Fractionation of pasteurized skim milk proteins by dynamic filtration

This paper describes a two-stage process for separating milk proteins from pasteurized skim milk in three fractions: casein micelles, β-Lactoglobulin (β-Lg) and other large whey proteins, and α-Lactalbumin (α-La). Casein micelles were extracted in the retentate of a microfiltration using rotating ceramic disk membranes. α-La and β-Lg transmissions remained between 0.8 and 0.98. Their yields in permeate reached 81% for α-La and 76.6% for β-Lg at a VRR of 5.4. The separation between β-Lg and α-La was carried out by UF using a rotating disk module equipped with a 50 kDa PES circular membrane. Permeate fluxes were very high, remaining above 340 L h−1 m−2 at VRR = 5 and 40 °C. α-La transmission remained generally between 0.2 and 0.13 giving yields from 28% to 34%. β-Lg rejection was above 0.94, giving a maximum selectivity of 4.2. These data confirm the potential of dynamic membrane filtration for separating α-La and β-Lg proteins from skim milk.