AU2014252686B2

AU2014252686B2 - Method for cooking a cooking product, and cooking device

Info

Publication number: AU2014252686B2
Application number: AU2014252686A
Authority: AU
Inventors: Nina Dohner; Pascal Feierabend
Original assignee: V-Zug AG
Current assignee: V-Zug AG
Priority date: 2013-04-08
Filing date: 2014-04-07
Publication date: 2017-09-14
Anticipated expiration: 2034-04-07
Also published as: SI2789918T1; CN105308393A; EP2789918B1; EP2789918A1; HK1221005A1; PL2789918T3; DK2789918T3; CN105308393B; AU2014252686A1; WO2014166005A1

Abstract

The invention relates to a method for operating an oven using hot steam and to an oven for carrying out the method. The cooking product (2) can be introduced into the cooking chamber (1) without a steam-insulating cover, and the cooking chamber temperature (TGR) in the cooking chamber (1) can be controlled for example by introducing steam in a metered manner such that the cooking product temperature (TGG) follows a time-dependent cooking-product-temperature target value curve (TGGS). The cooking-product-temperature target value curve (TGGS) has at least one first section and a second section which follows the first section, and the cooking-product-temperature target value curve has a greater increase in the first section than in the second section. Using said method, the cooking product (2) can be cooked quickly and gently even without using a bag.

Description

I-l:\p]w\lntcvwoveti'NRPnrtbl\lXX"vPLW\.t 5597638.1 .docx-31/08/2017 2014252686 31 Aug 2017

Method for cooking food and a cooking device

The invention relates to a method for cooking food, in particular with steam, and a correspondingly 5 designed cooking device. EP 723115 A2 describes a method for cooking meat wherein 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 10 temperature function. In this way a certain food temperature (core temperature) can be 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 15 temperature function must not be chosen to be too steep in order to avoid local overheating at the meat surface. EP2537418 Al describes a method for cooking food, for example meat, in a cooking device with steam, wherein the food is sealed in a bag. The cooking chamber is heated 20 with steam, wherein a food temperature is measured by a food temperature measurement probe and regulated by a regulating loop on an increasing ramp until it has reached an end food temperature. Simultaneously the cooking chamber temperature is supervised in order not to exceed a limit. Afterwards an 25 optional high temperature phase follows with increased temperature. The food can be cooked quickly and in a gentle manner by this method.

Although cooking with steam is recognized as gentle, the use of a bag for sealing the food is a 30 limitation in usability of the oven. Therefore an objective is to develop gentle steam cooking methods which do not depend on the sealing of the food in a bag and still allow a gentle cooking of the food.

According to the present invention, there is 35 provided a method for cooking food in a cooking device with a cooking chamber during a cooking period, wherein a food temperature (TGG) is measured and wherein at least during a food temperature regulating phase of the cooking period a cooking chamber temperature (TGR) in the cooking chamber M:\pl wVlntowoven'NRPartbl\DCGPLVv'\! 55V7638_ I .doex-31/08/2017 2014252686 31 Aug 2017 2 outside the food is controlled in such a way that the food temperature (TGG) follows a time-dependent desired food temperature function, wherein the food is inserted into the cooking chamber and the desired food temperature function 5 (TGGS) comprises at least two phases with different gradients, wherein the second phase, which follows the first phase, has a lower gradient as compared to the first phase.

In a method to operate an oven according to one embodiment of the present invention the food is inserted 10 into their cooking chamber and the cooking chamber temperature is controlled in the cooking chamber in such a way that the food temperature follows a time-dependent desired food temperature function, wherein the desired food temperature function has at least a first phase and a second 15 phase which follows the first phase and has a steeper gradient in the first phase as compared to the second phase.

For this purpose the cooking chamber is preferably heated by dosed insertion of steam (optionally by also using further heating means), with the result that a 20 more efficient heat input in the food is made possible without having to use a very high temperature in the cooking chamber .

In a further preferred version of the method the food is heated in the cooking chamber without a steam 25 isolated bag.

Preferably, the desired food temperature function is chosen such that it rises up to an end food temperature over time, such that the desired core temperature is reached at the end of the food temperature regulating phase. In a 30 preferred version of the invention the desired function is therefore an approximation to an exponential course of the food temperature with a steep temperature increase during the first phase and a flat convergence to the end food temperature during the second phase. In a particularly 35 preferred version of the invention the desired food temperature function is therefore monotonically increasing during the first and second phase, in particular strictly monotonic increasing, for 3 example linearly increasing, wherein the second phase follows immediately after the first phase. A transmission between the first and the second phase can lie in a food temperature interval between 10°C and 30°C below the end food temperature.

