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

Our results

Contents
  1. Introduction
  2. Research and Innovation 2018 - For Food and Biobased Products
  3. Dry-cured ham: a process simulator can now define routes of manufacture that yield lower-salt 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. Human milk digestion in the preterm infant: impact of technological treatments
  7. Research & Innovation 2017 - For Food and Biobased Products
  8. To stick or not to stick? Pulling pili sheds new light on biofilm formation
  9. When biopolymers selfassemble: a balance between energy and entropy.
  10. Mimicking the gastrointestinal digestion in a lab-on-a-chip:the microdigester
  11. How a milk droplet becomes a powder grain
  12. Research & Innovation 2016 - For Food and Bioproducts
  13. A new process for the biorefining of plants
  14. Under the UV light : the bacterial membrane
  15. Reverse engineering or how to rebuild ... bread!
  16. Green Chemistry: a step towards lipid production in yeast
  17. Individually designed neo-enzymes for antibacterial vaccines
  18. Multi-scale mechanical modelling: from the nanometric scale to the macroscopic properties of bread crumb
  19. Minimill: 500 g to assess the milling value of soft wheats
  20. Microbial production of lipids for energy or chemical purposes
  21. The discrete role of ferulic acid in the assembly of lignified cell wall
  22. Eco-design of composites made from wood co-products
  23. Analysis of volatile compounds enables the authentication of a poultry production system
  24. Nanoparticles as capping agents for biopolymers microscopy
  25. Pasteurisation, UHT, microfiltration...All the processes don't affect the nutritional quality of milk in the same way
  26. Integration of expert knowledge applied to cheese ripening
  27. Controlling cheese mass loss during ripening
  28. The shape memory of starch
  29. Research & Innovation 2015 - For Food & Biobased Products
  30. Behaviour of casein micelles during milk filtering operations
  31. Overaccumulation of lipids by the yeast S. cerevisiae for the production of biokerosine
  32. Sequential ventilation in cheese ripening rooms: 50% electrical energy savings
  33. An innovative process to extract bioactive compounds from wheat
  34. Diffusion weighted MRI: a generic tool for the microimaging of lipids in food matrices
  35. Characterization of a major gene of anthocyanin biosynthesis in grape berry
  36. New enzyme activity detectors made from semi-reflective biopolymer nanolayers
  37. Improving our knowledge about the structure of the casein micelle
  38. Heating milk seems to favour the development of allergy in infants
  39. Fun with Shape
  40. Using volatile metabolites in meat products to detect livestock contamination by environmental micropollutants
  41. SensinMouth, when taste makes sense
  42. A decision support system for the fresh fruit and vegetable chain based on a knowledge engineering approach
  43. SOLEIL casts light on the 3D structure of proteins responsible for the stabilisation of storage lipids in oilseed plants
  44. A close-up view of the multi-scale protein assembly process
  45. Controlling the drying of infant dairy products by taking water-constituent interactions into account
  46. Polysccharide nanocrystals to stabilise pickering emulsions
  47. Discovery of new degradative enzymes of plant polysaccharides in the human intestinal microbiome
  48. A durum wheat flour adapted for the production of traditional baguettes
  49. Virtual modelling to guide the construction of « tailored-made » enzymes
  50. How far can we reduce the salt content of cooked meat products?
  51. Diffusion of organic substances in polymer materials: beyond existing scaling laws
  52. Smart Foams : various ways to destroy foams on demand !
  53. Dates, rich in tannins and yet neither bitter nor astringent
  54. Sodium content reduction in food
  55. Research & Innovation 2014

Polysccharide nanocrystals to stabilise pickering emulsions

An emulsion is typically a metastable state that irreversibly evolves towards the separation of the two phases at variable time scales. In addition to their relative stability, the purpose of formulating emulsions is to have access to wide ranges of texture and viscoelasticity that can be used in fields as varied as agro-food, cosmetics, lubrication, chemical synthesis and even medicine. Normally, emulsions are stabilised with low-molecular-weight surface-active agents with rapid sorption/desorption dynamics at the interface, requiring a large quantity of surfactants to maintain interface stability. In the case of Pickering emulsions, stability is ensured by the presence of well-anchored particles at the interface, thus requiring a limited quantity of particles compared to conventional emulsifiers, a greater stability and a high degree of interfacial elasticity. These macroscopic properties can be explained by the modification of the nature of the interfaces that are more robust and rigid as a result of the high cooperative desorption energy specific to each particle.

Updated on 06/17/2013
Published on 06/04/2013
Keywords:

Pickering emulsions: atypical emulsions

 
These emulsions are currently the focus of renewed interest both because of their atypical properties that make it possible to decrease the quantity of surface-active agents used in current applications and as a result of the extensive research devoted to nano and microparticles in recent years. At the same time and in view of new regulations, considerable effort has been devoted to replacing synthetic surface-active agents with biological structures.   The renewable nature of the crystals places them in an ideal position on the emulsion market.  The combination of Pickering emulsion properties with those of biodegradability or the suitability of using polysaccharide micro and nanocrystals in the food industry therefore represents a new and considerable interest for applications, particularly in terms of fractionation and biorefining.

Cellulose nanocrystals : effective stabilisers  

Pickering oil-in-water emulsions were stabilised by crystals from different biological sources and notably from non-modified cellulose.   These crystals with their varied morphologies (Fig. 1a-b) were obtained either from the acid hydrolysis of natural structures (cotton, algal cell walls, bacterial cellulose) or from isolated and then recrystalised polysaccharide chains (recycling of textile waste, for example). We were able to visualise the crystals at the surface of oil droplets using different microscopic techniques (confocal laser scanning microscopy, atomic force microscopy and scanning electron microscopy) (Figs. 1c-f).  The different methods for preparing crystals allowed us to demonstrate that, in particular, the surface characteristics of crystals played a key role in emulsion stability and that this stability could be modified by the crystal surface charge.  The stability studies that we conducted revealed that the emulsions were resistant to large mechanical deformations and were stable over a wide range of temperatures (-20°C to 80°C), pH (1 to 13) and time scales (at least one year)

Polysaccharide nanocrystals : varied, biodegradable and renewable 

Polysaccharide crystals can replace particles derived from organic synthesis to stabilise Pickering emulsions in existing applications and can lead the way to new application fields for these emulsions as a result of the functional properties specific to biopolymers and the suitability or biocompatibility of the crystals for the food industry.     

Figure 1: Cellulose nanocrystals obtained by acid hydrolysis of cotton linters (1a) or of cladophora (algae) (1b); Emulsion formed from cellulose microcrystals under light microscopy (1c); under confocal laser scanning microscopy with staining of the hydrophobic phase with BODIPY (1d) and double staining with BODIPY and Calcofluor specific to the cellulose (1e) and under scanning electron microscopy (1f).. © INRA
Figure 1: Cellulose nanocrystals obtained by acid hydrolysis of cotton linters (1a) or of cladophora (algae) (1b); Emulsion formed from cellulose microcrystals under light microscopy (1c); under confocal laser scanning microscopy with staining of the hydrophobic phase with BODIPY (1d) and double staining with BODIPY and Calcofluor specific to the cellulose (1e) and under scanning electron microscopy (1f). © INRA

Références

See also

  • Patent : cathala et al.  N° FR 10 55 836 du 19 Juillet 2010.
  • Emulsions S.U. Pickering, J. Chem. Soc. 91 (1907) 2001