METHOD AND APPARATUS FOR PACKAGING RESPIRING PRODUCE

Abstract

A method of packaging respiring produce comprises the steps of:providing a portion of packaging material, in particular a polymeric packaging material;providing a portion of the produce;forming, from the portion of packaging material and the portion of the produce, a closed package defining a package volume and containing in the package volume the portion of produce and a modified atmosphere; wherein the modified atmosphere is modified with respect to the ambient atmosphere. The method further comprises generating an atmosphere modification gas and/or an atmosphere modification gas mixture and/or establishing a modified atmosphere having an elevated ozone concentration in the package volume. An associated apparatus is also provided.

Claims

1. A method of packaging respiring produce, comprising the steps of: providing an apparatus for manufacturing a modified atmosphere package; providing a portion of packaging material; providing a portion of the produce; forming, using the apparatus, from the portion of packaging material and the portion of the produce, a closed package defining a package volume and containing in the package volume the portion of produce and a modified atmosphere; wherein the modified atmosphere is modified with respect to the ambient atmosphere; characterised in that the method comprises generating a gas with the apparatus, said gas being one or more concentrated, enriched and/or purified gases or gas mixtures, compared to ambient air and establishing the modified atmosphere on the basis of the generated gas.

2. The method according to claim 1, wherein the step of generating the gas comprises taking in ambient air and generating from the air taken in at least one atmosphere modification gas and/or an atmosphere modifying gas mixture for establishing the atmosphere modification gas and/or atmosphere modifying gas mixture.

3. The method according to claim 1, wherein the step of generating the gas comprises generating an atmosphere modification gas being essentially nitrogen, oxygen, argon, carbon dioxide or ethylene.

4. The method according to claim 1, wherein the gas comprises ozone and wherein the method further comprises establishing the modified atmosphere in the package having an elevated ozone concentration in the package volume relative to an ozone concentration of ambient air.

5. The method according to claim 4, wherein the elevated ozone concentration is an ozone concentration of at least 3 ppm at the time of closing the package.

6. The method according to claim 4, wherein the ozone concentration is at most 5000 ppm at the time of closing the package.

7. A method according to claim 1, wherein the method comprises establishing the modified atmosphere in the package volume having an elevated ozone concentration, relative to an ozone concentration of ambient air, at the time of closing the package, by filling the package with an ozone containing gas.

8. The method according to claim 1, wherein the closed package is a controlled atmosphere package having a predetermined transmission rate for at least one component of the modified atmosphere.

9. The method according to claim 1, comprising providing the packaging material with one or more microperforations for determining a transmission rate for at least one compontent of the modified atmosphere.

10. The method according to claim 1, comprising determining a respiration property of the produce to be packaged and determining on the basis of the determined respiration property of the produce to be packaged at least one of: a composition of the modifying atmosphere, and number and/or a size of one or more microperforations to be made.

11. The method according to claim 1, wherein the produce comprises cut flowers, or flower bulbs.

12. The method according to claim 1, wherein the method comprises: forming, from the portion of packaging material and the portion of the produce, a produce-containing pre-package defining a pre-package volume for forming the closed package defining the package volume; at least partly evacuating the pre-package volume; establishing the modified atmosphere having an elevated ozone concentration in the pre-package volume and closing the pre-package, thus providing the closed package containing the modified atmosphere in the package volume having an elevated ozone concentration of at least 5 ppm at the time of closing the package.

13. The method according to claim 12, further comprising, prior to the step of at least partly evacuating the pre-package volume, an additional step of at least partly evacuating the pre-package volume; and a step of establishing a temporary modified atmosphere in the pre-package volume having an ozone concentration of at least 5 ppm for a limited duration; wherein the additional step of at least partly evacuating the package volume and the step of establishing a temporary modified atmosphere in the package volume may be repeated at least once.

14. The method according to claim 1, wherein the package is temperature controlled after closure.

15. The method according to claim 1, wherein the package is formed by tray sealing.

16. The method according to claim 1, wherein the method further comprises measuring at least one of the composition, an amount and a flow rate of at least one of ozone and the gas mixture when introducing the gas mixture into the packaging space; and/or wherein the step of forming the package containing the portion of produce and the modified atmosphere is performed in a packaging space comprising a gas inlet and a gas outlet, and the method comprises introducing the gas mixture into the package volume in the packaging space, the method then further comprising measuring at least one of a composition, an amount and a flow rate of gas at or near the gas inlet and/or at or near the gas outlet.

