Megan Holdstock publishes her paper in Soft Matter on dispersion behaviour of insoluble particles in non-aqueous media

Megan Holdstock (PhD Student, SOFI2 CDT and Nestle) publishes her first paper titled "Dispersion behaviour of insoluble particles with different surface properties in non-aqueous media – biopolymer based oleogels" in Soft Matter. In this work, pea protein isolate (PPI) particle behaviour was compared in detail with two types of model silica particles with known surface chemistry: hydrophilic and hydrophobic silica when dispersed in oil.  Rheological scaling models obtained two fractal dimensions: a higher intra-floc dimension and a lower network backbone dimension, suggesting that colloidal PPI and silica particles have an inhomogeneous microstructure with denser particle flocs compared to a relatively sparse backbone. Strikingly, networks of the smaller milled PPI particles (1 µm) had almost the same inter-floc and intra-floc fractal dimensions as the hydrophobic silica, suggesting that the average ‘surface’ character of the PPI may be close to that of the silica. Therefore, despite the complexity of the plant protein surface, parallels can be drawn with simpler colloidal systems. The particle-particle interactions of the milled protein and hydrophilic silica could be altered by pre-treating the particle surface with a high polarity solvent, leading to changes in network elasticities. Overall, the similarities in behaviour of the very different types of particles when dispersed in oil is quite remarkable, so that a greater understanding and control of the rheology of the protein-based systems seems possible, which could have many applications in various food and allied soft matter applications. The full text in Soft Matter can be followed here: https://doi.org/10.1039/D5SM00596E