The present invention relates to the field of cooking devices, and, more particularly, to cooking containers for use in a microwave oven for cooking meats, vegetables, and other food products.
Consumers often prefer to cook food in a microwave oven rather than conventional ovens because of the reduced cooking time required to heat foods in a microwave oven. Consumers also want to be provided with the opportunity to cook pre-packaged food products in the package in which they were purchased without the hassle of transferring the food from one container to the next.
Unfortunately, foods cooked in a microwave oven tend to be tough and/or dry in texture and consistency, rather than tender and moist. When liquid is added to the food in an attempt to retain moisture, the food can become soggy and undesirable. In addition, microwave ovens do not evenly distribute heat to the product being cooked. This results in a cooked food product that may be very hot in one area, but cold in another area. Because of these problems, many people consider microwave cooking to be problematic and generally undesirable.
One method for improving the texture and consistency of food cooked in a microwave oven is to use steam generated by the heated food product to assist in cooking the food. Cooking with steam not only provides moisture for the food being cooked, but also results in more consistent heating throughout the food product.
Specifically, a container using the steam generated by the heated food product to assist in cooking the food takes advantage of the ideal gas law, a distillation of several kinetic theories including Boyle's Law and Gay-Lussac's Law. More specifically, such containers take advantage of the proportional relationship between pressure and temperature when volume and number of gas molecules remain constant. This proportional relationship can be expressed as a mathematical equation, (P2/P1)=(T2/T1), where P1 is the initial pressure, P2 is the final pressure, T1 is the initial temperature, and T2 is the final temperature. Accordingly, any increase in pressure will result in a proportional increase in temperature that would not occur at ambient pressures. For example, if the pressure was to increases 1.2 fold (e.g., from 1 to 1.2 atmospheres), the temperature would also increase 1.2 fold (e.g., from 275 K to 330 K, which is an increase from 35° F. to 134° F.).
In order to steam cook a food product in a microwave oven, the steam must be retained within a cooking container; accordingly, the container must be at least partially sealed. When a sealed container is used to heat a food product contained therein, pressure rapidly builds as steam is generated from the heated food product. As heating continues, this pressure will continue to escalate until the container ruptures in some fashion, thereby relieving the pressure.
This relief often comes in the form of an explosion forcing an opening of the container and resulting in food being ejected therefrom. Not only does such an explosion create a mess, but it also undermines the attempt to use steam to cook the food product because the explosion causes a rapid release of the collected steam from the no longer sealed cooking environment. To avoid this problem, venting mechanisms may be provided to allow for controlled release of pressure and steam from the container. When such venting occurs, the enhanced heating environment created by the heightened pressure and contained steam is destroyed.
When preparing certain food products, this single treatment of pressure is beneficial to the cooking process, but is difficulties remain. For example, when preparing a cup or bowl of frozen soup using a single treatment of pressure, a lengthy cooking time is required to ensure that the center of the frozen bowl of soup is sufficiently heated. However, if the frozen soup is subjected to multiple treatments of pressure, the soup is cooked more evenly and the cooking time is reduced.
It is therefore the paramount object of the present invention to provide a microwave cooking container with a sequential venting arrangement that allows food product to be subjected to multiple pressure treatments.
This and other objects and advantages of the present invention will become apparent upon a reading of the following description.
The present invention is a microwave cooking container with a sequential venting arrangement that allows food product to be subjected to multiple pressure treatments during preparation. The structural features of the container of the present invention define an initial volume, holding food product, and at least one additional volume holding the initial volume. Additionally, there is a venting mechanism associated with each volume. It is not important which type of venting mechanism is used as long as it allows for a controlled release of pressure and steam from the volume after a desired pressure has been reached. For example, the venting mechanism may be a complex valve or a simple pin hole or a weakened portion in a seal enclosing the volume.
In the embodiment of the present invention depicted in
The container 10 of the present invention works in the following manner. When the container 10 is heated, pressure rapidly builds in the initial volume 14 as steam is generated from the heated food product. As heating continues, the pressure continues to build until the venting mechanism 15 associated with the initial volume 14 allows for a controlled release of pressure and steam. The steam is released from the initial volume 14 into the additional volume 24. As heating continues, the steam again causes pressure to build, this time within the additional volume 24, until controlled venting at the venting assembly 25 associated with the additional volume 24 occurs. Of course, the container may include subsequent volumes having associated venting mechanisms, allowing for subsequent pressure treatments.
The sequential venting of the container of the present invention results in the food product being subjected to an initial pressure treatment, followed by a drop in pressure before being subjected to one or more subsequent pressure treatments. Such sequential pressure treatments reduce the cooking time of food products, provide food products which are more evenly cooked, and result in prepared food products of a desired texture and consistency.
Of course, the container of the present invention may take various forms as long as the structural features enclose multiple volumes, as described above, and each volume has a venting mechanism associated therewith such that, when heated, food product is subjected to multiple treatments of pressure.
For example,
An additional alternative embodiment of the present invention is depicted in
Still additional embodiments of the present invention are depicted in
Of course, the embodiments depicted in the Figures are merely exemplary and it is contemplated that containers having a variety of structural features could be used without departing from the spirit and scope of the present invention as long as the structural features enclose at least one initial volume and at least one additional volume, holding the at least one initial volume, and each volume has a venting mechanism associated therewith.
Of course, the container of the present invention may include a variety of additional refinements. For example, in the case of the embodiment depicted in
It will be obvious to those skilled in the art that other modifications may be made to the invention described herein without departing from the spirit and scope of the present invention.
This application claims the benefit of U.S. Provisional Application No. 60/509,320 filed Oct. 7, 2003, which is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US04/14907 | 5/12/2004 | WO | 00 | 4/7/2006 |
Number | Date | Country | |
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60509320 | Oct 2003 | US |