GB2177678A - Heatpacks for food - Google Patents

Abstract

A heatpack base sheet (1) for use in making a pouch forming a virtually enclosed pack containing a prepared meal has tongues which define an opening 2 through which the meal may be deposited on a plate after heating. The base sheet may be of electrically non-conductive synthetic resin, if intended for use in a microwave oven, or may be of conductive foil if the meal is to be defrosted in a thermally-heated oven. A hole may be provided in the centre of the base sheet, surrounded by radially-extending slits which form the tongue or tongues. An underlay (4) may be provided to assist in securing the packed food in place in an attractive array, but allow it to pass out of the pack when heated. <IMAGE>

Description

SPECIFICATION Heatpacks for food This invention relates two heatpacksforfood, to be used in forming an integral part ofthe packaging, and also facilitate serving of food, such as pre-cooked or prepared meals.

Heating food from a frozen state is becoming an increasingly valuable method in both the catering and the domestic kitchen, using any type of oven. A particular advantage is offered by microwave ovens, because of their ability to defrost and cook food from the frozen state in a relatively short time, and this is particularly advantageous in the case of reheating a pre-cooked meal, when the time required becomes very short. However,there is a tendencyfor a preprepared meal so treated to overheat at its edges and form a dried ring around the dish before the centre is sufficiently hot, which is most unattractive.Thus, to ensure good presentation, it is necessary to transfer the hot meal from the heating dish to a clean prewarmed plate before serving, removing the dried portions in the process,which can betime-consuming, especially as the components of the meal need to be reassembled in an attractive array, ifthe maximum culinary effect isto be achieved. In the case of a thermal oven the meal may be heated on a suitable dish ortrayfor convenience, and then transferred to a serving plate.

In the case of a packed food that has been stored in a refrigerated or a chilled condition, and is to be served cold, the pack serves to retain and protectthe contents during the period required to bring itto room temperature after removal from a storage refrigerator or freezer, and the context of this Specification can be termed a "heating period".

One object ofthe present invention isto facilitate the serving of prepared food, particularly cooked meals defrosted and reheated on the serving plate, thus enabling an attractive meal to berapidlyserved in aconvenientmanner,whilstavoidingsomeofthe problems normally encountered.

Where used with a microwave oventhefood can be defrosted and prepared for serving on its serving plate, as heat induced into the food by the microwave radiation will warm the plate by thermal conduction during the defrosting and heating ofthefood. Inthe case of a thermally-heated over it is normally more convenient to use an over dish, because a serving plate could become too hot, and therefore it may remain necessary to transfer the heated meal on to a warmed plate for serving, but this process can also be facilitated in exemplary embodiments of the invention.

In accordance with one aspect ofthe invention there is provided a heatpack base sheet comprising a numberoftongues offoil orfilm of a material suitable for use with predetermined foodstuffs, said base sheet being provided to retain chilled or frozen food contained in a heatpack pouch formed using said base sheet, but opening freely to permitthe passage of said food through the resultant hole onto a serving plate when said food has been heated as required.

According to another aspect the present invention consists in a method of serving food comprising the steps of arranging food in an appetising array on a thinbase sheetoffilm orfoil that is formed in accord- ance with the first aspect, the food being arranged to coverthetongue ortongues, and then wrapped in a pouch formed using said base sheet, subsequently heating said pouch as necessary, and when ready for serving, lifting the pouch to allow the contents to pass through the opening and lie in an attractive predermined array on said plate.

Partially enclosing the meal in a foil orfilm cut in suchafashion,withahole beneath the meal large enough to allow easy removal of such a meal,yet small enough to prevent seepage during reheating.

assists even heating, and prevents the formation of a ring of burnt food on the plate. If only a singletongue is provided, then it will be formed bya narrowcut extending around three-quarters of the periphery of the base member, to lie contiguous with a marginal zone forming part of a completed heatpack pouch, or constituting an integral part thereof.

If there is a pluralityoftongues,thentheirneighbouring edges will lie substantially contiguous, and may extend so that the tips are each contiguous with atip of one ormore ofthe othertongues. Many configurations can be used, and the pattern of the cuts and the shaping ofthetongues can be selected in accordance with the particular food that is to be contained in a pouch.

A preferred configuration has radially-extending slits meeting ata central point to form a ring oftongues, each extending to that point. In an advantageous modification that has been found to be advantageous with some food combinations is a ring of such tongues, truncated to form a generally circularcentral aperture.

