Nanoscale effects on oil migration through triacylglycerol polycrystalline colloidal networks
Abstract
The following paper studies the effects of laminar shear on the nano- and meso-scale structure of polycrystalline materials (cocoa butter). Furthermore, the effect of laminar shear on the migration kinetics of stained triacylglycerol (TAG) oil through a polycrystalline colloidal TAG network was characterized and quantified. Several models were used to study this phenomenon. A low diffusion coefficient was observed in cocoa butter crystallized under shear. This suggested that the migration rate of liquid TAGs through a polycrystalline TAG network can be modified using external fields. A lower migration rate was observed in the shear-crystallized samples. These samples had a smaller crystallite size indicating that particles of this size will retard oil migration. The arrangement of the crystalline component also had a strong effect on the oil migration rate (OMR). Liquid oil diffusivity was decreased by about 4.6 to 30 times in samples that exhibited alignment of the crystalline material along a given axis. Moreover, the tortuosity of the diffusive path in the shear-crystallized samples was approximately 4 to 12.5 times higher than that of the static sample. Finally, the relationships between the structural factors (