EP2248737A1 - Packaging provided with a film with controlled deformation - Google Patents

Abstract

The assembly (1) has an inner package (7) closed by a sealing film (11) and containing a food product (5) to be heated and/or cooked. An outer package (9) has an opening through which the inner package is glided and removed. The outer package is provided with a maintaining unit for maintaining movable lateral flaps (13a) in a closed state until the end of heating by providing confined heating at certain threshold temperature and/or pressure before liberating opening of the flap. The film is covered by a retaining wall (9a) of the outer package. The sealing film is used as a DARFRESH(RTM: vacuum skin package type film). An independent claim is also included for a method for packaging and cooking a food product.

Description

Here is concerned a set adapted to be heated in a microwave heating chamber.
WO 02/060223 disclose such a set.

In front of the prior art, a problem may be related to the quality of cooking.

Another problem may be related to the food product that is desired to cook as expected (for example both bleeding and golden, if it is a red meat).

Another problem may be related to the knowledge that it may be useful for the consumer to have the moment when the food product contained in the set will be considered ready to eat.

• un emballage intérieur fermé par un film et renfermant un produit alimentaire à chauffer et/ou cuire,
• un emballage extérieur se présentant comme une boîte renfermant l'emballage intérieur et ayant une ouverture par où l'emballage intérieur peut être glissé et retiré, avec au moins un volet mobile par lequel peut être ouverte et fermée la boîte.

To aim for a solution to at least a part of the above problems, it is proposed to use a set as above and comprising:

• an inner packaging closed with a film and containing a food product to be heated and / or cooked,
• an outer packaging in the form of a box containing the inner package and having an opening through which the inner package can be slid and removed, with at least one movable flap through which the box can be opened and closed.

According to an additional feature, it is recommended that the film be stretchable and the outer packaging designed to counteract the deformation by a rigid wall, during heating of said assembly in the enclosure; this outer packaging is also provided with a means sensitive to heat and / or pressure and holds the shutter closed towards the end of the heating, ensuring a confined heating up to a certain threshold of temperature and / or pressure, before releasing the opening of said flap.

It will thus be usefully possible to deform the stretch film, both for the quality of the heating and / or cooking and to inform the consumer (by opening the flap) that the heated food product is ready to consume.

In addition, by managing the confinement, it will be possible to ensure a controlled exhaust of steam, at the moment a priori most appropriate for both heating and / or cooking and vis-à-vis the consumer, offering in particular the possibility that this Exhaust can intervene before the consumer recovers the product in the heating chamber, thus limiting the risks associated with this grip while an evaporation temperature has been reached.

To advantageously take advantage of the presence of the stretch film provided so as to close the inner packaging, it may also be interesting that this inner packaging comprises a container in the bottom of which will be (will have been) placed the food product and which will be closed by said stretch film, which will be vacuum plated, stretched, around the food product and along the bottom and side walls of the tray, at least before heating.

Thus, we can combine, with efficiency and cost control, conservation, heating performance and / or cooking with opening of the shutter.

Finally, the "stretch film" will be a film known in the field as a "superior film".

Still concerning this stretch film, it is advisable to close the inner packaging by sealing, so continuous, without zone weakened resistance, the film containing the container containing the food product.

And, to further improve the quality of the results, in particular heating and / or baking and relevant opening of the flap, it is furthermore advised that the means which keeps the shutter closed is adapted to be broken at heating, substantially when the pressure is maximum.

A priori, this moment will be located shortly before or during a loosening of said stretch film, or shortly after the deflation of this unsealed film.

Again for the quality of the results in particular heating and / or cooking and relevant opening of the shutter, it is furthermore recommended that, in the state where the / each shutter is closed, the outer packaging is then completely closed .

Thus, a solution with permanent communication passages (marked 60,160 or 260) between the inside of the outer package and the outside as in WO 02/060223 is then considered inappropriate. Moreover, there is no provision in this document means sensitive to heat and / or pressure that keeps the shutter until the end of the heating, ensuring a confined heating up to a certain temperature threshold and / or pressure, before releasing the flap opening.

Containment and heating and / or cooking are not treated in the same way. Moreover, the closing film 14,114,214 is not of the same nature. And consumer information is not taken into consideration.

In addition to a set of the above type, is also concerned here a preferred inner packaging for the aforementioned set, and a method of packaging and cooking.

