Abstract
The present invention relates to a temperature control device comprising a control unit for controlling a heating unit of a food cooking device according to the following control scheme: i) a preheating period for heating up the food to a first food temperature of at most 60 C.; ii) a temperature holding period for holding the food temperature within a temperature range of 30 C. to 70 C. for at least one minute; and iii) a heating period for heating up the food to a second food temperature of at most 100 C. This control scheme ensures that -glutamyl hydrolase is not thermally inactivated and thus can hydrolyze polyglutamate forms of folate into monoglutamate forms and that folate bioavailability during cooking processes is enhanced.
Claims
1. A temperature control device comprising a control unit for controlling a heating unit of a food cooking device according to the following control scheme: i) a preheating period for heating up the food to a first food temperature of at most 60 C.; ii) a temperature holding period for holding the food temperature within a temperature range of 30 C. to 70 C. for at least one minute; and iii) a heating period for heating up the food to a second food temperature of at most 100 C.
2. The temperature control device according to claim 1, further comprising a sensor input for receiving sensor data representing the food temperature.
3. The temperature control device according to claim 1, further comprising a food type input for receiving food type information identifying the type of food.
4. The temperature control device according to claim 1, wherein the control scheme further comprises a cooling period for cooling the food after the food temperature has reached the second food temperature.
5. The temperature control device according to claim 1, wherein the control unit is configured to control a cooling unit for cooling the food in a cooling period after the food temperature has reached the second food temperature.
6. The temperature control device according to claim 1, wherein the control unit is configured to control the heating unit in the temperature holding period to hold the food temperature in the range of 40 C. to 60 C.
7. The temperature control device according to claim 1, wherein the control unit is configured to control the heating unit in the temperature holding period to hold the food temperature within the temperature range of 30 C. to 70 C. for a holding time period in the range of 2 to 20 minutes, in particular 2 to 5 minutes.
8. A food cooking device comprising a heating unit and a temperature control device according to claim 1 for controlling the heating unit.
9. The food cooking device according to claim 8, further comprising a temperature sensor for sensing the food temperature and/or a food-related temperature from which the food temperature can be determined, wherein the temperature control device is configured to use the sensed temperature for controlling the heating unit.
10. The food cooking device according to claim 8, further comprising a user interface for receiving food type information identifying the type of food input, wherein the temperature control device is configured to use the food type information for controlling the heating unit.
11. The food cooking device according to claim 8, further comprising a food type sensor for sensing the type of food and generating food type information identifying the type of food, wherein the temperature control device is configured to use the food type information for controlling the heating unit.
12. The food cooking device according to claim 8, wherein the food cooking device is configured as baby food maker, multi-cooker, sous vide appliance, steamer, microwave oven, oven or hob.
13. A temperature control method for controlling a heating unit of a food cooking device according to the following control scheme: i) a preheating period for heating up the food to a first food temperature of at most 60 C.; ii) a temperature holding period for holding the food temperature within a temperature range of 30 C. to 70 C. for at least one minute; and iii) a heating period for heating up the food to a second food temperature of at most 100 C.
14. A temperature control method according to claim 13, wherein the control scheme further comprises a cooling period for cooling the food after the food temperature has reached the second food temperature.
15. A temperature control computer program comprising program code means for causing a computer to carry out the steps of the temperature control method as claimed in claim 13 when said computer program is carried out on the computer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. In the following drawings
[0040] FIG. 1 shows a schematic diagram of an embodiment of a food cooking device according to the present invention,
[0041] FIG. 2 shows a schematic diagram of an embodiment of a temperature control device according to the present invention,
[0042] FIG. 3 shows a schematic diagram of another embodiment of a food cooking device according to the present invention,
[0043] FIG. 4 shows a side view of an exemplary implementation of an embodiment of a food cooking device configured as baby food maker according to the present invention,
[0044] FIG. 5 shows a front view of an exemplary implementation of an embodiment of a food cooking device configured as a steamer according to the present invention,
[0045] FIGS. 6A and 6B show a flow chart of an embodiment of a method for cooking food using a temperature control method according to the present invention and typical cooking temperature profiles according to the present invention,
[0046] FIG. 7 shows the relationship between temperature and plant (beetroot) cell compartments integrity (heating time: 3 min),
[0047] FIG. 8 shows the relationship between the folate composition in broccoli with respect to the number of glutamate chains in polyglutamate forms of folate and two cooking methods, and
[0048] FIG. 9 shows the relationship between the folate composition in carrots with respect to the number of glutamate chains in polyglutamate forms of folate and two cooking methods.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0049] FIG. 1 shows a schematic diagram of an embodiment of a food cooking device 1 according to the present invention. The food coking device 1 comprises a temperature control device 2 including a control unit 3 for controlling a heating unit 4, which is configured for heating the food in the food container 5.
