The effects of pH adjustment, ionic strength and adding lambda-carrageenan (lambda-CG) to whey protein isolate (WPI) solutions on the transmission of transforming growth factor-beta2 (TGF-beta 2) through a 0.8 mu m pore size microfiltration (MF) membrane were investigated. Increasing pH (7-9) or adding NaCl (0.1 M) increased both the transmission of proteins and TGF-beta 2. Adding 0.01% lambda-CG to WPI solutions decreased both the transmission of proteins and TGF-beta 2 and increased membrane fouling. The highest membrane selectivity (0.28) and concentration factor (1.67) for TGF-beta 2 were obtained at neutral pH conditions without NaCl or lambda-CG. The addition of lambda-CG allowed the preparation of a retentate slightly enriched in TGF-beta 2 but also in immunoglobulins. (C) 2010 Elsevier B.V. All rights reserved.