NL2008389C2

NL2008389C2 - Improved process for wrapping poultry.

Info

Publication number: NL2008389C2
Application number: NL2008389A
Authority: NL
Inventors: Isabelle Chasson; Sebastien Osmond
Original assignee: Doux Frais
Priority date: 2011-03-03
Filing date: 2012-03-01
Publication date: 2012-10-30
Also published as: ES2387709A1; GB201203635D0; ITTO20120182A1; FR2972178A1; GB2488666A; NL2008389A; DE102012004196A1; BE1020270A3

Description

Improved process for wrapping poultry

The invention relates to a process for wrapping fresh, ready-to-cook poultry, to increase its shelf life.

5

For the purposes of the present invention, the term "fresh, ready-to-cook poultry" means whole, stripped poultry. This poultry is generally wrapped in a food-grade film and stored cold at a temperature of 0°C to +4°C before consumption.

10 Conventionally, the food-grade film used for wrapping fresh, ready-to-cook poultry is a stretchable polyvinyl chloride film. The shelf life for fresh, ready-to-cook poultry thus wrapped is typically about ten days. For a fresh, ready-to-cook chicken, it is generally, for example, 11 days.

15 This may seem quite long. However, if it is considered that ready-to-cook poultry is generally sold in supermarket distribution, this period is rather short, since, within these few days, the poultry must be conveyed to the supermarket shelves and then a certain amount of time must also be allowed for the poultry to be sold once it is on the shelf. The period remaining for the sale of the poultry is generally 20 6 days, which is quite short, and the poultry is occasionally not sold in time.

Consequently, the management of a supermarket ready-to-cook poultry shelf is difficult and losses arise (also known as "spoil") when the poultry has not been sold before the end of its use-by date.

25 French patent application FR 08 52262, of which the Applicant Company is the proprietor, describes a process for wrapping fresh, ready-to-cook poultry that makes it possible to increase the shelf life of this poultry by several days. This process comprises: - a step of forming a tube made of a heat-shrinkable, gas-barrier food-grade 30 film; - a step of introducing fresh, ready-to-cook poultry into this tube; 2 - a step of flushing the tube with CO2 alone or as a mixture with O2 and/or N2; - a step of sealing a first end of the tube; - a step of sealing a second end of the tube; and 5 - a step of shrinking the food-grade film around the poultry at a temperature of between 160 and 200°C.

However, the finished product obtained via this process has a wrinkled appearance a few days after packaging. This phenomenon increases throughout 10 the shelf life of the product. Thus, despite the prolonged shelf life by virtue of this process, consumers are sparingly tempted to purchase the product on account of its unappealing visual appearance.

The Applicant Company has indeed observed that placing the poultry under a 15 protective atmosphere in wrapping made of a hermetically sealed barrier film always generates a "ballooned" pocket.

It has especially been found that the excess gas still contained in the wrapping before its passage into the shrinking tunnel expands and comes up against the film when it shrinks. Consequently, the film is limited in its shrinkage by the gas under 20 low pressure. Within hours of packaging, the poultry absorbs the gases, especially C02. This absorption is then reflected by a kind a natural vacuum suction, since the rapid kinetics of absorption of the C02 and the use of a gas-barrier film do not make it possible to compensate for the "natural vacuum suction" by the arrival of another gas, for example the surrounding atmosphere.

25

Consequently, the excess film, limited in the course of its shrinkage, generates folds during the "natural vacuum suction", thus impairing the final appearance of the product on the shelves.

30 The Applicant Company has also demonstrated that the best indicator of the vacuum suction is the level of C02 inside the wrapping, and that this level decreases greatly within the first 48 hours after wrapping. For an initial gas 3 mixture comprising, for example, 80% by volume of CO2, the CO2 content thus falls to about 37% by volume after 48 hours. This CO2 content continues to fall throughout the shelf life, but stabilizes at about 27% by volume after about 18 days.

5

The Applicant Company was thus able to demonstrate that the level of CO2 and the folded appearance are correlated.

