Method and system for preparing food products

Abstract

A method (200) for preparing food is provided, the method comprising the step of heating (202) a food package (100) enclosing a food product (102), the food package (100) comprising a container (104) and a cover (106), the heating step (202) initiating or continuing a cooking process of the food product (102), the cooking process causing steam generation (204) and steam condensation (206), the cover (106) having a vent opening (108) for releasing excess steam caused by the steam generation (204). the step of reducing (208) the heating (202) of the food package (100), thereby reducing steam generation (204); and the step of applying (210) a label (126) to seal the vent opening (108), the label (126) being applied within a time window spanning between a threshold point where excess steam emission through the vent opening (108) is below a maximum threshold and an equilibrium point where steam generation (204) is balanced by steam condensation (206) such that excess steam emission through the vent opening (108) is above a minimum threshold.

Description

[Technical Field]

[0001] The present invention relates to a food product, in particular to a method for preparing a food product. The present invention also relates to a system for preparing a food product.

[0002] Background technology A growing global trend is the consumption of so-called ready-to-eat meals, i.e., meals that do not require cooking or are already prepared. Such meals are frozen or refrigerated to have a sufficiently long shelf life. Generally, frozen foods suffer from the drawbacks of poor taste, poor texture upon thawing, and unappetizing appearance over time, while refrigerated foods generally have an appetizing appearance but a significantly shorter shelf life. To extend the shelf life of such refrigerated ready-to-eat meals, pasteurization is often used. Conventionally, the pasteurization process is combined with the removal of oxygen from the interior of the food package to minimize bacterial growth, for example, by replacing the oxygen by injecting some other suitable food preservative gas into the food package.

[0003] In the cooking and pasteurization method used by the applicant, the food product is placed in a food package including a container with a cover, e.g., in the form of a see-through membrane, which is sealed along the edges of the container to form a completely sealed internal compartment. Furthermore, the cover may be provided with a one-way valve. The one-way valve may be configured to automatically open when an overpressure exceeds a certain threshold within the food package. Such overpressure occurs, for example, when the package is placed in a microwave oven and the food is cooked by exposure to electromagnetic radiation. This may also occur, for example, by convection in an oven with air heating and steam, or by exposing the package to thermal radiation, e.g., infrared radiation. During food cooking, a large amount of steam is generated. The steam builds up an overpressure such that the valve opens to release both oxygen and steam. Once the food product is cooked, the microwave heating or other heating source is shut off, thereby stopping steam generation. The one-way valve is then designed to close almost instantly due to the reduction in internal overpressure and the drop in temperature. The food package may then be cooled to an appropriate storage temperature and delivered to a retailer for later use. Typically, these one-way valves may have one-way valves that open at a relative overpressure in the range of 1 hPa to 10 hPa, compared to those used in connection with, for example, coffee packaging, which open at a relative overpressure of the order of 100 hPa. The term relative overpressure here should be interpreted as the amount by which the pressure inside the food package exceeds the pressure outside the food package, i.e., the difference between the internal pressure and the external pressure.

[0004] A common problem with many of the one-way valves suitable for food packaging known today is that the manufacturing processes involved are relatively complex, with numerous process steps and parameters that need to be continuously adjusted to reduce waste.

[0005] Therefore, there is a need to provide a more efficient method for sealing food packages. Additionally, there is a need to reduce the cost and / or environmental footprint associated with food packages. There is also a need to provide an efficient method for sealing food products to enable efficient production of food packages.

[0006] Summary of the Invention It is therefore an object of the present invention to provide a system and method for preparing food that alleviates all or at least some of the drawbacks of currently known solutions.

[0007] This object is achieved by a system and a method for preparing food as defined in the appended independent claims.The term exemplary is to be understood in the present context as serving as an example, instance or illustration.

[0008] According to a first aspect of the present invention, a method for preparing a food product is provided. The method includes heating a food product package enclosing the food product. The food product package includes a container and a cover. The heating initiates or continues a cooking process of the food product, which causes steam generation and steam condensation within the food product package. The cover has a vent opening for releasing excess steam caused by steam generation. The method further includes reducing the heating of the food product package, thereby reducing steam generation, and applying a label to seal the vent opening, thereby sealing the food product from the ambient atmosphere surrounding the food product package. The label is applied within a time window TL spanning between a threshold point TTP, where excess steam release through the vent opening is below a maximum threshold, and an equilibrium point TBP, where steam generation is balanced by steam condensation such that excess steam release through the vent opening is above a minimum threshold.

[0009] An advantage of the present method is that it provides a robust process for sealing food packages. More specifically, the present method enables efficient sealing of vent openings in food packages by utilizing the progression of steam generation and steam condensation that occurs during food cooking. In other words, the present method enables efficient sealing of food packages within a time window TL. Applying the label within the time window TL mitigates the buildup of excessive pressure within the food package, which could potentially damage the food package. Label leakage and / or damage can be further reduced. To this end, constraints on the selection of label materials and / or adhesives for fastening the label to the cover can be further reduced. This allows for simple and cost-effective sealing of food packages. A reduction in the need for complex labels can be further achieved. A manufacturing method for food packages that is easier to scale can also be achieved. Greater sustainability can also be achieved.

[0010] The application of the label within the time window TL further prevents the introduction of ambient gases from the environment into the food package. In other words, the seal occurs when there is overpressure within the food package. This can prevent contamination from the environment from entering the food package. This can provide food with a longer shelf life.

[0011] The term cooking should be interpreted broadly in this context. Cooking can be understood as the process of using heat to prepare food for consumption. Cooking can include pasteurization and / or sterilization of food by heat exposure. Cooking may also include a pasteurization process in which food is heated, usually to less than 100°C, to eliminate pathogens and extend the shelf life of the food.

