Apparatus and process for heat treating a packaged food product

A process for heat treating a packaged product comprising a product within a package with an apparatus for heat treating the packaged product in a heat treating process, the apparatus comprising:

• a. a channel with a channel length (L), a channel axis and a channel wall, wherein the channel wall surrounds a channel interior;
• b. a pressurizer configured to control the pressure of a liquid within the channel;
• c. a transport unit configured to transport the packaged product in a propagation direction through the channel;
• d. a first electrode, surrounding at least part of the channel interior over a first electrode length (L1), configured at a channel axis-to-first electrode length (D1);
• e. an electrode configuration comprising two sets of second electrodes and electrical conductive remote parts, arranged at both sides of the first electrode, wherein the two sets of second electrodes and the electrical conductive remote parts are in physical contact with each other via the electrically conductive remote parts, wherein the first and the second electrodes are arranged at a substantial mutual axial interspace between the first and the second electrodes respectively with each of the second electrodes being adjacent to the first electrode and arranged at a respective non-zero distance from the first electrode, and with each of the first and the second electrodes surrounding at least a part of the channel and coupled to a radio-frequency (RF) wave generator, wherein the second electrodes surrounding at least part of the channel interior over a second electrode length (L3) and configured at a channel axis-to-second electrode length (D3), and wherein the electrically conductive remote parts are configured at a channel axis-to-remote part length (D2) wherein D2>D3, and coaxially surrounding at least part of the channel interior over a remote part surrounding length (L4) for shielding at least part of the channel;
• f. the radio frequency (RF) wave generator configured to generate RF-waves between the first electrode and the second electrodes,
• wherein the first electrode and the second electrodes are embedded in the channel wall and are in physical contact with the interior of the channel, and wherein the channel wall further comprises an electrically insulating material;
• the process comprising transporting the packaged product through the channel filled with the pressurized liquid and heating the product in a treatment zone of the channel by generating RF-waves at a frequency selected from the range of 10-50 MHz emitted between the first electrode and the second electrodes, wherein the packaged product comprises a packaged food product, and wherein during processing the packaged food product is substantially surrounded by the liquid, and wherein the RF-waves form an electrical field and the process further comprises shielding the electrical field in the treatment zone using the electrically conductive remote parts, wherein the electrically conductive remote parts form a cavity around the treatment zone, the cavity being configured to substantially confine the electrical field.