The cooking duration or the end time when the food shall be finished can be preset. Preferably, the maximal cooking duration lies below 3h, which corresponds to a clearly shorter duration as compared to the usual soft cooking with steam.

Preferably, a preheating phase precedes the first and the second phase with the time dependent desired food temperature function. The preheating phase brings the food from an arbitrary initial temperature to a preprogrammed food temperature. It lies preferably in an interval between 20°C and 30°C, in particular preferably in an interval between 23°C and 27°C. Therefore the food is brought to an exactly determined temperature despite an arbitrary initial temperature, which for example can vary between cooling temperature and room temperature, before the first phase of the time dependent desired food temperature function begins.

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 that it surpasses the end food temperature by maximally 30°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, wherein the fixed limit temperature is smaller than 105°C. During the preheating phase the cooking chamber temperature is preferably limited to a range between 60°C and 80°C.

As soon as the corresponding limit temperature is reached, the temperature is decreased below the desired food temperature function in order to make sure

JHR/RN 3ab2e915e88843bfb5f7a8a263d4d259.8460729_l_16809D8C.docx 2014252686 31 Aug 2017

Il\p]w\Interwoven'NRPnrtbl\lXX'>PLW\l 559763«. I .docx-31/0S/2017 4 that the cooking chamber temperature doesn't increase further .

The invention is particularly suitable for cooking meat (wherein in the present context fish is also 5 counted as meat), because in this case the cooking process can be terminated after reaching the desired core temperature. In this case the end food temperature is chosen according to the generally known advantageous core temperature of the particular meat. The method may however 10 also be used for other types of food, e.g. vegetables.

Further embodiments, advantages and applications of the invention result from the dependent claims and from the now following description by means of the figures.

Thereby it is shown in: 15 Fig. 1 the most important components of a cooking device and

Fig. 2 the qualitative course of the food temperature TGG, the cooking chamber temperature TGR and the desired food temperature TGGS. 20 The cooking device according to Fig. 1 has a cooking chamber 1 for receiving the food 2, e.g. on a metal plate or a grid 3. Furthermore, the device has a controller 4 and a steam generator 5. The steam generator 5 serves to heat up the cooking chamber 1 by means of steam. The steam 25 generator 5 can produce overheated steam at a temperature above 100°C for example with additional hot air.

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 5 function, it may however also be e.g. a pure steam 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 such a function in a known way. Preferably, the mean 6 is formed such that the desired food temperature function TGGS comprises a first phase and a directly following second phase where in a food temperature regulating phase of the device initially increases from a start value and monotonically, in particular strictly monotonic, to an interim temperature, which lies for example 25°C below an end food temperature TGGE, and then increases with a flatter gradient, but still monotonically, in particular strictly monotonic, until the end food temperature TGGE. The gradients of the first and the second phase are set in such a way that the end food temperature TGGE is reached in a time period which can be set by a user via an input unit (not shown) of the oven. This time period can be of 3h or less.

Furthermore, the controller 4 comprises a first regulator 7 and a second regulator 8, each of which compare a current value with a 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 temperature measurement probe 9. The latter measures the food temperature TGG approximately in the middle of the food 2, i.e. so-called core temperature. The desired value TGGS of the food temperature is supplied by the means 6 as desired value 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.

JHR/RN 3ab2e915e88843bfb5f7a8a263d4d259.8460729_l_16809D8C.docx 6

The second regulator 8 is connected to a cooking chamber temperature measurement probe 10. 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 temperature TGR and generates from it a control signal for the steam generator 5. 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. If the device is controlled based on a preset cooking chamber temperature TGR, e.g. during the preheating phases described further, only this part of the control is necessary.

The regulators 7 and/or 8 or generally the controller 4 are advantageously formed in such a way that the cooking chamber temperature TGR doesn't surpass a limit temperature TLIM of 105°C. In this way a thermal damage of the food surface can be avoided.

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 method corresponds to only 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.

In the presently described operating mode the food temperature measurement probe 9 is first inserted into the food 2. In the embodiment according to Fig. 1 the measurement probe 9 has been inserted into the food 2 directly. A steam isolating bag, which protects the food from hot steam in the cooking chamber and which is described e.g. in EP 2537418 Al, is not used.

