In whey ultrafiltration (UF) production, two main problems are whey protein recovery and membrane
fouling. In this study, membrane coupling protein transglutaminase (TG) catalysis protein cross-linking
was investigated under different conditions to find out the best treatment. We found that the optimal
conditions for protein recovery involved catalyzing whey protein cross-linking with TG (40 U/g whey
proteins) at 40 C for 60 min at pH 5.0. Under these conditions, the recovery rate was increased
15–20%, lactose rejection rate was decreased by 10%, and relative permeate flux was increase 30–40%
compared to the sample without enzyme treatment (control). It was noticeable that the total resistance
and cake resistance were decreased after enzyme catalysis. This was mainly due to the increased particle
size and decreased zeta potential. Therefore, membrane coupling enzyme catalysis protein cross-linking
is a potential means for further use.