The present invention relates to a method of inactivation of plasmin enzyme in a milk-based product, wherein casein and whey protein are separated from a milk raw material by microfiltration to provide a casein concentrate as a microfiltration retentate having a whey protein content of less than 20 wt. %, based on the total protein content of the concentrate, and a whey protein concentrate as a microfiltration permeate the casein concentrate is subjected to a thermal treatment at a temperature in the range of about 72° C. to about 95° C. to provide a thermally treated casein concentrate and a milk-based product with a reduced plasmin activity comprising the thermally treated casein concentrate is provided. The milk-based products prepared by the method retain flawless organoleptic properties at different storage temperatures even under prolonged storage periods.
