EP1674407B1 - Food container and method for heating said container - Google Patents

Description

The present invention relates to a food product assembly.

Trapped trays containing food products that are heated in microwave ovens (MO) are already known. For these trays, during the regeneration of a food product packaged in this type of packaging, the water contained in the food will evaporate under the effect of the energy provided by the MO. The increase in pressure inside the packaging induced by the formation of vapor will cause uplift of the upper film. When a threshold pressure inside the package is reached, the solder edges will yield at a point that will be called a break point, in order to release this excess of steam. This phenomenon is known as "self venting". For products rich in water such as dishes in sauce, it can happen during the regeneration that the sauce brought to the boil, rises to the level of breaking point and escapes from the packaging and falls on the tray of the MO . This phenomenon is especially noted for sauces rich in foaming agents (milk proteins, mushroom extracts) as well as for emulsified sauces containing fresh cream, margarine, butter, oil and any other dispersed fat. in an aqueous phase. This phenomenon is all the more important as the power of the MOs used for the regeneration is important.

A food product assembly according to the preamble of claim 1 is disclosed by the document EP 531176 .

The object of the present invention is to provide the consumer with a set for food products regenerable MO, in which there is no risk of overflow of the food product during heating in said MO.

The present invention relates to a food product assembly according to claim 1.

Compared to the state of the art, the difference of the assembly according to the invention is that the tray is made of a material such that the rim of said tray is deformed under the effect of the MO, which avoids any leak of produced outside the tray. Indeed, during regeneration, the lid is lifted under the effect of pressure and will exert a force on the welding edges causing a vertical inclination of the rim of the tray. Therefore, when the threshold pressure is reached, the breakpoint will be oriented vertically thus forming a chimney allowing the steam to escape. Thus, the breaking point being oriented vertically, the boiling sauce can not pass over the rim and it will not escape the package.

• Résine ionomère,
• Copolymère d'éthylène et d'acide métacrylique (EMA),
• Polyéthylène basse densité (PE),
• Polybutylène,
• Résine adhésive,
• Polypropylène,
• Copolymère d'éthylène et d'acétate de vinyle (EVA) et
• Copolymère d'éthylène et d'alcool (EVOH).

As mentioned above, in order for the rim of the tray to rise properly, it must be made of a material that allows a good raising of said rim. Preferably, the tray material is a multi-layer composite comprising the following layers taken alone or in combination:

• Ionomer resin,
• Copolymer of ethylene and methacrylic acid (EMA),
• Low density polyethylene (PE),
• polybutylene
• Adhesive resin,
• polypropylene,
• Copolymer of ethylene and vinyl acetate (EVA) and
• Copolymer of ethylene and alcohol (EVOH).

The thickness of the wall of the tray is between 400 and 700 microns. Preferably, the thickness of the wall of the tray is between 400 and 500 microns.

It is also important in the assembly according to the invention that the side wall of the tray makes an angle between 1 and 5 ° with the vertical. The steep slope limits the access of the sauce to the breaking point. This steep slope also allows to significantly reduce the burnt appearance of the sauce that can be seen with trays having an angle between 5 and 10 °. With such trays, a film of sauce is formed on the walls of the container which dries out during regeneration and which, by the combined effect of heat, evaporation, the presence of reducing sugars as well as amino acids, will be the target of Maillard reactions causing a burned appearance on the walls of the tray.

• Résine ionomère,
• Copolymère d'éthylène et d'alcool (EVOH),
• Polyéthylène haute densité,
• Résine adhésive,
• EVA.

The operculum material is a multi-layer composite comprising the following layers taken alone or in combination:

• Ionomer resin,
• Copolymer of ethylene and alcohol (EVOH),
• High density polyethylene
• Adhesive resin,
• EVA.

The lid has a thickness between 100 and 150 microns.

The food composition contained in the tray is a refrigerated composition or a frozen composition. The regeneration is normally carried out by OM, but can also be carried out in a water bath. The food composition is selected from the group of compositions comprising sauce, pasta, rice, potatoes, vegetables, meat, fish and any other food product. It can be a complete dish as well as an accompaniment. The sauce composition is a composition comprising besides sauce, pasta, rice, potatoes, vegetables, fish, meat and any other food product.

The food composition occupies a volume of between 30 and 97% of the volume of the tray. Preferably, the food composition occupies between 60 and 97% of the volume of the tray. For products containing sauces rich in foaming agents and fat, the volume occupied by the product must not exceed 60% of the total volume of the container. For products rich in non emulsified sauces and low foaming agent, the volume of the product can occupy up to 97% of the volume of the tray.

The inclination of the weld edges during regeneration in the OM of the tray is favored by a rounded shape of the tray in its length. With this shape, the inclination of the weld edges is maximum in the middle of the curved walls of the tray and the breaking point will form at this location.

• une feuille de matériau plastique est thermoformée pour faire la barquette,
• le produit alimentaire est dosé dans ladite barquette,
• on fait le vide et simultanément, on scelle l'opercule sur le haut de la barquette.

