WO2012049270A1

WO2012049270A1 - Method of packaging fresh meat products

Info

Publication number: WO2012049270A1
Application number: PCT/EP2011/067933
Authority: WO
Inventors: Stefano Capitani
Original assignee: Cryovac, Inc.
Priority date: 2010-10-15
Filing date: 2011-10-13
Publication date: 2012-04-19
Also published as: EP2627564A1; EP2627564B1

Abstract

A process for the manufacture of a fresh meat package, by, optionally, placing the meat product (14) on a support member (6) and closing the package in a packagingstation (4) under a high oxygen-content atmosphere by means of a composite film (3), comprising an inner, food-contact, oxygen-permeable film (15) and an outer oxygen-impermeable film (16), so as to bind a confined volume (19) within the package containing at least an amount of oxygen effective to inhibit discoloration of the packaged meat product. The process comprises the steps of a. providing from at least a supply roll (1) an inner food-contact oxygen-permeable film (15) and an outer oxygen-impermeable film (16); b. unwinding the films (15, 16) and directing the films into the packagingstation (4); c. inspecting with regard to a predetermined range of wavelengths at least one of the films (15,16) by at least one light beam in order to detect whether the outer oxygen-impermeable film (16) is positioned externally tothe inner, food- contact, oxygen-permeable film (15) in the packagingstation (4).

Description

METHOD OF PACKAGING FRESH MEAT PRODUCTS

Field of the invention

The present invention relates to a method of packaging a fresh meat product on an optional support member, enclosed with a composite film comprising an inner, oxygen-permeable, and an outer, oxygen-impermeable, film where meat discoloration is prevented. In particular the method provides for a system which prevent the misplacement of the two films in the final package.

Background of the invention

US2009/022860 discloses a process for the manufacture of a fresh meat package by placing the meat product on a support member and closing the package in a lidding station under a high oxygen-content atmosphere by means of a composite lidding film.

The composite lidding film comprises an inner, food-contact, oxygen-permeable film and an outer oxygen-impermeable film. The composite lidding film is positioned over the meat product and heat-sealed to the periphery of the support member so as to bind a confined volume within the package containing at least an amount of oxygen effective to inhibit discoloration of the packaged meat product.

The process comprises the steps of:

a. providing the composite lidding film as a composite from a single supply roll, unwinding the film therefrom, and directing the film into the lidding station; and b. following unwinding and before entering into the lidding station, separating the oxygen-permeable film and the outer oxygen-impermeable film of the composite lidding film, then superposing the two films again before heat-sealing the films to the support member.

EP-A-690,012 describes a barrier package for fresh meat products where the meat product is loaded onto a support member, such as a tray, and the package is then closed by applying an inner oxygen-permeable film over the product and the support member and an outer oxygen-impermeable film over the oxygen- permeable one. The two films are at least 0.25 μηι apart, the space between them comprises an oxygen-permeable region and a minimum discrete free volume within the package is present to contain at least the amount of oxygen necessary to inhibit discoloration of the packaged meat product during its shelf- life. The teaching of EP-A-690,012 is that by keeping such a minimum gap between the two films the oxygen contained in the package will have access to the entire surface of the meat product, including the upper one where the inner oxygen permeable film is (or may come) in contact with the meat. Discoloration is thus prevented also when the packaged meat extends upwardly with respect to the height of the tray walls, which is the most critical situation in barrier packaging of fresh meat.

It is well known that to make the above processes effective the inner food- contact oxygen-permeable film and the outer oxygen-impermeable film must be positioned and sealed in a precise order over the meat product.

In particular, in order to prevent the meat discoloration, the food-contact, oxygen-permeable film must be positioned closer to the surface of the meat product than the outer oxygen-impermeable film.

However, during the packaging process, the rolls of films are often removed and repositioned on the packaging machine and this can result in an incorrect positioning of the two films with respect to one another.

Further, in the case of supplying the inner, food-contact, oxygen-permeable film and the outer oxygen-impermeable film as a composite lidding film from one single supply roll, one of the two films may unfold from the supply roll and invert the position of the two films on the supply roll and consequently in the lidding station over the meat product.

The erroneous positioning of the two films in the lidding station results in packaging errors obliging the meat products to be repacked.

The problem is particularly serious when the incorrect positioning of the two films is detected at the meat products wholesalers or retailers some hours after the packaging.

In this case, the erroneous positioning of the two films over the meat product results in the meat discoloration, preventing both the direct sale of the package and, due to time and costs constraints, the possibility of repackaging and selling of the meat products, with consequent waste of the whole batch.

