Effect of low-frequency pulsatile crossflow microfiltration on flux and protein transmission in milk protein fractionation

Pulsatile crossflow has often been suggested as a fouling mitigation concept for microfiltration. Besides beneficial effects regarding flux in the filtration of model suspensions, little is known about the effects on the fractionation efficiency when separating proteins in complex multi-component systems. Therefore, this study focusses on the impact of low-frequency pulsatile crossflow on fractionation efficiency during microfiltration of skimmed milk. We found a relaxation of the deposited casein layer during low-crossflow and thus low-transmembrane pressure phases. However, during high-crossflow and high-transmembrane pressure phases, the deposit layer is rapidly re-compressed. The results indicate that, due to this cyclic stress, the overall packing of the deposit layer increases over time and impairs the separation efficiency.