The food 2 provided with the measurement probe 9 is then inserted into the cooking chamber 1 and the cooking program is initiated. The following steps of this cooking program run automatically and are controlled by the controller 4. The course of the cooking tempera-

JHR/RN 3ab2e915e88843bfb5f7a8a263d4d259.8460729_l_16809D8C.docx 7 ture TGG, of the desired food temperature TGGS and the cooking chamber temperature TGR during the cooking program are shown in Fig. 2. Thereby, the food temperature TGG is illustrated with a dotted line overlaying the continuously drawn line of the desired food temperature value TGGS. The upper lines in Fig. 2 represent the cooking chamber temperature with two different courses TGR(1), TGR(2).

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. by a resistive heater or another suitable heating means.) The cooking program illustrated in Fig. 2 starts at a time tO where the cooking chamber temperature is 60°C.

During an optional first (pre-)heating phase, which serves for tempering the food in a gentle manner and for compensating different initial temperatures, the food is heated while measuring the food temperature. This phase ends at a time tl when the food has a selectable, preprogrammable food temperature, e.g. 20°C.

During a further optional second phase, which directly follows the first phase, the cooking for bigger food pieces is accelerated. The degree of acceleration can be evaluated by the course of the food temperature TGG during the first phase.

For example the cooking chamber temperature in the second phase can be derived from the duration of the first phase, where a first cooking chamber temperature TGR(l) is chosen at a duration not longer than a preset duration tl. This example this temperature is the initial temperature of 60°C. If the duration is longer than the preset duration tl, a second cooking chamber temperature TGR (2) can be chosen. This example this temperature is constantly 70°C as shown in Fig. 2 (after heating up) in order to accelerate the heating up of the food.

JHR/RN 3ab2e915e88843bfb5f7a8a263d4d259.8460729_l_16809D8C.docx 8

If the desired food temperature is still not reached after having reached a preset maximal duration tmax of the first phase, the first phase can be stopped and the following second phase can be initiated with a preset temperature which is even higher, e.g. 80°C. This course is not shown in Fig. 2.

In an alternative example the three temperature settings of 60°C, 70°C or 80°C for the second phase can also be derived from the gradient of the food temperature during the first heating phase.

During the optional second heating phase the food is heated up with the chosen cooking chamber temperature of 60°C, 70°C or 80°C until a (second) selectable food temperature, e.g. 25°C. If this temperature is not reached after a preset time t2, the cooking process is stopped by showing an error message to the user.

During these first two heating phases the temperature increase is determined by the cooking chamber temperature. The heating phase following these two optional preheating phases is controlled by the presetting of a desired food temperature function TGGS, i.e. a time dependent desired value TGGS of the food temperature TGG. In principle individual preheating phases can be controlled by a preset TGGS-function but such a control can increase the cooking chamber temperature TGR to a higher level than desired.

The desired value TGGS describes during the heating phase, as shown in Fig. 2, firstly a phase with steeply increasing desired values, followed by a flatter phase which ends by reaching the end food temperature TGGE. The desired food temperature function shown in Fig. 2 can be considered an exponential course of the type TGGE*(1-exp(-kt)) with k being a time constant which depends on the desired cooking time, which is approximated with two linear segments. As the curve initially increases steeper, it is avoided that the cooking chamber temperature TGR has a high value at the end of the heating

JHR/RN 3ab2e915e88843bfb5f7a8a263d4d259.8460729_l_16809D8C.docx 9 phase. On the other hand an overshoot of the food temperature in particular in case of small food pieces can be better avoided as compared to a simple linear course as described for example in EP 2537418 A1.

The gradient of the first, steeper phase of the desired food temperature function can be chosen in such a way that the maximal heat insertion into the core of the food is possible without affecting quality of the final product of the cooking process. For meat the gradient is in the range from about 0.7°C/min to 1.5°C/min, in particular from about l.l°C/min to 1.3°C/min.

The second phase starts at a time t3a when the food temperature is increased to the end food temperature TGGE except for a defined temperature difference ΔΤ. This difference ΔΤ can be chosen for example in a range between 10°C and 30°C or 15°C and 30°C below the end food temperature, preferably in a range between 23°C and 27°C below the end food temperature.

The gradient of the second phase can then be determined by the relation between the temperature ΔΤ and the remaining cooking time t3b - t3a.

During this second phase the food is approached preferably flat to the end food temperature TGGE preferably without overshooting of the food temperature and near to the end food temperature TGGE. In this way the subsequent cooking of the food after the end of cooking is limited.

