WO2006008398A1 - Flexible bag for cooking and packaging products, particularly perishable foodstuffs - Google Patents

Abstract

A flexible bag for cooking and packaging products, particularly perishable foodstuffs, comprising two partitions or panels (1A,1B) which are assembled in a tight manner, preferably by welding on two of the opposite sides or lateral edges (2A, 2B) thereof, said partitions (1A, 1B) also being assembled in a tight manner by welding on a third side (2C) which is perpendicular to the previous ones, whereas they are disjointed on at least the major part of the fourth side thereof such that an opening (3) can be made for the introduction of products that are to be cooked and packaged, characterized in that it is provided with a degassing vent (4) which is defined by an area or strip (5) used for welding the partitions (1A, 1 B) of the bag (1), extending parallel to one of the closed edges (2A, or 2B, or 2C) of the bag.

Description

Flexible bag and method for cooking and packaging products, including perishable foodstuffs.

The invention relates to a flexible bag for cooking and packaging products, and more particularly, perishable foodstuffs. It also relates to the packaging process using this flexible bag and the packaging of products obtained by the implementation of this method.

More specifically, the invention relates to a pouch or flexible pouch made of a heat-sealable plastic food material for cooking various consumables (vegetables, fruits, fish, meat, ready meals and other food preparations), by microwave heating, and the packaging of these products assuring them a shelf life of several days.

Food products ready to be consumed after a simple reheating in microwaves marketed in trays or in flexible bags, through the distribution channels, are highly appreciated by a large number of consumers, because of the time savings that they provide in the preparation of meals.

The methods and packages of the type flexible bags known from the state of the art consist of a pocket formed of two square or rectangular sheets of flexible heat-sealable plastics tightly assembled by heat-sealing on three of their sides, so as to provide a filling opening between the unassembled edges of their fourth side.

After introduction of the product to be treated in this flexible bag, the filling opening is closed by thermo-welding, leaving at least one interruption in the weld between the two walls of the bag, in order to create a passage for the exhaust steam produced inside the package during the cooking of said product. In the region of interruption of the weld, the facing surfaces of the two sheets constituting the bag are provided with a sealing compound whose characteristic is to melt under the effect of the heat during cooking, so as to allow the escape of steam through the degassing passage thus created and to solidify during cooling at the end of the cooking process, so as to close said passage and the packaging. Such methods and devices are, for example, known from FR-2,796,924 and WO-91/01927.

The implementation of these methods is rather complex, long and difficult if it is considered that it leads to a very precise special preparation of the packaging parts to be assembled. On the other hand, the control of the perfectly tight closure of the packages sealed by such degassing valves seems a priori difficult to achieve on a practical level.

According to another undisclosed method, the product to be treated is introduced into the packaging constituted by a tray or a flexible bag, the packaging is then closed by leaving at least one temporarily unfused zone of said walls, and the product is then heated. contained in the package in an installation comprising a heating station and finally closing the package hermetically by welding said walls in the or said region (s) temporarily not welded.

The implementation of such a process requires a conditioning and cooking installation for continuous production by means of a microwave tunnel with a minimum power of 24 Kw; such an installation is necessarily heavy and expensive and its use requires qualified technical personnel. In fact, the partial closure of the packaging in the form of a plastic bag, after its filling and before cooking the product, is carried out by a welding station equipping a vertical or horizontal bagging machine, while the total and hermetic closure after cooking, the bag is made by means of a welding equipment located immediately after the treatment cell in a tunnel acting trap and allowing the continuous output of the products after cooking. Such packaging and cooking facilities are reserved for large productions (for example 800 kg / hour), so that they are mainly intended for shippers of pre-cooked food products such as vegetables or fruits, or for manufacturers who produce quantities important preparations food or prepared meals, upstream of consumer sales channels.

