Patent ID: 8445052

Claim:
A process for producing substantially lactose-free milk, comprising the steps of: a) filtering an original milk using a single ultrafiltration stage, obtaining a single processed ultrafiltered retentate and a single processed ultrafiltered permeate, wherein: the single processed ultrafiltered permeate comprises lactose, minerals, non-protein nitrogen (NPN) and water; and the single processed ultrafiltered retentate comprises fat, proteins, NPN, minerals, lactose and water; b) filtering said single processed ultrafiltered permeate using a single nanofiltration stage obtaining a single processed nanofiltered permeate and a nanofiltered retentate, wherein said single processed nanofiltered permeate comprises water, monovalent mineral ions and NPN; c) mixing said single processed ultrafiltered retentate with said single processed nanofiltered permeate obtaining a milk mixture, wherein the ratio of the lactose concentration of said milk mixture to the lactose concentration of the original milk is in a range between 0.25-0.75 of the original milk; and d) hydrolysing the milk mixture obtaining a substantially lactose-free milk comprising less than 0.5 wt % lactose, wherein no other stages of filtration are used in the processing of the substantially lactose-free milk.