[0012] For purposes of this disclosure, the term "reducing," as it relates to heating, should be interpreted broadly. Thus, reducing can include reducing heat from a first temperature to a second temperature, where the second temperature is lower than the first temperature. Reducing can also include reducing heating to zero. It is understood that zero heating means no heating energy is supplied to the food package. It is noted that ambient temperature may exist around the food package. The reduction can be sudden or gradual. The reduction can also be gradual. Alternatively, reducing heating can be accomplished by removing the food package from the heating zone. The food package may be on a conveyor belt, which moves the food package from the heating zone. Reducing heating can, in some instances, be referred to as terminating heating. Reducing heating can, in other instances, be referred to as ceasing heating.

[0013] The term vapor may include water in the gas phase. Vapor may be water vapor. Vapor may be understood as a mixture of vapor and an aerosol of water droplets. Vapor may be understood as vapor obtained by heating a substance at its boiling temperature. Vapor may include gases and / or vapors originating from the food product when heated. Vapor may include gases emanating from within the food product package.

[0014] The term steam generation in this context should be understood as steam generated within the food package due to heating of the food. Steam generation can increase the pressure within the food package. Steam generation can create overpressure within the food package. Steam generation can cause the food package to expand. Excess steam can further escape through the vent opening, thereby reducing the pressure within the food package.

[0015] The term steam condensation in this context should be understood as the process by which steam in a food package changes into a liquid. In other words, water vapor in a container may condense. Condensation may reduce the pressure in the food package. The volume of steam in a food package may decrease due to steam condensation.

[0016] The term "maximum threshold" in this context should be understood as the value at which the label can be effectively attached to the cover. Values ​​greater than the maximum threshold may result in overflow from the vent opening being too large to attach the label to the cover. Alternatively, higher values ​​may damage the food package. In other words, the maximum threshold may relate to the maximum pressure value at which the food package is prevented from bursting due to excessive pressure generated within the food package. To this end, label damage due to film tension or loss of adhesion of the label to the cover may be avoided. This may maintain the integrity of the seal between the cover and the container. The seal between the cover and the container may, for example, withstand a pressure of approximately 150 mbar to 200 mbar. In some instances, the pressure within the food package may range from 10 mbar to 100 mbar. In other instances, the adhesion of the label to the cover may withstand a pressure of approximately 30 mbar. In such instances, the vent opening may be selected to have an opening size that reduces the pressure within the food package to less than 30 mbar. Sealing within the time window TL further mitigates the possibility that residual pressure associated with steam generation within the food package may damage the food package, thereby maintaining the food package seal.

[0017] The term minimum threshold value should be understood in the present context as the value at which there is still an overpressure in the package so that the inflow of gas from the surroundings is prevented.

[0018] The magnitude of vapor generation over time may be determined based on a first predetermined function and the magnitude of vapor condensation over time may be determined based on a second predetermined function, which may result in an improved determination of a suitable time window TL for applying a label.

[0019] The equilibrium point TBP may occur when the first predetermined function and the second predetermined function have a non-zero common solution, which may result in an improved determination of a suitable time window TL for applying a label.

[0020] The method may further include subjecting the food package to a cooling process to increase steam condensation, thereby shifting the cooling process so that the equilibrium point TBP occurs at a cooling point TCP that is earlier in time than the equilibrium point TBP. This provides improved adjustment of the time window TL for applying the label. A reduction in the accumulated pressure within the food package may also be achieved. The term "early" may be interpreted as "early in time," and the time is measured from the reduction in heating.

[0021] Cooling is applied to the outer surface of the cover, thereby efficiently cooling the vapor within the container. Cooling allows for earlier application of the label. Cooling further allows for improved determination of the appropriate time for sealing. The cooling process may be understood as auxiliary cooling, which further allows for adjustment of the time window TL for sealing the vent opening and thus the food package. The cooling process may include exposing the food package to a cooling gas. The cooling gas may be applied to the cover. The cooling gas may be air or a gas from a controlled gas source.

[0022] The method may include cooling the food package after the label is applied. The cooling may increase steam condensation, which may result in a reduction in pressure within the food package.

[0023] The cooling process may affect the second predetermined function such that a non-zero common solution with the first predetermined function occurs at a cooling point TCP that is earlier in time than the equilibrium point TBP, which may provide improved adjustment of the time window TL for applying labels.

[0024] The method may further comprise the step of subjecting the food package to an additional heating process before applying the label.

[0025] The additional heating process may shift the equilibrium point TBP in time, with the heating point THP occurring later in time than the equilibrium point TBP.

[0026] The additional heating process may affect the first predetermined function such that a non-zero common solution with the second predetermined function occurs at a heating point THP that is later in time than the equilibrium point TBP. The term later may be interpreted as later in time, where time is measured from the reduction in heating.

[0027] The additional heating may allow for adjustment of the point in time when the time window TL for applying the label occurs. The time window TL for sealing the vent opening may be extended. The pressure within the container may be further controlled by heating. The additional heating may increase steam generation. The pressure within the container may be increased.

[0028] The method may further include measuring, with a detection device, the magnitude of vapor generation over time; and measuring, with a detection device, the magnitude of vapor condensation over time.

[0029] The detection device may include a first sensor configured to monitor the magnitude of vapor generation and a second sensor configured to monitor the magnitude of vapor condensation.

[0030] The method may further include determining respective first and second predetermined functions based on the measured magnitude of steam generation and the measured magnitude of steam condensation over time, which may result in an improved determination of a time window TL suitable for applying the label.

[0031] The first sensor may be configured to measure the magnitude of steam generation and the second sensor may be configured to measure the magnitude of steam condensation.

[0032] The first sensor may be configured to measure the magnitude of vapor generation over time, and the second sensor may be configured to measure the magnitude of vapor condensation over time.