In the light of these drawbacks, the Applicant Company developed a novel wrapping process, which is the object of French patent application FR 10 50197, 10 which makes it possible to reduce the formation of folds after packing while at the same time maintaining the increase in shelf life of the final product obtained with the process described above, said process comprising: - a step of introducing fresh, ready-to-cook poultry into a tube or bag made of a heat-shrinkable gas-barrier food-grade film; 15 - a step of creating a protective atmosphere inside the tube or bag; - a step of sealing a first end of the tube or the open end of the bag; - when using a tube, a step of sealing a second end of the tube; and - a first step of shrinking the food-grade film around the poultry at a temperature of between 150 and 190°C; 20 characterized in that it comprises, after the first shrinking step, a step of storing the wrapped poultry for a period of 6 to 18 hours, followed by a second additional step of shrinking the food-grade film around the poultry, this second shrinking step being performed at a temperature ranging from 165 to 180°C.

25 However, the drawback of this process is imposing, firstly, the storage of the poultry for 6 to 18 hours, and, secondly, a second step of shrinking the film after storage. Although the product obtained by this process has a very markedly improved visual appearance when compared with the process comprising only one shrinking step, the costs incurred by the storage and the second step of shrinking 30 the film make this process too expensive and the products obtained are thus less economically viable.

4

In order to solve the technical problem mentioned previously, and in order to avoid the need to perform a second shrinking step after a few hours of storage, a solution might have been to modify the composition of the protective atmosphere so as to reduce the amount of CO2 that may be absorbed by the poultry. However, 5 C02 has a bacteriostatic effect and allows better storage of poultry. When the C02 content is lowered, for example in favour of nitrogen, the shelf life of the poultry is reduced.

It thus remains desirable to have access to a process able to maintain the attractive 10 appearance and the storage life of the final product obtained with the process described above, but without giving rise to a production surcharge.

Now, after in-depth research and numerous trials, the Applicant Company has, to its merit, developed a process for wrapping fresh, ready-to-cook poultry, 15 comprising: i. a step of introducing fresh, ready-to-cook poultry into a tube or a bag made of a heat-shrinkable, gas-barrier food-grade film; ii. a step of creating a protective atmosphere inside the tube or the bag; iii. a step of sealing a first end of the tube or the open end of the bag; 20 iv. when using a tube, a step of sealing a second end of the tube; and v. a step of shrinking the food-grade film around the poultry at a temperature of between 130 and 200°C; characterized in that it comprises a step of evacuating residual gas by applying a mechanical pressure to the poultry thus introduced into the tube or bag made of 25 heat-shrinkable food-grade film before performing step iv of sealing the second end of the film tube, or simultaneously therewith, this application of a mechanical pressure being performed by means of a block of foam with a density of between 15 and 20 kg/m3.

30 By means of this process, a final product that has a good shelf life and whose visual appearance, especially at the end of the shelf life, is markedly improved relative to that of the product obtained by the process described in French patent 5 application FR 08 52262 is obtained, without giving rise to a production surcharge.

The process according to the invention is performed for the wrapping of fresh, 5 ready-to-cook poultry.

Specifically, the phenomenon of folding of the film observed after wrapping poultry via the process described in French patent application FR 08 52262 is mainly observed for fresh, ready-to-cook poultry, which absorb the CO2 of the 10 modified atmosphere.

However, the process that is the subject of the present invention may also be used for the wrapping of cooked poultry when complete evacuation of the residual gas is desired. In particular, this may make it possible to use the same wrapping chain 15 for fresh, ready-to-cook poultry and for whole cooked poultry.

Shelf life

For the purposes of the present invention, the term "shelf life" means the period 20 between the date of slaughter of the product and the date at which the product is no longer consumable, either for bacteriological reasons, or for organoleptic reasons.

This shelf life is determined according to a microbiological validation protocol 25 defined according to standard NF 01-003. The test consists in searching for and counting various germs. These measurements take place on the day of slaughter, the day of the presumed end of life and 2 days after the date of presumed end of life for free-range poultry. These measurements are taken on two different productions with 5 samples. These measurements are taken under temperature 30 conditions of 0 to +4°C. The germs sought under these conditions, in the case of the fresh, ready-to-cook poultry, are hygiene indicator germs such as Pseudomonas, Escherichia coli, Coagulase + Staphylococci and Salmonella 6 (searched for on the skin of the neck). Other germs are searched at the end of life of the product, such as the lactic flora for products conditioned under a protective atmosphere, also stored in conditions of 0 to +4°C. The shelf life under these conditions thus corresponds to the number of days between slaughter and the time 5 at which the contamination limit is reached for at least one of the germs investigated. The reference value is 1 x 104 cfu/g for E-coli, 5 x 103 cfu/g for Coagulase + Staphylococci and 5 x 107 cfu/g for the lactic flora. The product is no longer consumable once there are (1) 3 out of 5 samples with values between the reference value and 10 times the reference value for at least one of the germs 10 investigated or (2) a sample for which the value for a germ is higher than 10 times the respective reference value.

