AU2012203403B2

AU2012203403B2 - Method for cooking food by means of steam

Info

Publication number: AU2012203403B2
Application number: AU2012203403A
Authority: AU
Inventors: Erwin Bucher; Nina Dohner
Original assignee: V-Zug AG
Current assignee: V-Zug AG
Priority date: 2011-06-21
Filing date: 2012-06-08
Publication date: 2016-11-10
Anticipated expiration: 2032-06-08
Also published as: PL2537418T3; CH702581B1; EP2537418B2; AU2012203403A1; CN102835892B; CN102835892A; DK2537418T4; CH702581A2; EP2537418A1; PL2537418T5; DK2537418T3; SI2537418T2; SI2537418T1; EP2537418B1

Abstract

Abstract In order to cook food, such as meat, in a 5 cooking device by means of steam the food (2) is enclosed in a bag (14) . Thereafter the cooking chamber (1) is heated by means of steam, wherein the food temperature (TGG) is measured by a food temperature measurement probe (10) and is regulated to a rising slope by means of a 10 regulating circuit until it reaches an end food temperature (TGGE) . At the same time it is ensured that the cooking chamber temperature does not surpass a limit (TLIM). Thereafter an optional high temperature phase is initiated with a higher temperature. By this method the 15 food can be cooked in a fast and gentle way. (Fig. 1) Fig. 1 tO t1 t2 t3 t4 t5 Fig. 2

Description

2012203403 20 Oct 2016 25 H:\plwtfnterwoven\NRPortbl\DCC\PLW\11795649_1 .docx-20/10/2016 - la -

The invention is related to a method for cooking food in a cooking device as well as to a corresponding cooking device according to the preamble of the independent claims. 5 EP723115 describes a method for cooking meat where the cooking chamber is heated up with hot air in a food temperature regulating phase in such a way that the food temperature follows a time-dependent desired food temperature function. In this way a certain food temperature (core temperature) can be 10 reached at a desired time. However, it has been found that it takes relatively long until the food has been cooked by following this procedure because the slope of the time-dependent desired food temperature function must not be chosen to be too steep in order to avoid local overheating at the meat 15 surface .

Embodiments of the invention seek to provide a method and a device of this type, which make it possible to cook the food quickly but at the same time in a gentle manner.

According to this, the food temperature is measured. Furthermore, a cooking chamber temperature in the cooking chamber outside the food is controlled, at least during a food temperature regulating phase of the cooking period, in such a way that the food temperature follows a time-dependent desired food temperature -2- 2012203403 08 Jun2012 function. For this purpose the cooking chamber is at least partially heated up by heated steam (optionally by also using further heating means), with the result that a more efficient heat input in the food is made possible 5 without having to use a very high temperature in the cooking chamber. In order to avoid a wash out of the food by the steam, the food is arranged in a bag in the cooking chamber.

Preferably, the desired food temperature 10 function is chosen such that it rises up to an end food temperature such that the desired core temperature is reached at the end of the food temperature regulating phase. In this case the cooking duration or the end time when the food shall be finished can be preset in the way 15 described in EP 723115.

Advantageously it should be taken care that the cooking chamber temperature never rises too much. In a preferred embodiment this can be achieved by controlling the cooking chamber temperature in such a way 20 that it surpasses the end food temperature by maximally 20°C, particularly maximally 15°C, particularly maximally 10°C. Alternatively or additionally the cooking chamber temperature can be controlled in such a way that it doesn't surpass a predefined fixed limit temperature, 25 wherein the fixed limit temperature is smaller that 90°C, particularly smaller than 80°C, particularly smaller than 70°C.

As soon as the corresponding limit temperature is reached, the temperature is lowered below 30 the desired food temperature function in order to make sure that the cooking chamber temperature doesn't rise further.

The invention is particularly suitable to cook meat (wherein in the present context fish is also 35 counted as meat), because in this case the cooking process can be terminated after reaching the desired core

P106999AU0O

RN 30.05.2012 H:\plwMnterwoven\NRPortbl\DCC\PLW\11795649_l docx-20/10/2016 2012203403 20 Oct 2016 - 3 - temperature. The method may however also be used for other types of food, i.e. vegetables.

