METHOD FOR PRODUCING A PACKAGED PORTION OF A FOOD PRODUCT, AND PORTION OBTAINED BY THIS METHOD

Abstract

The invention relates to a method for producing a packaged portion (100) of a food product, said method comprising the following steps: providing a cup (14) defining an interior space (16) for receiving the food product (12); cold dosing the food product (12), at a temperature below 50°C, into the receiving space (16) of the cup (14); covering the food product (12) by means of a thermally insulating lid (18) arranged so that thermally conductive flaps (22) of the cup (14) extend outside the lid (18) after the covering step; folding the flaps (22) over an outer face of the lid (18) opposite the receiving space (16); and heat-sealing the flaps (22) on the outer face.

Description

[0001] The present invention relates to a method for producing a sealed packaged portion of a food product.

[0002] Such a packaged portion is generally of the type comprising a cup defining a receiving space for the food product and a lid covering the food product and closing the cup, the thermally conductive flaps of the cup being folded over an external face of the lid opposite the receiving space and sealed to said external face, the food product being contained in the receiving space and covered by the lid.

[0003] The invention applies more particularly to the production of sealed packaged portions of cold-dosed food products, i.e. at a temperature below 50°C, such as, by way of non-limitation, fresh cheeses or cheeses obtained by a recombination process (e.g. cheeses described in WO 2006 / 030128 and WO 2008 / 151820) or by membrane techniques, packaged in a viscous liquid or pasty state, cold pack cheese, yogurt derivatives or any other fresh dairy product with live cultures, bouillon cubes or butter.

[0004] Most often, cold-packed food products, when packaged in individual portions, are simply wrapped in a sheet of flexible material folded around the portion of product. Examples of food products packaged this way include butter and fresh cheeses marketed, for example, under the Boursin® brand. This type of simple packaging has the disadvantage of not being airtight, leading to rapid drying of the product and therefore a reduced shelf life.

[0005] One objective of the invention is to obtain airtight packaging for a portion of cold-measured food product, thereby preventing the product from drying out and contributing to better product preservation over time and improved product quality. The product's shelf life will be increased and export possibilities expanded.

[0006] Processes for producing sealed, packaged portions of food products, enabling the airtight packaging of products requiring cold dosing, are known. These processes generally include the following steps: provision of a cup defining an internal space for receiving the food product, cold dosing of the food product into the receiving space of the cup, covering the food product with a lid arranged so that flaps of the cup are folded outwards from the cup after the covering step, and hot sealing of the flaps on an internal face of the lid facing the receiving space.

[0007] For the sealing stage, metal sealing jaws are most often used, which are heated to a temperature and clamp the flaps and the lid together, activating a heat-sealing varnish with which the flaps are coated.

[0008] Such a process is known, for example, from EP 1 072 535 and EP 2 284 082. One drawback of this process is that it results in the formation of a collar around the edge of the portion, making it unsightly and impractical. Another disadvantage is that it requires large quantities of packaging, which is not environmentally friendly.

[0009] Furthermore, there are known processes for producing sealed, packaged portions of food products that can be dispensed hot, i.e., at a temperature typically above 65°C, such as processed cheeses, which allow for the production of sealed, packaged portions without a peripheral collar. These processes generally include the following steps: provision of a metal cup defining an internal space for receiving the food product, hot dosing of the food product into the cup's receiving space, covering the food product with a metal lid arranged so that flaps of the cup extend outside the lid after the covering step, folding the flaps on an external face of the lid opposite the receiving space, and hot sealing of the flaps on the external face.

[0010] For the sealing stage, a metal sealing iron is most often used. This iron is heated and placed against the flaps, pressing them against the lid and activating a heat-sealing varnish that coats the flaps. The pressure and heat applied seal the flaps and the lid, which are in contact under the iron, and compress the portion. This compression gives the portion its final shape.

[0011] It would be desirable to be able to use such a process with a food product to be dosed cold, so as to obtain a sealed packaged portion of food product to be dosed cold that does not include a peripheral collar.

[0012] However, the fact that the food product is dispensed hot into the packaging is a key characteristic of these established processes. Indeed, the heat released by the food product after dispensing is used as a major source of heat to raise the heat-sealing varnish above its melting point, thus enabling its activation. This heat input allows the portions to be sealed in a time sufficiently short to meet industrial production rates.