The shelf life is also determined via organoleptic criteria at the end of life in order to identify visual or olfactory spoiling of the product.

15

The increase of the shelf life via the wrapping process according to the invention is understood relative to the processes for wrapping fresh, ready-to-cook poultry which do not comprise the step of flushing the tube made of food-grade film with CO2 alone or as a mixture with O2 and/or N2.

20

Poultry

For the purposes of the present invention, the term "poultry" means chicken, guineafowl, cockerel, turkey, duck, capon, wild game such as quail and pheasant, 25 and lagomorphs such as rabbit. The preferred types of poultry are chicken, turkey and rabbit, and in particular chicken.

Introduction of the poultry into a film tube 30 The first step of the poultry wrapping process according to the invention comprises the introduction of the fresh, ready-to-cook poultry into a tube or a bag made of a heat-shrinkable gas-barrier food-grade film.

7

The heat-shrinkable gas-barrier food-grade film used in the process of the invention may advantageously be a complex of simple polyolefin (polyethylene), barrier polyolefin (ethylene-vinyl alcohol) and antimisting polyolefin (polyethylene).

5

Such a film is sold especially by the company Sealed Air under the name "Film BDF®", for example under the reference Cryovac BDF® 750 or Cryovac BDF® 8050.

10 The fresh, ready-to-cook poultry is advantageously deposited on a support, such as an expanded polystyrene tray, before being introduced into the tube of food-grade film. It is then introduced with this support into said tube. However, it is possible to introduce the poultry alone into the tube, without a support. It is also possible to introduce the poultry into the tube with any type of food support, such 15 as a cardboard box, a rigid plastic tray, an expanded polystyrene tray, etc.

Step of creating a protective atmosphere

After the step of introducing the poultry into a tube or bag made of heat-20 shrinkable food-grade film, the process according to the invention comprises a step of creating a protective atmosphere inside the tube or bag.

For the purposes of the present invention, the term "protective atmosphere" means any gas or mixture of gases that improves the shelf life of the wrapped poultry.

25 Such a gas or mixture of gases is also referred to as a "protective gas" or a "mixture of protective gases".

In general, the oxygen content of the protective atmosphere is between 0 and 30% O2, preferably between 0.01% and 10%, more preferentially between 0.05% and 30 5% and even more preferentially between 0.01% and 3% O2.

8

Indeed, oxygen has a tendency to promote the bacteriological growth of the poultry, thus limiting its shelf life.

The creation of the protective atmosphere may be performed by flushing the tube 5 or bag with the protective gas or the mixture of protective gases, or, especially during the use of a bag, by sucking out the ambient atmosphere, followed by injecting the protective atmosphere.

In one embodiment of the invention, the gas used may be CO2 alone. It is thus 10 possible to increase the shelf life at a temperature of 0 to +4°C of fresh, ready-to-cook poultry by three to seven days. The shelf life at a temperature of 0 to +4°C of a fresh, ready-to-cook chicken is thus at least 13 days, preferably from 14 to 18 days and more preferentially from 15 to 16 days.

15 In another embodiment, a mixture of CO2, N2 and O2 may be used. This mixture advantageously comprises from 10% to 50% by volume of CO2, from 10% to 20% by volume of N2 and from 30% to 80% by volume of O2.

Very good results have been obtained during the use of a mixture of CO2 and N2. 20 According to one preferred embodiment, this mixture comprises from 50% to 90% by volume of CO2 and from 50% to 10% by volume of N2, preferably from 60% to 90% by volume of CO2 and from 40% to 10% by volume of N2, and even more preferentially about 80% by volume of CO2 and about 20% by volume of N2 or about 70% by volume of CO2 and about 30% by volume of N2.

25

The shelf life at a temperature of 0 to +4°C of fresh, ready-to-cook poultry is thus increased by at least three to seven days. The shelf life at a temperature of 0 to +4°C of a fresh, ready-to-cook chicken is thus at least 13 days, preferably from 14 to 18 days and more preferentially from 15 to 16 days according to the process of 30 the invention.