[0050] The temperature control device 2 is configured for controlling a heating unit 4 of a food cooking device 1 according to a control scheme. The control scheme particularly comprises the following steps:
[0051] i) a preheating period for heating up the food to a first food temperature of at most 60 C.;
[0052] ii) a temperature holding period for holding the food temperature within a temperature range of 30 C. to 70 C. for at least one minute;
[0053] iii) a heating period for heating up the food to a second food temperature of at most 100 C.
[0054] While existing cooking methods do not include a temperature holding period, this temperature holding period ensures that -glutamyl hydrolase is not thermally inactivated and thus can hydrolyze polyglutamate forms of folate into monoglutamate forms. Further, only monoglutamate forms of folate can be absorbed by human gut intestinal mucosal cells. Hence, the present invention enhances folate bioavailability during cooking processes.
[0055] FIG. 2 shows a schematic diagram of an embodiment of a temperature control device 2 according to the present invention. The temperature control device 2 comprises a control unit 3 and may further comprise a sensor input unit 6 and/or a food type input unit 7. While the sensor input unit receives temperature data corresponding to the temperature of the food in the food container 5, the food type input unit 7 receives data corresponding to the type of food in the food container 5. Both the sensor input unit and the food type input unit may pass their data on to the control unit 3.
[0056] FIG. 3 shows a schematic diagram of another embodiment of a food cooking device according to the present invention. The food coking device 1 comprises a temperature control device 2 including a control unit 3 for controlling a heating unit 4 and/or a cooling unit 8, which are also comprised in the food cooking device 2. While the heating unit 4 is configured for heating the food in the food container 5, the cooling unit 8 is configured for cooling the food in the food container 5.
[0057] FIG. 4 shows a side view of an exemplary implementation of an embodiment of a food cooking device 1 configured as baby food maker according to the present invention. The food container 5 is configured as a cylinder having a lid 9 for closing the food container 5 and is encased by the heating unit 4 for guaranteeing a heat distribution that is as uniform as possible. The heating unit 4 is controlled by the temperature control unit 2.
[0058] As shown in FIG. 4, the food cooking device 1 may further comprise a temperature sensor 10 integrated in the food container 5 for sensing the food temperature and/or a food-related temperature from which the food temperature can be determined, wherein the temperature control device 2 is configured to use the sensed temperature for controlling the heating unit 4. Further, a food type sensor 11 for sensing the type of food and generating food type information identifying the type of food may be provided, wherein the temperature control device 2 is configured to use the food type information for controlling the heating unit 4. Furthermore, a user interface 12 for receiving food type information identifying the type of food input, wherein the temperature control device 2 is configured to use the food type information for controlling the heating unit 4.
[0059] In another embodiment of a food cooking device 1 the temperature sensor 10 may not be integrated in the food container 5, but put in the food container 5 by a user itself.
[0060] The food type sensor 11 may be configured to be a spectrometer analyzing the type of food.
[0061] The user interface 12 may be configured to receive type of food data from the user, but other input data like a desired end temperature of a starting time for the cooking process are also conceivable.
[0062] FIG. 5 shows a front view of an exemplary implementation of an embodiment of a food cooking device 1 configured as a steamer according to the present invention. The food container 5 is configured as a cylinder comprising several food cooking compartments 13, 14, 15 having a lid 9 for closing the food container 5. Directly below the food container 5 there is a water tank 16. The water in the water tank 16 may be heated up by the heating unit 4, which is controlled by the temperature control device 2, such that steam is produced for steaming food located in the food cooking compartments 13, 14, 15 of the food container 5. The temperature control is both connected to a temperature sensor 10 integrated in the food container 5 sensing the food temperature and/or a food-related temperature from which the food temperature can be determined and to a user interface 12 receiving food type information identifying the type of food input.