The same technical problem of an undesired inversion of the two films may also occurs when the food product, optionally, positioned into a support member (i.e. in a tray), is entirely enclosed by a wrapping double film.

Examples of these double walled wrapped packages in which the films are sealed to themselves are disclosed for instance in EP385677A2 or EP755875A1. Independently on the over-wrap manufacturing process (including for instance HFFS horizontal form fill seal and VFFS vertical form fill seal), an accidental misplacement of the two films generally causes similar serious damages to the final packages as already explained above for tray lidded packages.

Summary of the invention

The Applicant, in order to solve the above problems, has conceived a process and an apparatus for the manufacture of a fresh meat package, wherein is provided at least one device and one step of inspecting the correct positioning of the two films over the meat product.

Accordingly, in a first aspect, the present invention relates to a process for the manufacture of a fresh meat package by, optionally, placing the meat product on a support member and closing the package in a packaging station, under a high oxygen-content atmosphere, by means of a composite film, comprising an inner, food-contact, oxygen-permeable film and an outer oxygen-impermeable film, so as to bind a confined volume within the package containing at least an amount of oxygen effective to inhibit discoloration of the packaged meat product, said process comprising the steps of:

a. providing from at least a supply roll an inner food-contact oxygen-permeable film and an outer oxygen-impermeable film;

b. unwinding the films and directing the films into the packaging station;

c. inspecting with regard to a predetermined range of wavelengths at least one of the films by at least one light beam in order to detect whether the outer oxygen-impermeable film is positioned externally to the inner, food-contact, oxygen-permeable film in the packaging station.

Said packaging station can be a wrapping, preferably a FFS, or a lidding station.

In this manner, in a simple way, the packaging errors connected to a wrong positioning of the two films in the packaging station are prevented and the correctness of the process is no longer related to the operator goodwill.

In the present invention "externally" means that in the final overwrapped o tray lidded package the outer oxygen-impermeable film is not contacting the food product while it is in contact with the inner, food-contact, oxygen-permeable film according to the sequence: outer oxygen-impermeable film / inner oxygen- permeable film / food product.

The present invention can further comprise at least one of the following preferred features. In one embodiment of the invention, the step of inspection comprises:

-transmitting at least one light beam in such a way to define a path;

-positioning at least one of the films in the path of the transmitted light beam; -detecting the transmittance value connected to at least one predetermined wavelength of the light beam passing through at least one of the films.

Advantageously in one embodiment of the invention, the step of inspection further comprises:

-signalling the detection of the film to a microprocessor in order to stop the process if the outer oxygen-impermeable film is not positioned externally to the inner food-contact oxygen-permeable film, in the packaging station.

Preferably in one embodiment of the invention the inner, food-contact, oxygen- permeable film and an outer oxygen-impermeable film, are provided as a composite film from a single supply roll.

In this preferred embodiment, the process further comprises the steps of:

-separating the oxygen-permeable film and the outer oxygen-impermeable film of the composite film, following unwinding and before entering into the packaging station and

-superposing the two films before heat-sealing the films to themselves or to the support member.

As stated before, the oxygen-permeable film and the outer oxygen-impermeable film may come from a single supply roll or from two distinct supply rolls.

Independently of the way they are supplied, the inspection step has to be performed when the two films are physically separated.

The step of inspection can be performed at any step of the process, provided that the two films are physically separated, but it is preferably carried out before the step of superposing the two films before heat-sealing the films to themselves or to the support member and this independently of the fact that the oxygen- permeable film and the outer oxygen-impermeable film come from a single supply roll or from two distinct supply rolls.

In the case of a single supply roll, the step of inspection is preferably carried out after the step of separating and before the step of superposing the oxygen- permeable film and the outer oxygen-impermeable film of the composite film, before entering into the packaging station.

Advantageously, the film positioned in the path of the transmitted light beam is the oxygen-impermeable film. In one embodiment of the invention, the predetermined wavelength of the light beam is within the range of 2000 nm to 4000 nm.

Preferably, the predetermined wavelength of the light beam is within the range of 2500 nm to 3500 nm.

In a second aspect, the present invention relates to an apparatus for the manufacture of a fresh meat package by, optionally, placing the meat product on a support member and closing the package under a high oxygen-content atmosphere by means of a composite film, comprising an inner, food-contact, oxygen-permeable film and an outer oxygen-impermeable film, comprising: -at least one unwinding station comprising at least one supply roll for supplying an inner, food-contact, oxygen-permeable film and/or an outer oxygen- impermeable film,

-at least one packaging station;

-at least one driving roll to guide, with a predetermined tension, the composite film from at least one supply roll to the packaging station;

-a least one device for inspecting with regard to a predetermined range of wavelengths at least one of the films (15, 16) by at least one light beam in order to detect whether the outer oxygen-impermeable film (16) is positioned externally to the inner, food-contact, oxygen-permeable film (15) in the packaging station.

