Search results for "protéines"
showing 10 items of 60 documents
New nanobiohybrid engineering composed of titanate nanoribbons for regenerative medicine
2012
This research work is devoted to new nanohybrid engineering composed of titanate nanoribbons for regenerative medicine. Over a first phase, nanoribbons were synthesized by hydrothermal treatment and their morphological, structural and chemical features were defined. A fine characterization by means of different techniques of transmission electron microscopy mainly enabled to determine their thickness; dimension which had never been measured so far. Subsequently, titanate nanoribbons were functionalized by different home-made heterobifunctional PEG. Those polymers present at one of their extremities specific functional groups being able to couple with numerous biological molecules. Some coll…
Meat substitutes: formulations and comparative analysis
2021
The nutritional quality of animal products is often overlooked in our consumers' imaginations. Sustainability for example, must takeinto account sustainability for humans, starting with meeting their nutritional needs as naturally as possible. For starters, the protein intake, inquantity per 100 g of edible food (usually cooked), greatly exceeds those of vegan equivalents, whether they are meat analogues made fromvegetable proteins or vegetarian dishes reputed to be sources of protein (chickpeas, hummus, lentils, tofu etc.). In addition, it is clear that animalproducts are protein sources of high nutritional quality (DIAAS 80) unlike vegetarian equivalents (DIAAS 80). Animal proteins ar…
Enzymatic cross-linking of pea proteins to produce microparticles : application to the encapsulation of riboflavin
2015
In this work, pea proteins behavior toward enzymatic gelation by microbial transglutaminase (MTGase) was studied at native state and after denaturation (chemical reduction or thermal denaturation). The final application was the formation of protein microparticules to encapsulate riboflavin, chosen as hydrophilic active molecule model. The extraction process of the pea protein fractions has been optimized in such a way to minimize as possible protein denaturation and recover native fractions rich in albumin (Alb) and globulin (Glob) or a mixture of both.The setting up of the enzymatic reaction monitoring methods has brought out their complementarity as well as their limits. Two new monitorin…
Identification of the Weevil immune genes and their expression in the bacteriome tissue
2008
Abstract Background Persistent infections with mutualistic intracellular bacteria (endosymbionts) are well represented in insects and are considered to be a driving force in evolution. However, while pathogenic relationships have been well studied over the last decades very little is known about the recognition of the endosymbionts by the host immune system and the mechanism that limits their infection to the bacteria-bearing host tissue (the bacteriome). Results To study bacteriome immune specificity, we first identified immune-relevant genes of the weevil Sitophilus zeamais by using suppressive subtractive hybridization (SSH) and then analyzed their full-length coding sequences obtained b…
Study of the interactions and physicochemical properties of pea and egg white protein mixtures : from the colloidal to the gelled state.
2022
In recent years, due to the growth of world population, people's consumption of animal protein has increased, leading to the increase of greenhouse gas emissions and land occupation. Therefore, it is necessary to partially replace animal protein with vegetable protein to increase the proportion of vegetable protein in daily consumption and developing mixed food systems seems to be one adequate solution. Pea proteins as a source of plant proteins have good nutritional properties but with limited functional properties while egg white (EW) has good functional properties such as gelling and foaming. Thereby, the physicochemical interactions from mixtures of both types of protein needs to be und…
Fermentation des protéines végétales : atouts organoleptique et nutritionnel
2015
Référence : 201511122426; Du fait de l’augmentation de la population de la planète, la production de protéines pour l’alimentation des populations et l’évaluation de la qualité de ces protéines pour satisfaire les besoins de l’Homme pourraient devenir des questions majeures dans les décennies à venir pour l’ensemble du monde. Le développement de nouveaux aliments optimisant l’apport protéique d’origine végétale parait également important dans certaines situations (personnes âgées, sportifs…) où les besoins nutritionnels sont modifiés au plan quantitatif et qualitatif. De nombreux problèmes ont été identifiés suite à l’incorporation de protéines végétales dans nos aliments. En particulier, d…
Technical improvements for analysis of recalcitrant proteins by LC-MS : the myccorhiza responsive membrane proteome as a case study
2012
Arbuscular mycorrhizas (AM) are widespread symbiotic associations between plant roots and AM fungi. Deep membrane alterations are the foremost morphological changes occurring in the host plant in response to AM symbiosis. Two-dimensional gel electrophoresis (2-DE) is the workhorse method in AM proteomics. Membrane proteins are under-represented in 2-DE because of their hydrophobicity, low abundance, and precipitation at their isoelectric point, thereby few are the identified membrane proteins involved in sustaining the AM symbiosis. Membrane proteomics is still challenging due to 2-DE related shortcomings, however latest trends and advancements in mass spectrometry (MS)-based quantitative p…
Salivary properties involved in astringency sensitivity in human differ as a function of age
2022
Astringency is an important sensory characteristic of foods and beverages containing polyphenols. However, astringency perception in elderly people is not documented. Current hypothesis on astringency mechanism involved aggregation of the mucosal pellicle by tannins and its protective role by salivary proteins in particular proline rich-proteins (PRPs). The aim of the present work was to evaluate sensitivity to astringency in function of age and saliva (flow and composition). Fifty-four panelists including (30 elderlies and 24 young) participated in this study. Astringency was evaluated by 2-Alternative Forced Choice procedure. For salivary PRPs, a western blot methodology was set up to eva…
Lifelong exposure to low dose xeno-hormones in rats : multi-generational effects of xeno-hormone mixtures on taste preferences, maternal behavior, an…
2012
During the last decade, the issue of health-related endocrine disruptors (ED) has been extended to the toxicity of mixtures. The objective of this study was to define the effects of lifelong exposure to ED mixtures, at low doses defined as "non-harmful" by the authorities. In this aim, the effects of mixtures combining genistein, vinclozolin and bisphenol A, have been investigated in the rat by using an integrative and multi-generational experimental approach which takes into account maternal behavior, feeding behavior and development. Our results show that these mixtures could: a) reduce maternal behavior, b) change taste preferences (sweet, salty), c) affect the development from the in ut…
Study of the dynamics of biomolecules by high speed atomic force microscopy and surface enhanced Raman spectroscopy
2015
This thesis focuses on the coupling of High–Speed Atomic Force Microscopy (HS-AFM) and Surface Enhanced Raman Spectroscopy (SERS) for biomolecule analysis. We have designed a fabrication protocol to manufacture “SERS-active” substrates. The efficacy of gold, silver and gold-silver bimetallic crystalline nanoparticle substrates were evaluated. We have investigated the impact of optical and morphological features of the substrates on Raman signal intensity by analyzing well-known samples such as bipyridine ethylene and methylene blue molecules. We took an interest in three distinct biological problematics with HS-AFM and SERS analyses. First, we have detected the chemical signature of cytochr…