GB2236469A

GB2236469A - Method of preparing a food product; packaged food product

Info

Publication number: GB2236469A
Application number: GB9018452A
Authority: GB
Inventors: Kazumitsu Taga; Morio Taniguchi; Ryusuke Nakanaga; Kayo Kataoka
Original assignee: House Food Industrial Co Ltd
Current assignee: House Foods Corp
Priority date: 1989-08-28
Filing date: 1990-08-22
Publication date: 1991-04-10
Anticipated expiration: 2010-08-22
Also published as: JPH0383562A; JP2640538B2; DE4027077C2; DE4027077A1; FR2651097B1; FR2651097A1; GB9018452D0; KR0149443B1; KR910004123A; GB2236469B

Abstract

In a method of preparing a food product, a paste topping is provided including (a) 15-30% by weight of oil fat or mixtures thereof, (b) 55-65% by weight of water and (c) 0.3-4% by weight of salt, wherein the sum of (a), (b) and (c) is preferably less than 90% by weight of said topping. The topping preferably contains skimmed dry milk and an emulsifier. The topping is applied to the food stuff disposed in a container made of a material permeable to microwaves, the container having a side and a bottom, both of which are at least partially made of a material impermeable to microwaves. Microwaves are applied until the topping is browned and the food stuff heated. A prepared, packaged food product comprises the container, a foodstuff in the container and the paste topping preferably separately sealed for example in a polypropylene pouch.

Description

SPECIFICATION

TITLE OF THE INVENTION

PREPARED PACKAGED FOOD FOR MICROWAVE COOKING AND METHOD OF PREPARING A FOOD PRODUCT BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to prepared, packaged food product to be cooked in a microwave oven; specifically it relates to food prepared in such a way that, when heated by microwave, the topping placed over the food takes on uniform browning in a short time.

The invention also reates to a method of preparing a food product by microwave and a product made by the method.

Description of the Prior Art

Gratin dishes, doria, coquille and other similar dishes are served with their surfaces lightly and evenly browned, which adds flavor and makes the food more appetizing.

A number of such food products packaged in sealed containers have been developed and marketed so that they can be readily enjoyed at home. These products, usually consist of prepared gratin dish with topping on their surface, are packaged and sealed in either aluminum or plastic-coated aluminum containers, and distributed at low temperatures. These products are distributed at low temperatures with the surface of the topping browned before packaging to eliminate the need for browning before serving. Since such food products are kept at low temperatures, they need a long time to become hot as treated in a microwave oven, and are also prone to be unevenly cooked and browned because the "hot spots" formed within the food during the radiation absorb more microwave energy than other parts of the food.

Microwave ovens are freguently used at home for cooking and warming food, however, they are generally considered inappropriate for cooking, for example, the above-mentioned gratin dishes, since food usually does not become browned as couked in a microwave oven.

Toaster-ovens, for example, are commonl- used fj.,. broi,-i-.t.. gratin dishes, however, their high c-nk4ng temperature limits the materials of containers to highly iieat-.t---.. it materials such as steel, and _t also makes the cooking more cumbersomp. Thus, there has benn a lonfelt need for a product which, when heated by means of microwave, takes on tasty, aromatic, and uniform browning.

One method to allow food to -,rown in a microwave oven is to use a piece of aluminum foil affixed to the center of the lid, but the temperature of the lid rises too high as the food temperature rises, letting some of the lid material dissolve into the food. Furt'-2r, it is troublesome t_ have the lid kept on while cooking, which may sometimes cause burnt fingers as the contents suddenly bubble out of the gap between the container and the lid since one cannot see contents in the container through the lid.

SUMMARY OF THE INVENTION

The object of the present invention is to provide microwavable food product, which can be heated readily and safely in a microwave oven at home and produces uniform browning in the topping placed over the food when cooked in a microwave oven.

The inventors found that the surface of food browned readily and evenly when filled in a container partially made of a material impermeable to microwaves and coated the surface of the food with a paste topping comprising oil and/or fat, water, and salt.