For use in microwave ovens the heatpack pouch will be formed with a base memberthatis ofan electrically non-conductive material, and if seepage is found to be a problem an underlay of imperforate material may be applied to the under surface ofthe packto hold the tongues in position during storage.

However, such an underlay has no real function during defrosting and heating, and would need to be removed from the serving plate without disturbing the heated food, and therefore it may be removed from the pack before the pouch is placed on its serving plate and inserted in the microwave oven.

For use in thermally-heated ovens of any type, the heat-pack pouch can be of electrically-conductive material, and a metallic foil is commonly used in making conventional trays or dishes for frozen food.

In embodiments constructed in accordance with the invention, such material can be used, provided with the tongue ortongues, if the pouch pack is an integral monolithic structure of a material thin enough to give tongues ofthe requisite flexibilityto allow free pas sage for the heated food. To complete a two-part pack a base memberwith tongues can be combined with a cover member, which can be electrically conductive if the pack is tp be used in a thermal oven. Alternatively, a non-conductive film can be usedfora cover, such as may be used in embodiments intended for microwave ovens. Materials are now available that ahe suit ableforeithertype of oven, and if so desired, a heatpack in accordance with the invention can be used employing such materials.

Moresignificantly, asthe use of a thermal oven involves heating the tray or dish on which the pouch is positioned to an uncomfortable temperature, it is advantageous in a thermal oven application to use an oven tray or dish andtransferthemealtoawarm serving plate. The presence of an underlay is then doublyadvantageous,asitwill provide strength and protection forthe tongues during storage, and facili- tate transfer of the packfrom the oven dish or tray to the serving plate before the underlay is peeled away and the pouch lifted to deposit the food on the plate.

Thus, there is an advantage in the use of a metallic foil underlay in all cases, as the userwill be naturally inclined to remove such a foil from a frozen pack before inserting the pouch into a microwave oven, and this instinctive approach will significantly reinforce any printed instructions orwarningsthat may be provided on the pouch or any outer packaging.

In the case of a thermally-heated oven such a metal- licfoil underlay can be assumed to be readify acceptable to the user, and will be left in position so that it provides a useful safeguard against seepage as a heated pouch is transferred to its serving plate, after which the underlay can be pulled awayfrom under the pouch. The underlay can be provided with an extending tag or strip on which instructions are provided, and which will serve as a gripping memberto facilitate removal.

The heatpack may incorporate a rigid cover, or reinforcing frame or ring to which the base member is attached orwhich is enclosed within the pouch.

The elements required to make up a heatpackcould be sold as a kit of parts for domestic use, enabling a housewife to prepare and store a number of meals at a convenient time for use later, for example, butthe majorfields of use are thought to be the retail trade and catering field.

The invention will now be described with reference to the drawings, in which: Figure lisa plan view of a base member sheet laid flat over an optional secondary underlay to constitute an open pouch in one exemplary embodiment of the invention; Figure 2a is a partly exploded view showing precooked meal in position on an open pouch basemember, and an associated cover sheet priorto assembly to form a closed pouch; Figure is a simplified perspective view of an assembled pouch readyto befrozen and further packaged; and Figure 3 is a front view of a reheated meal being removed from the pouch.

The invention is applicable to packs or pouches of material suitabie for use in anyform of thermal oven chamber, or of material suitable for microwave ovens, or by choice ofthe appropriate materials, packs or pouches may be formed for use in eithertype of oven, using a thermally-heated chamber, orinduc- ing heat by microwave radiation, Forsimplicitywe will first consider an exemplary embodiment designed for microwave use, with reference to Figure 1.

A base member 1 of electrically non-conductive transparent synthetic resin film has a generally circular hole 2 at its centre, and this is surrounded by a plurality of contiguous, truncated tongues formed by the provision of radially-extending slits 3. For storage this may be laid on a simple underlay sheet 4, ofan appropriate, non-toxic synthetic resin, as shown by a broken line rectangle in the drawing.In this embodiment a cooked meal 5 is then assembled centrally on the pouch exactiy as it will eventually appear on the plate, so that the hole 2 and radiating slits 3 are covered buy a margin of 3to 4 cm., as shown in Figure 2a, and the edges of the sheet 1 are then folded overthe meal 5 in parcel fashion and secured with a plastic clip our similar means (not illustrated) to complete the pouch, afterwhich,the entire assembly can then be frozen or chilled for storage, as the case may be.

