Fractionation is accomplished by exploiting the different crystallization temperatures of the TG composing the oil. If a
slow decrease of temperature is applied, then the TG molecules that have a small difference in crystallization temperatures will be crystallized at different times. This will result in a fine crystal size, and a high pressure will be needed to filter the oil. However, if a rapid temperature decrease occurs, molecules within a wide range of crystallization temperatures will be crystallized at about the same time. These crystals will agglomerate and stick to one another to form a bigger granularcrystal. As a result of fast processing the olein might be occluded inside the crystal granule. Consequently, the olein yield will decrease. Therefore, control of physical properties of the oil is needed to optimize the process.