Process for producing dairy products with a defined lactose content

A process for producing dairy products with a defined lactose content, comprising the following steps:

• (a) subjecting a starting milk to ultrafiltration for producing an ultrafiltration first permeate P1 and an ultrafiltration first retentate R1;
• (b) subjecting said ultrafiltration first permeate P1 to reverse osmosis for producing a second permeate P2 and a second retentate R2;
• (c) subjecting said second retentate R2 to decalcification;
• (d) subjecting the product of step (c) to ultrafiltration for producing an ultrafiltration third permeate P3 (lactose concentrate) and an ultrafiltration third retentate R3 (mineral concentrate);
• (e) mixing the ultrafiltration first retentate R1 with an amount of the ultrafiltration third permeate P3 and the ultrafiltration third retentate R3 each such that a standardized dairy product is obtained with defined concentrations of lactose and salts or minerals;
• and
• (f) hydrolyzing the standardized dairy product of step (e) while adding an amount of lactase such that a residual amount of lactose still contained in the product is completely broken down into glucose and galactose.