Scaling Behavior of the Elastic Modulus in Colloidal Networks of Fat Crystals

The scaling relationship between the shear elastic modulus and the solid fat content (SFC) was determined for anhydrous milk fat (AMF), palm oil (PO), and cocoa butter (CB). The fats were diluted with canola oil to achieve specific SFCs and crystallized at 5 °C for 24 h. SFC decreased linearly by increasing the canola oil mass fraction as determined by pulsed NMR. Log−log plots of the shear storage modulus (G‘) versus the solids' volume fraction (Φ = SFC/100) of the diluted fats were used to determine the fractal dimension (D) of the networks. Three different linear regions were identified for the range of dilutions studied. The scaling relationship of the stress at the limit of linearity (σo) to Φ indicated that the fats were in the weak-link rheological regime in all three regions. These results suggested that three different types of weak-link rheological regimes could be present in the same material depending on the SFC. Polarized light microscopy showed that varying the solid fat content (SFC) modifi...