The invention provides a flexible bag and a method for packaging and cooking food products with a simple and economical equipment easily used by a single person without special qualifications, this flexible bag and this process can advantageously be implemented for production smaller (for example for quantities less than 40 kg / hour), or even for very small quantities (for example less than 5 kg / hour).

According to the process of the invention, the product to be treated is introduced into a sachet or bag having an open side for this introduction and closed in a sealed manner on its three other sides, and in one of the ends of which is formed a degassing chimney which according to its situation can be opened or closed, is then closed, then fully sealed the introduction opening, by means of a suitable heat-sealing material, the end of the degassing chimney is opened by means of a cutting tool when said end is closed, then the product is heated in its packaging by passage in a microwave oven, then the open end of the degassing chimney is sealed, for example by means of a portable thermo-welding tool.

The pouch or flexible pouch for cooking and packaging according to the invention comprises two walls or panels sealingly assembled on two of its opposite sides or side edges, these walls being also assembled, in a sealed manner, by welding on a third perpendicular side. or substantially perpendicular to the preceding, while they are disjoined on at least most of their fourth side, so as to provide an opening for the introduction of the product (s) to be cooked and to condition said bag being remarkable in that it is provided with a degassing chimney delimited by a welding zone or band of the walls of the bag extending parallel to one of the closed edges of said bag. - AT -

According to a preferred embodiment, the degassing chimney is formed in one of the corners of the flexible bag and is delimited by a welding zone or band of the walls of the latter extending perpendicularly or approximately perpendicular to the side or end open said bag, and from said end.

According to an advantageous embodiment, the degassing chimney has an open end.

It is understood that the flexible bag and the method of the invention allow the packaging of products and especially edible products in their cooking package, using a material that can be very simple and light, easily used by a user. only person, without special qualifications.

On the other hand, they allow vacuum packaging of cooked or precooked products thus increasing their shelf life. Indeed, the heating of the content of the bag causes a vaporization of the liquid phase of this content and the degassing chimney allows the regulation of the resulting pressure inside said bag (for example between 0.1 and 0.8 bar) avoiding the bursting of it. Rapid cooling of the contents of the bag, after closure of the degassing chimney, causes condensation of the vapor remaining in said bag. This condensation causes a decrease in the pressure inside the bag and generates a vacuum effect causing a decrease in the volume of said bag and a retraction of the walls of the latter around its content which is thus packaged under vacuum.

According to a preferred embodiment, the intermediate welding strip delimiting the degassing chimney is partially shared by a longitudinal slot extending from the edge of the bag, so that said degassing chimney is in the form of a tubular tongue partially separated from the remaining portion of the package.

This tubular tongue facilitates the gripping of the bag at its exit from the microwave oven and its handling during the closure of said chimney by means of a manual thermo-welding tool. EIIe also constitutes a tear initiation allowing the manual opening of the bag to extract its contents or to create, manually, a degassing orifice avoiding the bursting of said bag during heating of its contents in the microwave before consumption of the products qu it encloses.

In addition, the degassing chimney thus formed is, after opening of its end, a pouring spout facilitating the draining of the exudate resulting from the cooking of certain vegetables (asparagus, leeks, etc.).

The above and other objects, features and advantages will become more apparent from the following description and accompanying drawings in which:

Figure 1 is a plan view, partially cut away and schematic, of a preferred embodiment of the cooking bag according to the invention.

Figures 2 to 8 are plan views and schematic illustrating an interesting example of preferred implementation of the method of cooking and packaging products according to the invention.

Figure 9 is a plan view, partially cut away and schematic, of a second embodiment of the cooking bag according to the invention.

FIG. 5A is a schematic plan view illustrating an additional phase of the cooking method using a bag according to FIG. 9.

Figure 10 is a plan view, partially broken away and schematic, of a third embodiment of the cooking bag according to the invention.

