An article includes a heating medium injector, a mixture flow path, and a vacuum chamber. The heating medium injector has a heating medium path connected to receive a heating medium such as steam and a product path connected to receive undenatured meat protein. The heating medium injector also includes a mixing structure and a mixture outlet. The mixing structure comprises a structure within the heating medium injector at which the heating medium path and product path merge and the mixture outlet is connected to receive material from the mixing structure. The mixture flow path defines a mixture flow path volume and is connected at one end to the mixture outlet of the heating medium injector and at the opposite end to the vacuum chamber. Undenatured meat protein is contained within the vacuum chamber outside of the mixture flow path volume.

A heating medium injector includes an injector structure defining a heating medium flow path and a product flow path. The heating medium flow path extends to a contact location, while the product flow path also extends to the contact location. The contact location comprises a location at which the heating medium flow path and product flow path merge within the injector. A mixture flow path is defined within the injector structure between the contact location and an injector outlet of the injector structure and is defined at least in part by a mixture flow path outer surface comprising a mixture flow path wall. A cooling structure extends along both a product flow path boundary wall and the mixture flow path wall so as to traverse a plane extending transverse to the foodstuff flow path at the contact location.

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.

A heating medium injector includes an injector structure defining a heating medium flow path and a product flow path. The heating medium flow path extends to a contact location along an axis of the injector, while the product flow path also extends to the contact location along the injector axis. The contact location comprises a location at which the heating medium flow path and product flow path merge within the injector. In a region along the injector axis, the product flow path is defined between a first flow surface and a second flow surface. The first flow surface comprises a surface of a boundary wall separating the heating medium flow path from the product flow path and the second flow surface comprises a surface of an opposing second boundary wall. The second flow surface is in substantial thermal communication with a second flow surface cooling structure.

A method is provided for thermal treating a food product in a thermal treatment unit with the food product having a casing comprising a protein, or hybrid casing. The method involves providing the food product, subjecting the food product to a brine solution, conveying the food product into the unit, and subjecting the food product to a thermal treating step. The thermal treating step includes at least: a) drying the food product, and b) subsequently, further thermal treating the food product. The method further involves: determining the denaturation temperature of the protein, and setting the parameters of the climate in the unit such that the dew point of the air of the unit is equal to or lower than the determined denaturation temperature, wherein step a) ends in case the surface temperature of the casing is equal to the dew point of the air of the unit.