION:Online on Zoom URL:https://lindico453.srv.lu.se/event/159/contributions/1109/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote talk - Structure and rheology of stimuli responsive nanoce llulose interfacial layers DTSTART;VALUE=DATE-TIME:20210610T070000Z DTEND;VALUE=DATE-TIME:20210610T074000Z DTSTAMP;VALUE=DATE-TIME:20260529T212547Z UID:indico-contribution-178-1108@lindico453.srv.lu.se DESCRIPTION:Speakers: Peter Fischer (ETH Zurich\, Switzerland)\nThe use of particles such as nanocelluloses\, i.e. cellulose nanocrystals (CNC) and nanofibrils (CNF) received increasing attention for the Pickering stabiliz ation of fluid interfaces [1]. The adsorption of nanocellulose and nanocel lulose-protein composites at oil-water or air-water interfaces facilitates the formation of stable and biocompatible emulsions and foams but depends heavily on the particles’ surface properties. In this contribution\, we review the structure of differently designed adsorption layers by neutron reflectivity and interfacial rheology measurements as a function of physi co-chemical boundaries conditions (pH\, salts\, enzymes) [2\, 3]\, surface properties of the cellulose crystals (natural\, methylation\, esterificat ion) [4\, 5]\, and protein or polysaccharide addition [6]. Native unmodifi ed CNC (hydrophilic\, negatively charged\, and anisotropic nanoparticles) showed negligible viscoelasticity that could be increased by charge screen ing due to a shift from repulsive to attractive CNC interactions. Methylat ed CNCs formed dense monolayers with higher dynamic moduli compared to nat ive CNCs and could be thermo-gelled into multilayers. The esterified CNCs formed aggregated clusters at the interface\, resulting in a Maxwellian fr equency behavior with distinctive relaxation times\, a rarely observed phe nomenon for interfacial layers. Scattering length density profiles obtaine d from neutron reflectivity measurements are used to elucidate the thickne ss and roughness of the adsorption layer\, and in case of nanocellulose-pr otein composites\, their spatial composition. Supported by in vivo digesti on experiments in humans we rationalize the design principles of nanocellu lose-stabilized emulsions and foams for food and drug delivery vehicles [7 ].\n\n[1] Bertsch P\, Fischer P: Adsorption and interfacial structure of n anocelluloses at fluid interfaces\, Advances in Colloid and Interface Scie nce 276 (2020) 102089\n[2] Bertsch P\, Fischer P: Interfacial rheology of charged anisotropic cellulose nanocrystals at the air-water interface\, La ngmuir 35 (2019) 7937.\n[3] Scheuble N\, Geue T\, Windhab EJ\, Fischer P: Tailored interfacial rheology for gastric stable adsorption layers\, Bioma cromolecules 15 (2014) 3139.\n[4] Bertsch P\, Diener M\, Adamcik J\, Scheu ble N\, Geue T\, Mezzenga R\, Fischer P: Adsorption and interfacial layer structure of unmodified nanocrystalline cellulose at air/water interfaces\ , Langmuir 34 (2018) 15195.\n[5] van den Berg MEH\, Kuster S\, Windhab EJ\ , Adamcik J\, Mezzenga\, R\, Geue T\, Sagis LMC\, Fischer P: Modifying the contact angle of anisotropic cellulose nanocrystals: Effect on interfacia l rheology and structure\, Langmuir 34 (2018) 10932.\n[6] Scheuble N\, Lus si M\, Geue T\, Carriere F\, Fischer P: Blocking gastric lipase adsorption and displacement processes with viscoelastic biopolymer adsorption Layers \, Biomacromolecules 17 (2016) 3328.\n[7] Scheuble N\, Schaffner J\, Schum acher M\, Windhab EJ\, Liu D\, Parker H\, Steingoetter A\, Fischer P: Tail oring emulsions for controlled lipid release: Establishing in vitro-in viv o correlation for digestion of lipids\, ACS Appl. Mater. Interfaces 10 (20 18) 17571.\n\nhttps://lindico453.srv.lu.se/event/159/contributions/1108/ LOCATION:Online on Zoom URL:https://lindico453.srv.lu.se/event/159/contributions/1108/ END:VEVENT END:VCALENDAR