9

The best results, both as regards the shelf life of the final product and as regards its visual appearance (especially the colour) at the end of the shelf life, were obtained with a mixture of about 70% by volume of CO2 and about 30% by volume of N2.

5

The gas injection rate during the step of flushing with CO2 alone or as a mixture with O2 and/or N2 is advantageously at least 100 1/min, preferably at least 120 1/min and even more preferentially about 1501/min 10 Steps of sealing and shrinking

Once the poultry is in the film tube or in the bag, the steps of sealing the tube are performed by means of techniques that are well known to those skilled in the art. The sealing may, for example, be performed via welding means, for instance a 15 welding bar or ultrasound.

Sealing of the tube makes it possible to obtain hermetically closed wrapping.

After the sealing step, a step of shrinkage of the food-grade film around the 20 poultry is performed at a temperature sufficient to enable shrinkage of the film around the poultry, and especially between 130 and 200°C, preferably between 140 and 180°C and even more preferentially between 150 and 165°C.

A person skilled in the art will adjust the temperature of the shrinkage step 25 according to the nature of the heat-shrinkable gas-barrier film used for wrapping the poultry.

During the step of shrinkage of the food-grade film around the poultry, the ambient air, including the controlled atmosphere inside the tube of food-grade 30 film, is heated to these temperatures, leading to shrinkage of the food-grade film around the poultry.

10

The shrinking temperature is chosen by a person skilled in the art according to the nature of the heat-shrinkable film used. If the properties of the film allow it, shrinkage at lower temperatures may be envisaged, provided that the food-grade film is, after shrinkage, well taut around the poultry.

5

Once the film has thus been tightened around the poultry, a cold air knife may advantageously be applied in order to fix the film better in its position. The temperature of the cold air is advantageously between 4 and 10°C.

10 Step of evacuation of the residual gas

The wrapping process according to the invention moreover comprises a step of evacuating residual gases after the step of flushing the tube with CO2 alone or as a mixture with O2 and/or N2. Thus, the amount of residual gases around the poultry 15 is considerably reduced.

This is particularly advantageous, since the shrinkage of the food-grade film around the poultry takes place all the better when the amount of gas around the poultry is low. This step of evacuation of the gas thus makes it possible to obtain a 20 wrapped product that has a smooth appearance throughout the shelf life of the poultry, without the need for a second step of shrinkage of the film.

The step of evacuation of residual gases is performed by applying a mechanical pressure to the poultry thus introduced into the film tube before performing step iv 25 of sealing the second end of the film tube, or simultaneously therewith.

It should be noted that such a step of evacuating residual gases by pressing the poultry in the film tube before the step of sealing the second end of the film tube has already been envisaged in prior art processes. However, the Applicant has, to 30 its credit, discovered, after numerous trials, that by applying a mechanical pressure to the poultry by means of a foam with a particular density and/or shape, the removal of the gas can be improved, such that the amount of residual gases 11 around the poultry after sealing of the second end is reduced, thus facilitating the shrinkage of the food-grade film around the poultry. The wrapped poultry then has very little gas that can be absorbed during its storage, which considerably limits the formation of folds on the wrapping.

5

The Applicant has in particular, to its credit, demonstrated that the density of the block of foam, and/or the shape of the imprint hollowed into the block of foam, are deciding factors for optimizing the evacuation of residual gases.

10 The pressing is performed using a block of foam with a density of between 15 and 20 kg/m3.

In particular, the foam may have a density of between 16 and 19 kg/m , preferably between 16 and 18 kg/m3 and more preferentially about 17 kg/m3.

15 The block of foam may be formed from any type of material with the desired density. The material is especially an easily compressible, flexible material of low hardness.

The elongation (longitudinal and transverse) of the material may be up to 120% 20 and is preferably about 110%.

In particular, the material may have a tensile strength (longitudinal and transverse) of between 50 and 100 KPa, preferably between 60 and 80 KPa and more preferentially between 65 and 75 KPa.

25

The material may also have a compressive strength at 25% of between 0.5 and 5 KPa, preferably between 1 and 4 KPa and more preferentially between 1 and 3 KPa.

30 The material may moreover have a compressive strength at 50% of between 0.5 and 5 KPa, preferably between 1 and 4 KPa and more preferentially between 2 and 4 KPa.

