Detection of multi-dimensional heating patterns in thermal food processes using thermochromic inks

1. A method of processing a packaged model food composition comprising:

creating a model food composition by mixing a model food material and 0.05 wt. % to 20 wt. % of one or more irreversible thermochromic inks;

wherein one or more irreversible thermochromic inks exhibit a variable change in more than one color parameter in response to temperature change across a selected temperature range;

packaging the model food composition by filling a food processing container with the model food composition and sealing the food processing container; and

processing the packaged model food composition in a thermal process.

2. The method of claim 1 , the thermal process comprising an electromagnetic wave based thermal process.

3. The method of claim 1 , wherein the thermal process includes heating the packaged model food composition to a temperature within a selected temperature range.

4. The method of claim 1 , wherein the thermal process includes heating the packaged model food composition within a selected temperature range from 20 degrees C. to 150 degrees C.

5. The method of claim 1 , wherein processing the packaged model food composition includes transporting the packaged model food composition along a conveyor to a microwave generating device that irradiates the packaged model food composition for a predetermined amount of time.

6. The method of claim 1 , further comprising identifying and recording changes in at least one color parameter of the irreversible thermochromic ink.

7. The method of claim 1 , further comprising identifying and recording changes in at least one color parameter of the irreversible thermochromic ink at 800 or more distinct locations within the packaged model food composition.

8. The method of claim 7 , further comprising using the recorded changes to construct a three-dimensional temperature distribution profile of the packaged model food composition.

9. The method of claim 1 , wherein mixing a model food material and 0.05 wt. % to 20 wt. % of an irreversible thermochromic ink results in a mixture that exhibits average dielectric properties that are less than 10 percent different than for the model food material by itself.

10. The method of claim 1 , wherein the irreversible thermochromic ink is synthetic and inedible.

11. A method for detecting a heating pattern within a packaged model food composition comprising:

processing a packaged model food composition using a thermal process across a selected temperature range, the model food composition comprising a model food material and 0.05 wt. % to 20 wt. % of one or more irreversible thermochromic inks;

wherein the one or more irreversible thermochromic inks exhibit a variable change in more than one color parameter in response to temperature change across the selected temperature range;

recording more than one change in a color parameter of the one or more irreversible thermochromic inks within the processed model food composition; and

assembling a 3-dimentional heating pattern within the processed model food composition using the recorded color parameter changes.

12. The method of claim 11 , wherein a change in a color parameter at a unique location of the processed model food composition indicates a heated location, and no change in a color parameter at a location of the processed model food composition indicates a non-heated location.

13. The method of claim 11 , the color parameter comprising a CIE L*, CIE a*, or CIE b* color dimension.

14. The method of claim 11 , wherein each temperature across the selected temperature range corresponds to a unique set of color parameters for the irreversible thermochromic ink, the unique set of color parameters comprising a unique CIE (L*, a*, b*) value set for each temperature.

15. A method for detecting a high-resolution temperature distribution within a packaged model food composition comprising:

processing a packaged model food composition using a thermal process across a selected temperature range, the model food composition comprising a model food material and 0.05 wt. % to 20 wt. % of one or more irreversible thermochromic inks;

wherein the one or more irreversible thermochromic inks exhibit a variable change in more than one color parameter in response to temperature change across the selected temperature range;

sectioning the processed model food composition into a plurality of sections, each in an x direction, a y direction, or a z direction;

recording images at a plurality of locations within each of the plurality of sections using an imaging device to obtain a color measurement containing one or more color parameters unique to each of the plurality of locations;

assembling a 3-dimentional temperature distribution profile within the processed model food composition.

16. The method of claim 15 , the color parameter comprising a CIE L*, CIE a*, or CIE b* color dimension.

17. The method of claim 15 , wherein each temperature across the selected temperature range corresponds to a unique set of color parameters for the irreversible thermochromic ink, the unique set of color parameters comprising a unique CIE (L*, a*, b*) value set for each temperature.

18. The method of claim 15 , wherein a color measurement is recorded in increments in the x direction and the y direction of each of the sections such that a three-dimensional mesh of at least 800 color measurements is recorded for the packaged model food composition.

19. The method of claim 18 , wherein the color measurements are used to assemble a 3-dimentional temperature distribution profile within the processed model food composition.

20. The method of claim 15 , the imaging device comprising a spectrophotometer or a high resolution digital camera.