[0013] A problem arises when replacing the hot dosing step with a cold dosing step. Indeed, by dosing the food product inside the portion at a temperature below the melting point of the heat-sealing varnish, the food cannot contribute to heating the varnish beyond its melting point; on the contrary, the food absorbs a large portion of the heat supplied by the sealing iron. Therefore, replacing the hot dosing step of the aforementioned process with a cold dosing step considerably lengthens the sealing time, making it impossible to maintain an industrial production rate. Another observed drawback is that the heating of the food product inside the packaging, induced by the sealing iron, degrades the organoleptic qualities of the food.

[0014] A solution to the aforementioned problem is proposed in EP 2 177 437. It consists of heating the cup by induction at the time of sealing.

[0015] However, this solution is complex and costly to implement. Furthermore, it does not completely resolve the problem of food product heating up and the resulting risk of loss of organoleptic qualities.

[0016] Finally, CH 674 347 is known to be a sealed packaged portion of processed cheese in which the lid on which the flaps of the cup are folded includes a layer of plastic material.

[0017] One objective of the invention is to enable a simple and inexpensive sealing of a packaged portion of food product, in which the food product must be dispensed cold, without forming a protruding collar on the outside of the portion. Other objectives are to avoid heating the food product contained within the portion during sealing, and to allow for maintaining an industrial production rate.

[0018] To this end, the invention relates to a process for producing a packaged portion of a food product, comprising the following steps: provision of a cup defining an internal space for receiving the food product, cold dosing, at a temperature below 50°C, of ​​the food product into the receiving space of the cup, covering the food product by means of a thermally insulating lid arranged so that flaps of the cup, thermally conductive, extend outside the lid after the covering step, folding the flaps on an external face of the lid opposite the receiving space, and hot sealing the flaps on the external face.

[0019] The fact that the lid is thermally insulating greatly limits the loss of heat to the food product during sealing, which helps to achieve the dual objective of reducing sealing time and preventing the food product from heating up.

[0020] According to particular embodiments of the invention, the process also has one or more of the following characteristics, taken individually or in any technically possible combination(s): The sealing step includes the following substeps: ∘ application of at least one hot sealing iron to the flaps, the flaps being interposed between said sealing iron and the lid, and ∘ activation of at least one heat-adhesive material provided at the interface between the flaps and the lid by means of heat supplied to the heat-adhesive material by the sealing iron or each sealing iron; the step of applying the sealing iron or each sealing iron includes the successive applications of two sealing irons to the flaps;The flaps comprise an inner face oriented towards the receiving space, an outer face oriented away from the receiving space, and have a first surface heat transfer coefficient between their inner and outer faces; the lid comprises an inner face oriented towards the receiving space and has a second surface heat transfer coefficient between its outer and inner faces, and the ratio of the first surface heat transfer coefficient to the second surface heat transfer coefficient is greater than or equal to 400, in particular greater than or equal to 800; the first surface heat transfer coefficient is greater than or equal to 10⁷ Wm⁻².K⁻¹, in particular greater than or equal to 1.3 x 10⁷ Wm⁻².K⁻¹; the second surface heat transfer coefficient is less than or equal to 2.5.10 4< Wm -2< .K -1< , in particular less than or equal to 1.7.10 4< Wm -2< .K -1< ;The flaps have a thermal conductivity greater than or equal to 200 Wm⁻¹·K⁻¹; the lid has a thermal conductivity less than or equal to 0.5 Wm⁻¹·K⁻¹; the flaps are composed mainly, and preferably more than 70%, of metal, in particular aluminum; the lid is composed mainly, and preferably more than 90%, of plastic, in particular expanded plastic; the plastic is a polymer, for example expanded oriented polypropylene; the lid comprises a layer of plastic and a metallization layer deposited on at least one face of the plastic layer, said metallization layer being interposed between the heat-sealable material and the plastic layer.

[0021] "In the context of the present invention, 'portion' means a quantity of food product in a packaging containing a quantity weighing between 5 and 250g."

