THE FRACTAL NATURE OF FAT CRYSTAL NETWORKS

Glycerol tristearate aggregates in olive oil are shown to have a fractal structure. The fractal dimension, as deduced from light scattering experiments, is d = 1.7, which is in line with predictions of recently developed aggregation models. The fractal dimension increases with time to d = 2.0, indicating that the aggregate structure becomes more compact as a result of ageing. No influence of the application of shear on the structure of the aggregates is detected. An interpretation of rheological data for glycerol tristearate networks is presented in the framework of fractal theory. It is shown that the elastic modulus and the yield stress vary with particle concentration according to a power law. From the power-law dependence the fractal dimension of the aggregates is calculated to be d = 2.0, in line with the results of light scattering experiments.