Characterization of the stearin obtained by thermal fractionation of anhydrous milk fat

Abstract

Thermal fractionation of anhydrous milk fat with high initial content of low molecular weight TAGs was performed based on a 22 factorial experimental design with three central and two axial points. The independent variables were the crystallization temperature and the cooling rate. A 2.0 L agitated glass reactor was used and the rotation was kept at 20 rpm. The filtration was performed under vacuum (500 mmHg), using a 14 μm average pore diameter filter paper. Curves of isothermal crystallization of the stearin fraction showed that increasing the crystallization temperature, increases the induction period and decreases the maximum solid content of stearin. An increase of the crystallization temperature resulted in an increase in solid fat content. All runs achieved an efficient fractionation using a single separation step and stearin with defined characteristics can be obtained adapting the process conditions.