[0063] FIG. 6A shows a flow chart of an embodiment of a method for cooking food using a temperature control method according to the present invention. After preparing the food it is important that the food temperature is held within a temperature range of 30 C. to 70 C. for at least one minute during a temperature holding period before high temperature cooking.
[0064] FIG. 6B shows a typical cooking temperature profile according to an embodiment of the present invention. During phase 1, a preheating period, the foods are preheated from the start temperature to the beginning temperature of phase 2. Instead of heating up the foods further in a continuous manner, phase 2 represents a low temperature holding period, in which the food temperature range is set within 40 C. to 60 C. At such temperature range, heat input on vegetables can destroy cell compartments so that both -glutamyl hydrolase and folate can be released from their own organelles, respectively. But such levels of temperature cannot inactivate most -glutamyl hydrolase, as a result, -glutamyl hydrolase can hydrolyze polyglutamate forms of folate into monoglutamate forms (and shorter chains of polyglutamate forms of folate) within minutes. And only monoglutamate forms of folate can be absorbed by human gut intestinal mucosal cells. Hence, the bioavailability of monoglutamate forms of folate from vegetables is higher than the mixture of mono- and polyglutamate forms of folate. In phase 3, a heating period, the foods are heated up until the accepted doneness level. The heating methods in phases 1-3 can be any of current available heating and temperature control technologies. Phase 4 represents a cooling period, in which the food is cooled to accepted temperature. The methods of cooling can be any of available methods including active and passive cooling methods.
[0065] FIG. 7 shows the relationship between temperature and plant (beetroot) cell compartments integrity during a heating time of 3 minutes. As shown in FIG. 7 the integrity of plant cells decreases with temperature. Heat treatment at 40 C. food temperature for 3 minutes can destroy 20% plant cells, while heat treatment at 60 C. food temperature for 3 minutes can destroy 60% plant cells. Although higher food temperatures, for example 70 C., can destroy more plant cells, such higher temperatures can bring more side effects, especially on heat-sensitive nutrients, which is considered as major drawback of high temperature. Therefore, a temperature range between 30 C. to 70 C. is selected for the temperature holding period in the temperature control method according to this invention.
[0066] FIG. 8 shows the relationship between the folate composition in broccoli with respect to the number of glutamate chains in polyglutamate forms of folate and two cooking methods, cooking method 1 being an existing cooking method of a baby food maker and cooking method 2 being a cooking method including the temperature control method according to this invention. As can be seen from FIG. 8, cooking method 1 discloses less folate content the shorter the glutamate chains in polyglutamate forms of folate become. Contrary to method 1, method 2 discloses more folate content the shorter the glutamate chains in polyglutamate forms of folate become, with two-chain polyglutamate forms of folate and monoglutamate forms being an exception. In cooking method 1, a higher concentration of long chains polyglutamate was found, while in cooking method 2, the folate composition shift from long chains to short chains with a higher concentration in short chains (n=1-5).
[0067] FIG. 9 shows the relationship between the folate composition in carrots with respect to the number of glutamate chains in polyglutamate forms of folate and two cooking methods, cooking method 1 being an existing cooking method of a sous vide appliance and cooking method 2 being a cooking method including the temperature control method according to this invention.
[0068] As can be seen from FIG. 9, a higher ratio of long chain of polyglutamate forms of folate were found in carrots treated with cooking method 1, while a higher ratio of short chain polyglutamate forms of folate and monoglutamate folates were observed in carrots with cooking method 2. This fact indicates more enzyme activities of -glutamyl hydrolase on deconjugation of polyglutamate forms of folate during cooking method 2.
[0069] Therefore, cooking vegetables according to method 2 folates can be absorbed easier.
[0070] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.
[0071] In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
[0072] A computer program may be stored/distributed on a suitable non-transitory medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.
[0073] Any reference signs in the claims should not be construed as limiting the scope.
