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

Our results

  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

Diffusion weighted MRI: a generic tool for the microimaging of lipids in food matrices

In food science, intramuscular fat plays an important role in meat quality. It also influences the diffusion of salt and water in cured products. Lipids that penetrate into foods during processing must also be controlled in order to improve the nutritional value of processed foods, particularly by focusing on the end quantity of lipids.

MRI is the tool that is the most effectively adapted to the non-destructive analysis of fat distribution and content at the voxel scale

To investigate fat distribution, most MRI applications use contrasts in relaxation rates (T1 or T2) or in chemical shift (difference in NMR resonance frequency) between lipids and other tissues.   
An original approach using diffusion weighted MRI was developed to image fat distribution in muscles.  This technique is based on the considerable difference between the apparent diffusion coefficients of water and those of lipids, since water diffuses much more rapidly than lipids as a result of their different molecular weights.  With this diffusion weighted technique, the more the protons are mobile (protons in water molecules present in muscular fibre), the more their signal is reduced.  It is therefore possible to optimise the imaging method so as to turn off the water signal and, thus, to specifically image the lipids.     
The main advantage of this technique is that it makes it possible to obtain a large spatial resolution.  Its major disadvantage is its sensitivity to movements, which is generally not a problem when studying foods.

We applied this technique to imaging lipids in beef that was shallow-fried at 130 and 180°C

For this study, diffusion weighted MRI was conducted at 400 MHz within a microimaging system (Bruker, GmbH, Ettlingen, Germany) of the INRA platform, Magnetic Resonance Imaging of Biological Systems.  This platform includes the only broadline NMR equipment of its kind in France, allowing us to obtain previously unknown information about the structure and properties of foods, as well as to optimise their construction.   
This high-resolution imagery (0.5x0.5x0.1 mm) enabled us to determine the oil absorption profile with a much greater precision (0.1 mm) than that of biochemical analysis methods that require slicing according to the direction of penetration.

Coupe centrale longitudinale d’un cylindre de viande bovine crue (en haut) et frite à 130°C (en bas). L’huile sur la surface de friture, ainsi que le gras intramusculaire sont visibles en hyper signal. Chaque image consiste en une matrice de 64 x 320 pixels correspondant à un champ de vue de 32 par 32 mm.. © INRA
Coupe centrale longitudinale d’un cylindre de viande bovine crue (en haut) et frite à 130°C (en bas). L’huile sur la surface de friture, ainsi que le gras intramusculaire sont visibles en hyper signal. Chaque image consiste en une matrice de 64 x 320 pixels correspondant à un champ de vue de 32 par 32 mm. © INRA

Figure 1 :Central longitudinal section of a cylinder of raw beef (above), and beef fried at 130°C (below).  The oil on the frying face as well as the intramuscular fat is visible in hypersignal.  Each image consists of a matrix of 64 x 320 pixels corresponding to a field of vision of 32 x 32 mm.

This generic method could be applied when knowledge of the distribution of lipids in a food product is necessary to optimise a process (cooking or curing) or a formulation

These results are therefore a major contribution to the improvement of product quality, particularly sensory and nutritional, and to the development of new foods.    

Sylvie CLERJON, INRA Theix UR370 Qualité des Produits Animaux, Equipe STIM
Other contact(s):
Plate-Forme de Résonance Magnétique des Systèmes Biologiques

See also

  • Clerjon, S. and Bonny, J.M. (2011). Diffusion-weighted NMR micro-imaging of lipids: application to food products, in: J.P. Renou, P. S. Belton, and W. Graham Eds.:, Magnetic Resonance in Food Science, RSC, Cambridge.
  • Clerjon, S. and Bonny, J.M. (2009). Suivi de la migration des lipides de friture dans la viande par micro-imagerie RMN. XXIième Conférence du Groupement français d’Etude de la Résonance Magnétique, Fréjus, France.