Advantageously, in one embodiment of the invention the device for inspecting at least one of the films by at least one light beam at a predetermined frequency comprises:

- at least one light energy transmitting module for transmitting light energy;

- at least one light energy receiving module for receiving and detecting-light energy at a predetermined wavelength;

-said at least one light energy receiving module and said at least one light energy transmitting module are arranged to define a path of the transmitted light beam.

Preferably, the light energy receiving module and the light energy transmitting module are arranged to define a path of the transmitted light beam.

In one embodiment of the invention, the light energy transmitting module comprises at least one light emitting element.

Preferably, the light emitting element comprises an infrared light source.

Advantageously in one embodiment of the invention, the device for inspecting at least one of the films by at least one light beam at a predetermined wavelength further comprises:

- at least one microprocessor to stop the functioning of the apparatus;

- at least one transmitting unit connected to said at least one light energy receiving module and transmitting a signal to the microprocessor in order to stop the functioning of the apparatus.

Preferably in one embodiment of the invention, the unwinding station comprises one single supply roll for supplying the inner, food-contact, oxygen-permeable film and the outer oxygen-impermeable film as a composite film.

Advantageously, at least one separating pole for separating the two films of the composite film is provided upstream from said at least one packaging station. Brief description of the drawings

Further features and advantages of the present invention will become more apparent from the following detailed description of some preferred embodiments of an apparatus for the manufacture of a fresh meat package in accordance with the present invention, taken with reference to the accompanying drawings. In these drawings:

- Fig. 1 is a simplified cross-sectional schematic view of one embodiment of a packaging apparatus for carrying out the process of the invention;

- Fig. 2 is an enlarged simplified cross-sectional schematic view of one embodiment of a portion of the packaging apparatus of fig 1 ;

- Fig. 3a is an enlarged simplified cross-sectional schematic view of a first embodiment of the separating poles 5 and of the device for inspecting the films of the packaging apparatus according to present invention;

- Fig.3b is an enlarged simplified cross-sectional schematic view of a second embodiment of the separating poles 5 and of the device for inspecting the films of the packaging apparatus according to present invention.

Detailed description of the preferred embodiments

The packaging process according to the present invention can be run on a conventional packaging machine for wrapping applications, preferably for FFS applications, or for tray lidding applications by introducing therein only minor modifications for the separation of the composite film into its components before entering the wrapping or lidding station.

Wrapping machines or apparatus that can suitably be adapted to run the process of the present invention include for instance Horizontal form fill seal HFFS

llapak machines (Delta line with double unwinding shaft, LD2000, LD3000, DeltaBDF) or Ulma machines (Baltic, Artie, Pacific), or Vertical form fill seal VFFS Hayssen or Bosch (aquarius) or BGpack (vetta3348) equipments.

Lidding machines or apparatus that can suitably be adapted to run the process of the present invention include for instance Multivac T400, T550, T700 and T800 by Multivac Sep. GmbH, Mondini E340, E380, E390 or E590 by Mondini S.p.A., Ross A20 or Ross S45 by Ross-Reiser, Meca-2002 or Meca-2003 by Mecaplastic, the tray lidding machines S6000, A5, A7 or A10 manufactured by Sealpac and the like machines.

The packaging machine or apparatus 100 for the manufacture of a fresh meat tray lidded package schematically illustrated in Fig. 1 , has an unwinding station 1 and a series of driving rolls 2 to guide, with the correct tension, the unwound composite lidding film 3 to the lidding station 4. Two separating poles 5 are used to separate the two films of the composite lidding film composite 3. Said poles, which in the packaging machine of Fig. 1 are positioned just before the entrance of the lidding station 4, could be positioned anywhere along the film path, from the unwinding station 1 to the lidding station 4, and fixed securely to the machine frame. Fixing can be through one single end of each pole or preferably both ends to avoid undesired swinging. The support members 6, that in the embodiment of Fig. 1 are illustrated as shaped trays, are brought into the lidding station 4 by means of a conveyor 7. The lidding station is essentially a vacuum chamber including an upper chamber 8 and a lower chamber 9, that can be moved vertically, in opposite directions, to open and close the lidding station 4. The lower chamber 9 includes a carrier plate for nesting the support members