12

In particular, the material used for the block of foam according to the invention may have the property of absorbing water.

According to one preferred embodiment, the foam is a polymer foam, such as a 5 latex foam, a polyether foam or a polyurethane foam, and more preferentially a polyurethane foam, for instance those sold by the company Plastiform’s under the reference PU - Ether density 17 kg/m3 white.

The block of foam may come in various shapes, for example any volume of 10 round, oval, square or rectangular cross section.

When the process is used for wrapping a fresh, ready-to-cook chicken, the block of foam may, irrespective of its shape, be inscribed in a rectangular parallelepiped having: 15 - a length of between 20 and 40 cm, preferably between 25 and 35 cm and more preferentially from 26 to 33 cm; a width of between 15 and 35 cm, preferably between 20 and 30 cm and more preferentially from 23 to 28 cm; a height of between 5 and 25 cm, preferably between 10 and 20 20 cm and more preferentially from 12 to 16 cm.

According to a particularly preferred embodiment, the block of foam is hollowed in part of its height in a shape corresponding to the upper part of the poultry to be wrapped, said upper part especially comprising the thighs and wishbone, said 25 hollowed foam thus being suitable for fitting the shape of the upper part of the poultry onto which it is pressed so as to evacuate the maximum amount of residual gas around the poultry before step iv of sealing the second end of the film tube, or simultaneously therewith.

30 13

Second step of optional shrinkage

In certain rare cases, in the hours following packaging, the poultry may absorb some of the CO2. The surplus film, which is, however, considerably limited by the 5 pressing and shrinkage steps, may then generate folds that impair the final appearance of the product on the supermarket shelves.

In this case, a second step of shrinkage of the food-grade film around the poultry, after storing the wrapped poultry for a period of 6 to 18 hours, may be envisaged.

10

Such an even more optimized process is more expensive due to the second shrinkage step. In order to be economically viable, it is preferably used for the wrapping of high-quality products.

15 The inventors have found that below six hours, the adsorption of CO2 is not yet sufficiently advanced. There is therefore still a surplus of gas keeping the film smooth and taut. Beyond eighteen hours, the very advanced adsorption of the CO2 establishes a vacuum suction that is too high to enable a second shrinkage step at a temperature of 160 to 180°C to be performed.

20

It is thus preferable to store the poultry for between 5 and 18 hours and preferably between 6 and 12 hours.

The second shrinkage step makes it possible to remove the folds that might have 25 formed during storage and thus to obtain true smoothing of the film around the poultry.

In one particular embodiment, the second shrinkage step, when it is performed, is carried out at a temperature of between 165 and 175°C and preferentially at a 30 temperature of about 170°C. Thus, optimum smoothing of the folds is obtained.

14

It has been observed that the majority of the folds in the film that are formed during the storage step are on the top of the wrapped poultry. During the second shrinkage step, it is thus advantageous to orient hot air, heated to the temperatures indicated above, first onto the top of the poultry and then onto the sides in order to 5 further improve the smoothing effect.

As indicated above, the ambient air, including the controlled atmosphere inside the food-grade film tube, is heated to a temperature of between 160 and 180°C, preferably between 165 and 175°C, and even more preferentially to about 170°C 10 during the second step of shrinkage of the food-grade film around the poultry. Under these conditions, the food-grade film shrinks again and becomes taut around the poultry. Once the film is thus taut around the poultry, a cold air knife is advantageously applied in order to better fix the film in its final position. The temperature of the cold air is advantageously between 4 and 10°C.

15

Machines used

The steps of introduction of the poultry, of creation of a protective atmosphere inside a film tube, the steps of sealing the ends of the tube, and of pressing of the 20 poultry performed in the context of the process according to the invention may, for example, be performed using a horizontal bagging machine. Such bagging machines are well known to those skilled in the art and sold, for example, by the company ULMA under the name Pacific.

25 The step of shrinkage of the film around the poultry is for its part performed, for example, using a shrinkage tunnel such as the one sold under the reference CJ61 by the company Sealed Air Cryovac.

In particular, the process according to the invention may thus, preferably, be 30 performed using a ULMA horizontal bagging machine sold under the name Pacific, completed with a shrinkage tunnel such as the one sold under the reference CJ61 by the company Sealed Air Cryovac.

