Abstract: An apparatus for heat treating a food product by injection of steam therein in order to provide a sterilization, pasteurization and/or a homogenization of the product. The apparatus comprises a mixing chamber comprising a steam injection inlet, a product inlet and an outlet for the treated product, a rotatable shaft disposed within the mixing chamber, a plurality of discs, each disc comprising at least one product passage opening, wherein the discs are disposed substantially co-axially upon the shaft, and a device for rotating the shaft with the discs.

Abstract: An apparatus and a method for heat treating a fluid product by injection of steam therein in order to provide a sterilization, pasteurization and/or a homogenization of the product. The apparatus includes a mixing chamber having a steam injection inlet, a product inlet, and an outlet for the treated product, a rotatable shaft disposed within the mixing chamber, a plurality of discs each comprising at least one product passage opening, the discs being disposed substantially co-axially on the shaft, and a motor for rotating the shaft with the discs. The invention also relates to a shaft to be used for homogenizing and mixing in an apparatus or a process for heating by steam injection a fluid product.