17. An apparatus for manufacturing a modified atmosphere package, comprising: a device for forming, from a portion of packaging material and a portion of produce, a closable package, when closed defining a package volume and containing in the package volume the portion of produce and a modified atmosphere; a supply of an atmosphere modification gas and/or an atmosphere modifying gas mixture; a device for providing on the basis of the atmosphere modification gas and/or the atmosphere modifying gas mixture of the supply a gas mixture in the package volume for establishing the modified atmosphere in the package volume, wherein the supply comprises a gas generator for generating one or more concentrated, enriched and/or purified gases or gas mixtures, compared to ambient air.

18. The apparatus of claim 17, wherein the supply is configured to take in ambient air and to generate from the ambiet air taken in at least one of the atmosphere modification gases and/or the atmosphere modifying gas mixtures for establishing the atmosphere modifying gas mixture.

19. The apparatus of claim 17, wherein the gas generator is configured to generate an atmosphere modification gas being essentially nitrogen, oxygen, argon, carbon dioxide or ethylene.

20. The apparatus of claim 17, wherein the apparatus comprises a supply of ozone and the apparatus is configured for, based on the ozone, establishing a modified atmosphere in the package volume having an elevated ozone concentration.

21. The apparatus of claim 20, wherein the supply of ozone comprises an ozone converter configured to convert oxygen into the ozone, wherein the ozone converter is configured to take in ambient air and to convert oxygen in the ambient air taken in into the ozone; and/or wherein the gas generator is configured to generate oxygen or at least an oxygen-rich gas mixture, the ozone converter is at least one of fluidly connected and fluidly connectable with the gas generator, and the ozone converter is configured to convert at least part of the oxygen generated by the gas generator into the ozone.

22. An apparatus for manufacturing a modified atmosphere package comprising: a device for forming, from a portion of packaging material and a portion of produce, a closable package, which when closed defines a package volume containing in the package volume the portion of produce and a modified atmosphere; a supply of ozone; and a device for providing a gas mixture comprising ozone from the supply of ozone in the package volume for establishing a modified atmosphere in the package volume having an elevated ozone concentration, characterised in that the elevated ozone concentration is at least 3 ppm at the time of closing the package.

23. The apparatus according to claim 22, wherein the supply of ozone provides the ozone as a gas into the package prior to closing.

24. The apparatus according to claim 17, comprising a supply of one or more atmosphere modifying gases and/or atmosphere modifying gas mixtures, for providing the modified atmosphere with a reduced oxygen concentration compared to the ambient atmosphere at the time of closing the package; and/or for providing the modified atmosphere with an elevated concentration of carbon dioxide compared to the ambient atmosphere at the time of closing the package.

25. The apparatus according to claim 17, wherein the apparatus is configured to close the package, and/or wherein the apparatus comprises at least one of, a vacuum pump, a perforator for providing the packaging material with one or more microperforations, a controller for the perforator, when present, a camera, and a system for determining a target package atmosphere.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0101] The above-described aspects will hereafter be more explained with further details and benefits with reference to the drawing showing an exemplary embodiment.

[0102] FIG. 1 schematically shows an embodiment of an apparatus and indicates at least part of an embodiment of a method.

DETAILED DESCRIPTION OF EMBODIMENTS

[0103] It is noted that the drawings are schematic, not necessarily to scale and that details that are not required for understanding the present invention may have been omitted. The terms “upward”, “downward”, “below”, “above”, and the like relate to the embodiments as oriented in the drawings, unless otherwise specified. Further, elements that are at least substantially identical or that perform an at least substantially identical function are denoted by the same numeral, where helpful individualised with alphabetic suffixes.

[0104] Further, unless otherwise specified, terms like “detachable” and “removably connected” are intended to mean that respective parts may be disconnected essentially without destruction of either part, e.g. excluding structures in which the parts are integral (e.g. welded or molded as one piece), but including structures in which parts are attached by or as mated connectors, fasteners, releasable self-fastening features, etc.