(not shown in Fig.1 ), which plate can be lifted upwardly for the sealing step. The lower chamber also has a vacuum port 10 and a port 1 1 for injecting the desired gas. The upper chamber 8 is equipped with heat-sealing frames (not shown in Fig.1 ), that are designed to match with the periphery of the support members 6 and that contour cavities sufficiently shallowed not to contact the lidding films covering the packaged products during the sealing step. Once the support members 6 are correctly positioned in the lower chamber 9, the upper chamber 8 and the lower chamber 9 move as indicated by the arrows to close the chamber. Port 10 is then actuated to vacuumize the chamber, including the space between the support members 6 and the lidding film 3, and when evacuation is complete, or when the pressure inside the chamber has reached the set value, port 10 is closed and port 1 1 is opened to inject the desired atmosphere.

The gas flushed in will have a high oxygen content (i.e., a content higher than that of the atmosphere) that however will depend on the type of meat packaged and will be set to suitably inhibit meat discoloration during the whole shelf-life of the packaged product. In particular, for fresh red meat the gas flushed in will preferably have an oxygen content of at least 60 % by volume, based on the total volume of gas flushing, preferably at least 80 %, and more preferably at least 85 %. Generally, however oxygen will be admixed with a small amount of an inert gas such as nitrogen, argon, carbon dioxide and the like gases. For poultry meat, on the other hand, a lower oxygen content would be sufficient to inhibit meat discoloration and the gas flushed into the package will thus typically contain an amount of oxygen as low as 30 % of the total volume of gas flushed, preferably a composition of e.g. 30 % of oxygen and 70 % of nitrogen.

Once the desired gas pressure is reached within the chamber and around the product to be packaged, port 1 1 is closed and the carrier plate nesting the support members in the lower chamber 9, is lifted upwardly to push the periphery of said support members, covered by the composite lidding film, against the heated sealing frames in the upper chamber 8, so as to heat-seal, by pressure, the periphery of the support members to the oxygen-permeable film 15 and the oxygen-permeable film 15 to the oxygen-impermeable one 16 at said periphery. The sealing frames are generally equipped with knives contouring the sealing frames on the outside to separate the single end packages from the skeleton of the composite lidding film. When the heat-sealing step is completed, the lower chamber 9 and the upper chamber 8 open up, the end packages are removed from the chamber and the skeleton of the composite lidding film is wound up on a scrap roll 12 at the exit of the lidding station. In the embodiment of Fig. 1 , the reference number 14 represents the fresh meat products to be packaged.

In the embodiment of Fig. 1 , which referes to a tray lidding station, the separation is achieved by two poles 5, the two poles would preferably be idle as each of them could rotate separately to match the direction of the film contacting it and this could reduce the friction. The direction of travel of the films and the rotation of the poles in Fig. 3a and 3b are indicated by arrows. However, the separation could even be obtained by a single pole that is fixed or can rotate freely.

It would also be possible to use more than two poles, differently disposed, or to provide for two or more separating steps along the film path.

Suitable materials for the manufacture of the pole(s) are metal, fiberglass, polycarbonate, stone, etc. Possibly, they might be coated with an anti- sticking polymeric material, such as for instance a Teflon(R) layer.

In the present invention all the variables described above for tray lidding applications applies to wrapping equipment(s) as well.

The composite film 3, closing in tray lidding applications the support members 6, is a composite of an inner food-contact oxygen-permeable film 15 and an outer oxygen-impermeable film 16.

Oxygen-permeable films 15 are films that show an OTR of at least 2,000 cm³/m² .d.atm when measured at 23°C and 0% of relative humidity, such as for instance at least 2,500 cm³ /m² .d.atm or at least 3,000 cm³ /m² .d.atm or at least 3,500 cm³ /m² .d.atm, and more preferably at least 4,000 cm³ /m² .d.atm, such as for instance at least 5,000 cm³/m² .d.atm or at least 8,000 cm³/m² .d.atm or at least 10,000 cm³ /m² .d.atm, measured under the same conditions as above.

The oxygen-permeable film 15 can be a mono-layer or a multi-layer film. While the number of layers is not critical, preferred oxygen-permeable films will however contain 1 , 2 or 3 layers.

Its thickness in fact can be as high as 50 μηι or even more, but preferably it should be maintained below 15 μηι, more preferably below 12 μηι and even more preferably below 10 μηι. Typically it will have a thickness of from about 6 or 7 μηι to about 15 μηι.

