Using SESANS to complete our understanding of the structural basis for the rheology of molten chocolate

Molten chocolate is a dense suspension of solids (mainly sugar) in oil, to which surfactants have been added to improve the flow properties, either during manufacture or in the consumers mouth ('mouth feel'). The way a suspension of grains flows is thought to be determined by the way in which the grains are arranged relative to each other: when jammed together, with friction between grains dominating, a finite yield stress must be applied to get the material to flow; when separated by a lubricating layer it is the viscosity of this lubricating layer that dominates. SESANS is a special scattering technique than enables the correlations between particles that are of dimensions much greater than the neutron wavelength and so lie outside the SANS window. Just the technique that we need to help understand why the surfactant affect the flow of chocolate, whether in processing or in the mouth.