Microstructure of fat crystallizing on a collagenous surface

The effect of surface quality on fat crystallization was examined for glass and gelatin surfaces using three-dimensional polarized light microscopy in an attempt to develop a model system for how fat may crystallize in arteries. A mixture of the high-melting fraction of milk fat and triolein was crystallized from 60 °C to 30 °C at a rate of 0.5 °C/min on both glass and gelatin surfaces. Crystallization of fat on the gelatin surface led to an increase in the amount of nucleation and resulted in a more even distribution of crystal mass than crystallization on the glass surface. No evidence of crystal precipitation or glass surface crystallization was evident. We postulate that the gelatin acted as a template for nucleation. Similar trends were identified using fractal analysis. Fat crystallized on gelatin had a higher fractal dimension than fat crystallized on glass.