Compositional analysis of dairy side streams and assessment of their applicability as diafiltration media

The direct utilisation of side streams from membrane processing and evaporation is of great potential interest for dairies to reduce water consumption. In an analytical screening of 89 industrially obtained processing side streams, samples varied in pH and conductivity in broad ranges of 4.22 to 7.56 and 0.001 to 0.949 Siemens per meter, respectively. Detailed compositional data of the side streams enabled an assessment of their applicability as diafiltration (DF) media for milk protein purification during microfiltration (MF) or ultrafiltration (UF). Microfiltration experiments with simulated nanofiltration (NF) permeates showed that slight compositional variations of DF media can significantly affect milk filtration performance.