For the first, it is recommended that its closure film is sealed to a rigid or semi-rigid film container having a bottom wall having an inner face which has depressions and bumps substantially marrying an absorber means. exudates bound to it by plaxage.

Thus, we will promote discretion, conservation and mechanical strength.

• en prévoyant que :
  1. a) on place le produit alimentaire dans un premier emballage comprenant un film de fermeture fixé de façon étanche à un support,
  2. b) on place le premier emballage dans une boîte le renfermant et qui est pourvue d'au moins un volet mobile pour entrer et sortir le premier emballage,
  3. c) on ferme le ou chaque volet, et on place ainsi le tout dans une enceinte de chauffage par micro-ondes où on assure un chauffage confiné,
• en utilisant comme film un film étirable sous la pression de chauffage et, comme boîte, une boîte présentant une paroi rigide contrariant l'étirement sous pression dudit film sous l'effet des micro-ondes,
• en prévoyant, lors de l'étape c), de chauffer jusqu'à créer un étirement dudit film, puis une séparation entre le film et son support,
• et, lors de cette séparation ou consécutivement à elle, en assurant une ouverture du volet, par rupture sous l'effet de la chaleur et/ou la pression, d'un moyen de retenue qui maintenait ce volet jusqu'alors fermé.

Regarding the process, it is advised that it ensures the packaging and microwave cooking of a food product,

• providing that:
  1. a) placing the food product in a first package comprising a closure film fixed in a sealed manner to a support,
  2. b) placing the first package in a box containing it and which is provided with at least one movable flap to enter and exit the first package,
  3. c) the shutter or each shutter is closed, and the whole is thus placed in a microwave heating enclosure where a confined heating is provided,
• by using as film a stretchable film under the heating pressure and, as a box, a box having a rigid wall counteracting the stretching under pressure of said film under the effect of microwaves,
• by providing, in step c), heating to create a stretch of said film, and then a separation between the film and its support,
• and, during this separation or consecutively to it, ensuring an opening of the flap, by rupture under the effect of heat and / or pressure, a retaining means which held the flap previously closed.

Again, we can usefully use the deformation of the stretch film, both for the quality of heating and / or cooking and to inform the consumer (by opening the flap) that the heated food product is ready to consume, this while managing the steam release.

As part of this process, it is also advisable to use a box such that, closed shutter, it is closed completely; see in this regard the remarks already made vis-à-vis WO 02/060223 .

• figure 1, les deux emballages, le second ouvert, sorti du four dans lequel le tout a été chauffé pour que le produit soit prêt à consommer,
• figure 2, l'emballage intérieur avec le film plaxé sur le produit,
• figure 3, un détail de la figure 1, en vue de dessous suivant la flèche III,
• figure 4, une vue de dessous de l'emballage extérieur de la figure 1,
• figure 5, l'ensemble des deux emballages conditionnés, avec le produit, dans l'enceinte de chauffage peu avant ou au moment de la fin de la durée de chauffage qui a été imposée par l'utilisateur,
• figure 6, un développé à plat de l'emballage extérieur,
• figure 7, un emballage avec un film supérieur plaxé sur le produit, et
• figure 8, une coupe locale suivant la ligne VIII-VIII fig.7.

Other features and advantages of the assembly and the process here concerned will appear again with reference to the attached figures in which we see, without limitation:

• figure 1 the two packages, the second open, taken out of the oven in which the whole has been heated so that the product is ready to consume,
• figure 2 , the inner packing with the film attached to the product,
• figure 3 , a detail of the figure 1 , in view of below according to the arrow III,
• figure 4 , a bottom view of the outer packaging of the figure 1 ,
• figure 5 , all of the two packages packaged, with the product, in the heating chamber shortly before or at the end of the heating period that has been imposed by the user,
• figure 6 , a developed flat of the outer package,
• figure 7 , a package with a top film attached to the product, and
• figure 8 , a local section along line VIII-VIII fig.7 .

Figure 1 , the assembly 1 is adapted to be heated in a heating chamber 3a of a microwave oven 3.

For this and the prior storage of the food product 5 it contains, the assembly 1 comprises an inner packaging 7 initially closed, containing the product 5 to be heated and / or cooked, and an outer packaging 9 (90 figure 3 ) at least partially doubling the inner packaging.

The product 5 is typically a fresh product, possibly already slightly golden or precooked, such as a meat or a fish to cook or finish cooking.