According to the present invention, there is provided a method for cooking food in a cooking device with a cooking 5 chamber during a cooking period, wherein a food temperature is measured and wherein at least during a food temperature regulating phase of the cooking period a cooking chamber temperature in the cooking chamber outside the food is controlled in such a way that the food temperature follows a 10 time-dependent desired food temperature function, wherein the cooking chamber is at least partially heated up by heated steam and in that the food is arranged in a bag in the cooking chamber.

The invention will now be described, by way of non- 15 limiting example only, with reference to the accompanying drawings, in which:

Fig. 1 the most important components of a cooking device and

Fig. 2 the qualitative course of the food temperature TGG, 20 the cooking chamber temperature TGR and the desired food temperature TGS.

The cooking device according to Fig. 1 has a cooking chamber 1 for receiving the food 2, i.e. on a metal plate or a grid 3. Furthermore, the device has a controller 4 and a steam 25 generator 5. The steam generator 5 serves to heat up the cooking chamber 1 by means of steam. Further means for heating up the cooking chamber may also be present, e.g. resistive heaters. The cooking device is preferably an oven with a steam cooking function, it may however also be e.g. a pure steam 30 cooking device.

The controller 4 comprises, amongst others, means 6 for generating a desired food temperature function, meaning a time-dependent desired value TGGS of the food temperature TGG. The means 6 may e.g. be a memory and computing means which generate 35 such a function in a known way. Preferably, the means 6 is formed such that the desired food temperature function rises monotonously in a food temperature regulating phase of the device starting from a start value, particularly -4- 2012203403 08 Jun2012 strictly monotonously, up to an end food temperature TGGE.

Furthermore, the controller 4 comprises a first regulator 7 (i.e. loop controller) and a second 5 regulator 8 (i.e. loop controller), each of which compare a current value with desired value and generate a controlling variable in such a way that the current value adapts to the desired value.

The first regulator 7 is connected to a food 10 temperature measurement probe 10. The latter measures the cooking chamber temperature TGG approximately in the middle of the food 2, this being the so-called core temperature. The desired value TGGS of the food temperature is supplied by the means 6 as desired value 15 to the regulator 7. The regulator 7 compares the food temperature TGG and its desired value TGGS and generates from it a desired cooking chamber temperature TGRS which is chosen in such a way that the food temperature TGG tends to reach its desired value TGGS. 20 The second regulator 8 is connected to a cooking chamber temperature measurement probe 11. It measures the cooking chamber temperature TGR. The second regulator receives the desired value TGGS from the first regulator, compares it with the current cooking chamber 25 temperature TGR and generates from it a control signal for the steam generator. This control signal controls the steam generation and is chosen in such a way that the cooking chamber temperature TGR tends to reach its desired value TGRS. 30 The regulators 7 and/or 8 or generally the controller 4 are advantageously formed in such a way that the food temperature doesn't surpass a limit temperature TLIM, at least during a part of the cooking process, not even if a higher cooking chamber temperature would 35 actually be desirable for reaching the desired value TGGS. In this way a thermal damage of the food surface can be avoided. The limit temperature TLIM is preferably P106999AU00

RN 30.05.2012 -5- 2012203403 08 Jun2012 chosen depending on the desired end food temperature TGGE, particularly in such a way that the limit temperature TLIM is maximally 20°, particularly maximally 15°, particularly maximally 10°, higher than the end food 5 temperature TGGE. Additionally or alternatively, the limit temperature TLIM may also be chosen independently from the end food temperature. In this case the value of the limit temperature TLIM is of preferably maximally 90°C, particularly maximally 80°C, particularly maximally 10 70°C. The limit temperature TLIM normally depends on the food to be cooked.

In the following the cooking method carried out with the above cooking device will be described. It has to be noted, though, that the described cooking 15 method only matches one of multiple possible operating modes of the cooking device. The cooking device is normally able to cook food also by employing other conventional methods.