Referring to the drawings to describe an advantageous embodiment of the cooking bag and implementation of the packaging method and cooking according to the invention. In the following statement:

the word "product" shall be understood to mean a wide variety of foodstuffs such as vegetables (potatoes, carrots, cauliflowers, turnips, asparagus, etc.), fruits (apples, pears, plums, etc.), meat, fish, ready meals and other food preparations;

the word "conditioning" when not used as a name supplement in the expression "packaging method" means an article consisting of a package (bag) and the food product contained therein.

the word "cooking" designates both a complete cooking of the foods making them ready to be consumed, possibly after a simple reheating, an incomplete cooking (precooking, bleaching);

the word "end" refers to the open side of the bag and the opposite side or bottom of it.

According to the preferred embodiment illustrated in FIG. 1, the cooking and conditioning bag 1 consists of two walls or panels 1A, 1B of flexible plastics material assembled in a sealed manner, preferably by welding, on two of their opposite sides or side edges, for example by welding their edges 2A, 2B. Said walls are also assembled, sealingly, by welding on a third side 2C perpendicular or substantially perpendicular to the previous, so as to form a rectangular or square pocket. Said walls 1A, 1B are disjoint on at least most of their fourth 2D side opposite said third side 2C, so that an opening 3 is formed between the disjointed edges of said fourth side, for the introduction of products to treat.

This flexible pouch can be made of any food grade plastic having the required qualities such as microwave and light transparency, flexibility, compliance with food regulations, impermeability to water, heat shrinkability, resistance to melting and the migration of its components to food. For example, envelope 1 can be made of polyethylene or polyethylene terephthalate (PET) and, more specifically and preferably, retractable polyolefin anti-fog, extruded multilayer structure.

According to an important characteristic arrangement of the invention, the bag is provided with a degassing conduit or chimney delimited by a welding zone or strip of the walls 1A, 1B of said bag extending parallel to one of the welded edges of this bag. latest.

According to the preferred embodiment shown in FIG. 1, the bag 1 is provided with a degassing chimney 4 having an open end 4a delimited by a zone or strip 5 of the walls 1A, 1B extending perpendicularly or approximately perpendicular to the open edge

2D or open end of said bag and from said open edge.

According to an advantageous embodiment, the degassing chimney 4 is delimited by a welding zone or strip 5 of the walls 1A, 1B of the bag 1, extending parallel or approximately parallel to the lateral edges

2A, 2B of said bag, close to one (2B) thereof. In this way, the degassing chimney 4 is located in one of the corners of the bag 1.

According to an advantageous embodiment, the welding strip 5 delimiting the degassing chimney 4 is partially shared by a longitudinal slot 6 extending from the edge 2D of the bag which leads to said weld strip 5, so that said chimney degassing is in the form of a tubular tongue 7 partially separated from the remaining portion of the bag.

The degassing chimney may have a length of the order of 1/4 to 1/5 with respect to the length of the bag. When the bag 1 is flat, the degassing chimney 4 has a width not exceeding 20 mm and preferably a width of the order of 15 to 18 mm. This width is different according to the weight and volume of the packaged product and intended to be cooked, so as to determine a passage section for the escape of steam to maintain an overpressure of the order of 0.1 to 0, 8 bar inside the bag during the cooking phase. For example, it may be of a greater width or equal to 15 mm for 500 g of product and a width greater than or equal to 18 mm for 700 g of product. On the other hand, in order to facilitate the hermetic reclosing of the bag after cooking or treatment of the product, the weld strip is cut longitudinally over a length of the order of 45 mm corresponding to the length of the tubular tongue 7.

Figures 2 to 8 illustrate the successive steps of a preferred embodiment of the packaging and cooking method according to the invention, using the flexible bag described above, these drawings showing by way of example, the cooking and the packaging of vegetables such as carrots C and potatoes P.

The food products to be treated C, P (fruits, vegetables or other) are introduced into the bag 1 (Figure 2) through the opening 3 formed between the disjointed edges of its end or side 2D, manually or with the aid of a bagging device.

