Apparatus and process for heat treating a packaged food product

Abstract

The invention provides an apparatus (for heat treating a packaged food product), comprising (a) a channel surrounding a channel interior, (b) a pressurizer, (c) a transport unit, (d) a first electrode, surrounding at least part of the channel interior over a first electrode length, (e) an electrode configuration comprising (i) a second electrode surrounding at least part of the channel interior over a remote part surrounding length (for shielding at least part of the channel), and (f) a radio frequency wave generator configured to generate RF-waves between the first and second electrode. With such apparatus efficiently energy may be coupled into the packaged food product, for instance for heating a meal and/or for pasteurizing a food product. A further advantage of the present apparatus and such process is that it may be configured to be used in a continuous process.

1 . An apparatus for heat treating a 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 (L 1 ), configured at a channel axis-to-first electrode length (D 1 );   e. an electrode configuration comprising (i) a second electrode, arranged at a non-zero inter electrode distance (L 2 ) from the first electrode, the second electrode surrounding at least part of the channel interior over a second electrode length (L 3 ) and configured at a channel axis-to-second electrode length (D 3 ), and (ii) an electrically conductive remote part, in electrically conductive contact with the second electrode, configured at a channel axis-to-remote part length (D 2 ) wherein D 2 >D 3 , and surrounding at least part of the channel interior over a remote part surrounding length (L 4 ) for shielding at least part of the channel;   f. a radio frequency (RF) wave generator configured to generate RF-waves between the first electrode and the second electrode,   
       wherein the first electrode and the second electrode 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. 
     
     
         2 . The apparatus according to  claim 1 , wherein the radio frequency (RF) wave generator is configured to generate RF-waves between the first electrode and the second electrode at a frequency selected from the range of 10-50 MHz, wherein the packaged product comprises a packaged food product, and wherein the second electrode is earthed. 
     
     
         3 . The apparatus according to  claim 1 , wherein the radio frequency (RF) wave generator is configured to generate over the first electrode and the second electrode an oscillating voltage in the range of 100-50,000 V. 
     
     
         4 . The apparatus according to  claim 1 , wherein the channel axis-to-first electrode length (D 1 ) is in the range of 15-100 mm, and wherein the radio frequency (RF) wave generator is configured to generate RF-waves between the first electrode and the second electrode at a frequency selected from the range of 25-29 MHz. 
     
     
         5 . The apparatus according to  claim 1 , wherein the channel axis-to-first electrode length (D 1 ) is larger than 100 mm, and wherein the radio frequency (RF) wave generator is configured to generate RF-waves between the first electrode and the second electrode at a frequency selected from the range of 12-14 MHz. 
     
     
         6 . The apparatus according to  claim 1 , having a ratio of the channel axis-to-remote part length (D 2 ) to the channel axis-to-second first electrode length (D 1 ) in the range of D 2 /D 1 =1.5-7, and wherein the channel has a cylindrical shape and wherein the electrically conductive remote part has a cylindrical shape over the remote part surrounding length (L 4 ), in particular having a circle a cylindrical shape. 
     
     
         7 . The apparatus according to  claim 1 , wherein the pressurizer is configured to maintain the liquid within the channel, during use of the apparatus, at a pressure selected from the range of 1.5-6 bar. 
     
     
         8 . The apparatus according to  claim 1 , wherein the electrode configuration comprises two sets of second electrodes and electrically conductive remote parts, arranged at both sides of the first electrode, wherein the two sets of second electrodes are in physical contact with each other via the electrically conductive remote parts. 
     
     
         9 . A process for heat treating a packaged product comprising a product within a package with the apparatus according to  claim 1 , 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 between the first electrode and the second electrode. 
     
     
         10 . The process according to  claim 9 , wherein the frequency is selected from the range of 12-29 MHz. 
     
     
         11 . The process according to  claim 9 , further comprising applying an oscillating voltage between the first electrode and the second electrode in the range of 100-50,000 V and maintaining the liquid within the channel at a pressure selected from the range of 1.5-6 bar. 
     
     
         12 . The process according to  claim 9 , wherein the packaged product comprises a packaged food product, and wherein the process is a continuous process. 
     
     
         13 . The process according to  claim 9 , further comprising optimizing the electrical energy input and output. 
     
     
         14 . The process according to  claim 9 , wherein the product comprises a food product and wherein the food product comprises a product selected from the group consisting of a meal, a meal component, a potato, a vegetable, meat, a dairy product, and a soup. 
     
     
         15 . The process according to  claim 9 , wherein the package is electrically insulating, wherein the liquid comprises one or more of de-ionized water and oil, wherein the first electrode and the second electrode are in physical contact with the pressurized liquid, wherein the process comprises transporting the packaged food product through the channel filled with the pressurized liquid with a transport speed in the range of 0.1-10 cm/sec, and wherein the second electrode is earthed. 
     
     
         16 . An apparatus, comprising (a) a channel surrounding a channel interior, (b) a pressurizer, (c) a transport unit, (d) a first electrode, surrounding at least part of the channel interior over a first electrode length, (e) an electrode configuration comprising (i) a second electrode surrounding at least part of the channel interior over a remote part surrounding length, and (f) a radio frequency wave generator configured to generate RF-waves between the first and second electrode.