Studies on microfiltration as a method of de-lipidization of whey for production of whey protein concentrate

Cross-flow microfiltration (MF) of whey was carried out as a de-lipidizatio n treatment prior to ultrafiltration (UF) for pilot-scale production of whe y protein concentrate (WPC). Under isobaric MF conditions, the initial perm eate flux was higher at a higher pressure (1.5 bar), but it declined sharpl y and in effect, reached a lower equilibrium value than that at the lower p ressure (1.0 bar), where an almost uniform flux (mean, 74.3 Im(-2) h(-1) as compared to 75.8 Im(-2) h(-1) at 1.5 bar) was observed. When the pressure was increased stepwise during the run from initial 1.0 bar to 1.5 bar and a t a later stage to 2.0 bar, the flux increased sharply at each stage. Therm ocalcic pre-treatment of whey (0.025 Mol CaCl2, 55 degreesC for 8 min) marg inally improved flux during MF, the average values being 74.5 and 79.8 Im(- 2) h(-1) for untreated and treated whey, respectively. The protein permeati on generally decreased as the MF run progressed, but it was somewhat higher for treated (54.9%) than that of untreated whey (48.4%). Without the pre-t reatment of whey, protein permeation was slightly higher (50.5%) at 1.5 bar than that at 1.3 bar (48.4%). The effect of MF of whey on the permeate flu x during subsequent UF was studied as a function of time. Though the initia l flux for microfiltered whey was higher than that for non-microfiltered wh ey, the final equilibrium flux was lower. Compositional analysis indicated a definite reduction (72.1%) in the fat content of WPC as a result of MF de -lipidization.