If the user wishes to choose the operating 20 mode described herein, he packs the food 2 into a bag 14 before cooking. For this purpose, a, preferably flexible, bag 14 is used, which can be sealed in a gas-tight manner. Optionally, the bag 14 may have an overpressure valve in order to release gas coming out of the food to 25 the environment.

Preferably, the bag with the food is at least partially evacuated before cooking, such that it is under underpressure with respect to the cooking chamber 1 and abuts against the food. 30 The bag 14 has multiple advantages. On the one hand it avoids that the food is washed out by condensing steam, as already mentioned. Furthermore, it keeps the juice as well as possible marinades and spices within the food, particularly when it is at least 35 partially evacuated.

It also avoids that the food is dried out, thus improving the heat transfer in the food, this P106999AU00

RN 30.05.2012 -6- 2012203403 08 Jun2012 resulting amongst others in the possibility of increasing the core temperature or the food temperature, respectively, faster.

An at least partial evacuation of the bag 14 5 also has the advantage that the heat transfer from the cooking chamber 1 to the food is better than in case the bag wouldn't rest against the food.

Before cooking, the food temperature measurement probe 10 is inserted into the food. In the 10 embodiment according to Fig. 1 the measurement probe 10 has been inserted into the food 2 through a sealing plate 15 and the bag 14. It is the task of the sealing plate 15 to seal the location where the measurement probe 10 has entered the food through the bag. The sealing plate 15 15 preferably consists of an elastic material with sealing properties, like e.g. an elastomer, and is glued to the bag 14. Other sealing means of suitable types are also conceivable.

Alternatively to this, the food temperature 20 measurement probe 10 can also be inserted into the food 2 before the latter is inserted into the bag 14. In this case the food temperature measurement probe 10 can e.g. communicate with the controller 4 in a wireless way, or a cable can be guided to the exterior through the bag 25 opening 16.

The food 2 provided with the measurement probe 10 and sealed in the bag 14 is then inserted into the cooking chamber 1, and the cooking program is initiated. The following steps of this cooking program 30 run automatically and are controlled by the controller 4. The course of the cooking temperature TGG, of the desired food temperature TGGS and the cooking chamber temperature TGR during the cooking program are shown in Fig. 2.

The cooking program starts at a time tO. 35 First the steam generator 5 is activated, such that the cooking chamber temperature TGR starts increasing. (Optionally the cooking chamber can be also heated e.g. P106999AU00

RN 30.05.2012 -7- 2012203403 08 Jun2012 by a resistive heater or another suitable heating means.) At a time tl (which can be identical to the time tO or which can be after the time tO) the food temperature regulating phase starts, during which the desired food 5 temperature is generated by the means 6 and the regulators 7 and 8 operate as described above. In the present embodiment the food temperature regulating phase extends over the time interval tl to t4.

The desired food temperature function is 10 shown in Fig. 2 exemplarily in a dashed way as a slope which rises linearly e.g. from the ambient temperature at the time tl up to the end food temperature TGGE at the time t4. The time interval tl to t4 may be preset depending on the food type. Alternatively or additionally 15 it can also be preset, within certain boundaries, by the user by inputting the time t4, e.g. in the way described in EP 723115. For meat, the duration from tl to t4 preferably amounts to 0.5 - 3 hours, particularly 1-2 hours. 20 In the example according to Fig. 2 the food temperature at the time tl is relatively low (e.g. because the food comes out of the refrigerator), this being the reason why the first regulator 7 tends to prescribe a relatively high desired cooking chamber 25 temperature TGRS, which is, however, prevented by reaching the upper limit TLIM at the time t2. In the example according to Fig. 2, in the time interval t2 to t3 the desired cooking chamber temperature TGRS is limited to TLIM. By this, an excessive overheating of the 30 food surface is avoided. This is only an example - depending on the food, weight and temperature as well as further parameters the upper limit TLIM may also be reached in other process phases or even never.