It will generally contain polyolefins or modified polyolefins as the polyolefin and modified polyolefin resins that are oxygen-permeable and heat-sealable resins. One outer surface of the oxygen-permeable film should in fact heat-seal to the periphery of the support member 6 and the other outer surface should heat-seal to the oxygen-impermeable film 16.

However, in certain cases the oxygen-permeable film 15 may comprise different resins e.g. suitably selected for the food-contact layer to be heat-sealable to the support member 6. As an example when the support member 6 is formed of polyethyleneterephthalate (PET), the inner oxygen-permeable film may be multi- layer film comprising a very thin (1-2 μηι) outer food-contact layer of PET and the other outer layer of a resin suitable to heat-seal to the oxygen-impermeable film 16, provided the multi-layer film is oxygen-permeable as defined above. Preferably, the oxygen permeable film is a heat-shrinkable film, wherein the term "heat-shrinkable" as used herein is intended to mean that the film is biaxially oriented and when heated at a temperature of 120°C for 4 seconds shows a % free shrink in each of the longitudinal and transversal directions of at least 10% (measured according to ASTM D2732).

The oxygen-permeable film may contain appropriate amounts of additives normally used in film manufacture, such as slip and anti-block agents e.g., talc, waxes, silica, and the like, antioxidants, fillers, pigments and dyes, cross-linking inhibitors, cross-linking enhancers, UV absorbers, antistatic agents, anti-fog agents or compositions, and the like additives known to those skilled in the art of packaging films.

In a preferred embodiment, the oxygen-permeable film 15 will comprise anti-fog agents or compositions to prevent formation of water droplets on the film surface facing the fresh meat product. The anti-fog agents can be admixed to the polymers or polymer blends of the heat-sealable layer or of an inner layer, if any, before (co)extrusion of the film or an anti-fog composition can be coated onto the surface of the pre-made oxygen-permeable film.

The oxygen-impermeable film will have an oxygen transmission rate (OTR) lower than 300 cm³ /m² .d.atm when measured at 23°C and 0% of relative humidity, such as for instance lower than 250 cm³ /m² .d.atm or lower than 200 cm³ /m² .d.atm or lower than 150 cm³ /m² .d.atm, and more preferably lower than 100 cm³ /m² .d.atm, such as for instance lower than 75 cm3 /m2 .d.atm or lower than 50 cm³ /m2 .d.atm or lower than 30 cm³ /m² .d.atm, measured under the same conditions as above.

It should have oxygen-barrier properties and be heat-sealable to the oxygen- permeable film.

Preferably, the oxygen-impermeable film 16 will therefore be a multi-layer film comprising at least an oxygen-barrier layer, the thickness of which should be set to achieve the desired OTR for the film indicated above, and a heat-sealable layer that allows heat-sealing of the oxygen-impermeable film to the oxygen- permeable one. Polymers that can suitably be employed for the oxygen barrier layer are PVDC, EVOH, polyamides and blends thereof, wherein EVOH, polyamides, and their blends are the preferred resins. Typically, the heat- sealable layer will comprise polyolefins and/or modified polyolefins as defined above.

Other layers can be present, if desired, such as for instance a second outer layer which may have a composition equal to or different from the heat-sealable layer, tie or adhesive layers, containing polyolefins and/or modified polyolefins, to improve the bond between the barrier layer and the heat-sealable layer and optionally between the barrier layer and the other outer layer, a seal-assist layer, i.e. an internal film layer adjacent to the heat-sealable one, etc.

Preferably, the thickness of the oxygen-impermeable film (16) will be lower than 25 μηι, more preferably lower than 20 μηι, and even more preferably lower than 18 μηι.

The two films, i.e. the oxygen-impermeable film 16 and the oxygen-permeable film 15, have completely different light absorption properties.

In detail, the Applicant has found that at predetermined wavelengths of a light beam the oxygen-permeable film 15 is almost completely transparent while at the same wavelengths the oxygen-impermeable film 16 is more opaque.

The Applicant has conceived how to use the different absorption properties of the two films 15, 16 in order to detect their correct positioning in the lidding station 4.

According to one particular aspect of the present invention, the packaging wrapping or lidding machine or apparatus 100 for the manufacture of a fresh meat package comprises at least one device 21 for inspecting at least one of the films 15, 16 by at least one light beam in order to detect whether the outer oxygen-impermeable film 16 is positioned externally to the inner, food-contact, oxygen-permeable film 15 in the packaging, i.e. lidding station 4.

The device 21 for inspecting at least one of the films 15, 16 by at least one light beam comprises:

-at least one light energy transmitting module 23 for transmitting light energy; -at least one light energy receiving module 24 for receiving and detecting light energy at predetermined wavelengths or wavelength range.