Further objects, features and embodiments of the present invention will become apparent from the Detailed Description of the

Preferred Embodiments which follows.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a method of preparing a food product comprising the steps of:

providing a paste topping comprising (a) 15-30% by weight of oil, fat or mixtures thereof, (b) 55-65% by weight of water, and (c) 0.3- 4% by weight of salt; providing a container comprising a material permeable to microwaves, and having a side being at least partially made of a material impermeable to microwaves and a bottom being at least partially made of a material impermeable to microwaves; placing a food stuff in the container; coating the food stuff with the paste topping; and irradiating the container with a quantity and frequency of microwave radiation sufficient to brown the topping and heat the food stuff.

The present invention also provIdes a prepared, packaged food product, comprising:

a container comprising a material permeable to microwaves and having a side being at least partially made of a material impermeable to microwaves, and a bottom being at least partially made of a material impermeable to microwaves; food stuff disposed in the container; and paste topping separately sealed comprising (a) 15-30% by weight of oil, fat or mixtures the--eof, (b) 55-65% by weight of water, and (c) 03-4% by weight of salt.

The prepared food 1Droduct according to -.he Fresent invention may be, for e-.-imple. e comprising macaroiii and!-r other ingredients which, when covered with paste topping and cooked under a high temperature, take on attractive, flavorful, and tasty browning.

Examples of the prepared food include gratin dishes, doria and coquille.

The food stuff itself may consist of such ingredients as, for example, macaroni, ravioli, gyoza dumplings and/or other pasta; meat and meat products; seafood, fish and fish productst vegetables; fruit and --uit products; eggs and egg products; and bechamel sauce, dressing and other sauces. The food stuff may be cooked in tne usual way, while the ingredients and methods for cooking may be varied to those well known to those skilled in the art depending on the dishes to be prepared.

Materials permeable to microwaves for preparing a containpr used in the present invention is permeable to 80% of 500-1500 watt, 2,400-2,500 MHz microwave radiation when made into 1 mm-thick sheet,. Examples of the material permeable to microwaves include polypropylene and other polymer material, glass, ceramics, and paper, any of which may be suitable for the container according to the present invention.

Materials impermeable to microwaves for preparing the container of the present invention reflect not less than 99% of the microwaves under the conditions defined above. An example of the material impermeable to microwaves includes a 7 U m-thick aluminum foil The container used in the present invention may be in a shape of polygonal, oval, or circular. A preferred container for the present invention is, for example, a 200 cc plastic container in oval shape with 100cd in base area and 2 cm in height.

With respect to the above, preferred container embodiment, (a) a side of the container is made of a meterial impermeable to microwaves at least in an area contacting the food stuff, and (b) a bottom of the container is made of a material impermeable to microwaves at least in an area comprises a periphery of the bottom of the container. By arranging a material impermeable to microwaves in such a way as that described above, most of the microwave energy generated in a microwave oven is concentrated on the surface of the food disposed in the container, which enable a paste topping applied on the surface of the food stuff to become evenly and lightly browned during microwave radiation.

In the case where the side of the container, which is permeable to microwave, is coated with a material impermeable to microwaves, the material impermeable to microwaves may cover not less than about 90% of an area contacting the food stuff uniformly filled in the container, i.e., an area of the side of the container that is level and below the surface of the food stuff. The area of the side of the container which contacts the food stuff may include not more than 10% of uncoated area depending on the molding process or the shape of the container. The side of the container may be coated completely with the materi-.1 impermeable to microwaves.

In the case where t"ie mater;-il imDeri"-iable to microwaves is coated at least in an area comprises a F-,-riphiry of the bottom of the contain:-, made material perr,.able to microw:-,es, the coating may be extended from the entire periphery or a part of the periphery of the bottom of the container toward the center of the bottom. The coated area of the bottom of the container may include a coated area which does not contact with the periphery of the bottom of the container. The bottom of the container made of the material permeable to microwaves may be coated with the material impermeable to microwaves not less than 10% of the total area ef the bottom of the co-ainer. The bottom of the container may be completely coated with the material impermeable to microwaves.

The container according to the present invention may be coated with the material inpermeable to microwdves either on the inside or on the outside of the container. The greater the coated area is, the more microwaves are concentrated to the surfart- of the food, however, heating becomes less efficient which results in slowing down the rise in food temperature. The smaller the coated area is, on the other hand, the quicker the food temperature rises, however, microwaves are less concentrated on the surface, which makes it more difficult to obtain uniform browning in the topping placed over the food stuff. Therefore, the area to be coated with the material impermeable to microwaves should be determined according to the type of the food stuff to be filled into the container as well as the type and amount of the paste topping. If the area coated with the material impermeable to microwaves is smaller, it is desirable to attach feet to bottom of the container, since the heating efficiency may vary greatly depending on the output energy of a microwave oven or the material of the rotating table.