[0033] The opening size of the ventilation opening is 1 mm 2 ~8mm 2 Within the range of 2 mm 2 ~4mm 2 in the range of 1000 to 2000 mm, most preferably 3 mm 2 ~4mm 2 may be in the range of

[0034] This allows the opening size to be small enough to maintain overpressure within the food package, but still allow for efficient release of excess steam caused by steam generation. This may prevent damage to the food package. This may prevent the food package from bursting. In other words, excess steam may be understood as the amount of steam generated within the food package that can be released due to overpressure created within the food package. The opening size may also be referred to as the opening area.

[0035] The equilibrium point TBP can be shifted in time by selecting the opening size of the vent opening.

[0036] The vent opening may comprise a flap that extends around part of the periphery of the vent opening. The advantage is that the flap provides an adjustable opening with an effective opening size that is a function of the steam flow through the vent opening. The term flap may be interpreted as a flexible protrusion that extends at least partially over the vent opening. This allows the flap to cover at least part of the vent opening.

[0037] Thus, the opening size can be changed during food preparation. The opening size can be larger when steam generation is high, for example, when heat is applied to the food, and smaller when heat is reduced. The opening size can be larger at the beginning of the cooking process and smaller at the end of the cooking process. The flap can be a cutout in the cover. As steam flow from the food package increases, the flap can be lifted, increasing the effective opening size of the opening.

[0038] The vent opening may have an adjustable opening size, the adjustable opening size being provided by a cover including at least a portion of an expandable film, the vent opening being disposed within the expandable film, the expandable film expanding in response to overpressure caused by steam generated by heating, the expandable film being capable of stretching outward to provide a larger opening in response to an increase in pressure within the food package, and the expandable film being capable of at least partially recovering its shape after a decrease in pressure within the food package.

[0039] According to a second aspect of the present invention, there is provided a system for preparing food products. The system includes a heating means configured to heat a food product package containing the food product. The food product package includes a container and a cover. The heating initiates or continues a cooking process of the food product. The cooking process causes steam generation and steam condensation within the food product package. The cover has a vent opening for releasing excess steam caused by steam generation. The system further includes a label applicator configured to apply a label to the cover such that the label covers the vent opening, thereby sealing the food product from the ambient atmosphere surrounding the food product package. The label is applied within a time window TL spanning between a threshold point TTP, at which excess steam release through the vent opening is below a maximum threshold, and an equilibrium point TBP, at which steam generation is balanced by steam condensation such that excess steam release through the vent opening is above a minimum threshold. This second aspect of the present invention has the same advantages and preferred features as the aforementioned first aspect of the present invention.

[0040] The heating means may be a microwave source for heating the food product, alternatively the heating means may be an infrared (IR) source, a convection heater or a steam generator.

[0041] Heating of the food package may be accomplished by heating the food package using microwave power, or alternatively, heating of the food package may be accomplished by heating the food package using infrared (IR) power, heating the food package using a convection heater, or heating the food package using steam.

[0042] The system may further include a cooling device configured to cool the food package, thereby subjecting the food package to a cooling process that increases steam condensation, such that the equilibrium point TBP occurs at a cooling point TCP that is earlier in time than the equilibrium point TBP.

[0043] The system may be further configured to subject the food package to an additional heating process prior to applying the label. The additional heating process may be accomplished by a heating means. The additional heating means may be a microwave source for heating the food product.

[0044] The additional heating process may be achieved by an additional heating element. The additional heating element may include a heating filament. The additional heating element may be configured to provide heat by radiative heating. The additional heating element may be an infrared radiation source. The additional heating element may be a microwave source.

[0045] The system may further comprise a detector for measuring the magnitude of vapor generation over time and for measuring the magnitude of vapor condensation over time.

[0046] The detection device may include a first sensor configured to monitor the magnitude of vapor generation and a second sensor configured to monitor the magnitude of vapor condensation.

[0047] The method may further include calibrating the vapor generation and vapor condensation over time. The sensing device may be configured to determine the magnitude of the vapor generation and vapor condensation over time such that the first and second predetermined functions, respectively, may be determined.

[0048] Further embodiments of the invention are defined in the dependent claims. It should be emphasized that when used in this specification, the term "comprises / comprising" is to be interpreted as specifying the presence of stated features, integers, steps or components. It does not exclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0049] These and other features and advantages of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

[0050] Further objects, features and advantages of embodiments of the present invention will become apparent from the following detailed description, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0051] [Figure 1a] FIG. 1 is a schematic diagram of a food product being prepared in accordance with some embodiments. [Figure 1b] FIG. 1 is another schematic diagram of a food product being prepared in accordance with some embodiments. [Figure 1c] FIG. 1 is yet another schematic diagram of a food product being prepared in accordance with some embodiments. [Figure 2] FIG. 1 is a schematic diagram of a method for preparing a food product according to some embodiments. [Figure 3a] FIG. 1 is a schematic diagram of a food product being prepared in accordance with some embodiments. [Figure 3b] FIG. 1 is another schematic diagram of a food product being prepared in accordance with some embodiments. [Figure 3c]FIG. 1 is yet another schematic diagram of a food product being prepared in accordance with some embodiments. [Figure 4] FIG. 2 is a schematic diagram illustrating steam generation and steam condensation S as a function of time t according to some embodiments of a method for preparing food products. [Figure 5] FIG. 2 is a schematic diagram illustrating steam generation and steam condensation S as a function of time t according to some embodiments of a method for preparing food products. [Figure 6] FIG. 1 is a schematic diagram of a system for preparing food products, according to some embodiments. [Figure 7a] 10A-10C are schematic diagrams of vent openings in a cover according to some embodiments. [Figure 7b] 10A-10C are schematic diagrams of vent openings in a cover according to some embodiments. [Figure 7c] 10A-10C are schematic diagrams of vent openings in a cover according to some embodiments. [Figure 7d] 10A-10C are schematic diagrams of vent openings in a cover according to some embodiments.

