The presence of divalent ionic species in many food streams are a drawback for further processing steps such as membrane filtration, crystallisation and chromatographic ion exclusion. Cationic ion exchange resins operating in Na or K form have been widely used for eliminating the divalent ions for which they present a high affinity. However the presence of complexing agent reduces the decalcification yield. Our study has demonstrated that a combination of a strong base resin and a strong acid cation resin regenerated in series with a monovalent salt solution can improve the decalcification process in whey products. Used prior to the nanofiltration step, the new decalcification process permits to produce a highly
demineralised whey, up to 70% whereas without such a pre-treatment only 30% or 45% with diafiltration are obtained. Furthermore additional benefits are anticipated either in the production of lactose after crystallisation or by downsizing the demineralisation unit.