[0022] Other features and advantages of the invention will become apparent from the following description, given solely by way of example and with reference to the accompanying drawings, in which: there Figure 1 is a perspective view of a portion packaged according to a first embodiment of the invention, during production, at a stage of covering the food product contained in the portion, the Figure 2 is a perspective view of the packaged portion of the Figure 1 Once completed, the Figure 3 is a cross-sectional view, taken according to plan III-III of the Figure 1 , from a portion of a tub of the packaged portion of the Figure 1 , there Figure 4 is a cross-sectional view, taken according to plan IV-IV of the Figure 1 , a lid for the packaged portion of the Figure 1 , THE Figures 5 à 9 are cross-sectional views, taken according to the VV plane of the Figure 2 , of the packaged portion of the Figure 1 during successive stages of a production process for said packaged portion, the Figure 10 is a perspective view of a portion packaged according to a second embodiment of the invention, during production, at a stage of covering the food product contained in the portion, the Figure 11 is a perspective view of the packaged portion of the Figure 10 Once completed, the Figure 12 is a cross-sectional view, taken according to plan XII-XII of the Figure 10 , from a portion of a tub of the packaged portion of the Figure 10 , there Figure 13 is a cross-sectional view, taken according to plan XIII-XIII of the Figure 10 , a lid for the packaged portion of the Figure 10 , and the Figures 14 à 18 are cross-sectional views, taken according to plan XIV-XIV of the Figure 11 , of the packaged portion of the Figure 10 during successive stages of a production process for said packaged portion.

[0023] The packaged portion 10, shown on the Figures 1 et 2 , is a packaged portion of food product containing a food product 12. It includes a cup 14 defining a space 16 for receiving the food product 12, and a lid 18 for covering the food product 12 and closing the cup 14.

[0024] Food product 12 is, for example, a product based on fresh dairy curd, alone or in mixture, or a cheese resulting from a recombination process.

[0025] The bucket 14 has a bottom 19, a peripheral side wall 20 projecting from the periphery of the bottom 19, substantially perpendicular to it, and flaps 22 extending from an upper edge 24 of the side wall 20 opposite the lower edge 26 of connection of the side wall 20 to the bottom 19. The receiving space 16 is defined between the bottom 19 and the side wall 20.

[0026] In the example shown, background 19 has a general triangular shape. Alternatively, background 19 can have any other shape, for example, a disc or a rectangle.

[0027] Each flap 22 extends from the upper edge 24 of the side wall 20 to a free edge 28. The distance from the free edge 28 to the upper edge 24 is preferably less than the distance from the upper edge 24 to the lower edge 26.

[0028] In this first embodiment, the cup 14 comprises a single sheet 30, folded over itself, forming the base 19, the side wall 20 and the flaps 22. An example of folding this sheet 30 to form the cup 14 is given for example in FR 2 888 571.

[0029] Sheet 30 is thermally conductive. In particular, sheet 30 has a thermal conductivity greater than or equal to 200 Wm⁻¹·K⁻¹. For this purpose, sheet 30 is composed mainly, and preferably more than 70%, of metal, in particular aluminum.

[0030] In particular, as seen on the Figure 3 , the sheet 30 has a multilayer structure comprising: a main layer 32 of metal, in particular of aluminium, defining an inner face 40 of the sheet 30, oriented towards the receiving space 16, and an outer coating 34, deposited on a face of the main layer 32 opposite the inner face 40 and defining an outer face 36 of the sheet 30, oriented opposite the receiving space 16.

[0031] The main layer 32 constitutes more than 70% of the thickness of the sheet 30. It preferably has a thickness between 10 and 12 µm.

[0032] The exterior coating 34 typically comprises a non-heat-adhesive lacquer layer, for example, a nitrocellulose lacquer layer. The exterior coating 34 has a thickness of between 2 and 4 µm.

[0033] The thickness of the sheet 30, taken between its outer face 36 and inner face 40, is therefore less than 20 µm, and in particular less than 15 µm. The sheet 30 thus has a first surface heat transfer coefficient, between its inner face 40 and outer face 36, greater than or equal to 10⁷ Wm⁻².K⁻¹, in particular greater than or equal to 1.3 x 10⁷ Wm⁻².K⁻¹.

[0034] It should be noted that, since sheet 30 constitutes flaps 22, the inner face 40 and outer face 36 also constitute inner and outer faces of said flaps 22.

[0035] The inner face 40 is covered with an inner coating 38 distinct from the sheet 30. This inner coating 38 includes a heat-adhesive layer 42, defining an inner face 44 of the coating 38 oriented towards the receiving space 16.

