Lactose-removing milk process for lactose-free milk production

A lactose-removing milk process for production of milk having a lactose content between 2.7% and 3.5% w/w, comprising

• standardizing semi-skim milk to 1.4 to 2.2% w/w of fat content;
• subjecting the semi-skim milk to an ultrafiltration UF step to produce an UF permeate and an UF retentate,
• subjecting the UF permeate to a diafilteration step and a nanofiltration NF step to produce a NF permeate diafiltered and a NF retentate diafiltered, which is maintained in a concentration of from 9 to 13 degrees Bx, while the diafilteration step is performed, until recovering the same volume of UF permeate;
• mixing the NF permeate diafiltered with the UF retentate to reconstitute the milk, achieving a desired lactose, lipid and protein content;
• subjecting the reconstituted milk to an UHT process;
• enzymatically hydrolyzing remaining lactose in the reconstituted milk from the UHT process, and
• packaging the reconstituted and enzymatically hydrolyzed milk;
• wherein the reconstituted milk having been subjected to the UHT process and to the enzymatically hydrolyzing has a lactose content between 2.7% and 3.5% w/w.