For optimum heating efficiency and quality of browning of the topping, using an oval container, for example, with 30-50% of its bottom coated with the material impermeable to microwaves from the periphery, in a doughnut fashion, is preferable. In order to tightly seal the container containing the food stuff, the container is provided with a lid which can be preferably removed readily by pealing off from the body of the container.

The paste topping according to the present invention may be a pasty substance that is placed almost evenly over the food stuff in the container prior to microwave cooking. The paste topping is separately sealed from the food stuff disposed in the container. One who wishes to cook the prepared food of the present invention may peal open the container to uncover the food stuff and coat the food stuff with the paste topping, and cook in a microwave oven for a prescribed time.

The paste topping may contain (a) 15-30% by weight of oil and/or fat, (b) 55-65% by weight of water, and (c) 0.3-4% by weight of salt, and the sum of (a), (b) and (c) may be less than 90% of the total weight of the paste topping.

The paste topping, which is preferably filled and sealed tightly in a polypropylene pouch or the like and provided together with the food stuff disposed in the container, has a viscosity convenient for squeeAng out from the pouch which enable one to coat the paste topping ear,.ly and-,--7enly on '-he surface of the stuff food in the container. If the paste tk.pping contains too little salt, it du,s not -sufficiently:-,rowned wzien coo--d in a microwave oven. If the paste topping contains too murh oil andlor fat and too much water, the topping flows out of the pouch which results in difficulty in coating the paste topping evenly over the food stuff. If the paste topping does not contain enough oil ind water, it becomes difficult to squeeze out,the paste topping from the pouch. If the topping contains too much salt, it overbrowns before the entire gratin dish is heated. If the sum of (a), (b) and (c) is 90% or more of the total 2C weight of the paste topping, the topping does not become efficiently browned as cooked in a microwave oven. In addition to the above ingredients, the paste topping may contain dry milk, casein and other proein components as well as sucrose, lactose and other sugars. 25 The above paste topping, when frozen and formnd into a block measuring 40 mm in length, 40 mm in width, and 18 mm in height and then heated in the microwave oven at 180-watt output until the center of the topping reaches at 700C, spreads over an area of not less than 2.89 times, preferably 2.89-2.98 times of the original area (40 mm x 40 mm) in the bottom. If the rate of the spread is too small, the topping will not be distributed to cover the entire surface of the food stuff in the container when cooked in a microwave oven.

When the food stuff in the container is cooked in a microwave oven together with the paste topping placed over the surface of the food stuff, the food stuff warms up while at the same time the paste topping browns lightly and evenly, which makes the food of the present invention a tasty dish with full aroma. One embodiment of the present invention is to fill 170 g of food stuff in an oval 200 cc container, 35% of whose bottom is coated in the periphery with the material impermeable to microwaves, cover the food stuff with 40 g of the paste topping, and then cook in the microwave at 500 watts for 4 minutes to produce the finished dish.

Since the food stuff itself is filled and sealed in the container and the paste topping is separately sealed, the dish of the present invention can be kept at room temperature with little alteration in quality and appearance with passage of time, and is particularly suitable for storing at home.

A tasty, aromatic dish with uniform light browning on top can be cooked in a microwave oven by means of the present invention by filling prepared food stuff in the container which has a side and a bottom, both of which are at least partially made of a material impermeable to microwaves, and covering the food stuff with the paste topping that browns when cooked in a microwave oven. Cooking the:food of the present invention in a microwave oven is easy and convenient, and thus is ideal for home cooking since contents never boil out of the container.

EXPERIMENTAL Example 1 Containers Bottoms and sides of plastic containers (oval shape of 140 mm maximum di4 eter, lJ mm r---',,ium diameter, and 25 mm deep) were coa-- , with aluminum foil in varying areas as shown in Table 1.

Gratin Dish parts by weight of boiled macaroni, 20 parts by weight of onions, 15 parts by weight of chicken pieces, 2 parts by weight of mushrooms and 100 parts by weight of bechamel sauce, totaling 170 parts by weight'were put together and mixed.