Depending on the type of product treated, a quantity of liquid water may be added, for example a volume of the order of 5 to 10 ml of liquid water (FIG. 3). This liquid water may be pure water or flavored water or mixed with a flavoring agent or flavor, or one or more other additives.

The bag is hermetically sealed by welding the edges of the introduction opening, by means of a heat-sealing apparatus T (FIG. 4) allowing the production of a welding strip 8 along said edges (FIG. 5). .

The sachet is introduced into a heating chamber preferably constituted by a microwave oven 9 (FIG. 6). Heating the contents of the sachet causes vaporization of the liquid phases contained in said sachet, swelling of the flexible walls of the latter, and expansion of the internal volume of said sachet under the pressure of the vapor produced; the degassing chimney 4 regulates this pressure by allowing the escape of the excess gaseous fluid.

At the end of the cooking step, the sachet is quickly closed in a sealed manner by hermetically sealing the degassing chimney 4, by thermo-welding the end of the latter, constituted by the free end of the tubular tongue 7 according to the example described, for example by means of a hand tool or portable thermal gripper T (FIG. no to that used to close the bag after filling (Figure 4).

Preferably, the conditioning process is terminated by a sudden cooling of the bag, for example by soaking in a cold water bath contained in a tank 11 (FIG. 8). This sudden cooling causes a rapid condensation of the water vapor remaining in the bag at the time of its hermetic closure, and, as a result, a rapid decrease in the pressure inside the bag. This has the effect of creating a vacuum effect inside the bag resulting in a retraction of the latter allowing a natural evacuation of said bag.

The embodiment shown in Figure 9 differs from that just described in that the free end of the degassing chimney 4 is closed by a weld 4b.

In this case, during the implementation of the cooking process using a bag of this type, it is necessary to insert a step of opening the degassing stack 4 (FIG. 5A) between the previously described steps of closing the bag after filling (Figure 4) and introduction of the filled bag into the microwave oven (Figure 6), this opening can be performed automatically or manually using a machine or a suitable cutting tool O .

According to the embodiment illustrated in FIG. 10, the walls or flexible panels 1A and 1B of the bag 1 are tightly assembled on three of their sides 2A, 2B, 2C and are not welded on their fourth 2D ₁ side. so as to constitute the opening 3 of said bag. According to this embodiment, the degassing chimney 4 is disposed on the closed end side of the bag 1. In this case, the degassing chimney 4 is delimited by a band or welding zone 5 extending parallel or approximately parallel to the side edges 2A, 2B of the bag, close to one (2A) thereof and from the welding zone 2C of the end edge or closed transverse edge of the bag. According to this embodiment, the welding strip 5 can also be advantageously shared by a longitudinal slot 6 extending from the closed edge of the bag to which said solder strip 5 terminates, and it comprises an end sealed by example by a weld 4b.

During the implementation of the cooking process using such a bag, the goods P, C, are introduced into the bag 1, through the opening 3. It then proceeds to the sealing of the bag by welding the edges of the introduction opening by means of a suitable heat-sealing apparatus, allowing the realization of a weld strip 8 along said edges. In this case, it is also necessary to insert a step of opening the degassing stack 4 between the steps of closing the bag after filling (FIG. 4) and introducing the filled bag into the microwave oven (FIG. Figure 6).

It is observed that in addition to its functions of regulating the vapor pressure during the heating step and the gripping tab facilitating handling, the degassing chimney 4-7 can act as a spout allowing, before opening the sachet in order to consume its contents, to recover easily and without risk of spattering, the exudate enclosed in said bag so that it can be eliminated or used for culinary purposes (sauce funds for example).

The packaging and the packaging method according to the invention can be carried out using a simple, lightweight, economical and easily usable welding material. It may be, for example, a device in the form of a portable manual clamp consisting of a handle equipped at its end with a heating jaw with a length at least equal to the dimension of the side the bag left open to house the product and a width greater than the width of the degassing chimney, this hot plier for:

- completely close by manual tightening the open side of the bag to accommodate the product; after cooking, closing or closing said bag hermetically by sealingly obstructing the degassing chimney which, if necessary, has been previously cut manually by means of scissors or a knife in order to proceed to its opening before the passage to the microwave.

