Rangées de graines.. © INRA, Elena Schweitzer © Fotolia

Our results

Contents
  1. Introduction
  2. Human milk digestion in the preterm infant: impact of technological treatments
  3. Research & Innovation 2017 - For Food and Biobased Products
  4. The way in which proteins aggregate when heated may change their sensitising potency
  5. Enhancing the viability of spray-dried probiotic bacteria by stimulating their stress tolerance
  6. To stick or not to stick? Pulling pili sheds new light on biofilm formation
  7. When biopolymers selfassemble: a balance between energy and entropy.
  8. Mimicking the gastrointestinal digestion in a lab-on-a-chip:the microdigester
  9. How a milk droplet becomes a powder grain
  10. Research & Innovation 2016 - For Food and Bioproducts
  11. A new process for the biorefining of plants
  12. Under the UV light : the bacterial membrane
  13. Reverse engineering or how to rebuild ... bread!
  14. Green Chemistry: a step towards lipid production in yeast
  15. Individually designed neo-enzymes for antibacterial vaccines
  16. Multi-scale mechanical modelling: from the nanometric scale to the macroscopic properties of bread crumb
  17. Minimill: 500 g to assess the milling value of soft wheats
  18. Microbial production of lipids for energy or chemical purposes
  19. The discrete role of ferulic acid in the assembly of lignified cell wall
  20. Eco-design of composites made from wood co-products
  21. Analysis of volatile compounds enables the authentication of a poultry production system
  22. Nanoparticles as capping agents for biopolymers microscopy
  23. Pasteurisation, UHT, microfiltration...All the processes don't affect the nutritional quality of milk in the same way
  24. Integration of expert knowledge applied to cheese ripening
  25. Controlling cheese mass loss during ripening
  26. The shape memory of starch
  27. Research & Innovation 2015 - For Food & Biobased Products
  28. Behaviour of casein micelles during milk filtering operations
  29. Overaccumulation of lipids by the yeast S. cerevisiae for the production of biokerosine
  30. Sequential ventilation in cheese ripening rooms: 50% electrical energy savings
  31. An innovative process to extract bioactive compounds from wheat
  32. Diffusion weighted MRI: a generic tool for the microimaging of lipids in food matrices
  33. Characterization of a major gene of anthocyanin biosynthesis in grape berry
  34. New enzyme activity detectors made from semi-reflective biopolymer nanolayers
  35. Improving our knowledge about the structure of the casein micelle
  36. Heating milk seems to favour the development of allergy in infants
  37. Fun with Shape
  38. Using volatile metabolites in meat products to detect livestock contamination by environmental micropollutants
  39. SensinMouth, when taste makes sense
  40. A decision support system for the fresh fruit and vegetable chain based on a knowledge engineering approach
  41. SOLEIL casts light on the 3D structure of proteins responsible for the stabilisation of storage lipids in oilseed plants
  42. A close-up view of the multi-scale protein assembly process
  43. Controlling the drying of infant dairy products by taking water-constituent interactions into account
  44. Polysccharide nanocrystals to stabilise pickering emulsions
  45. Discovery of new degradative enzymes of plant polysaccharides in the human intestinal microbiome
  46. A durum wheat flour adapted for the production of traditional baguettes
  47. Virtual modelling to guide the construction of « tailored-made » enzymes
  48. How far can we reduce the salt content of cooked meat products?
  49. Diffusion of organic substances in polymer materials: beyond existing scaling laws
  50. Smart Foams : various ways to destroy foams on demand !
  51. Dates, rich in tannins and yet neither bitter nor astringent
  52. Sodium content reduction in food
  53. Research & Innovation 2014

Nanoparticles as capping agents for biopolymers microscopy

The way a biopolymer interacts with surrounding molecules in plants, foams, emulsions or food matrices can be studied by microscopy provided that the biopolymer can be selectively labelled.

Updated on 06/17/2013
Published on 06/11/2013
Keywords:

Quantum dots (semi-conductor nanocrystallites with strong fluorescence properties) and gold nanoparticles can be used as probes for such a task

However, such particles need to be protected by a shell when synthesized in order to prevent their aggregation and precipitation, thereby making their manipulation easier. Most of the capping agents currently used are synthetic molecules. The use of generic molecules from agricultural resources appears to be a powerful, attractive and safer environmental approach.

Nanosomes of plant origin for the synthesis of nanoparticles

We have shown that hydroxylated fatty acids form nanosomes in water (i.e., micelles with a hydrophilic core).
Figure 1 : acide junipérique (WOH), dérivé mercapto (WSH) et illustration des nanosomes en solution aqueuse.. © INRA
Figure 1 : acide junipérique (WOH), dérivé mercapto (WSH) et illustration des nanosomes en solution aqueuse. © INRA

Figure 1: Juniperic acid (WOH), mercapto derivative (WSH) and diagram of nanosomes in an aqueous solution

We developed novel methods for using such nanosomes as capping agents for the synthesis of quantum dots and gold nanoparticles. We produced quantum dots composed of cadmium selenure or sulphate with strong photoluminescent properties, together with gold nanoparticles that are highly soluble in water or organic solvents.

Diagram of a gold nanoparticle encapsulated in a nanosome. © INRA
Diagram of a gold nanoparticle encapsulated in a nanosome © INRA

 
The so-formed nanoparticles appear to be made of a crystalline metal core embedded within the nanosomes. The fatty acid shell thus efficiently protects nanoparticles against aggregation and precipitation.

Figure 2 :(a) Photographies de solutions de quantum dots de séléniure de cadmium stabilisés (par trois types de nanosomes) émettant dans le visible (a1, a2, a3) et en fluorescence (a1’, a’2, a’3)  ;(b) Quantum dots à base de sulfure de cadmium observées par microscopie à force atomique (AFM) et(c) observés par microscope électronique à transmission.. © INRA
Figure 2 :(a) Photographies de solutions de quantum dots de séléniure de cadmium stabilisés (par trois types de nanosomes) émettant dans le visible (a1, a2, a3) et en fluorescence (a1’, a’2, a’3) ;(b) Quantum dots à base de sulfure de cadmium observées par microscopie à force atomique (AFM) et(c) observés par microscope électronique à transmission. © INRA
(a) quantum dots solutions from cadmium selenure stabilised (with 3 types of nanosomes) emitting in the visible (a1, a2, a3) and by  fluorescence (a1’, a’2, a’3) 
(b) quantum dots composed cadmium selenure observed by atomic force microscopy (AFM) and,
(c) by transmission electron microscope

Further developments in imaging

These nanoparticles will be further used for labelling model proteins or antibodies of food interest via covalent coupling reactions. This will make it possible to study these molecules using original in vivo and in vitro imaging methods.

A partnership betwen chemists, physico-chemists and physicists

These works have been dealt at the Biopolymers, Interactions and Assemblies Unit (INRA Nantes), in partnership with:
Centre de Recherche Paul Pascal (CNRS) Pessac : caracterisation of the assemblies by neutron diffusion
Laboratoire Léon Brillouin, CEA Saclay : experiments.
Laboratoire de Catalyse en Chimie Organique de l’Université de Poitiers : application in organic synthesis.
IInstitut des Matériaux de Nantes : physicochemical caracterisation of the quantum dots
UMR CNRS 6230-Université de Nantes : chemical changing of the quantum dots.