A method of manufacturing the assembly could be substantially as follows:

• a sheet of plastic material is thermoformed to make the tray,
• the food product is dosed in said tray,
• Vacuum and simultaneously seal the operculum on the top of the tray.

The packaging is carried out under a vacuum of the order of 10 to 300 mbar.

When the assembly according to the invention is manufactured, it is preserved either under refrigeration or in frozen form.

• on place l'ensemble dans un système de chauffage par micro-ondes,
• on démarre le chauffage par MO,
• on chauffe jusqu'à ce que l'opercule se déforme sous l'effet de la montée en pression à l'intérieur de la barquette et se délamine partiellement sur une partie du pourtour de ladite barquette et
• on poursuit le chauffage ou la cuisson.

The advantages of the assembly according to the invention are fully visible at the time of use by the consumer. A method of heating and / or cooking an assembly according to claim 1 is described above, wherein

• the set is placed in a microwave heating system,
• we start the heating by MO,
• heated until the lid deforms under the effect of the rise in pressure inside the tray and partially delaminates on a portion of the periphery of said tray and
• heating or cooking is continued.

As already mentioned above, during heating or cooking, the deformation of the lid allows the rim of the tray to rise.

The break point normally appears after 2 to 4 minutes. The heating time is between 30 seconds and 10 minutes. Preferably, the heating time is of the order of 6 minutes.
For heating, the duration is shorter, in addition to the size of the tray and in case of cooking, the duration is longer.

• Fig. 1 est une vue en perspective de la barquette utilisée,
• Fig. 2 est une coupe longitudinale de l'ensemble selon l'invention,
• Fig. 3 est une vue de dessus de l'ensemble selon l'invention et
• Fig. 4 est une vue de l'ensemble au moment de l'ouverture de l'opercule.

The following description is made in connection with the drawings in which:

• Fig. 1 is a perspective view of the tray used,
• Fig. 2 is a longitudinal section of the assembly according to the invention,
• Fig. 3 is a top view of the assembly according to the invention and
• Fig. 4 is a view of the assembly at the time of opening of the lid.

The tray 1 comprises a bottom 2, a side wall 3 and a flange 4. This tray is made of a multi-layer material PP, EVOH, EVA having a thickness of 500 microns. It has a capacity of 330 or 430 ml and is intended to contain a frozen dish of 150 to 400g.

The figure 2 shows the tray 1 containing a prepared dish 5 and a lid 6 closing the top of the tray.

The figure 3 shows that the tray 1 has a rounded wall in the outward length and it is substantially in the middle of this length in 7 that the seal delaminates and gives a breaking point which the steam will escape. The tray may also have a rounded width, in which case the round is inward.

The figure 4 shows finally that when heating in a furnace MO or any other heating element, the lid 6 is lifted under the effect of the rise in pressure, which raises the rim 6 of the tray up reach the breaking point. The rim is raised around the edge of the tray and as it is raised, even at the time of the break nothing can flow on the tray of the furnace MO.

Example

We have a set according to the invention of 330 ml containing 100 g of fish and 100g of sauce. The whole is frozen. It is placed in a furnace MO of power 1000 W and the heating is started. After 6 minutes, the dish is warmed and the lid has opened a distance of 20 mm. The edge of the tray has risen over the entire periphery and nothing has flowed on the plateau of the MO.

Claims (9)

1. Assembly for food product that is heated up in microwave ovens comprising

   - a tray (1) with a lip (4), a side wall (3) and a bottom (2),

   - a lid (6) sealed onto the whole periphery of said tray partly onto the lip and onto the top of the side wall, directly adjacent to said lip, and

   - a refrigerated or frozen food composition (5) contained in said tray, the lid coming substantially into contact with the food composition; and

   the assembly is characterised in that the side wall (3) of the tray (1) makes an angle of between 1 and 5 deg. with the vertical, and in that the wall (3) of the tray (1) is rounded along its length.
2. Assembly according to claim 1, characterised in that the material of the tray (1) is a multilayer composite comprising a PP or EVOH layer.
3. Assembly according to claim 2, characterised in that the thickness of the wall of the tray (1) is between 400 and 700 µm.
4. Assembly according to any of the claims 1 to 3, characterised in that the material of the lid (6) is a Surylin, EVOH, or Surylin multilayer composite.
5. Assembly according to claim 4, characterised in that the lid (6) has a thickness of between 100 and 150 µm.
6. Assembly according to claim 1, characterised in that the food composition (5) is selected from the group of compositions comprising sauce, pasta, rice, potatoes, vegetables, meat, fish and any other food product.
7. Assembly according to claim 6, characterised in that the sauce composition is a composition comprising, in addition to the sauce, pasta, rice, potatoes, vegetables, fish, meat and any other food product.
8. Assembly according to any of claims 1 to 7, characterised in that the food composition (5) occupies a volume of between 30 and 97 % of the volume of the tray.
9. Assembly according to any of claims 1 to 8, characterised in that the food composition (5) is packaged under a vacuum of between 10 and 300 mbar.

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