As shown in the embodiments of figures 1-3, the light energy receiving module 24 and the light energy transmitting module 23 are positioned next to the separating poles 5.

In the embodiment of figure 3a, the light energy receiving module 24 and the light energy transmitting module 23 are positioned just downstream from the two separating poles 5, but as shown in figure 3b they could be positioned upstream from the separating poles 5 without departing from the scope of the present invention.

The light energy receiving module 24 and the light energy transmitting module 23 are arranged to define a path 22 of the transmitted light beam.

Preferably, the light energy receiving module 24 and the light energy transmitting module 23 are arranged in such a way to define a right linear path 22 for the transmitted light beam.

The light energy receiving module 24 and the light energy transmitting module 23 are opposed to each other with respect to one of the films 15, 16.

In the embodiment of Fig. 3a the detection is achieved by positioning the light energy receiving module 24 and the light energy transmitting module 23 in such a way to be opposed with respect to the oxygen-permeable film 15. However, as shown in figure 3b, preferably the light energy receiving module 24 and the light energy transmitting module 23 could be positioned on the oxygen-impermeable film 16.

The light energy transmitting module 23 comprises at least one light emitting element. Preferably, the light emitting element comprises an infrared light source to focus the light on one of two films 15, 16.

In a preferred embodiment, the light energy-receiving module 24 comprises two receiver devices, each comprising an infrared (optical) bandpass filter that is tuned to permit light which has predetermined wavelength to pass through only, and a transmittance sensor to detect the transmittance at a specific wavelength. In a more preferred embodiment, one of the two receiver devices is set at a wavelength at which both the oxygen-permeable film 15 and the oxygen- impermeable film 16 similarly absorb ("white" reference), while the other receiver device is set at a wavelength at which only the oxygen-impermeable film 16 absorbs. The measurement of the transmittance is made by comparison between the values at the two selected wavelengths, thus eliminating any interfering absorption or deviation due to non-barrier resins, contaminating light from the environment, presence of powders etc.

By applying this double wavelengths receiving module to the oxygen- impermeable film 16, any significant difference in the transmittance would be only ascribed to the presence of an absorbing barrier layer within the film.

Preferably, one of the two infrared (optical) bandpass filters allows the passage of light at about 2800 nm (nanometres) while the other one allows the passage of light at about 3000 nm(nanometres).

In the embodiment of figures 1-3 the wavelength selection is obtained by the bandpass filters of light energy-receiving module 24, however, in alternative, it could be achieved by a light energy transmitting module 23 able to transmit at least a light beam at predetermined wavelengths and/or wavelength ranges. In a preferred embodiment, the device 21 for inspecting at least one of the films 15, 16 by at least one light beam further, as better shown in figure 2 has:

-at least one microprocessor 26 (an industrial pc or a pic) to stop the functioning of the apparatus;

-at least one transmitting unit 25 connected to the light energy receiving module 24.

The transmitting unit 25 transmits a signal to the microprocessor 26 in order to stop the functioning of the apparatus 100 if the outer oxygen-impermeable film 16 is not positioned over the inner, food-contact, oxygen-permeable film 15 in the packaging, i.e. lidding station 4.

In particular, the microprocessor 26 receives from the transmitting unit 25 the values of transmittance detected by the two transmittance sensors, preferably set at two wavelengths as explained above, and compares them in order to detect the presence of the outer oxygen-impermeable film 16.

In the embodiment of figure 3a, if the gap between the two values of transmittance is higher than a previously set threshold, this means that the inner oxygen-permeable film 15 is not positioned between the light energy receiving module 24 and the light energy transmitting module 23, consequently the two films 15, 16 have been wrongly positioned.

In this case, the microprocessor 26 stops the functioning of the apparatus 100. In the embodiment of figure 3b, if the gap between the two values of transmittance is lower than a previously set threshold, this means that the outer oxygen-impermeable film 16 is not positioned between the light energy receiving module 24 and the light energy transmitting module 23 and consequently the two films 15, 16 have been wrongly positioned.

Also in this case, the microprocessor 26 stops the functioning of the apparatus. The process for the manufacture of a fresh meat package by, optionally, placing the meat product 14 on a support member 6 and closing the package in a packaging, i.e. lidding, station 4 under a high oxygen-content atmosphere by means of a composite film 3, carried out by the apparatus 100 above described and shown in figure 1 comprises the following steps.

Initially, the inner food-contact oxygen-permeable film 15 and the outer oxygen- impermeable film 16 are provided by the supply roll 1.

