The Effect of Shear on the Microstructure and Oil Binding Capacity of Wax Crystal Networks

This study examines the effect of shear on the microstructure and oil binding capacity of three wax oleogels. For crystallization under a cooling rate of 1.5 °C/min, shear decreased crystal size, but increased the box-counting fractal dimension (Db) and decreased the pore area fraction (AFp) of the RBX oleogel network, creating a tortuous network for loosely-bound oil to migrate through that increased the oil binding capacity compared to statically cooled RBX gels For SFX oleogels, crystal size decreased under shear, while for CLX, crystal size drastically increased, causing an increase in oil loss for both. Trends for pore area fraction and fractal dimension were not consistent for oleogels structured by different waxes, which may be due to inherent differences in crystal surface quality and available area for oil adsorption. Under both high and low cooling rates, shear increased the oil binding capacity of a commercial peanut butter stabilizer. The effect of shear under rapid cooling for wax oleogels was more difficult to discern due to confounding effects of shear and cooling rate.