[0052] MODE FOR CARRYING OUT THE INVENTION In the following detailed description, embodiments of the present invention will be described. However, it should be understood that, unless specifically indicated otherwise, features of different embodiments are interchangeable between the embodiments and may be combined in different ways. In the following description, numerous specific details are set forth to provide a more thorough understanding of the present invention, but it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures or functions are not described in detail in order to avoid obscuring the present invention.

[0053] In the following description of exemplary embodiments, the same reference numerals refer to the same or similar components. Although terms such as "first," "second," etc. may be used to describe various elements in this specification, it will be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another.

[0054]

[0013] Figures 1a-1c are schematic diagrams of a food product being prepared according to some embodiments. Figure 2 is a schematic diagram of a method for preparing a food product according to some embodiments. With reference to Figures 1a-1c and 2, a process for preparing a food product is described according to some embodiments. Figure 1a shows a food product package 100. A food product 102 is placed in the food product package 100. More specifically, the food product package 100 encloses the food product 102. The food product package 100 includes a container 104 and a cover 106. The container 104 and the cover 106 are positioned to enclose the food product 102. The cover 106 includes a vent opening 108 for releasing excess steam generated within the food product package 100.

[0055] FIG. 1b further illustrates the food package 100 during preparation of the food product 102. The method 200 for preparing the food product 102 includes a step 202 of heating the food product package 100. The heating step 202 initiates or continues the cooking process of the food product 102. The heating step 202 may cause pasteurization of the food product. The heating step 202 may induce boiling of the food product 102. The heating step 202 may induce heating of the food product 102 to 100°C. The heating step 202 may be below 100°C to eliminate pathogens and extend the shelf life of the food product 102. The heating step 202 may be induced by a heating means 107. The heating means 107 may be configured to heat the food product package 100 containing the food product 102. The heating means 107 may be a microwave source 109. The microwave source 109 may be configured to heat the food product 102. The heating step 202 may be configured to heat the food product 102 to the boiling point of the food product 102. The boiling point may vary depending on the ambient pressure. The boiling point may be food-dependent. The heating temperature may be, for example, in the range of 80°C to 120°C.

[0056] The cooking process induced by the heating step 202 causes steam generation 204 and steam condensation 206 within the food package 100. Diagram 110 of FIG. 1b illustrates, by way of example, steam generation (204) and steam condensation (206) S as a function of time t. The magnitude of steam generation over time is illustrated in diagram 110 by steam generation function 112, see the solid curve. The magnitude of steam condensation over time is illustrated in diagram 110 by steam condensation function 114, see the dashed curve. Steam generation 204 and steam condensation 206 affect pressure 116 within the food package, as indicated by region 118 in diagram 110. In other words, pressure 116 can be described by region 118 formed between steam generation function 112 and steam condensation function 114. The greater the pressure 116 within the food package 100, the correspondingly larger region 118.

[0057] The pressure 116 may create an overpressure 120 within the food package. The overpressure is caused by steam generation 204 during heating of the food package 100. The overpressure 120 may cause the cover 106 to expand, increasing the volume within the food package 100. The cover 106 may form a convex shape. The food package 100 may release excess steam through the vent openings 108, as shown by arrows 122 in FIG. 1b. This may regulate the pressure 116 within the food package 100.

[0058] The method 200 may further include a step 208 of reducing heating 202 of the food package 100. The reducing step 208 is indicated by arrow 123 in FIG. 1b. This reduces steam generation 204, as also shown in FIG. 110. This may result in a reduced flow of steam through the vent opening 108, as indicated by arrow 124, which is smaller than arrow 122 in FIG. 1b. A reduced pressure within the food package 100 is further achieved by the step 208 of reducing heating 202.

[0059] The method 200 further includes the step 210 of applying a label 126 to seal the vent opening 108 , thereby sealing the food product 102 from the ambient atmosphere 128 surrounding the food product package 100 .

[0060] The label 126 is applied 210 within a time window TL that spans time. The time window TL is indicated by the area 129 within the dotted line in FIG. 110. The time window TL spans between a threshold point TTP, where the release of excess steam 124 through the vent opening 108 is below a maximum threshold, and an equilibrium point TBP, where steam generation 204 is balanced by steam condensation 206 such that the release of excess steam 124 through the vent opening 108 is above a minimum threshold. In other words, in some embodiments, the method includes applying 210 the label 126 to seal the vent opening 108 during a time window that spans between the first time that gas flow from the food package 100 falls below a threshold and the time before gas flow from the food package 100 becomes negative. In other words, the label 126 is applied when the gas flow (e.g., liters / minute) is above zero but below a threshold.

[0061] An advantage of the present method is that it provides a robust process for sealing food packages. More specifically, the present method enables efficient sealing of vent openings in food packages by utilizing changes in steam generation and steam condensation that occur during food cooking. In other words, the present method enables efficient sealing of food packages within the time window TL. The application method of the label 126 within the time window TL mitigates the buildup of excessive pressure within the food package 100, which could damage the food package. This can further reduce leakage and / or damage to the label 126. To this end, the constraints on the selection of label materials and / or adhesives for fastening the label 126 to the cover 106 can be further reduced. This can result in simple and cost-effective sealing of food packages. This can further reduce the need for complex labels.

[0062] With further reference to diagram 110 of FIG. 1b, the magnitude of steam generation over time can be determined based on a first predetermined function. Steam generation function 112 can be a first predetermined function. The magnitude of steam condensation over time can be determined based on a second predetermined function. Steam condensation function 114 can be a second predetermined function. The first function can be numerically approximated, for example, by fitting the function to a series of data points obtained from measuring the flow rate of steam through vent opening 108 with an appropriate flow sensing device while food package 100 is heated at one or more specific temperatures over time. Because steam generation depends on several parameters (e.g., the type of food in the container, the shape of the container, the temperature), different functions can be obtained for different “scenarios.” Similarly, the second predetermined function can be numerically approximated by fitting the function to a series of data points obtained from measuring the amount of steam condensing in an experimental setting.

[0063] The equilibrium point TBP may occur when the first predetermined function 112 and the second predetermined function 114 have a non-zero common solution 115.