15

The details and embodiments described in relation with the general description of the invention obviously also apply to the two variants described above. The invention will now be illustrated by the non-limiting examples that follow.

5 Figure 1 is a photograph in top view of the hollowed block of foam used in the pressing step of the process according to the invention.

Figure 2 is a photograph in bottom view of the block of foam of Figure 1.

10 EXAMPLES

EXAMPLE 1 (according to the prior art) A trussed, stripped, whole chicken is wrapped using a Pacific model Ulma 15 Packaging horizontal bagging machine according to the following process: 1. manual unstacking of a polystyrene tray on a conveyor belt; 2. manual placing of a trussed whole stripped chicken in the tray; 3. transfer of the tray and the chicken via the conveyor belt; 4. formation of a film tube around the conveyor belt by unrolling a heat- 20 shrinkable, gas-barrier food-grade film (Cryovac BDF 750 sold by the company Cryovac) in a single reel from top around the conformer; 5. release of the connecting part of the film, under the conveyor belt, in a rotary jaw which seals the film longitudinally; 6. insertion of the chicken in its tray into the film tube created in the preceding 25 step; 7. flushing of the tube with a mixture of 70% CO2 and 30% N2 at a flow rate of 150 1/minute via a lance; 8. sealing of the tube at its end leaving the bagging machine via a second accompanying j aw; 30 9. transfer of the chicken in its tray to the bottom of this tube; 16 10. evacuation of the residual gas with a foam press that is solidly attached to the second accompanying jaw, and which presses on the chicken in the tube closed at one end so as to chase the residual gas therefrom; 11. sealing of the second end of the tube and then cutting of the film so as to 5 create a hermetic bag; 12. transfer of this bag into a shrinkage tunnel; 13. shrinkage of the film under the action of hot air (between 155 and 160°C), the film shrinks during the approximately 2 metres of the tunnel, and thus becomes taut around the chicken; 10 14. on leaving the shrinkage tunnel, a cold air knife fixes the film in its final position.

The foam used in step 10 of the process has a density of about 25 kg/m3 and is in the form of a rectangular block having the following dimensions: 15 - height: about 14 cm length: about 30 cm width: about 25 cm.

The block of foam is, in particular, not hollowed out over part of its height in a 20 shape corresponding to the upper part of the poultry to be wrapped.

The chicken thus wrapped is stored at a temperature of 0 to +4°C and an ambient air humidity of 90%.

EXAMPLE 2 (according to the invention) 25 A trussed, stripped, whole chicken is wrapped using a Pacific model Ulma Packaging horizontal bagging machine according to the following process: 1. manual unstacking of a polystyrene tray on a conveyor belt; 2. manual placing of a trussed, whole, stripped chicken in the tray; 30 3. transfer of the tray and the chicken via the conveyor belt; 17 4. formation of a film tube around the conveyor belt by unrolling a heat-shrinkable, gas-barrier food-grade film (Cryovac BDF 750 sold by the company Cryovac) as a single reel via the top around the conformer; 5. release of the connecting part of the film, under the conveyor belt, in a 5 rotary jaw that seals the film longitudinally; 6. insertion of the chicken in its tray into the film tube created in the preceding step; 7. flushing of the tube with a mixture of 70% CO2 and 30% N2 at a flow rate of 1501/minute via a lance; 10 8. sealing of the tube at its end leaving the bagging machine via a second accompanying j aw; 9. transfer of the chicken in its tray to the bottom of this tube; 10. evacuation of the residual gas with a foam press that is solidly attached to the second accompanying jaw, and which presses on the chicken in the tube 15 closed at one end so as to chase the residual gas therefrom; 11. sealing of the second end of the tube and then cutting of the film so as to create a hermetic bag; 12. transfer of this bag into a shrinkage tunnel; 13. shrinkage of the film under the action of hot air (between 155 and 160°C), 20 the film shrinks during the approximately 2 metres of the tunnel, and thus becomes taut around the chicken; 14. on leaving the shrinkage tunnel, a cold air knife fixes the film in its final position.

25 The foam used in step 10 of the process is marketed by the company Plastiform’s under the reference PU - Ether density 17 kg/m3 white and is in the form of a rectangular block having the following dimensions: height: about 14 cm length: about 30 cm 30 - width: about 25 cm.