Paste Topping_ 20 parts by weight ol vegetable oil, 20 parts by weight of skimmed dry milk (water content about 4%), 59 parts by weight of water, 1 part by weight of salt, 0.05 part by weight of stabilizer (phosphate), 0.1 part by weight of emulsifying agent (lecithin) were mixed and then cooked at 60 'C with constant mixing to prepare the paste topping. The obtained paste topping contiL;..'.-.ed 20% by weight of oil, 60% by weight of water, and 1% by weight of salt.

- 1 0 - Each of the above-mentioned plastic containers was filled with 170 parts by weight of gratin ingredients, which was then covered with 20 parts by weight of paste topping, followed by being heated in the microwave oven (500 watts) for 4 minutes to check out how the paste topping browned. The results are shown in Table 1.

- 1 1 - tO L.0 C31 0 0 Table 1

Sample A B Evaluation 1 Area that comes in 100 Ent.'re surf4ce browned, although area near the side contact with food browned more than the center.

2 Entirely 100 Entire surface browned. Food at the bottom warmed up a little m -e slowly.

3 Entirely so Food warmed up evenly, although browning was slightly Periphery of the bottom lighter than sample 2.

4 Entirely 10 Browning was even lighter than Sample 3.

Periphery of the bottom Food at the Lottem warmed up a little more quickly than other parts.

Sample for 1 None 100 Food warmed up quickly at the side, and boiled before ccmparison the surface begined to brown. Center of the food was lukewarm.

Sample for 2 Entirely 0 A part of food at the bottom started boiling before comparison the surface begined to brown.

A. Aluminum-foil coating on the side of the container B. Aluminum-f iol coating in the bottom of the container (percentage of coated area with respect to the entire bottan area.) 11 0, 11 As seen in Table 1, the food of the present invention filled in the container that has been coated with aluminum foil on the side at least in the area contacting the food stuff disposed in the container and on the bottom around the periphery, took on flavorful taste with even browning.

Example 2 Containers The containers of Sample 2 in Example 1 were used in this experiment. Gratin Dish Same as those used in Example 1. Paste Topping Vegetable oil, skimmed dry milk (water content of about 4%), salt, stabilizer (phosphate) and emulsifying agent (lecithin) were mixed in varying proportions so that the percentages of oil, water, and salt in the paste topping came out as shown in Table 2. The resulting mixture was cooked at 60 C with stirring to prepare the paste topping samples.

The dishes were cooked according to the method and conditions described in Example 1. Results obtained are shown in Table 3.

1 - 1 3 - Table 2

Sample Oil Water Salt Total 15 55 0.3 70.3 6 20 60 1.0 81.0 7 30 55 1.0 86.0 8 20 65 3.0 88.0 Comparative Examples 3 10 so 0.1 60.1 4 10 55 0.3 65.3 5 15 50 0.3 65.3 6 15 55 0.1 70.1 7 30 60 3.0 93.0 8 35 56 3.0 88.0 9 35 55 3.0 93.0 15 70 3.0 88.0 11 20 70 3.0 93.0 12 20 60 5.0 85.0 Total percentage of oil, water and salt in the paste topping.

1 4 Table 3

C. Ease of squeezin out D. Spreading when heated E. Browning Sample -- C D E Evaluation 0 0 0 Had the consistency of rather hard cream cheese. Browned somewhat lightly but fairly nicely.

6 0 0 Smooth and easy to distribute.

7 0 Q Spread thinly when heated and browned nicely.

8 @ 0 @ Easy to squeeze out and spread well when heated. Browned nicely.

Sample for 3 X X X Distributed poorly and unevenly.

comparison Sample for 4 A Did not spread well. Part of the gratin boiled.

comparison Sample for 5 A Hard and difficult to be distributed. Did not spread well.

comparison Sample for 6 0 0 X Spread smoothly but did not brown.

comparison Sample for 7 0 @ Topping warmed up rapidly. Changed color but did not form brown crust.

comparison Sample for 8 0 Spread when heated but did not brown well.

comparison Sample for 9 X 0 X Changed color but did riot brown.

comparison Sample for 10 0 A Started to burn after 3 minutes, but did not form brown crust.

comparison Sample for 11 0 A X Fl out of trie pouch. Browned very little.

comparison Sample for 12 0 Browned nicely, but the bottom warmed up very slowly.

comparison Evaluation Symbols Ease of squeezing out: @ very easy to squeeze out and to handle, Oeasy to squeeze out and to handle, nsrather hard to squeeze out, X hard to squeeze out.