[0036] The heat-sealable layer 42 is made of a heat-sealable material suitable for bonding with a compatible material when heated above a threshold temperature. This heat-sealable material is preferably a low-temperature heat-sealable material, meaning that the threshold temperature is below 75°C. However, the threshold temperature remains above 58°C to prevent any interaction between the heat-sealable layer 42 and the food product 12 at the normal storage temperature of the food product 12. The threshold temperature is typically the melting temperature of the heat-sealable material.

[0037] The heat-adhesive layer 42 includes, for example, a vinyl layer.

[0038] Preferably, as shown, the inner coating 38 comprises, in addition to the heat-adhesive layer 42, a protective layer 46 interposed between the heat-adhesive layer 42 and the sheet 30. This protective layer 46 is suitable to protect the sheet 30 against corrosion.

[0039] Protective layer 46 includes, for example, a vinyl layer.

[0040] As an alternative (not shown), the inner coating 38 consists of the single heat-adhesive layer 42, which is then preferably adapted to protect the sheet 30 against corrosion.

[0041] Examples of other materials that may be included in the composition of the heat-adhesive layer 42 and / or the protective layer 46 are lacquer-type materials, including, for example, plasticized PVC-type polymers, or copolymers of PVC with ethylene, vinyl laurate or vinyl acetate, or olefin-based polymers such as ethylene, butadiene, and their copolymers, or ester-based polymers such as PLA, vinyl acetate, vinyl esters of fatty acids, acrylic acid fatty alcohols and methacrylic acid fatty alcohols, or polymers based on terephthalic acid and modified or unmodified ethylene glycol, and materials obtained by extrusion of a polymer, typically a polyolefin based on ethylene, butadiene and their copolymers, and / or a vinyl polymer based on vinyl chloride, and / or vinyl esters of acids fatty acids, and / or fatty alcohols of acrylic acid, and / or fatty alcohols of methacrylic acid,said extrusion being typically carried out by curtain technology of the raw material in a viscous liquid state, by curtain technology of the material in the form of an aqueous suspension or emulsion, by coating a suspension or emulsion of polymer in water, for example by spraying or wiping with a brush or tape.

[0042] The total thickness of the inner coating 38 is preferably between 4 and 6 µm.

[0043] Back to Figures 1 et 2 The bucket 14 also includes a tear guide element 48 in the sheet 20. This guide element 48 typically consists of at least one guide strip attached to the inner face 40 of the sheet 30 and sealed to it. An example of the arrangement of said guide strip on the inner face 40 is given in FR 2 888 571.

[0044] The lid 18 is opposed to the bottom 19 relative to the receiving space 16, that is to say that the receiving space 16 is interposed between the lid 18 and the bottom 19.

[0045] Lid 18 is substantially flat.

[0046] The cover 18 is thermally insulating. In particular, the cover 18 has a thermal conductivity less than or equal to 0.5 W / m².K⁻¹. To this end, the cover 18 is composed mainly, and preferably more than 80% or even more than 90%, of plastic, in particular expanded plastic. This plastic is advantageously a polymer, for example oriented polypropylene (OPP).

[0047] In particular, as seen on the Figure 4 , the lid 18 has a multi-layer structure comprising: a main layer 50 of plastic material, in particular of expanded plastic material, for example of expanded OPP, and an external coating 52.

[0048] The main layer 50 constitutes more than 90%, preferably more than 99%, of the thickness of the lid 18. In particular, it has a thickness of between 20 and 60 µm, preferably between 30 and 40 µm.

[0049] The main layer 50 defines an internal face 54 of the lid 18, oriented towards the receiving space 16.

[0050] The external coating 52 is deposited on a face of the main layer 50 opposite the internal face 54. It defines an external face 56 of the cover 18 oriented opposite the receiving space 16.

[0051] The external coating 52 comprises a metallization layer and is advantageously composed of said metallization layer. This metallization layer forms a barrier to light and gases that protects the food product 12. It is preferably composed mainly of aluminum.

[0052] The external coating 52 advantageously has a thickness of a few angstroms. To achieve this, the metallization layer is deposited by vacuum evaporation of the metal constituting said layer. Thus, the effect of the metallization layer on the thermal conductivity of the cover 18 is negligible.

