A system includes a vacuum chamber, a vacuum source, and a mixture flow path adapted to be connected to receive the output of a direct steam injector. The vacuum source is operatively connected to a vacuum port of the vacuum chamber, while a product outlet port from the vacuum chamber is adapted to be connected to an arrangement for removing treated product from the vacuum chamber. The mixture flow path includes a flow path segment outside of the vacuum chamber volume and a flow path segment within the vacuum chamber volume. At least some of a surface defining the flow path segment within the vacuum chamber is in substantial thermal communication with one or more cooling structures.