18

The block of foam was hollowed out over part of its height in a shape corresponding to the upper part of the poultry to be wrapped, so as to fit the shape of the upper part of the poultry onto which it is pressed.

5 The chicken thus wrapped is stored at a temperature of 0 to +4°C and an ambient air humidity of 90%.

The appearance of the wrapping obtained in Examples 1 and 2 was compared after 18 hours of storage.

10

The wrapping obtained with the process of Example 1 is much more folded than that of Example 2, the appearance of which is close to the wrapping obtained immediately after shrinkage, before storage.

Claims

A method for packaging ready-to-cook fresh poultry, comprising: 5 i. a step of applying a ready-to-cook fresh poultry into a tube or bag of a food foil that is thermally shrinkable and forms a barrier to gas; ii. a step of creating a protective atmosphere in the tube or bag; Iii. a step of sealing a first end of the tube or the open end of the bag; iv. when a tube is used, a step of sealing a second end of the tube; and v. a step of shrinking the food foil around the poultry 15 at a temperature between 130 and 200 ° C; characterized in that it comprises a step of discharging residual gas by applying a mechanical pressure to the poultry thus provided in the tube or bag of thermally shrinkable food foil prior to performing the step iv of sealing the second end of the foil tube, or 20 wherein, simultaneously with this, this mechanical pressure is carried out by means of a block of foam with a density between 15 and 20 kg / m 1.

2. The packaging method according to claim 1, characterized in that the foam has a density between 16 and 19 kg / m1, preferably between 16 and 18 kg / m1 and more preferably a density of approximately 17 kg / m1. Packaging method according to one of claims 1 or 2, characterized in that the foam is a polymer foam, preferably a polyurethane foam.

A packaging method according to any one of claims 1-3, characterized in that the block of foam is hollowed out over a part of its height in a form corresponding to the upper part of the poultry to be packaged, the upper part in particular the thighs and the breastbone comb wherein the hollowed-out foam is thus adapted to fit in the form of the upper part of the poultry against which it is pressed, so as to discharge the maximum amount of residual gas around the poultry before the step of sealing the second end of the foil tube.

The packaging method according to any one of claims 1-4, characterized in that the step of shrinking the food foil around the poultry is carried out at a temperature between 140 and 180 ° C, preferably between 150 and 165 ° C.

Packaging method according to one of claims 1 to 5, characterized in that the protective atmosphere consists of a mixture of CO2 and N2.

Packaging method according to one of claims 1 to 6, characterized in that the mixture of CO2 and N2 comprises 50 to 90 volume percent CO2 and 50 to 10 volume percent N2, preferably 50 to 80 volume percent CO2 and 50 to 20 volume percent N2, and even more preferably comprises approximately 80 volume percent CO2 and approximately 20 volume percent N2, or comprises approximately 70 volume percent CO2 and approximately 30 volume percent N2.

Packaging method according to one of claims 1-7, characterized in that the rinsing of the tube with CO2 alone or as a mixture with O2 and / or N2 is carried out with a gas flow rate of at least 100 1 / minute, preferably of at least 100 120 1 / minute, and even more preferably of about 150 1 / minute. 30

The packaging method according to any of claims 1-8, characterized in that the poultry is selected from chicken, turkey, duck, rabbit, capon, guinea fowl, pheasant and quail.

Packaging method according to one of claims 1 to 9, characterized in that the poultry is a fresh, whole, ready-to-cook / bake poultry.

11 Method for packaging fresh and ready-to-eat poultry, comprising: 10 i. a step of forming a tube of a food foil that is thermally shrinkable and forms a gas barrier; ii. a step of applying a ready-to-cook fresh poultry in this tube; Iii. a step of establishing a protective atmosphere in the tube; iv. a step of sealing a first end of the tube; v. a step of sealing a second end of the tube; Vi. a first step of shrinking the food foil around the poultry at a temperature between 130 and 200 ° C; vii: a step of storing the packaged poultry for a period of 6 to 18 hours, and viii: a second step of crimping the food foil around the poultry, this second crimping step being carried out at a temperature ranging from 165 up to 180 ° C, characterized in that it comprises a step of discharging residual gas by applying a mechanical pressure to the poultry thus arranged in the foil tube prior to performing the step v of sealing the second end of the foil tube, or wherein, at the same time, this application of a mechanical pressure is carried out by means of a block of foam with a density between 15 and 20 kg / m 3.