Fractionation of milk proteins on pilot scale with particular focus on β-casein

The aim of this study was to increase the yield and purity of casein fractions at pilot scale and determine the main process parameters influencing the isolation of β-casein, such as cold extraction time, separation speed. The fractions were obtained from micellar casein by means of selective precipitation following separation by a nozzle centrifuge. The purities, which were calculated based on the total casein content of the β-casein fraction, and the yields achieved for β-casein ranged from 68.7 to 89.6% and from 10 to 32%, respectively. For the other two fractions, αS- and κ-casein, the obtained purities were 61% and 43%, respectively. Using the proposed isolation method, high purities for the β-casein fraction were achievable; however, the other two fractions, αS- and κ-casein, need further improvement.