Spreading when heated: spreads nicely, 0 spreads fairly, does not spread well, X does not spread at all.

Browning: @ Browns very nicely, 0 browns well, rowns slightly, X does not brown.

As seen in the evaluation shown in Table 3, the best results J.0 were obtairic, vith the paste topping composed of 15-30% by weight of oil andlor fat, 55-65% by weight of water, and 03-0.4% by weight of salt, and the sum of these components is less than 90% of tne total weight of titc. toppin,.

Although the invention is described in terms of several preferred embodiments, one of ordinary skill in the art will recognize that modifications and improvements may be made while remaining within the scope of the present invention.

I 1 1 - 1 6 -

Claims

What is claimed is:

1. A method of preparing a food product, comprising the steps of: providing a paste topping comprising (a) 15-30% by weight of oil, fat or mixtures thereof, (b) 55-65% by weight of water, and (c) 0.3- 4% by weight of salt;' providing a container comprising a material permeable to microwaves, and having a side being at least partially made of a material impermeable to microwaves and a bottom being at least partially made of a material impermeable to microwaves; placing a food stuff in the container; coating the food stuff with the paste topping; and irradiating the container with a quantity and frequency of microwave radiation sufficient to brown the topping and heat the food 15 stuff.

2. A method according to claim 1, wherein the sum of (a), (b) and (c) is less than 90% of the weight of the topping.

3. A method according to claim 1, wherein the topping further comprises skimmed dry milk.

4. A method according to claim 1, wherein the topping further comprises an emulsifier.

5. A method according to claim 1, wherein said side of the - 1 7 container is made of material impermeable to microwave radiation at least in an area contacting said food stuff.

6. A method according to claim 5, wherein said bottom of the container comprises a periphery made of material impermeable to microwaves.

7. A method accoding to claim 1, wherein said material permeable to microwaves is permeable to 80% of 500-1500 watt, 2,400 - 1 r, 2,5C."-!--iz microwave radiation.

8. A tiethod accoding to c..aim 1, wherein -aid material imper-:.table tn microwaves reflects 99% of 500-1500 watt, 2,400-2,500 MHz microwave radiation.

9. A prepared packaged food product, comprising:

a container comprising a material permeable to microwaves and having a side being at least partially made of a material imperme--b-'a to microwaves, and a bottom be-ng at leas,' _ rtially made 20 of a material impermeable to microwaves; food stuff disposed in the container; and paste topping comprising (a) 15-30% by weight of oil, fat or mixtures thereof, (b) 55-65% by weight of water, and (c) 0.3-4% by weight of salt. 25

10. A product according to claim 9, wherein said topping is separately sealed.

11. A product according to claim 9, wherein the sum of (a), (b) and (c) is less than 90% by weight of said topping.

12. A product according to claim 9, wherein said topping further comprises skimmed dry milk.

13. A product according to claim 9, wherein said topping 10 further comprises an emulsifier.

14. A product according to claim 9, wherein said side of the container is made of a material impermeable to microwaves radiation in an area contracting said food stuff.

15 15. A product according to claim 9, wherein said bottom of the container comprises a periphery made of a material impermeable to microwaves.

16. A product according to claim 9, wherein said material impermeable to microwaves is permeable to 80% of 500-1,500 watt, 2,400-2,500 MHz microwave radiation.

17. A method accroding to claim 1, wherein said material impermeable to microwaves reflects 99% of 500-1,500 watt, 2,400-2,500 MHz microwave radiation.

1 9

18. A food product made according to the process recited in any one of claims 1-8.

Published 1991 at The Patent OfficL. State House. 66171 High Holborn. London WC1R41P. Further copies may be obtained from Sales Branch. Unit 6. Nine Mile Point. Cwmfelinfach, Cross Keys, Newport. NPI 7HZ. Printed by Multiplex techniques ltd. St Mary Cray. Kent.