In any case the food temperature rises and it 35 reaches such a high value at the time t3 that the regulator 7 prescribes a desired cooking chamber temperature TGRS which is lower than TLIM, and an actual P106999AU00

RN 30.05.2012 -8- 2012203403 08 Jun 2012 regulation of the food temperature TGG to the corresponding desired value TGGS can take place. In this way the food temperature TGG follows the desired food temperature function until the time t4. 5 In the example according to Fig. 2 a high temperature phase is carried out after the food temperature regulation phase, starting from the time t4. Its aim is to clear the juice which came out of the food as well as to brown a little the food surface, this being 10 considered advantageous, particularly for meat.

For this, the cooking chamber temperature is kept during the high temperature phase at least for a minute at at least 80°C, advantageously during 1 to 10 minutes at 80° to 100°C. 15 After the high temperature phase the cooking chamber temperature TGR should be decreased as soon as possible in order to avoid temperature damages inside the food. For this, the cooking chamber may be ventilated, or, speaking more generally, more intense ventilation 20 takes place in the high temperature phase as compared to the food temperature regulating phase.

Thereafter the food is finished and may be taken out of the cooking chamber. 25 Notes:

The steam generator 5 can generate steam at around 100°C. It is however conceivable that a steam generator 5 is used which generates overheated steam at a temperature above 100°C. 30 The described method is well suited, as mentioned at the beginning, for meat in particular. In this case the end food temperature TGGE is chosen according to the generally known advantageous core temperature of the respective meat type. 35 The method may however also be used e.g. for vegetables. In this case the food temperature at the end P106999AU00

RN 30.05.2012 -9- 2012203403 08 Jun2012 of the food temperature regulating phase shall be kept at the desired end food temperature TGGE for a while.

The temperature TGR in the cooking chamber 1 is preferably always below 100°C during the entire 5 method. Despite this, a good heat input into the food is possible by using steam.

While preferred embodiments of the invention have been described in this application, it is clearly noted that the invention is not restricted to them and 10 may be carried out in other ways within the scope of the now following claims.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference numerals in the following claims do not in any way limit the scope of the respective claims. P106999AU00

RN 30.05.2012

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. Method for cooking food in a cooking device with a cooking chamber during a cooking period, wherein a food temperature is measured and wherein at least during a food temperature regulating phase of the cooking period a cooking chamber temperature in the cooking chamber outside the food is controlled in such a way that the food temperature follows a time-dependent desired food temperature function, wherein the cooking chamber is at least partially heated up by heated steam and in that the food is arranged in a bag in the cooking chamber.
2. Method according to claim 1, wherein the desired food temperature function is chosen such that it rises monotonously up to an end food temperature.
3. Method according to claim 2, wherein the cooking chamber temperature is controlled in such a way that it doesn't surpass a limit temperature, wherein the limit temperature is chosen depending on the end food temperature, and particularly wherein the limit temperature is maximally 20°C, particularly maximally 15°C, particularly maximally 10°C, higher than the end food temperature.
4. Method according to claim 1 or 2, wherein the cooking chamber temperature is controlled in such a way that it doesn't surpass a limit temperature, wherein the fixed limit temperature is smaller than 90°C, particularly smaller than 80°C, particularly smaller than 70°C.
5. Method according to any one of the preceding claims, wherein a high temperature phase is carried out after the food temperature regulating phase, during which the cooking chamber temperature is kept at at least 80 °C during at least one minute.
6. Method according to claim 5, wherein the cooking chamber temperature is kept at 80° to 100° during 1 to 10 minutes during the high temperature phase.
7. Method according to claim 5 or 6, wherein, after the high temperature phase, the cooking chamber temperature is reduced by a more intense ventilation of the cooking chamber as compared to the food temperature regulating phase.
8. Method according to any one of the preceding claims, wherein the bag containing the food is at least partially evacuated before cooking.
9. Method according to any one of the preceding claims, wherein the measured food temperature is compared with a desired food temperature derived from the desired food temperature function by means of a first regulator and, depending on this, a desired cooking chamber temperature is generated, and the measured cooking chamber temperature is compared to the desired cooking chamber temperature by means of a second regulator and depending on this a steam generator is controlled, wherein the steam is generated by the steam generator.
10. Method according to any one of the preceding claims, wherein the food to be cooked is meat.
11. Method according to any one of the preceding claims, wherein the food temperature is always below 100°C during a duration of the method.