[0064] The method 200 may further include measuring 214 the magnitude of vapor generation over time with a sensing device, and measuring 216 the magnitude of vapor condensation over time with a sensing device.

[0065] The detection device may include a first sensor configured to monitor the magnitude of vapor generation and a second sensor configured to monitor the magnitude of vapor condensation.

[0066] The method may further include determining 218 first and second predetermined functions based on the measured magnitude of steam generation and the measured magnitude of steam condensation over time, respectively, which may result in an improved determination of a suitable time window TL for applying the label.

[0067] FIG. 1c shows the food package 100 after a label 126 has been applied to cover the vent opening 108, thereby sealing the food package 100. The food package 100 may cool after sealing. The cooling may be to the ambient temperature surrounding the food package 100. As the container cools, steam therein may condense, resulting in a negative pressure 130 within the container. Thus, the method 200 may be understood as providing 220 a negative pressure within the food package 100. The negative pressure 130 may sometimes be referred to as a "vacuum." The method 200 for preparing the food product 102 may be understood to include cooking and vacuum-packaging within the same food package 100. Thus, the method 200 may provide a cooked, pasteurized, and vacuum-packaged food product 102. The negative pressure 130 may cause the cover 106 to contract, reducing the volume within the food package 100. The cover 106 may form a concave shape, as shown in FIG. 1c.

[0068] The method 200 for preparing the food product 102 may further include a step 222 of subjecting the food product package to a cooling process 224, as shown in FIG. 2. FIGS. 3a-3c are schematic perspective views of a food product being prepared according to some embodiments. FIG. 3a shows the food product package 100 during the preparation of the food product 102, and FIG. 132 shows, by way of example, the generation 204 and condensation 206 of steam S as a function of time t. The magnitude of steam generation over time is shown in FIG. 132 by the steam generation function 112, see the solid curve. The magnitude of steam condensation over time is shown in FIG. 132 by the steam condensation function 114, see the dashed curve. The steam generation 204 and steam condensation 206 may generate a pressure 116 within the food product package 102, shown by region 118 in FIG. 132. The pressure 116 may be an overpressure 120, which is caused by steam generation 204 during heating of the food product package 100. The overpressure 120 may cause the cover 106 to expand, increasing the volume within the food package 100. The cover may form a convex shape. However, the vent openings 108 may release excess steam through the vent openings 108, as shown by arrows 124, as described in connection with FIG. 1b.

[0069] The cooling process 224 may be provided by a cooling device 134. The cooling process 224 causes an increase in vapor condensation 206. This is illustrated in FIG. 3b by the cooling-modified vapor condensation function 136, shown by the dashed curve. As shown in FIG. 3b, the cooling process 224 thereby shifts the equilibrium point TBP in time so that it occurs at the cooling point TCP. The cooling point TCP occurs earlier in time than the equilibrium point TBP. Here, earlier should be interpreted as earlier in time as measured from the reduction in heating 208. The reduction in heating 208 is indicated by arrow 123 in FIG. 3b. This provides improved adjustment of the time window TL for applying the label. This may further result in a reduction in pressure 116 within the food package 100. In other words, the pressure 116 within the food package 100 may thereby be efficiently adjusted by the cooling process 224.

[0070] In other words, the cooling process 224 can affect the second predetermined function so that a non-zero common solution 115 with the first predetermined function occurs at the cooling point TCP, which is earlier in time than the equilibrium point TBP. This provides for improved adjustment of the time window TL for applying the label. The improved adjustment of the time window TL can be further understood by comparing the region 138 within the time window TL enclosed by the steam generation function 112 and the modified steam condensation function 136 in FIG. 3b with the total region 140 formed by the steam generation function 112 and the steam condensation function 114 when the cooling process 224 is not occurring. The lower pressure caused by the cooling process 224 corresponds to a smaller region 138 than the region 140 associated with the absence of the cooling process.

[0071] The cooling process 224 may include exposing the food package to cooling gas 142, as shown in Figure 3a. The cooling gas may be applied to the cover 106. The cooling gas 142 may be air or a gas from a controlled gas source.

[0072] The cooling process 224 may occur (222) prior to the step 210 of applying the label 126. Alternatively, the cooling process 224 may occur (222) on the food package 100 during the step 210 of applying the label 126.

[0073] A cooling process 224 may be applied to the exterior surface of the cover, thereby efficiently cooling the vapor within the food package 100. The cooling process 224 may allow for earlier application 210 of the label 126. Cooling may further allow for improved determination of the appropriate time for the sealing step 212.

[0074] The method 200 may include a step 225 of cooling the food package after the label is applied. This may result in a reduced pressure within the food package. The cooling may increase condensation of steam within the food package 100. A reduction in pressure within the food package 100 may be achieved.

[0075] 3c shows the food package 100 after a label 126 has been applied (210) to cover the vent opening 108, thereby sealing (212) the food package 100. The food package 100 may be cooled after the sealing step 212. Cooling may be to the ambient temperature surrounding the food package 100. As the food package cools, steam therein may condense, which may result in a negative pressure 130 inside the food container.