The two films 15, 16, provided as a composite film 3, are unwound from the supply roll 1 and directed into the packaging, i.e. lidding, station 4 by means of the roll 2.

Following unwinding and before entering the packaging, i.e. lidding, station 4, the two films 15, 16 of the composite film 3 are separated by means of the two separating poles 5.

During this step, at least one of the films 15, 16 is inspected by at least one light beam at a predetermined wavelength in order to detect whether the outer oxygen-impermeable film 16 is positioned in the right position to be placed externally, i.e over the inner, food-contact, oxygen-permeable film 15 in the lidding station 4.

In detail, with respect to figure 1 , the light emitting element of the light energy transmitting module 23 transmits at least one light beam on the film 15.

The light beam is received by the light energy receiving module 24 in such a way to define a substantially linear light path for the light beam between the light energy emitting module 23 and the light beam receiving module 24.

The film 15 flows in the path of the transmitted light beam.

The light beam receiving module 24, by the transmittance sensor detects the transmittance value of the light beam connected to a predetermined wavelength. In detail, one of the two infrared (optical) bandpass filters allows the passage of the light at 2800 nm (nanometres) while the other one allows the passage of the light at 3000 nm(nanometres).

At this point, the microprocessor 26 receives from the transmitting unit 25 the values of transmittance detected by the two transmittance sensors and compares them in order to detect the presence of the outer oxygen- impermeable film 16.

If the gap between the two values of transmittance is higher than a previously set threshold, the microprocessor 26 stops the functioning of the apparatus 100. Vice versa, if the gap between the two values of transmittance is lower than a previously set threshold, the microprocessor 26 does not stop the functioning of the apparatus 100. In this case, the inner oxygen-permeable film 15 is, in fact, positioned correctly between the light energy receiving module 24 and the light energy transmitting module 23, consequently the two films will be correctly positioned in the lidding station 4. However, preferably, the light emitting element of the light energy transmitting module 23 transmits at least one light beam on the film 16 as represented in figure 3b.

Downstream from the two separating poles 5, before entering the packaging, i.e. lidding, station 4, the two films are superposed again one over the other.

The two films 15, 16 enter the packaging, i.e. lidding station 4 as a composite film, being superposed one to the other whit a thin air layer entrapped therebetween.

In the meantime, the support members 6, that in the embodiment of figure 1 are illustrated as shaped trays, are brought into lidding station 4.

The support member 6 can be flat or substantially planar but it is preferably formed in the shape of a tray. That is, the support member 6 necessarily includes product support surface for receiving and supporting the product being packaged and a periphery to which the oxygen-permeable film is sealed. Preferably, the support member includes a downwardly formed cavity and an upper flange, wherein the product support surface is defined by the downwardly formed cavity and the upper flange is the periphery of the support member. The support member 6 is optional in case of wrapping applications, in which the food product can be packaged as such, even without any support.

In case of tray lidding applications, in the lidding station 4 the composite film is positioned over the meat product and heat sealed to the periphery of the support member 6 so as to bind a confined volume within the package containing at least an amount of oxygen effective to inhibit discoloration of the packaged meat product.

In a preferred tray lidding embodiment the lidding films, or at least the inner oxygen-permeable one, are biaxially oriented and heat-shrinkable and the packaging process involves a heat-treatment to get the shrink thereof and cure any wrinkles in the lids. Such a heat-treatment may be a separate step following the heat-sealing one or, preferably, it is part of the heat-sealing step, i.e. the temperature reached in the sealing station due to the presence of the heat- sealing frame is sufficient to get the desired shrink of the lid(s).

As in the lidding process of the present invention the two films enter into the lidding station 4 as a composite, being superposed one to the other with the thin air layer entrapped therebetween, it is not expected that the distance between the two lidding films in the end package may be higher than 1 mm.

The present invention has been described with reference to some embodiments thereof. Many modifications can be made in the embodiments described in detail, still remaining within the scope of protection of the invention, defined by the following claims.

Claims

1. A process for the manufacture of a fresh meat package by, optionally, placing the meat product (14) on a support member (6) and closing the package in a packaging station (4) under a high oxygen-content atmosphere by means of a composite film (3), comprising an inner, food-contact, oxygen-permeable film (15) and an outer oxygen-impermeable film (16), so as to bind a confined volume (19) within the package containing at least an amount of oxygen effective to inhibit discoloration of the packaged meat product, said process comprising the steps of:

a. providing from at least a supply roll (1) an inner food-contact oxygen- permeable film (15) and an outer oxygen-impermeable film (16);

b. unwinding the films (15, 16) and directing the films into the packaging station (4);

c. inspecting with regard to a predetermined range of wavelengths at least one of the films (15, 16) by at least one light beam in order to detect whether the outer oxygen-impermeable film (16) is positioned externally to the inner, food- contact, oxygen-permeable film (15) in the packaging station (4).

