Separation of casein from whey proteins by dynamic filtration

It has been proven that functional properties of milk proteins can improve the quality and nutritional value of foods. This paper investigates the separation of whey proteins from casein micelles using a Multi Shaft Disk (MSD) module and a rotating disk dynamic filtration module. The MSD module was equipped with 6 ceramic membranes of 0.2 mu m pores. PVDF and Nylon membranes of 0.2 mu m pores were tested in the rotating disk module. Permeate flux with the MSD module increased with TMP and rotation speed, reaching a maximum of 132 L h(-1) m(-2) at 1931 rpm. alpha-Lactalbumin (alpha-La) and beta-Lactoglobulin (beta-Lg) transmissions also increased with rotation speed, ranging from 25% at 1044 rpm to 40% at 1931 rpm. With a Nylon membrane, the rotating disk module yielded lower permeate fluxes than the MSD module, while when equipped with a PVDF membrane it provided higher permeate fluxes than the MSD, but casein micelles rejection was lower. alpha-La and beta-Lg transmissions were higher with the rotating disk module, using Nylon and PVDF membranes, than for the MSD. From this comparison. it can be concluded that the MSD module gave the best compromise between high permeate flux, high alpha-La and beta-Lg transmissions and high casein micelles rejection. (C) 2009 Elsevier B.V. All rights reserved.