The newly extruded milk contains lysozyme and other antibacterial active ingredients. The lysozyme activity of a cup of raw milk was reduced by 50% when heated in the microwave oven to 50 degree. However, if raw milk is heated to 50 degree using a conventional heat source, the lysozyme activity in it is almost the same as before heating
When raw milk is heated to 100 degree, lysozyme activity is completely inactivated.
the enzyme is inactivated not by heating but by the microwave that generates heat.