Using neutrons to improve meat alternatives
There is wide-scale concern about the impact of meat production on climate change due to associated land degradation, water consumption and greenhouse gas emissions. A shift towards consumption of plant-based meat alternatives could offer benefits for both the environment and human health.
To encourage consumers to switch to a more plant-based diet, meat-analogues would ideally be cheap and replicate the taste and sensory experience of meat. To achieve this requires an understanding how internal microstructures affect the macroscopic properties (texture, taste, etc.) of food.
To obtain a qualitative and quantitative 3D-understanding of food composite materials, several complementary characterisation techniques can be used. Often this includes microscopy or X-ray tomography. Less well-known (but just as valuable) are neutron techniques, such as Spin-Echo Small-Angle Neutron Scattering (SESANS), which can be used to ‘look inside’ the bulk of a food composite.
Scientists at Delft University of Technology and Wageningen University used neutrons to study two meat analogues: calcium caseinate and an anisotropic Soy protein Isolate-vital wheat gluten biopolymer blend.
One study investigated the size and shape of air bubbles in calcium caseinate. Neutron techniques allowed a relatively large sample size to be probed, providing information on bubble width and deformation direction that agreed well with the same results obtained from the other techniques employed on smaller samples.
Another study was on the bulk and surface structure of the Soy protein Isolate biopolymer blend. Neutrons were able to determine the orientation distribution of the fibres and the number of fibre layers. The measured fibre thickness also confirmed results from another technique used.
"A combined use of several characterisation techniques is necessary for better understanding of the nature of plant-based meat replacers as well as their functionality and structuring mechanisms."
Georgios A. Krintiras
Delft University of Technology