[0076] FIG. 4 shows a schematic diagram 144 illustrating steam generation and steam condensation S as a function of time t according to one example of a method 200 for preparing a food product. Referring to FIGS. 2 and 4, the method 200 may further include a step 222 of subjecting the food product package to an additional heating process 226 prior to the step 210 of applying the label 126. The additional heating process 226 may shift the equilibrium point TBP in time, as shown in FIG. 4, occurring at a heating point THP later in time than the equilibrium point TBP. The term later refers to a heating point THP occurring at a later time than the TBP, measured from the reduction in heating 208 indicated by the arrow 123 in FIG. 4. The additional heating process 226 is applied at a later time than the heating 202, relative to cooking the food product. The additional heating process 226 may be understood to occur after the reduction in heating 208. The additional heating applied may be reduced from a heating power for initiating or continuing the cooking process for the food product to a lower power for additional heating. The additional heating process 226 may be caused by a reduction in heating. In other words, heating may continue over time, but the heating power may decrease over time. According to one example, the additional heating may be within a range of 5% to 20% of the heating power used to initiate or continue cooking the food. According to one example, the heating may be 10% of the heating power used to initiate or continue cooking. The reduction in heating power may be a gradual or gradual reduction in heating power. The reduction in heating power may be a reduction in heating temperature. Thus, the additional heating process may be achieved by the heating means used for heating. The heating means may be a microwave source for heating the food. Alternatively, the additional heating process may be achieved by an additional heating element. The additional heating element may include a heating filament. The additional heating element may be configured to provide heat by radiant heating. The additional heating element may be an infrared radiation source.

[0077] FIG. 4 further illustrates that the additional heating process 226 can affect the first predetermined function such that the non-zero common solution 115 with the second predetermined function occurs at a heating point THP that is later in time than the equilibrium point TBP. In other words, the steam generation function 112 can be modified by the additional heating process, as indicated by the tail 146 of the modified steam generation function 148. This causes the time window T L to be extended in time by the additional heating process 226. Thus, the additional heating process 226 can allow for adjustment of the point in time at which the time window T L for applying the label occurs. The time window T L for sealing the vent opening can be extended. The pressure within the container can be further controlled by heating, as indicated by region 150. The additional heating process 226 can increase steam generation 204. The pressure within the food package can be increased by the additional heating process 226.

[0078] FIG. 5 shows a schematic diagram 152 illustrating steam generation and steam condensation S as a function of time t according to some embodiments of a method 200 for preparing a food product 100. As illustrated in FIG. 5, the method 200 may include a step 222 of subjecting the food package to an additional heating process 226 and a cooling process 224. The cooling process 224 may be applied during the additional heating process 226, as shown in FIG. 5. The combined additional heating process 226 and cooling process 224 allows for a temporal shift of the equilibrium point TBP to a combined heating and cooling point THCP. The combined heating and cooling point THCP is earlier in time than the heating point THP and results from a purely additional heating process as described above. In other words, the combined heating and cooling may result in a modified steam generation 148 and a modified steam condensation function 136. Here, earlier should be interpreted as earlier in time as measured from the reduction in heating 208 indicated by arrow 123 in FIG. 5. This may result in improved control of the pressure within the food package. An improved adjustment of the time window TL for applying the labels is further provided.

[0079] The method 200 may further include a step 125 of cooling the food product 100 after the step 210 of applying the label 126. The step 125 of cooling is indicated by an increase in steam condensation 136.

[0080] FIG. 6 is a schematic diagram of a system 300 for preparing food products according to some embodiments. FIG. 6 shows a food package 100 containing a food product 102 at different times as it is transported within the system 300. The system 300 includes a heating means 107 configured to heat the food package 100 containing the food product 102. The heating means 108 may be a microwave source 109. The food package 100 includes a container 104 and a cover 106. The heating initiates or continues the cooking process of the food product 102 as described above. The cooking process causes steam generation and steam condensation within the food package 100. The cover 106 has a vent opening 108 for releasing excess steam caused by steam generation. The system 300 further includes a label applicator 152 configured to apply a label 126 to the cover 106 such that the label 126 covers the vent opening 108, thereby sealing the food product 102 from the ambient atmosphere 128 surrounding the food package 100. In other words, the food package is thereby sealed. The label 126 is further applied within a time window TL, as explained above, spanning between a threshold point TTP, where excess steam emission through the vent opening 108 is below a maximum threshold, and an equilibrium point TBP, where steam generation is balanced by steam condensation, such that excess steam emission through the vent opening is above a minimum threshold.

[0081] The label 126 may be an adhesive label. The label 126 may include a layer with barrier properties, such as polypropylene, to limit the transport of oxygen from the environment into the food package 100.

[0082] The container may be flexible. The container may be a plastic container. The plastic container may be a flexible plastic container.

[0083] The food product 102 is not intended to be limited to any particular form or type of food product. The methods for preparing the food product may be applicable to meat, fish, vegetables, and / or seafood, for example. The food product may, in other examples, be in the form of a ready-to-eat meal.

[0084] The heating means 107 may be a microwave source for heating the food product 108. The microwave power used in the microwave source may be in the range of 400W to 1000W, for example, for heating food packages. The microwave power used for heating may be varied within the heating tunnel. The microwave power may be varied over time. Greater microwave power may be used to induce boiling of the food product.

[0085] The system may further include a cooling device 134. The cooling device 134 is configured to cool the food package 100, thereby subjecting the food package to a cooling process that increases steam condensation, thereby shifting the cooling process so that the equilibrium point TBP occurs at a cooling point TCP that is earlier in time than the equilibrium point TBP. The cooling device 134 may include a gas outlet. The cooling device 134 may be further configured to expose the food package 100 to cooling gas 142, as shown in FIG. 3a. The cooling gas 142 may be sprayed onto the cover 106. The cooling gas 142 may be air or a gas from a controlled gas source.

[0086] The system 300 may further be configured to subject the food package to an additional heating process before applying the label. The additional heating process may be achieved by heating means 107. The heating means may be a microwave source for heating the food. The additional heating process may alternatively be achieved by an additional heating element 154. The additional heating element 154 may include a heating filament. The additional heating element 154 may be configured to provide heat by radiative heating. The additional heating element 154 may be an infrared radiation source.

[0087] 6 and 2, the system may further include a sensing device 156 for measuring (214) the magnitude of steam generation over time and for measuring (216) the magnitude of steam condensation over time. The sensing device 156 may include a first sensor 158 configured to monitor the magnitude of steam generation and a second sensor 160 configured to monitor the magnitude of steam condensation. The reduced heating may be caused by transport of the food product package 100 from a heating tunnel configured to heat the food product.

