Desalting Milk and Whey by Ion Retardation and Gel Filtration

Abstract

Gel filtration on Sephadex G-10 and Bio-Gel P-2 and ion retardation on a Resin AG 11A8 were applied to desalting Cottage cheese whey.Gel filtration revealed difficulties when protein and lactose were collected. Lactose was not separated from calcium salts because of their similar elution volumes, and the whey was diluted to a large extent due to differences in elution volumes between protein and lactose fractions.More than 88% of calcium and 40% of ash were removed from 200ml of Cottage cheese whey with 100ml of the ion retardation resin. This desalting capacity was low compared to 450ml of the whey on a mixed bed of Dowex 1 and 50. However, the ion retardation is simpler, since a one-step washing of the resin with 0.1 n NaOH was sufficient to regenerate. Two hundred milliliters of skimmilk were desalted with 40% desalting and 45% decalcification on 100ml of the Resin AG 11A8. The mixed bed of ion exchangers did not desalt skimmilk because of coagulation of casein on the cation exchanger.