Researchers have attempted to quantify the 3-dimensional structures arising from fat aggregation in edible fats and oils for many years, since these might help in identifying the right fat for a desired functionality. Much has been done using NMR, microscopy, XRD and DSC. The technique of Ultra-Small Angle X-ray Scattering (USAXS) enables one to identify structures with characteristic spatial scales between ~50 Å and ~105 Å corresponding to X-ray scattering vector, q, in the region 10-1 Å‑1 < q < 5 x 10-4 Å-1. This region gives information about the sizes of aggregating particles as well as the 3-dimensional structures that they form. We have used the newly upgraded Bonse-Hart camera in the 15ID beam line at the Advanced Photon Source (APS), in Argonne National Laboratory, Argonne USA. We measured the X-ray scattering intensity, I(q), of four different solids (tristearin, tripalmitin, trimyristin and trilaurin) in two different oils (triolein and trilinolein) at different solid fat contents (SFC). The Beaucage and Hammouda models implemented in the unified-fit of the APS Irena software were used to find: 1-radii of gyration, Rg, of particles and their aggregates and 2-the regions of q for which log [I(q)] exhibited linearity which would yield the fractal dimensions, D. We shall report and discuss details of our results for both D and Rg for different oils and solids and compare them with simulations.
Fernanda Peyronel fsvaikau@uooguelph.ca
