Effects of high pressure on constituents and properties of milk

High pressure (HP) treatment has significant and, in many cases, unique effects on many constituents of milk. The structure of casein micelles is disrupted and the whey proteins, α-lactalbumin and β-lactoglobulin, are denatured, with the former being more resistant to pressure than the latter. Pressure-induced shifts in the mineral balance in milk also occur and moderately high pressures (100–400 MPa) induce the crystallisation of milk fat. However, milk enzymes seem to be quite resistant to pressure. As a result of pressure-induced effects on individual milk constituents, many properties of milk are affected. HP treatment increases the pH of milk, reduces its turbidity, changes its appearance, and can reduce the rennet coagulation time of milk and increase cheese yield, thereby indicating potential applications in cheese technology. However, to fully understand the effects of HP treatment on milk and to evaluate the full potential of this process in dairy technology, further research is required in several areas, including the reversibility of pressure-induced changes in milk and the physical stability of HP-treated milk. [Copyright &y& Elsevier]