[0053] The thickness of the lid 18, taken between its internal face 54 and external face 56, is therefore greater than 20 µm, and in particular greater than 30 µm. The lid 18 thus has a second surface heat transfer coefficient, between its internal face 54 and external face 56, less than or equal to 2.5 x 10⁴ Wm⁻².K⁻¹, in particular less than or equal to 1.7 x 10⁴ Wm⁻².K⁻¹.

[0054] The ratio of the first heat transfer coefficient to the second heat transfer coefficient is thus greater than or equal to 400, and in particular greater than or equal to 800. This large difference between the first and second heat transfer coefficients ensures that, in the event of application of a hot element to the outer face 36 of the flaps 22, the heat will be rapidly transferred from the hot element to the interface between the flaps 22 and the lid 18, but that this heat will leak much more slowly through the lid 18 to the food product 12.

[0055] The outer face 56 is coated with a heat-adhesive coating 58, separate from the cover 18.

[0056] This heat-sealable coating 58 consists of a heat-sealable material suitable for bonding with a compatible material when heated above a threshold temperature. This heat-sealable material is preferably a low-temperature heat-sealable material, meaning that the threshold temperature is below 75°C. However, the threshold temperature remains above 58°C to prevent any interaction between the heat-sealable coating 58 and the food product 12 at the normal storage temperature of the food product 12. The threshold temperature is typically the melting temperature of the heat-sealable material.

[0057] The adhesive materials of the heat-adhesive coating 58 and the heat-adhesive layer 42 are compatible materials.

[0058] Back to Figures 1 et 2 , the flaps 22 are folded over the outer face 56 of the lid 18 and are hermetically sealed to said outer face 56 by means of the heat-adhesive coating 58 and the heat-adhesive layer 42. The flaps 22 are in particular folded inwards towards the inside of the cup 14 relative to the side wall 20.

[0059] A production process for the packaged portion 10 will now be described, with reference to Figures 5 à 9 .

[0060] Firstly, as can be seen on the Figure 5 , sheet 30 is folded to form cup 14. For this purpose, sheet 30 is folded for example as described in FR 2 888 571.

[0061] Next, as shown in the Figure 6 , the food product 12 is dosed cold, i.e. at a temperature below 50°C, in the receiving space 16 of the cup 14. The food product 12 is in particular dosed at a temperature between 0 and 30°C, preferably between 0 and 20°C and more particularly between 5 and 15°C.

[0062] Then the food product 12 is covered by means of the lid 18. For this purpose, the lid 18 is inserted between the flaps 22, its inner face 54 being oriented towards the food product 12, and it is lowered between the flaps 22 until it is in contact with the food product 12, as shown in the Figure 7 . Thus, at the end of this covering step, the flaps 22 extend outside the lid 18, that is to say that the lid 18 is interposed between the flaps 22 and the food product 12.

[0063] Covering the food product 12 with the lid 18 is followed by a step, shown on the Figure 8 , folding of the flaps 22 towards the inside of the cup 14, on the external face 56 of the lid 18.

[0064] Then, as depicted on the Figure 9 , the flaps 22 are heat-sealed under pressure on the external face 56 of the cover 18.

[0065] This sealing of the flaps 22 on the lid 18 preferably includes, as shown, a pre-sealing step and a final sealing step.

[0066] The pre-sealing step comprises applying a first hot sealing iron 60 to the flaps 22, the flaps 22 being interposed between said first iron 60 and the lid 18, the first sealing iron 60 pressing the flaps 22 against the lid 18. The final sealing step comprises applying a second hot sealing iron 62 to the flaps 22, the flaps 22 being interposed between said second iron 62 and the lid 18, the second sealing iron 62 pressing the flaps 22 against the lid 18. Said applications are successive, following one another preferably with a time interval of less than 2 seconds.

[0067] Each of the sealing irons 60, 62 includes a hot metal element 64, i.e. at a temperature typically above 120°C, defining a contact face 65 with the flaps, said contact face 65 having substantially the shape of the contour of the lid 18. Preferably, however, the metal element 64 is at a temperature below 140°C, so as to prevent its application against the flaps 22 from damaging the plastic of the lid 18.

[0068] In order to prevent the metal member 64 from coming into contact with the cover 18, which could damage the cover 18, a recess 66 is formed in the center of the metal member 64, the contact face 65 defining the periphery of said recess 66.