[0088] The sensing device 156 may include a control system configured to determine the magnitude of steam generation over time and the magnitude of steam condensation over time based on measuring sensor data. The sensor data may relate to pressure and / or flow data. The sensing device may include a pressure sensor. The pressure sensor may be a steam pressure transmitter. The sensing device may include a moisture sensor configured to detect steam released from the food product. The sensing device may include a humidity sensor. The sensing device may include a weight sensor configured to measure the amount of steam generated and / or the amount of steam condensed. The sensing device may include a sensor for determining the liquid level within the food package. The sensing device may include a flow sensor. The first and / or second sensors may be a pressure sensor, a flow sensor, or a humidity sensor.

[0089] The food packages 100 may be positioned on a conveyor belt 161. The food products 100 may be transported through a heating tunnel while the food packages 100 are being heated.

[0090] The time window in which label 126 applies may be in the range of 2 to 20 seconds. Additional heating may further increase the time window.

[0091] The cover is exemplified here as a film. The film may be an extruded film. The cover may alternatively be a lid. The container is exemplified here as a tray. In other examples, the container may be, for example, a can. The container and cover may be the same material. In other examples, the container and cover may form a bag. Thus, the container and cover may be formed together. The bag may be referred to as a food packaging bag. The container and cover may form a pouch. The pouch may be a stand-up pouch.

[0092] The cover may comprise a ductile material such as polyamide. The cover may further comprise a barrier material such as polypropylene and / or polyamide. The barrier material may act as a barrier material to prevent oxygen diffusion into the food package. The cover may further comprise a material suitable for attachment to the container by heating or welding. Examples of such materials may be polypropylene or polyethylene, depending on the material used for the container. The cover may further be sealed to the container at a joint around the edge of the container. The cover may be in the form of a laminate. The laminate may comprise layers of polyamide and polypropylene. The cover may be placed on the container such that the polypropylene layer is positioned closer to the interior of the container than the polyamide layer.

[0093] The ventilation opening is 1mm 2 ~8mm 2 Within the range of 2 mm 2 ~4mm 2 in the range of 1000 to 2000 mm, most preferably 3 mm 2 ~4mm 2The opening size may be within the range of 1 / 2 psi. This allows the opening size to be small enough to maintain overpressure within the food package, but allows for efficient release of excess steam caused by steam generation. This can prevent damage to the food package. A larger opening can reduce the pressure within the food package. The equilibrium point TBP can be further shifted in time by selecting the opening size of the vent opening. The term opening may also be interpreted as a trough hole.

[0094] Label 126 may be an adhesive label in some examples.

[0095] Label 126 may, in some examples, be a one-way valve. The one-way valve may be configured to open when the pressure within the food package exceeds a pressure threshold created by post-heating the food package, for example, when the sealed food product is heated for consumption. Method 200 may reduce the need for a one-way valve. A less complex single-wave valve may be used.

[0096] 7a through 7d are schematic diagrams of a vent opening in the cover 106 according to some embodiments. FIGS. 7a through 7c illustrate that the vent opening 108 may include a flap 162. FIG. 7a is a schematic side view of the vent opening, and FIGS. 7b and 7c are schematic top views of the vent opening 108 according to two examples. The flap 162 includes an extension that overhangs a portion of the periphery 164 of the vent opening 108. The flap may have an extension such that the flap covers at least a portion of the vent opening 108. The flap 162 may completely cover the vent opening 108. In other words, the flap 162 may cover at least a portion of the vent opening 108. The flap 162 may form part of the cover 106. The flap may overlap the vent opening. Alternatively, a layer may be attached to the cover, and the layer includes a flap such that at least a portion of its flat portion overlaps the vent opening.

[0097] An advantage is that the flap 162 provides an adjustable opening size 166, with the effective opening size being a function of the flow of steam 168 through the vent opening 108. Stated another way, the effective opening area of ​​the vent opening can vary with the steam flow. FIG. 7b illustrates a circular flap 162. FIG. 7c illustrates an alternative flap 162. The flap 162 of FIG. 7c has a semicircular shape, also referred to as a half circle. It should be noted that the flap may have alternative shapes, such as a rectangular, triangular, or oval shape, according to other embodiments.

[0098] The flap provides an adjustable opening with an effective opening size that is a function of pressure, i.e., steam flow through the vent opening. The opening may be semicircular in shape. The opening may be circular in shape. The opening may be rectangular in shape.

[0099] Thus, the opening size can be changed during the food preparation process. The opening size can be larger when steam generation is high, for example, when heat is applied to the food, and smaller when the heat is reduced. The opening size of the vent opening can be larger at the beginning of the cooking process and smaller at the end of the cooking process. In other words, a possible solution is to cut a flap into the lidding film. As steam flow from the food package increases, the flap is lifted, increasing the effective opening size of the vent opening. The equilibrium point TBP can be further shifted in time by changing the opening size of the vent opening. The vent opening can be formed in the cover before the cover is attached to the container. The vent opening can be formed in the cover when the food is heated. The vent opening can be formed in the expanded food. Steam generation can expand the food. In some examples, the container and cover can together form a pouch, and the pouch contains the food. The vent opening can also be formed in the pouch when heated. This allows the pouch to expand due to steam generation before the vent opening is formed. The food package may alternatively be a bag and the vent opening may be formed in the bag when heated.

[0100] The method may further include forming a vent opening in the cover during heating of the food product, thereby providing a cover with a vent opening. The forming of the vent opening may provide a flap.

[0101] FIG. 7d shows another vent opening having an adjustable opening size 166. The adjustable opening size 166 is provided by a cover 106 including at least a portion of an expandable film 170, with the vent opening 108 disposed within the expandable film, which expands in response to overpressure 120 caused by steam generated by heating. The expandable film 170 may stretch to provide a larger opening size in response to increased outward pressure within the food package. In other words, the area of ​​the vent opening may increase. The expandable film 170 may at least partially recover its reduced shape after heating. The deformation of the expandable film 170 in response to increased pressure within the food package may be elastic deformation. The expandable film 170 may be an elastic film.

