Denaturation of β-lactoglobulin and native enzymes in the plate exchanger and holding tube section during continuous flow pasteurization of milk

The denaturation of β-lactoglobulin, alkaline phosphatase and lactoperoxidase and changes in the proteolytic activity, were studied at the heating and holding sections of a plate heat-exchanger, during treatment of milk under different conditions of temperature and flow rate. The heating rate contributed considerably to the heat-induced changes in the milk components during continuous flow pasteurization, whereas these indicators were less susceptible to differences in the holding times. Information gained in such studies on the denaturation effects occurring in the different sections could be useful in the design of heat exchangers and holding tubes.