[0069] An insulating insert 68 is housed in said recess 66 and is flush with the contact face 65. This prevents the pressure exerted by the sealing irons 60, 62 on the flaps 22 from causing deformation of the sealed portion 10 at its periphery.

[0070] This insulating insert 68 is made of a high melting point thermoplastic or thermoset material, for example bakelite, bakelized cotton fabric, or polyetheretherketone.

[0071] When each sealing iron 60, 62 is applied against the flaps 22, heat is transferred from the sealing iron 60, 62 to the heat-sealable coating 58 and the heat-sealable layer 42 through the flaps 22. This heat transfer is rapid, since the flaps 22 are thermally conductive. The cover 18, being insulating, prevents the heat transferred to the heat-sealable coating 58 and the heat-sealable layer 42 from escaping into the food product 12. This heat accumulates at the interface between the flaps 22 and the cover 18, causing a rapid rise in the temperature of the heat-sealable coating 58 and the heat-sealable layer 42 to a temperature exceeding the threshold temperature of the heat-sealable materials they constitute. The said heat-adhesive materials are thus activated by this heat and form a bond between the flaps 22 and the lid 18. It is this bond which ensures the sealing of the flaps 22 to the lid 18.

[0072] It should be noted that using the successive application of the two sealing irons 60, 62, rather than the application of a single sealing iron, makes it possible to significantly reduce the application time of each sealing iron 60, 62 to obtain a tight seal of the portion 10. It is thus possible to increase the production rate of the packaged portion 10 until reaching a rate identical to the production rate of hot dosed processed cheese portions.

[0073] The description of the packaged portion 10 given above is largely applicable to the packaged portion 100 shown on the Figures 10 is 11. For the sake of simplicity, identical reference signs have therefore been used to designate the elements common to the 10 and 100 packaged portions, and the common characteristics have been omitted from the description below.

[0074] The packaged portion 100 differs primarily from the packaged portion 10 in that the sheet 30 does not form the base 19 of the cup. Unlike the packaged portion 10, the base 19 here comprises a base 102 sealed to the sheet 30. The sheet 30, however, still forms the side wall 20 and the flaps 22.

[0075] With reference to the Figure 12 The base 102 is substantially flat. It has an internal face 104, oriented towards the receiving space 16, and an external face 106 oriented in the opposite direction to the receiving space 16.

[0076] The outer face 106 is coated with a heat-adhesive coating 108, separate from the base 102.

[0077] This heat-sealable coating 108 consists of a heat-sealable material suitable for bonding with a compatible material when heated above a threshold temperature. This heat-sealable material is preferably a low-temperature heat-sealable material, meaning that the threshold temperature is below 75°C. However, the threshold temperature remains above 58°C to prevent any interaction between the heat-sealable coating 108 and the food product 12 at the normal storage temperature of the food product 12. The threshold temperature is typically the melting temperature of the heat-sealable material.

[0078] The adhesive materials of the thermo-adhesive coating 108 and the thermo-adhesive layer 42 are compatible materials.

[0079] In the example shown, the base 102 is identical to the lid 18. This makes it easier to produce the packaged portion 100.

[0080] The sheet 30 includes a border region 110 connected to the side wall 20 by the lower edge 26 of the latter. This border region 110 is folded and hermetically sealed on the outer face 106 of the base 102.

[0081] This two-part design of the cup 14 (the sheet 30 and the base 102) allows the wrapped portion 100 to have an original shape. In particular, this two-part design of the cup 14 makes it easy to give the wrapped portion 100 the cylindrical shape of revolution visible on the Figures 10, 11 , a shape which is more difficult to achieve with a one-piece cup 14 as is the case for the packaged portion 10. This construction of the cup 14 makes it possible to obtain a cylindrical portion without any fold on the side wall 20 and to have the tear guide strip in the sheet 30 positioned along the lower 26 and upper 24 edges of the side wall 20.

[0082] Another difference between packaged portion 100 and packaged portion 10 is that packaged portion 100 includes two gripping tabs 112 housed in the receiving space 16. The first of these tabs 112 straddles the side wall 20 and the lid 18, being sealed to the lid 18, and the second tab 112 straddles the side wall 20 and the base 102, being sealed to the base 102. These tabs 112 facilitate the removal of the lid 18 and the base 102 by a consumer after the side wall 20 has been torn off.

