Structure and dynamics of food materials
Food products are both soft materials and structured materials, and the scattering of X-rays and neutrons is used by the University of Copenhagen to advance the tools accessible to the Danish food industry.
The LINX team at the University of Copenhagen (KU) primarily uses small-angle X-ray and neutron scattering (SAXS and SANS). By recording how beams of X-rays or neutrons are scattered by materials, the LINX team can determine the nanoscale structure of many manmade and natural materials. The range of possible materials that can be studied is extremely broad and includes natural polymers (plant fibres, starch and cellulose), food products, and a range of self-assembled systems, such as emulsions and micelles. The common property of all these systems is that they have structure on a length scale ranging from 1-1000 nm, which is precisely the range that can be studied under relevant conditions using small-angle scattering.
There is a reason that either X-rays or neutrons can be used in a scattering experiment, and that is because they provide complementary information about materials. The information that you can get from a single measurement is limited by the difference in how X-rays and neutrons interact with the constituents of the material. For X-rays, this is their interaction with electrons, and for neutrons, this is their interaction with nuclei. By choosing X-ray or neutron scattering or a combination of both, it is possible to maximise the information about the structure that can be gained.
By using small-angle scattering with different forms of radiation, it is already possible to understand materials over a wide range of length scales (1-1000 nm) and with different contrast (electron density from X-rays or nuclear density from neutrons). However, the LINX team at KU is constantly seeking new methods and techniques to gain additional insight into materials.
Read the interesting one pagers from this project:
Techniques and Methods
One area that the LINX team at KU is now actively advancing is the studying the nanoscale and microscale structures of food products. The structure of food is very important for both taste and mouth feel. For example, the protein casein in milk assembles into spherical structures (called micelles), which are responsible for the change in appearance texture when milk is turned into yoghurt or cheese. Casein micelles are just one of many structures that can be determined using SAXS and SANS. Other examples under investigation by the LINX team at KU include gels and emulsions.
The LINX team at KU is making a concerted effort to increase the application of these scattering techniques in food science in Denmark. Along with applying conventional scattering methods (SAXS and SANS), the LINX team at KU is developing the use of several complementary techniques. These techniques increase the amount information that can be gained from a scattering measurement, either to gain information about the dynamics of the motion of particles in time or to gain structural information at larger length scales (1000 times greater than SAXS or SANS). It is the goal of this project at KU to develop these techniques to the point where food companies may directly use and benefit from them, leading to much improved fundamental understanding of food materials as well as enabling the development new products.
Participants: University of Copenhagen.
Title: Development of Capabilities in Food and Colloid Science (KU GDP).