If frozen,the lowerfilm underlay4 may be peeled away, leaving the remaining pouch with its contents to be packed in an airtight outer cover (not shown), or if preferred, the film underlay 4 may remain as part of the original package, and may carry a notice that it needs to be removed before heating in the case of a microwave oven embodiment, ortho be removed after the reheating step has been accomplished, in the case ofthethermally-heated oven embodiment. As a further alternative, the underlay can be attached to, or form an integral partof,thesheet 1,folded back underneath as a flap to form an underlay that will be removed together with the base sheet 4 when the meal has been defrosted and heated, as will be described.

Figure 2a shows details of a modified exemplary embodiment, in which the meal 5 is laid on a base sheet of a size sufficient to leave an adequate margin around the meal, and a cover sheet ibis then laid over the assembly and sealed to the base sheet at or near its outer edges to form a pouch 1 c, as shown in Figure 2b. In this casethe underlay 4 can be flap on the base sheet 1 orthe cover sheet 1 b, by appropriate positioning before the meal is put into place.

To heat a frozen or chilled meal,the pouch and its contents are removed from the outer pack and placed on a serving plate 6, which will need to be heatresistant if a normal fuel-burning type of oven is used, but merely non-conductive electrically if used ion a microwave oven. The covered, but not sealed, effect of the folded pouch will allow the enclosed food to heat more evenly than if heated in an open dish, and, as the edge of the food is in contact with the pouch and not the plate, no unsightly ring will show around the perimeter of the finished meal.

After removal from the oven, the pouch is removed from the meal 5 bycarefullyliftingthe pouch up wards, as illustrated in Figure 3,the hole and radiat- ing slits 2 and 3then forming an opening large enough to allow removal with minimal disturbance to the food, leaving a finished meal5 with a freshlyprepared appearance served on a clean hot plate 6.

The pouch in this embodiment is made of a flexible synthetic resin film with non-toxic properties, that is stable attemperatures between -30 C and 1 20"C, such as is commonly used in the manufacture of "boil in the bag" covers.

The overall size of the open pouch should be such as to allow its edges to be folded neatly overto fully cover the food with sufficient excess to accommodate the chosen means offastening, if the separate cover sheet 1 b shown in Figure 2a is not used.

Afurther alternative is the use of a base sheet 1 that has an extension at one edge to form a cover sheet when folded over, after the meal has been put into position. The folded material can the be sealed around the periphery to form the required pack. The underlay can be sealed to the base sheet in the same operation, if it is not an integral flap on the base sheet 1. In orderto ensure a minimum disturbance ofthe cooked meal during removal ofthe pouch, an underlay can be formed by two flaps that slighty overlap below the centre ofthe hole 2, and such flaps can be integral with the base sheet to extend one from each of two opposed edges, or, if separate from the base sheet, can be pre-arranged to be suitably sealed at two opposed edges as the cover sheet is sealed.

Byway of example, the width of the opening formed by the hole 2 and the radiating slits 3 should be 6to 8 cm smallerthanthatdesiredforthefinished diameter of the meal 5, to prevent seepage during reheating, and the diameter if the hole 2 should be such as to allow the tongues formed between the radiating slits 3 to be sufficiently long to be held in place bytheweight of the meal 5, before and during freezing,whilst not being so long as to cause excessive disturbancetothe finished meal Son removal. It will be readily appa rent to the skilled readerthatthe precise dimensional relationships of hole, slits and the pre-positioned meal will be dependent to some degree on the natureofthefootstuffs.

If the packed meal is not intended for defrosting in a microwave oven, then one or more sections ofthe pack can be of a thin metallic foil or metallised synthe- tic resinfilm, although it is normally preferableto haveatransparentcovertoenablethemealto be visible for inspection before cooking or defrosting, as the case may be. Should the nature of the food, orthe desired shape ofthe meal require it, an outerframeor ring-shaped member can be positioned on the base sheet to surround the meal and support the cover.

This can be a reinforcing attachment to the base sheet, or a separate item, to be removed after the covering has been removed. It may consist of foil, if not intended for microwave ovens, ora suitableselected synthetic resin collar if it is required to be suitable for any type of oven. If desired, the cover can be a monolithic dome or inverted dish, in which case a base sheet member is attached to the bottom rim of the one-piece cover, or of a ring or frame. A base member can then be formed by a plurality of discrete, separate tongues positioned to extend inwardlyfrom the bottom rim.