[0105] FIG. 1. shows schematically an apparatus 1 for manufacturing modified atmosphere packages 3. The apparatus 1 comprises a package forming device 5 for forming, from portions of packaging material 7 and portions of produce 9, modified atmosphere packages 3 each defining a package volume V and containing in the package volume V a portion of produce 9 and a modified atmosphere. Here, the packaging material is supplied as a web of a packaging film 11 on a roll 13 for forming packaging portions, e.g. bags or tray lids, but other forms and types of packaging material are also possible; e.g. two or more types of packaging material may be provided, such as trays and sealing film (not shown). In FIG. 1 the produce is provided as separate portions 9 by a produce transporter 14, but other ways of providing the produce as, or into, portions 9 may be used. Here, the apparatus 1 is configured to form and fill the packages 3 and also to close and separate them. The package forming device may comprise an ozone generator 6 for generating ozone within a package volume-to-be of a package as it is formed and/or filled, and/or for generating ozone within a package volume of a package once formed and filled.

[0106] The apparatus 1 comprises a supply 15 of one or more different atmosphere modification gases including an optional supply 16 of pressurised air, e.g. in the form of a compressor 17 provided with optional filters 18 and/or other pre-treatment portions e.g. humidity and/or temperature controllers. A supply tank 20 may be provided for pressurized air instead of the compressor 17 and/or as a buffer tank for the compressor 17, preferably (de-) connectable via a coupling and/or switching valve etc. generally indicated with reference symbol 19.

[0107] Further optional supplies of different atmosphere modification gases are optionally provided. E.g. CO.sub.2 and N.sub.2, are provided here in the form of gas bottles 21, 22.

[0108] The supply 15 further comprises an optional gas generator 50, for generating one or more concentrated and/or enriched and/or purified gases or gas mixtures, compared to ambient air, in particular nitrogen or at least a nitrogen enriched gas mixture. Also or alternatively, the gas generator may preferably generate one or more of oxygen, carbon dioxide and argon gas or at least an oxygen/carbon dioxide/argon enriched gas mixture, respectively. The desired gas (mixture), in particular nitrogen and/or oxygen, may be generated by chemical processes and/or by physical processes such as separation of the desired component from a source gas mixture which may preferably be ambient air.

[0109] The pressurised air supply 16 and the gas generator 50 may be fluidly connected (e.g. by a gas conduit 51) for supplying the one (16, 50) with a product from the other (50, 16) or the other way around.

[0110] The generated gas or gases may be fed to the package forming device 5 (see below) and/or stored in one or more optional buffer tanks, e.g. supply tanks 21, 22, which may be (de-) connectable via a coupling and/or a switching valve etc. 19.

[0111] The apparatus 1 further is provided with an optional supply 23 of ozone, here in the form of an ozone generator e.g. an oxygen supply and UV-light sources and/or spark dischargers. The oxygen for ozone formation may be provided from any suitable source such as a separate tank 24 as shown and/or a gas generator 50 (e.g. by a gas conduit 54). Also or alternatively, the ozone generator 23 may form the ozone from oxygen present in the pressurised air from the pressurised air supply 16 and/or from oxygen present in ambient air taken in by the ozone generator 23. A total amount of ozone in a package atmosphere may be provided by a combination of ozone supplied from the ozone generator 23 and ozone generated within the package using the ozone generator 6.

[0112] One or more of atmosphere modification gas(es) may be supplied pressurised so that they may be transported by flowing under their own pressure so that one or more propellers are not needed; however, these may be provided. Also or alternatively, one or more suction devices, e.g. suction fans, may be provided also for transporting one or more of the atmosphere modification gas(es). Note that a gas flow of one gas (mixture) may be used for affecting and/or introducing a second gas, e.g. by use of a venturi effect.

[0113] The apparatus 1 comprises a device 25 for providing a gas mixture of one or more of the atmosphere modification gases from (one or more of the various supplies 16, 20, 21, 22, 23, 50 of) the supply 15 in the package volume V of each package 3 as that is formed.

[0114] Here, the device 25 comprises a manifold 27 connected by a gas supply conduit 31 to the package forming device 5. The manifold 27 and an optional feedback sensor signal line 33 are connected to an optional controller 29. A controller, e.g. the controller 29, may be connected to one or more of the pressurised air supply 16, the gas generator 50, the ozone generator 23, and/or to one or more gauges, valves, switches, pressure regulators, controls etc. for operating the respective portions of the apparatus.

[0115] Note that, although not shown, a gas circulation system may be provided for circulating at least a portion of the gas mixture through at least part of the supply 15 and possibly through at least part of the package forming device and along a suitable gas sensor for at least one of, gradually increasing and/or stabilizing a gas component concentration and/or a gas composition, in particular with respect to an oxygen and/or ozone concentration.

