Proteolysis of high-pressure-treated Gouda cheese

The possibility of accelerating Gouda cheese ripening by high-pressure trea tment (50-400 MPa, 20-100 min) was investigated by comparison of different indices for cheese ripening with these of unpressurized cheese for up to 42 d ripening. Increasing the pressure and holding time led to an increase in the pH-shift? that is the difference between the pH of pressurized and unp ressurized cheese. Pressure treatment did not influence the pH 4.6-soluble N, phosphotungstic acid soluble N or free amino acid content. Also, no cons istent differences in SDS-PAGE profiles were observed between cheeses that were pressurized and those that were not. Hence, the proteolysis by chymosi n and plasmin, and the proteinase/peptidase system of the starter was not i nfluenced by pressure treatment of Gouda cheese, under the conditions speci fied. Moreover, the use of a holding time of 3 d at 50 MPa did not lead to accelerated Gouda cheese ripening. (C) 2000 Elsevier Science Ltd. All right s reserved.