Application of a membrane technology to remove bacteriophages from whey

Whey from former cheese batches can be recycled either to increase the yield or to improve texture properties of fat reduced cheeses. However, in the case of the presence of bacteriophages, pasteurization may not be sufficient to eliminate phages in whey. Therefore, in this work, a cross-flow membrane filtration process was designed to separate whey proteins from whey-derived phages. Filtration experiments were carried out using native whey as model filtration medium, three polyethersulfone membranes (100, 300 and 500 kDa) that were studied in detail, and lactococcal phage P008. Filtration performance was characterized by phage retention, total whey protein permeation, and permeation of the major whey proteins α-lactalbumin and β-lactoglobulin. Filtration experiments showed that it is possible to reduce the number of phages in whey by filtration to a level at which subsequent phage multiplication is minimized and, concomitantly, high protein permeation through the membrane is ensured.