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

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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

Multi-scale mechanical modelling: from the nanometric scale to the macroscopic properties of bread crumb

Cereal products are the basis of our diet. Their texture is a relevant indicator of sensory perception. Mechanics of Materials allows us to extract objective data about mechanical behaviour of such products including ultimate properties and their breakdown. Using Finite Element simulation, scientists study relationships between the structure of a given product and its mechanical properties at different scales. The Finite Elements Method predicts these properties for “virtual” structures that match “real” structures. It was applied to the case of cellular products such as bread crumb. Numerical results revealed a non-negligible role of cell architecture on the elasticity of bread crumb structures in addition to the major role of the void content. Mechanical modelling will be applied to the mastication of cereal products. This approach will relate the process to the functional properties in order to more effectively predict the breakdown of these products for improved digestion.

Updated on 06/17/2013
Published on 06/10/2013
Keywords:

Material sciences applied to cereal products

Cereal products are the basis of our diet. Their texture is a relevant indicator of sensory perception. Material mechanics cannot be separated from structural information that is closely linked to the mechanical behaviour of products, which is why it is important to study mechanical property-structure relationships.  As a result of the variability of the size of structural heterogeneities, these relationships must be broken down at different scales.
Digital techniques are absolutely necessary for the construction of robust mechanical models capable of making realistic predictions, given the impossibility of measuring the effect of certain heterogeneities (for example, the in situ measurement of a cell wall property in a cellular material).
The Finite Element Method (FEM), known for its deterministic description, increasingly integrates the complexity of structures. Application of the FEM is highlighted in the following examples within the framework of the study of starch-based cereal products.
Digital simulation using Finite Element Analysis, coupled with an adequate deterministic model, allows a prediction of the mechanical behaviour of these products in relation to their structure. Better still, this type of approach anticipates these same properties for "virtual structures" comparable to "real" structures. Virtual generation designates structural possibilities for improving products by standard food transformation processes. The results obtained are illustrated below in the case of cellular products such as bread crumb through the application of a deterministic multi-scale approach.

 

Simulation at different scales reveals the mechanical behaviours of a bread crumb  

Starting with the composite that forms the cell wall, simulation of the nanoindentation test reveals the major role of the starch-zein interface (Fig. 1) .  This effect is flagrant when we look at the behaviour at the microstructure scale.  In order to better understand the role of the interface, it is possible to extrapolate on the basis of an average interface effect, thanks to the notion of interphase properties. Behaviour modelling thus becomes more coherent with mechanical tests. Nevertheless, the validity of this coherence is relative to the observation scale and requires a homogenisation approach to make the necessary transition from the microstructure scale to the macroscopic scale. As long as this transition does not take place, the variability of mechanical properties measured at the macroscopic scale cannot be explained.

Figure 1 : (a) Simulation d’un essai de nano-indentation : échelle de l’interface. (b) Modèle à trois phases: échelle de la microstructure. (c) Simulation d’un essai de flexion: échelle macroscopique. (d) Modèle élastique associé à une structure cellulaire à base d’amidon (mie de pain): échelle du produit transformé.. © INRA
Figure 1 : (a) Simulation d’un essai de nano-indentation : échelle de l’interface. (b) Modèle à trois phases: échelle de la microstructure. (c) Simulation d’un essai de flexion: échelle macroscopique. (d) Modèle élastique associé à une structure cellulaire à base d’amidon (mie de pain): échelle du produit transformé. © INRA

Figure 1: (a) Simulation of a nanoindentation test: interface scale. (b) Three-phase model: microstructure scale. (c) Simulation of a bending test: macroscopic scale. (d) Elastic model linked to a starch-based cell structure (bread crumb): transformed product scale.

Applying mastication models

While waiting for the implementation of such an approach, we were able to identify the mechanical behaviour of starch-zein composites at the macroscopic level using an inverse approach.
In this case, the material is said to be homogeneous in that the microstructure is implicitly involved in its behaviour.  Given the cell wall properties, it was possible to describe the simulation of the behaviour of a processed product. Numeric results reveal a non-negligible role of the cellular architecture on the elasticity of bread crumb-type structures in relation to the dominant role of the vacuum.
The application of mechanical models of mastication of cereal products is in progress.  This approach will make it possible to link the process to utilisation properties in order to more effectively predict the degradation of these products to improve their digestion.

Partners

  • UMR Centre des Sciences du Goût et de l'alimentation (CSGA) CNRS, INRA, Université de Bourgogne et AgroSup Dijon
  • Laboratoire de Mécanique de Lille est une Unité Mixte de Recherche (UMR 8107) entre le CNRS et l'Université des Sciences et Technologies de Lille
  • Laboratoire de Science et Ingénierie des Matériaux et Procédés, CNRS-INP Grenoble-Université Joseph Fournier 
  • GéM : Institut de Recherche en Génie Civil et Mécanique, CNRS-Université de Nantes-Ecole Centrale de Nantes 
  • FEMTO-ST : Franche-Comté Electronique, Mécanique, Thermique et Optique – Sciences et Technologies CNRS-Université de Besançon 

See also