Crystallization of structured lipids from milkfat and corn oil

Abstract

Structured lipids can be obtained by blending and chemical interesterification of fats and oils, resulting in products with physical, chemical and nutritional characteristics that are different from the original lipids. The most important physical properties of these lipids, such as consistency and plasticity, may be influenced by their crystalline structure. The objective of this study was to observe the changes in the crystal network of structured lipids obtained from milkfat and corn oil. The kinetic crystallization curves were plotted from the solid fat content of the samples as a function of time. From the calculation of the Avrami parameters, the crystallization rates and the types of nucleation and crystal growth were determined. Polarized light microscopy provided images of crystals obtained by high and low cooling rate methods, from which the number of crystals, crystallized area and fractal dimension of the samples were determined. The correlation between the results indicated that the addition of corn oil did not cause substantial changes in the crystal network structure, but only decreased the content of crystallized fat. The interesterification reactions and the addition of corn oil did not alter the size and shape of the crystals.