As the heating is not completed or almost completed, the inner packaging 7 is closed by a plastic stretch film 11, of course quality (therefore compatible) food.

This film may in particular be a coextruded film adapted to the packaging of fresh or frozen products, especially under vacuum. Frozen or fresh products or those that can be fully or partially pre-cooked are also concerned.

Like all the components of Set 1, it will therefore be "microwaveable" (adapted to be heated by microwaves).

It may be a microwavable "upper film" DARFRESH (TM) film from CRYOVAC.

It is therefore advisable here to use an upper film 11 of the "skin" type (skin) forming an oxygen barrier.

In particular figure 2 it can be seen that the inner packaging 7 will advantageously comprise a container 15 in the bottom of which the food product 5 has been placed here and which is thus closed by the film 11.

For the preservation of the product, this film 11 was plated around the product 5 and over the bottom 15a of the tray. It is sealingly attached to the support 15, preferably on the upper peripheral rim 15b thereof.

Prior evacuation will have closely clad (by plaxing), stretching the film 11 around the product 5 and thus along the bottom and side walls of the tray 15.

Thus, the use of a method of the "Cryovac Darfresh®" type is recommended which provides for online thermoforming of rigid and flexible barrier laminates (here the elements respectively 15 and 11). In this way, vacuum trapping of a flexible barrier laminate 11 with a "second skin" effect will be obtained. A vacuum pump will first allow evacuation with heating of the upper film 11 by a heating dome, to the required temperature (typically around 200 ° C) and then, as part of a gentle ventilation process, the upper film will mold itself by adopting perfectly the shape of the product, after which it will be sealed by heat and pressure on the lower film (tray 15).

According to an important characteristic, we see figure 1 or 3 that the stretched film 11 is covered (here on top) by a retaining wall 9a which doubles this film, at a distance from it, in this state where it is plated on the product.

This wall 9a belongs to the outer packaging considered, 9 figure 1 which ensures a maintenance of said wall above the film for at least a portion of the time during which an internal increase in the pressure in the closed inner package 7, following placement and heating of said assembly in the enclosure 3a , will create a deformation of the film to the outside, this deformation being thwarted by the wall 9a.

This wall 9a is less deformable than the film 11 at the same pressure.

Figure 1 , the wall 9a is held in place since the outer packaging 9 (identified 900 fig.4 ) is in the form of a sheath provided with at least one opening 9b on at least one of its sides.

Through this opening, the inner package 7 can be slid into, and removed from, the sheath, one of the side walls is thus defined by the aforementioned retaining wall.

Figure 1 it can be seen that the sheath in question is in the form of a box completely enclosing the inner package 7 and which is provided with at least one movable flap 13a through which the opening 9b and thus the box can be opened and closed.

Thus, a certain confinement will be able to be ensured inside the outer package as long as the shutter is closed, while there is heating said assembly in the enclosure.

Favorably, the wall 9a will extend substantially parallel and at the level of the open upper surface 19 of the tray (top of the side walls), so as to act on the deformation of the film towards the outside when the latter substantially reaches this level , heating. A flat, rigid wall belonging to a parallelepiped box will be suitable.

Preferably, this retaining wall will comprise, or be made of, cardboard. Thus, it will combine low cost, ease of manufacture / formatting, compatibility with microwaves and food, mechanical and thermal stability, ability to carry a message for example advertising (printing or otherwise).

Returning to the mobile flap 13a of the packaging box, it is important, as this form "box".

First, if the / each component allows to completely close the outer packaging, such a box protects the inner packaging 7, or even facilitates packaging.

But in addition, shutter (s) closed (s), we will be able, during the heating of the complete assembly in the enclosure, ensure real containment inside the outer packaging.

Moreover, by managing / controlling, heating or just after, the conditions of opening / closing of this (s) component (s), we will be able to tell the user if his product is ready or not ready to be consumed .

To promote all or part of these effects, it is recommended that the shutter be kept closed by a means of closure 17 adapted to allow the flap 13a to open by local delamination of the outer packaging material.

In particular if the outer packaging is in or based on cardboard, it will be preferred that the / each movable flap concerned is retained closed on this packaging, as figure 3 by a strip of continuous or discontinuous adhesive existing between the flap and a zone of the outer packaging that the latter covers, closed. The reference 17a figure 5 shows a strip of discontinuous glue.