[0102] The vent openings in the expandable film may be slits, which may have an extension in the range of 1 mm to 8 mm, preferably in the range of 2 mm to 4 mm, and most preferably in the range of 3 mm to 4 mm.

[0103] The vent opening may be formed in the cover by piercing the cover with a sharp, smooth tool, preferably a needle-shaped tool. Alternatively, the vent opening may be formed by laser cutting, punching, or melting. The opening may be provided in the center of the cover. This allows the vent opening for the overpressure caused by cooking to form the highest point of the food package when the cover is facing upward toward the bottom of the container, allowing steam to efficiently escape through the vent opening.

[0104] It should be noted that the word "comprising" does not exclude the presence of other elements or steps than those listed, and the words "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. Furthermore, it should be noted that any reference signs do not limit the scope of the claims, and that the invention may be implemented at least partly by both hardware and software, and that several "means" or "units" may be represented by the same hardware.

[0105] The above-mentioned and described embodiments are given as examples only and do not limit the present invention. Other solutions, uses, objects, and functions within the scope of the invention claimed in the patent embodiments described below should be apparent to those skilled in the art.

Claims

1. A method for preparing a food product, said method (200) comprising: heating (202) a food package (100) enclosing the food product (102), the food package (100) comprising a container (104) and a cover (106), the heating (202) initiating or continuing a cooking process of the food product (102), the cooking process causing steam generation (204) and steam condensation (206) within the food package (100), the cover (106) having a vent opening (108) for releasing excess steam caused by the steam generation (204); reducing (208) the heating (202) of the food package (100), thereby reducing the steam generation (204); applying (210) a label (126) to seal the vent opening (108), thereby sealing the food product (102) from the ambient atmosphere (128) surrounding the food package (100), the label (126) being applied within a time window (TL) spanning between a threshold point (TTP) at which the excess steam release through the vent opening (108) is below a maximum threshold and an equilibrium point (TBP) at which the steam generation (204) is balanced by the steam condensation (206) so that the excess steam release through the vent opening (108) is above a minimum threshold; Including, method.

2. a magnitude of the steam generation (204) over time is determined based on a first predetermined function, and a magnitude of the steam condensation (206) over time is determined based on a second predetermined function; The method of claim 1.

3. the equilibrium point TBP occurs when the first predetermined function and the second predetermined function have a non-zero common solution (115); The method of claim 2.

4. the method (200) further comprising the step (222) of subjecting the food package (100) to a cooling process (224) such that the steam condensation (206) increases, whereby the cooling process (224) shifts the equilibrium point TBP to occur at a cooling point TCP that is earlier in time than the equilibrium point TBP.

4. The method according to any one of claims 1 to 3.

5. the cooling process (224) affects the second predetermined function such that the non-zero common solution (115) with the first predetermined function occurs at the cooling point TCP, which is earlier in time than the equilibrium point TBP. The method of claim 4 when dependent on claim 3.

6. the method (200) further comprises the step (222) of subjecting the food package (100) to an additional heating process (226) prior to the step (210) of applying the label (126); 6. The method according to any one of claims 1 to 5.

7. the additional heating process (226) shifts the equilibrium point TBP in time, the heating point THP occurring at a later time than the equilibrium point TBP; The method of claim 6.

8. the additional heating process (226) affects the first predetermined function such that the non-zero common solution (115) with the second predetermined function occurs at a heating point (THP) that is later in time than the equilibrium point (TBP); The method of claim 6 when dependent on claim 3.

9. The method (200) the step (214) of measuring the magnitude of the steam generation over time with a detector (156); and the step (216) of measuring the magnitude of the steam condensation over time with the detector (156). further comprising:

9. The method according to any one of claims 1 to 8.

10. The detection device (156) a first sensor (158) configured to monitor the magnitude of the steam generation; and a second sensor (160) configured to monitor the magnitude of the steam condensation. Equipped with 10. The method of claim 9.

11. The opening size of the ventilation opening (108) is 1 mm ２ ~8mm ２ Within the range of 2 mm ２ ~4mm ２ in the range of 3 mm, most preferably ２ ~4mm ２ is within the range of 11. The method according to any one of claims 1 to 10.

12. The equilibrium point TBP is shifted in time by selecting the opening size of the vent opening (108).

12. The method according to any one of claims 1 to 11.

13. the vent opening (108) includes a flap (162) that extends over a portion of the perimeter (164) of the vent opening (108); 13. The method of any one of claims 1 to 12.

14. the vent opening (108) has an adjustable opening size (166), the adjustable opening size (166) is provided by a cover (106) including at least a portion of an expandable film (170), the vent opening (108) is disposed within the expandable film (170), and the expandable film (170) expands in response to an overpressure (120) caused by the steam generated by the heating (202); 13. The method of any one of claims 1 to 12.

15. A system for preparing food, said system (300) comprising: a heating means (107) configured to heat (202) a food package (100) containing the food product (102), the food package (100) comprising a container (104) and a cover (106), the heating (202) initiating or continuing a cooking process of the food product (102), the cooking process causing steam generation (204) and steam condensation (206) within the food package (100); and the cover (106) having a vent opening (108) for releasing excess steam caused by the steam generation (204). a label applying device (152) configured to apply (210) the label (126) to the cover (106) such that the label (126) covers the vent opening (108) and thereby seals (212) the food product (102) from an ambient atmosphere (128) surrounding the food package (100), the label (126) being applied within a time window (TL) spanning between a threshold point (TTP) at which the excess steam release through the vent opening (108) is below a maximum threshold and an equilibrium point (TBP) at which the steam generation (204) is balanced by the steam condensation (206) such that the excess steam release through the vent opening (108) is above a minimum threshold; Equipped with system.

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