Such constructions as have been described above are also particularly suited for packs required to store delicate foodstuffs that are not to be served hot, but merely allowed to heat up the ambient room temperature and served cold. The choice offoil orfilm material will obviously be primarily determined by the requirement for storage of the foodstuff in this case.

Claims (22)

1. A heatpack base sheet for use in packaging a prepared meal for cold storage in a chilled orfrozen state, said base sheet comprising a number of ton guesoffoilorfilm ofa materialsuitableforusewith predetermined foodstuffs, said base sheet being provided to retain chilled orfrozen food contained in a heatpack pouch formed using said base sheet, but opening freely to permit the passage of said food through the resultant hole onto a serving plate when said food has been heated as required.

2. Aheatpackmemberas claimed in Claim 1,in whichthereisonetongue,formed byacutinsaid base sheet that extendsthree-quarters of the way around said base sheet.

3. A heatpack member as claimed in Claim 1, in which there is a plurality of contiguoustongues.

4. A heatpack member as claimed in Claim 3, in which said tongues are truncated to leave a central hole.

5. A heatpack member as claimed in any preceding Claim in which said member is a film of a synthetic resin material that is electrically non-conductive.

6. A heatpack member as claimed in any one of Claims 1 to 4, in which said member is an electricallyconductive foil or metallised film suitable for use in a thermally-heated oven.

7. A heatpack member as claimed in Claim 5, in which said synthetic resin material is suitable for use in a thermally-heated oven.

8. Aheatpackmember as claimed in Claim 1,sub- stantially as described with reference to Figure 1 or Figures 2a and 2b.

9. Aheatpackcomprising a basesheetasclaimed in any preceding Claim, in combination with a foil or film underlay positioned beneath said tongue ortongues before said meal is pre-arrnged on said base sheet and enclosed for storage in a pouch which comprises said base sheet.

10. A heatpack as claimed in Claim 9, in which said underlay is of the same material as said base sheet.

11. A heatpack as claimed in Claim 10, in which said underlay is an integral extension from one edge of said base sheet.

12. A heatpack as claimed in Claim 10, in which said underlay is formed by two overlapping portions extending from opposed edges of said base sheet.

13. Aheatpackasclaimed inanyoneofCiaim9, 10 or 12, in which said underlay is securely attached to said pack so as to be removed with the base sheet when said pouch is heated and the meal readyfor serving.

14. A heatpack as claimed in any one of Claim 9 to 13, in which said pouch isformed byfolding the outer edges of said base sheet over and securing the overlapped edges to form a virtually sealed cover.

15. A heatpack as claimed in any one of Claim 9to 13, in which said pouch is formed by positioning a coversheetoverthe pre-arranged meal and sealing it to the peripheral edges of said base sheet.

16. A heatpack as claimed in Claim 15, when dependent upon any one of Claims 9, 10 or 12, where said underlay is not integral with said base sheet, but is attached thereto during the sealing of said cover.

17. A heatpackas claimed in anyone of Claims 14 to 16, in which said pouch incorporates a reinforcing upstanding frame or collar positioned upon said base sheetto surround said meal within said pouch, qra rigid inverted dish or dome serving as a covered enclosure to complete said pouch.

18. A heatpack as claimed in Claim 17, in which said tongues are discrete films secured to the bottom rim of said rigid member.

19. A heatpack as claimed in any one of Claims 9 to 18, substantially as described with reference to Figure 1 or Figures 2a and 2b.

20. A method of serving food comprising the steps of arranging the food in an appetising array on a thin base sheet of film orfoil as claimed in any one of Claims 1 to 8, thefood being arranged to coverthe tongue or tongues, and then wrapped in a pouch formed using said base sheet, subsequently heating said pouch as necessary, and when ready for serving, lifting the pouch to allow the contents to pass through the opening and lie in an attractive predetermined array on said plate.

21. A method of serving food comprising the steps of arranging the food in an appetising array on a thin base sheet of film orfoilthatcomprises part of a heatpackas claimed in any one of Claims 9 to 19, the food being arranged to cover the tongue ortongues, and then wrapped in a pouch formed using said base sheet, subsequently heating said pouch as necessary, and when ready for serving, lifting the pouch toallow the contents to pass through the opening and lie in an attractive predetermined array on said plate.

22. A method of serving food, as claimed in Claim 20 or 21, substantially as described with reference to Figures 1 or2 and Figure 3.