So, seen from below as fig.4 , here with two side flaps 13a, 13b, these shutters will be closed, attached to the outside of the box, and not in, as often.

In other words, the or each movable flap will preferably be folded and closed on the outer package, over the wall 9c opposite to said retaining wall 9a. It will be understood that this wall 9c will be the bottom wall of the sheath, that is to say the one by which the said conditioned assembly is placed, thus avoiding the user being tempted to open it before heating.

In practice, it is even recommended that the outer packaging comprises two said openings, on two opposite sides, each of which can be closed and opened by a movable flap, here folded, such as 13a, 13b figure 4 , one of them being preferably retained closed on an area of the considered package with a lower mechanical strength than that of the other component. Thus, at a given physical condition, such as a specific pressure, one of the shutters will open, the other will not.

Without risk that the inner tray slips unexpectedly, since only one of the shutters will be open, the user will see the heat / vapor escape through the open flap (a priori arranged in front of him), opening the shutter further indicating that his product is ready. In addition, with the outer packaging in a thermal insulating material, such as cardboard, it will not risk burning itself out of the aforementioned assembly of the oven.

In practice, to prepare the outer package to be closed, we can cut the agreed area of it to half-flesh and paste the shutter there, by a polyamide glue, allowing, if using cardboard, ensure ease of cutting and gluing in large series, low cost and with appropriate food compatibility. The area concerned is located 18 figure 4 , at the right of the adhesive strip, thus allowing delamination at the moment of opening of the flap 13a.

Figure 6 21a, 21b, two pre-cuts made through part of the thickness of the wall 9c of the bottom of the package 9, facing the flap 13a to control its control opening. This is a solution for the abovementioned half-flesh weakening which must favor the controlled opening here of the flap 13a. 23a indicates the direction of the fibers of the board, on the schematic plate: perpendicular to the direction 23b which passes through the two opposite flaps 13a, 13b. the package will preferably be in one piece, cut as appropriate (see illustration where the dashed lines such as mark the areas of folds made by thin lines of surface cuts).

Due to the slight swelling of the outer package at least at the end of heating, which will generate an effort in particular on the means (17,17a) of controlled opening of this package, the area where is this means must a priori affect the loosening zone of the film at the periphery of the support 15 which will be located nearby, even if the product would be off-center in this direction (thereby shortening the loosening distance of the film 11) .

• on placera le produit alimentaire 5 dans un premier emballage 7 adapté pour être chauffé par micro-ondes et comprenant le film 11 fermant cet emballage (puisqu'étant soumis au vide dans le cas de la barquette de la figure 2),
• on recouvrira ensuite une partie au moins de l'emballage 7 par un second emballage adapté lui aussi pour être chauffé par micro-ondes, mais réalisé en un matériau moins déformable, à la même pression, que celui du premier emballage 7, de sorte que ce second emballage puisse avoir, sous pression, une action sur la déformation sous pression dudit film 11,
• le moment venu, on placera le tout (boîte toujours fermée si on a utilisé l'emballage 9) dans l'enceinte de chauffage 3a où on le chauffera par micro-ondes, jusqu'à créer une déformation dudit film, par gonflement, cette déformation étant donc contrariée par l'action de retenue du second emballage (qui pourra malgré tout se déformer légèrement sous la pression du film),
• puis on retirera le tout hors de l'enceinte, après que ledit gonflement du film 11 ait provoqué (typiquement par contre-pression) une ouverture du premier emballage 7 et par conséquent le dégonflement du film.

By using all or part of the above characteristics, it will therefore be possible to implement a method for packaging and cooking a food product in which:

• the food product 5 will be placed in a first packaging 7 adapted to be heated by microwaves and comprising the film 11 closing this packaging (since it is subjected to vacuum in the case of the tray of the figure 2 )
• at least part of the package 7 will then be covered by a second packaging, which is also adapted to be heated by microwaves, but made of a less deformable material, at the same pressure, than that of the first package 7, so that this second package may have, under pressure, an action on the deformation under pressure of said film 11,
• when the time comes, we will place the whole (box always closed if we used the packaging 9) in the heating chamber 3a where it is heated by microwave, to create a deformation of said film, by swelling, this deformation is therefore thwarted by the retaining action of the second package (which may still slightly deform under the pressure of the film),
• then remove the whole from the enclosure, after said swelling of the film 11 has caused (typically by back pressure) an opening of the first packaging 7 and therefore the deflation of the film.