As shown in FIG. 2 a protective condition makes sure that the temperature of the cooking chamber is limited to a maximal temperature TLIM of 105°C during the whole phase. This temperature can be reached by using overheated steam and can even be exceeded.

The described method is suitable in particular for meat, as initially mentioned. But the method can also be applied for example for vegetables. In this case the cooking chamber temperature should be kept at the de-

JHR/RN 3ab2e915e88843bfb5f7a8a263d4d259.8460729_l_16809D8C.docx 2014252686 31 Aug 2017 I-l:\p]w\Intevwoveti'NRPortbl\lXX">PLW\155V7638_l.tlocx-31/08/2017 10 sired end food temperature TGGE for a certain time at the end of the food temperature regulating phase.

The food can be roasted, e.g. in a pan, if a distinct encrustation is desired. 5 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 may be carried out in other ways within the scope of the now following claims . 10 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 acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) 15 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 20 word "comprise", and variations such as "comprises" or "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.

Claims

Claims

1. Method for cooking food in a cooking device with a cooking chamber during a cooking period, wherein a food temperature (TGG) is measured and wherein at least during a food temperature regulating phase of the cooking period a cooking chamber temperature (TGR) in the cooking chamber outside the food is controlled in such a way that the food temperature (TGG) follows a time-dependent desired food temperature function, wherein the food is inserted into the cooking chamber and the desired food temperature function (TGGS) comprises at least two phases with different gradients, wherein the second phase, which follows the first phase, has a lower gradient as compared to the first phase.
2. Method according to claim 1, wherein the cooking chamber is heated up at least partly by hot steam.
3. Method according to claim 1 or 2, wherein the food is heated up in the cooking chamber without a steam isolated bag.
4. Method according to one of the preceding claims, wherein the desired food temperature function (TGGS) is chosen such that the temperatures of the first and of the second phase increase monotonically until a final food temperature (TGGE).
5. Method according to claim 4, wherein the first and the second phase are linear and the first phase passes over to the second phase at a temperature which is chosen a range between 10°C and 30°C below the end food temperature (TGGE) .
6. Method according to one of the preceding claims, wherein the gradient during the first phase is at least on average between 0.7°C/min and 1.5°C/min.
7. Method according to one of the preceding claims, wherein the gradient in the second phase is determined by the temperature difference between the food temperature at the end of the first phase and the end food temperature (TGGE) and by a remaining cooking time at the end of the first phase.
8. Method according to one of the preceding claims, wherein a preheating phase precedes the desired food temperature function (TGGS) with the at least two phases, which preheating phase brings the food to a determined temperature at the beginning of the first phase.
9. Method according to claim 8, wherein the cooking chamber temperature (TGR) is limited to a range between 60°C and 80°C during the preheating phase.
10. Method according to claim 8 or 9, wherein the food temperature (TGG) is measured during the preheating phase and parameters for determining following cooking chamber temperatures (TGR(l), TGR(2)) are derived from the course of the food temperature.
11. Cooking device suitable for carrying out a method according to one of the preceding claims with a cooking chamber for receiving the food, a food temperature measurement probe for measuring the food temperature (TGG) of the food, and a controller, which is designed to control the cooking chamber temperature (TGR) in the cooking chamber during the food temperature regulating phase such that the food temperature (TGG) of the food follows a time-dependent desired food temperature function (TGGS) and such that the desired food temperature function (TGGS) has at least two phases with different gradients, wherein the second phase, which follows the first phase, has a lower gradient compared to the first phase.
12. Cooking device according to claim 11 with a steam generator for heating the cooking chamber with steam.
13. Cooking device according to claim 11 or 12, wherein the food temperature measurement probe for measuring the food temperature (TGG) of the food is designed without a steam isolated bag.
14. Cooking device according to one of the claims 11 to 13, wherein the controller is designed in such a way that the gradient of the desired food temperature function (TGGS) in the first phase is at least on average between 0.7°C/min and 1.5°C/min.
15. Cooking device according to one of the claims 11 to 14, wherein the controller is designed in such a way that it determines the gradient in the second phase by the temperature difference between the food temperature at the end of the first phase and the end food temperature (TGGE) and a remaining cooking time at the end of the first phase.
16. Cooking device according to one of the claims 11 to 15, wherein the controller is designed in such a way that it measures the food temperature (TGG) during a heating phase which precedes the desired food temperature regulating phase with the at least first and second phases and that it determines parameters for adjusting following cooking chamber temperatures (TGR) from the course of the food temperature .