A new method for the permanent selective heating of the continuous phase of a dispersion food medium, was proposed. This method can be implemented in a unit comprising a heater and valve-pulsatory mass-and-heat-exchange apparatus (VPMA). We propose to use for selective heating of the continuous phase a permanent process according to which the separation of the dispersion food medium into phases, the transport of the dispersed phase, and its mixing with the heated continuous phase are combined in the same VPMA. A mathematical model of the unit was developed for the cases of cocurrent-flow and counterflow heaters. Analytical solutions to the model equations were obtained. The parameters affecting the result of permanent selective heating of the dispersion food medium in the unit were determined. (c) 2005 Elsevier Ltd. All rights reserved.