A detailed study of the inactivation of Staphylococcus aureus and Yersinia enterocolitica by high-pressure homogenisation was performed at, respectively, 25 and 35 different combinations of process temperature and process pressure covering a range of 5-50 degreesC and 100-300 MPa. It appeared that in the entire studied pressure - temperature domain, S. aureus was more resistant to high-pressure homogenisation than Y. enterocolitica. Furthermore, the effect of the process pressure oil the inactivation of S. aureus was considerably smaller than on the inactivation of Y enterocolitica. Also, temperature between 5 and 40 degreesC did not affect inactivation of S. aureus by high-pressure homogenisation, while Y enterocolitica inactivation was affected by temperature over a much wider range. Different mathematical models were compared to describe the inactivation of both bacteria under the experimental conditions applied. Such pressure-temperature inactivation models form the engineering basis for design, evaluation and optimisation of high-pressure homogenisation processes as a new preservation technique. (C) 2003 Elsevier Science B.V All rights reserved.