The invention also relates to packages of cooked, pre-cooked or blanched food products (vegetables) comprising:

a flexible bag 1 made in the manner previously described, and;

- A foodstuff (P, C) treated by the implementation of the cooking process described above.

Claims

1. Flexible bag for cooking and packaging products, including perishable foodstuffs comprising two walls or panels (1A, 1B) tightly assembled, preferably by welding, on two of their opposite sides or side edges (2A , 2B), these walls (1A, 1B) also being welded together on a third side (2C) perpendicular or substantially perpendicular to the previous ones, while they are disjoint on at least the major part their fourth side, so as to provide an opening (3) for the introduction of products to cook and condition, characterized in that it is provided with a degassing chimney (4) delimited by a zone or strip of welding (5) the walls (1A, 1B) of the bag (1) extending parallel to one of the closed edges (2A, or 2B, or 2C) of said bag. 2. flexible bag according to claim 1, characterized in that the degassing chimney (4) is executed in one of the corners of the bag. 3. Flexible bag according to one of claims 1 or 2, characterized in that the degassing chimney (4) is defined by a welding zone (5) of the walls (1A, 1B) of the bag (1) s' extending parallel or approximately parallel to the side edges (2A, 2B) thereof, near one (2B) thereof and from the edge (2D) having the opening (3) for introducing said bag . 4. Flexible bag according to one of claims 1 or 2, characterized in that the degassing chimney (4) is defined by a welding zone (5) of the walls (1A, 1B) of the bag (1) s' extending parallel or approximately parallel to the side edges (2A, 2B) thereof, near one (2B) thereof and from the weld zone (2C) of the closed end of said bag. 5. Flexible bag according to any one of claims 1 to 4, characterized in that the welding strip (5) defining the degassing chimney (4) is partially shared by a longitudinal slot (6) extending from the edge (2D or 2C) of the bag (1), so that said degassing chimney is in the form of a partially separate tubular tongue (7) of the remaining part of said bag. 6. Flexible bag according to any one of claims 1 to 5, characterized in that the degassing chimney (4) has an open end (4a) or closed (4b). 7. Flexible bag according to any one of claims 1 to 6, characterized in that the degassing chimney (4-7) has a passage section for the exhaust of the excess steam to maintain an overpressure of the from 0.1 to 0, 8 bar inside the bag during its cooking phase. δ. Flexible bag according to Claim 7, characterized in that, when the bag is flat, the degassing stack (4-7) has a width of the order of 15 to 20 mm, preferably a width of 15 to 18 mm. and / or a length of the order of 1/4 to 1/5 with respect to the length of the bag (1). 9. Process for cooking and packaging products, especially perishable foodstuffs using a flexible bag according to any one of claims 1 to 8, characterized in that: the food products to be treated (C, P) are introduced into the sachet (1) through the opening (3) constituted by its open side; the bag is sealed by welding the edges of the introduction opening (3); the end (4b) of the degassing chimney (4) is opened by cutting off said end, if the bag comprises a closed degassing chimney; the bag and its contents are introduced into a heating chamber (9), preferably constituted by a microwave oven; - At the end of the firing step, the venting chimney (4) is hermetically sealed by thermofusion of its end. 10. The method of claim 9, characterized in that an additional liquid is also introduced into the package, before the firing step. 11. A method according to one of claims 9 or 10, characterized in that one proceeds to a sudden cooling of the packaged product immediately following the step of closing the degassing stack (4). 12. Packaging of foodstuffs, characterized in that it comprises: - a flexible bag (1) hermetically sealed and made according to any one of claims 1 to 8, and, a foodstuff (P, C) housed in this flexible bag and cooked by the implementation of the cooking method according to any one of claims 9 to 11.