[0083] The production process for packaged portion 100 is otherwise substantially identical to the production process for packaged portion 10. The only difference between these processes lies in the step of supplying the bucket 14, which here comprises the following steps: folding the sheet 30 to form a tube, for example by rolling the sheet 30 around a mandrel, introducing the base 102 inside the tube, the base 102 being oriented perpendicular to the axis of the tube, until it is flush with the tear guide element 48, folding the edge region 110 onto the outer face 106 of the base 102, and hot sealing the edge region 110 onto the outer face 106.

[0084] For a description of the remainder of the production process for packaged portion 100, the reader is referred to the description of the production process for packaged portion 10. Figures 14, 15, 16, 17 And 18 corresponding respectively to Figures 5, 6, 7, 8 And 9 .

[0085] Thanks to the process described above, it is therefore possible to easily produce sealed, airtight packaged portions of food products to be dispensed cold, without the packaged portion having a peripheral collar.

[0086] This process can also be easily implemented, as it requires very little adaptation of existing production machines already used for the production of sealed packaged portions of hot dosed food products: most of the existing tools can in fact be reused, the main adaptations to be made consisting of the addition of anti-static bars to limit the risk of static linked to the use of plastic material, the modification of the supply reels of material constituting the lid, and the addition of an additional sealing station.

Claims

1. A method for producing a packaged food product portion (10, 100), comprising the following steps: - providing a cup (14) defining an inner area (16) for receiving the food product (12), - cold pouring, at a temperature below 50°C, the food product (12) into the receiving area (16) of the cup (14), - covering the food product (12) using a lid (18) arranged such that flaps (22) of the cup (14), which are thermally conducting, extend toward the outside of the lid (18) after the covering step, - folding the flaps (22) on an outer face (56) of the lid (18) opposite the receiving area (16), and - heat-sealing the flaps (22) on the outer face (56), characterized in that the lid (18) is thermally insulating.

2. The production method according to claim 1, wherein the sealing step comprises the following sub-steps: - applying at least one hot sealing iron (60, 62) on the flaps (22), the flaps (22) being inserted between said sealing iron (60, 62) and the lid (18), and - activating at least one thermo-adhesive material (46, 58) provided at the interface between the flaps (22) and the lid (18) using heat provided to the thermo-adhesive material (46, 58) by the or each sealing iron (60, 62).

3. The production method according to claim 2, wherein the step for applying the or each sealing iron (60, 62) comprises the successive applications of two sealing irons (60, 62) on the flaps (22).

4. The production method according to any one of the preceding claims, wherein the flaps (22) comprise an inner face (40) oriented toward the receiving area (16), an outer face (36) oriented away from the receiving area (16), and have a first surface heat transfer coefficient between their inner and outer faces (36, 40), the lid (18) comprises an inner face (54) oriented toward the receiving area (16) and has a second surface heat transfer coefficient between its outer and inner faces (54, 56), and the ratio of the first surface heat transfer coefficient to the second surface heat transfer coefficient is greater than or equal to 400, in particular greater than or equal to 800.

5. The production method according to the preceding claim 4, wherein the first surface heat transfer coefficient is greater than or equal to 107 W.m-2.K-1, in particular greater than or equal to 1.3.107W.m-2.K-1.

6. The production method according to claim 4 or 5, wherein the second surface heat transfer coefficient is less than or equal to 2.5.104W.m-2.K-1, in particular less than or equal to 1.7.104W.m-2.K-1.

7. The production method according to any one of the preceding claims, wherein the flaps (22) have a thermal conductivity greater than or equal to 200 W.m-1.K-1.

8. The production method according to any one of the preceding claims, wherein the lid (18) has a thermal conductivity less than or equal to 0.5 W.m-1.K-1.

9. The production method according to any one of the preceding claims, wherein the flaps (22) are made up primarily, and preferably more than 70%, of metal, in particular aluminum.

10. The production method according to any one of the preceding claims, wherein the lid (18) is made up primarily, and preferably more than 90%, of plastic, in particular expanded plastic.

11. The production method according to claim 8, wherein the plastic is a polymer, for example expanded oriented polypropylene.

12. The production method according to claim 8 or 9 combined with claim 2 or 3, wherein the lid (18) comprises a layer of plastic material (50) and a metallization layer (52) deposited on at least one face of the plastic layer (50), said metallization layer (52) being inserted between the thermo-adhesive material (58) and the plastic layer (50).