2. The process according to claim 1 wherein said packaging station is a wrapping, preferably a FFS, station or a lidding station.

3. The process according to claims 1 or 2, wherein the step of inspection comprises:

-transmitting at least one light beam in such a way to define a path;

-positioning at least one of the films (15, 16) in the path of the transmitted light beam;

-detecting the transmittance value connected to at least one predetermined wavelength of the light beam passing through at least one of the films (15, 16).

4. The process according to claims 1 to 3, wherein the step of inspection further comprises:

-signalling the detection of the film (15, 16) to a microprocessor (26) in order to stop the process if the outer oxygen-impermeable film (16) is not positioned externally to the inner food-contact oxygen-permeable film (15), in the packaging station (4).

5. The process according to claims 1 to 4, wherein the inner, food-contact, oxygen-permeable film (15) and the outer oxygen-impermeable film (16), are provided as a composite film (3) from a single supply roll (1).

6. The process according to claim 5, further comprises the step of:

- separating the oxygen-permeable film (15) and the outer oxygen-impermeable film (16) of the composite film (3), following unwinding and before entering into the packaging station (4) and

-superposing the two films again before heat-sealing the films to themselves or the support member.

7. The process according to claims 1 to 6, wherein the step of inspection is carried out during the steps of separating and superposing before heat-sealing the inner oxygen-permeable film (15) and the outer oxygen-impermeable film (16) of the composite film (3).

8. The process according to any one of the preceding claims, wherein the film positioned in the path of the transmitted light beam is the oxygen-impermeable film (16).

9. The process according to any one of the preceding claims wherein the predetermined wavelength of the light beam is within the range of 2000 nm to 4000 nm, preferably within the range of 2500 nm to 3500 nm.

10. Apparatus (100) for the manufacture of a fresh meat package by, optionally, placing the meat product (14) on a support member (6) and closing the package under a high oxygen-content atmosphere by means of a composite film (3), comprising an inner, food-contact, oxygen-permeable film (15) and an outer oxygen-impermeable film (16), comprising:

-at least one unwinding station (1) comprising at least one supply roll (1) for supplying an inner food-contact oxygen-permeable film (15) and/or an outer oxygen-impermeable film (16),

-at least one packaging station (4);

-at least one driving roll (2) to guide, with a predetermined tension, the composite film (3) from at least one supply roll (1) to the packaging station (4); -a least one device (21) for inspecting with regard to a predetermined range of wavelengths at least one of the films (15, 16) by at least one light beam in order to detect whether the outer oxygen-impermeable film (16) is positioned externally to the inner, food-contact, oxygen-permeable film (15) in the packaging station.

1 1. The apparatus according to clami 10 wherein said packaging station is a wrapping, preferably a FFS, station or a lidding station.

12. The apparatus (100) according to claims 10 or 1 1 wherein the device for inspecting respect to a predetermined range of wavelengths at least one of the films (15, 16) by at least one light beam comprises:

-at least one light energy transmitting module (23) for transmitting light energy; -at least one light energy receiving module (24) for receiving and detecting light energy at a predetermined wavelength;

said at least one light energy receiving module (24) and said at least one light energy transmitting module (23) are arranged to define a path (22) of the transmitted light beam.

13. The apparatus (100) according to claim 12, wherein said at least one light energy transmitting module (23) comprises at least one light emitting element.

14. The apparatus according to claim 13, wherein said at least a light emitting element comprises an infrared light source.

15 The apparatus according to claims 10 to 14 9 wherein the device for inspecting at least one of the films (15, 16) by at least one light beam at a predetermined wavelength further comprises:

-at least one microprocessor (26) to stop the functioning of the apparatus;

-at least one transmitting unit (25) connected to said at least one light energy receiving module (24) and transmitting a signal to the microprocessor (26) in order to stop the functioning of the apparatus.

16. The apparatus according to claims 10 to 15 wherein said at least one unwinding station (1) comprises one single supply roll (1) for supplying the inner, food-contact, oxygen-permeable film (15) and the outer oxygen-impermeable film (16) as a composite film (3).

17. The apparatus according to claims 10 to 16 wherein at least one separating pole (5) for separating the two films of the composite film (3) is provided upstream from said at least one packaging station (4).