Milk fat fractionation by solid-layer melt crystallization

The layer crystallization process has the potential to produce the same mil k fat fractions as can be obtained by the suspension crystallization proces s. That is, milk fat fractions with solid fat content melting profiles simi lar to those obtained by suspension fractionation can be produced with this technique. The fatty acid profiles as well as the melting enthalpies of th e different fractions confirm the separation of milk fat by the layer techn ique. Furthermore, there is potential to improve the results of separation presented in the first part of this paper. The two sources of improvement, temperature control of the process and controlled nucleation, lead to (i) a smooth crystalline layer with a low amount of entrapped mother liquor, con trary to the layers composed of agglomerated needles, and (ii) a good quali ty of attachment of the crystalline layer to the cooled surface. Moreover, the product quality can be increased using sweating as a postcrystallizatio n step. "Sweating by warm gas" seems to have a better outlook concerning ha ndling and controlling the process than "sweating by warm tube" because slo ughing of the crystal layers can be avoided. Further investigations of the mass ratio of sweating fraction and amount of product as well as the aspect of energy consumption will determine the technical feasibility of solid-la yer crystallization for fractionation of milk fat.