The figure 5 schematically this, in connection with the use of the box 9. Typically, this deflation will be achieved by local loosening of the film at a location on the periphery of the blister pack 15.

• d'intégrer ou de pourvoir un emballage extérieur 9 d'un moyen d'échappement de vapeur hors de ce second emballage (ouverture du volet dans l'exemple précité),
• et d'assurer de préférence une ouverture de cet emballage extérieur sensiblement au moment du dégonflement du film 11.

It will also be noted that with, for example, the hot-pressed shutter solution under pressure during the separation provided between the film and its support 15 (or following this separation), the solution presented here allows:

• to integrate or provide an outer package 9 of a steam escape means out of this second package (opening of the flap in the aforementioned example),
• and preferably to provide an opening of this outer package substantially at the time of deflation of the film 11.

• on aura favorablement placé le premier emballage 7 dans une boîte, telle 9, le renfermant entièrement et appartenant au second emballage, la boîte étant pourvue d'au moins un volet mobile, tel 13a, pour entrer et sortir le premier emballage,
• puis on aura fermé le ou chaque volet, de sorte à assurer un certain confinement à l'intérieur de l'emballage extérieur 9, ceci tant que le volet sera resté fermé, alors qu'on aura chauffé ledit ensemble dans l'enceinte, telle 3a.

In the foregoing, it will also be noted that during the above-mentioned stages of recovery and then heating:

• the first package 7 will be favorably placed in a box, such as 9, enclosing it entirely and belonging to the second package, the box being provided with at least one movable flap, such as 13a, to enter and exit the first package,
• then the shutter or each shutter will have been closed, so as to ensure a certain confinement inside the outer packaging 9, as long as the shutter remains closed, while the said assembly has been heated in the enclosure, such as 3a.

Then, under the swelling pressure of the film 11, and / or the internal moisture / vapor produced by the exudates and heating temperature, provision is made for the closed means for holding one of the flaps (such as 13a fig.1 ) is substantially broken when the pressure is maximum shortly before or during loosening of the film, or shortly after deflation of the unsealed film. A priori, with a solution using a polyamide glue, the opening of the flap 13a will intervene shortly before or during the loosening of the film.

Thus, the closed holding means of the outer package until towards the end of the heating will be favorably sensitive to the heat and / or the inflation pressure of the film 11 and will therefore perform its function of closing and / or confining to a certain threshold of temperature and / or pressure.

Optionally a steam exhaust means other than such a glued flap could be suitable. A valve, as is already known, could be used on the outer package.

In terms of implementation conditions, for a steak of beef about 100-150g pre-grilled for its surface to be marked, the heating in the enclosure 3a may last 50 to 70s, at 900W approximately.

It will also be noted that the upper film 11 could be sealed to a rigid or semi-rigid lower structure having a shape other than a tray, such as a flat plate.

Figures 7-8 the package 7 contains a means 100 for absorbing exudates from the food product 5 and a rigid or semi-rigid film container 15 having a bottom wall 150 against an inner face 151 of which the means 100 is disposed.

Flexible, the absorber means is adapted to be shaped in the shape of at least a portion of said inner face of the wall that it thus marries, covering it.

This means 100 is therefore a sheet which serves as a blotter, with absorption capacity of flowing products, liquid or semi-liquid.

Figure 7 , we note also that it is almost "invisible", although its presence is real, under the transparent stretch film 11 which covers it and the plate on the bottom 150.

This airtight plating (known as "plaxage") results from the air gap established under the film 11.

In particular for maintaining the integrity of the product during its storage, the exudate absorbing means adheres to the inner face 151 of the wall it covers.

In order to provide the exudate absorber means with an appropriate appearance and thus its presence does not alter the consumer's perception of the packaged product, the exudate absorber means 100 and said inner face 151 will be favorably dark in color. , preferably black and shiny, and will be adapted so that the absorber means is thus linked by lamination with this inner face.

It can also be seen that this inner face 151, and here the entire bottom wall, has depressions 30 and bumps 28 substantially wedge blotter 100.

This will be beneficial to the good conservation of the product (the troughs creating areas of recovery of exudates at a distance from the product) and at increased rigidity of the film 15, without excess thickness.

It will also be noted the shape in relatively narrow lines of the bumps 28 and the greater width of the intermediate lines in the form of hollow channels 30. These lines are here rectilinear. Cross lines could for example also be suitable, even bumps in the form of studs.

Claims (14)

Assembly (1) adapted to be heated in a microwave heating enclosure (3a), this assembly comprising: an inner package (7) closed by a film (11) and enclosing a food product (5) to be heated and / or cooked, - an outer packaging (9,9a) in the form of a box containing the inner packaging (7) and having an opening through which the inner packaging (7) can be slipped and removed, with at least one flap (13a, 13b ) movable by which can be opened and closed the box, characterized in that the film (11) is stretchable and the outer packaging is designed to counteract the deformation by a rigid wall (9a), during heating of said assembly (1 ) in the enclosure (3a); this outer package being provided with a means (17) sensitive to heat and / or pressure and which keeps the shutter closed towards the end of the heating, ensuring a confined heating up to a certain temperature threshold and / or pressure, before releasing the opening of said flap. Assembly (1) according to claim 1, characterized in that the flap (13a, 13b) movable is located on one side of the box other than that which covers the closing film (11). Assembly (1) according to claim 1 or 2, characterized in that the inner package (7) comprises a tray (15) in the bottom of which is placed the food product (5) and which is closed by said film stretcher (11), which is vacuum-plated, stretched, around the food product and along the bottom and side walls of the tray, at least before heating. Assembly (1) according to one of the preceding claims, characterized in that said means (17) which keeps the flap (13a) closed is adapted to be broken at heating, substantially when the pressure is maximum, shortly before or during loosening stretch film (11), or shortly after the deflation of said unsealed film. Assembly (1) according to one of the preceding claims, characterized in that said means (17) which keeps the shutter (13a) closed is adapted to be broken at heating, by an effect on it of the stretchable film (11) stretched by pressure. Assembly (1) according to one of the preceding claims, characterized in that, the / each shutter closed, the outer package is completely closed. Assembly according to one of the preceding claims, characterized in that the closing means (17) is adapted to allow the flap (13a, 13b) to open by local delamination of the outer packaging material (9). Assembly (1) according to one of the preceding claims, characterized in that the outer package (9) is made of or made of cardboard and the closing means (17) comprises a continuous adhesive strip (17a) or discontinuous between the flap (13a, 13b) and a zone (18) of the outer packaging that it covers, closed. Assembly (1) according to one of the preceding claims, characterized in that said or each movable flap (13a, 13b) is closed on the outer packaging (9) over the wall of the outer packaging which is that by which said assembly (1) is placed and which is opposite to that (9a) which covers the closing film (11). Assembly (1) according to one of the preceding claims, characterized in that the outer package (9) comprises two said openings, on two opposite sides, each of which can be closed and opened by a said movable flap (13a, 13b), one of them (13a) being held closed on one zone of the outer packaging with a lower mechanical strength than that of the other flap (13b), so that at a determined physical condition, such as a determined pressure, one of the shutters opens, the other not. Inner package for the assembly according to one of the preceding claims, characterized in that the closure film (11) is sealed to a rigid or semi-rigid film container (15) having a bottom wall (153). having an inner face (151) having depressions (30) and bumps (28) substantially embossed with exudate absorbent means (10,100). A method of packaging and microwave cooking a food product, wherein: a) placing the food product (5) in a first package (7) comprising a closure film (11) sealingly attached to a support (15), b) placing the first package (7) in a box (9) enclosing it and which is provided with at least one movable flap (13a, 13b) to enter and exit the first package, c) the one or each shutter (13a, 13b) is closed, and the whole is thus placed in a microwave heating chamber (3a) in which a confined heating is provided, characterized in that: a stretch film under the heating pressure is used as the film (11) and, as a box, a box having a rigid wall which contrasts the stretching under pressure of said film (11) under the effect of the microwaves, during step c), heating is carried out until a stretching of said film (11) is obtained, then a separation between the film and its support (15), - and, during this separation or consecutively to it, ensures an opening of the flap (13a), breaking under the effect of heat and / or pressure, a retaining means (17, 17a) which maintained this shutter until then closed. Packaging and cooking method according to claim 12, characterized in that a box (9) is used such that, closed shutter, it is closed completely. Packaging and cooking method according to Claim 12 or 13, characterized in that a container (15) is used as support (15) in the bottom of which the food product (5) is placed and which is closed by said stretchable film (11). ), which is vacuum-plated, stretched around the food product and along the bottom and side walls of the tray, before heating in the enclosure (3a).

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