[0116] As indicated in FIG. 1, the apparatus 1 further comprises a perforator, here a (possibly pulsed) laser 35 providing a (pulsed) laser beam 36, and a camera 37 for imaging microperforations and/or other control processes. The laser 35 and the camera 37 are operably connected with a perforation controller 39 for operational control, quality control and/or feedback control of the laser 35. The controller 39 may be programmable for determining one or more of the number, size and positions of the microperforations.

[0117] Further, not shown in any detail, the apparatus 1 may comprise a detector 41 and a calculator 43 configured to determine, e.g. by measuring and calculating on the basis of measurement results, one or more respiration properties, e.g. an O.sub.2 consumption and/or CO.sub.2-production of the produce to be packaged and, based on that/those, determining one or more of a composition of the target modified atmosphere, a composition of the modifying atmosphere, a number and/or size of one or more microperforations (to be) made in the packaging material of the package(s).

[0118] Two or more of the gas mixture controller 29, the perforation controller 39, the detector 41, the calculator 43 and an optional controller for the ozone generator 6 may be interconnected and/or integrated in one combined controller.

[0119] The package forming device 5 may be a tray sealing device, forming packages from a tray, which may have the form of a box, a shell or other receptacle, and providing the tray with a lid; the lid may be a film or another box, shell or similar object. The lid may be sealed onto the tray by heat sealing.

[0120] Preferably, the package forming device 5 is a MAP tray sealer, comprising an enclosed packaging space at least partly defined by one or more openable and closable covers. The produce portions 9 may be provided as separate portions to be placed in a tray in the device 5 or they may be supplied as portions 9 in individual trays (not shown).

[0121] In a typical example, one or more produce portions 9, each in a tray without a lid or with an only partly closed lid thus forming an open pre-package are placed in the packaging space;

[0122] the packaging space is closed off from the environment; the atmosphere in the packaging space and the one or more pre-packages therein is at least partly evacuated, e.g. to an underpressure relative to ambient pressure of about −0.3 bar, or lower like about -0,5 bar, or even as low as about −0.75 bar (i.e. about 70 kPa, about 50 kPa and, respectively about 25 kPa absolute pressure remaining; 1 bar=100 kPa);

[0123] a flushing gas mixture comprising ozone at an elevated concentration, e.g. pressurised air containing ozone at a concentration in a range 7-5000 ppm is introduced in the packaging space and the one or more pre-packages therein;

[0124] the thus formed flushing atmosphere is maintained for a limited time, e.g. for a time in a range of 5-120 seconds;

[0125] the one or more pre-packages therein are again at least partly evacuated as before,

[0126] the flushing and subsequent evacuation steps may be omitted or be repeated one or more times with the same or different ozone-containing gas mixtures;

[0127] an atmosphere modification gas mixture comprising ozone at an elevated concentration, e.g. containing ozone at a concentration in a range 7-5000 ppm is introduced in the packaging space and the one or more pre-packages therein, the atmosphere modification gas mixture may comprise air or another gas mixture, e.g. having reduced oxygen concentration and elevated carbon dioxide concentration compared to the ambient atmosphere;

[0128] the packages are closed, wherein the packaging material preferably is provided with one or more microperforations, or has been provided with one or more microperforations previously;

[0129] the packaging space is again evacuated and/or flushed to remove remaining ozone, e.g. being flushed with a gas that is at least substantially ozone-free and/or strongly reactive with ozone, and the packaging space is opened freeing the closed package(s) 3. The thus provided package(s) 3 may be refrigerated, stored and/or transported for sale.

[0130] For increasing processing speed, during establishing of the modified atmosphere in a (pre-)package volume and/or any optional associated flushing steps, a portion of oxygen may be converted into ozone and stored for use in a subsequent instance of establishing a modified atmosphere in a (pre-)package volume and/or any optional associated flushing steps.

[0131] It is noted that any package as presently provided may contain smaller packages. Further, such smaller packages may also be according to the present concepts.

[0132] As an example, 9 bunches of cut roses (variety “H3O”) were bought from a wholesaler, fresh from the morning's flower auction. The bunches were put in regular water and left at room temperature for three days without treatment. Then they were heavily contaminated with botrytis mold taken from (purposefully) molded strawberries. A packaging setup was made comprising a tubular polymeric packaging foil and an ozone generator. Bunches of roses were individually packaged in a portion of the packaging foil; the filled pre-packs were flushed with a mixture of ozone and air and closed, while flushing the package so that each package had a well-established elevate ozone concentration. Half of the thus-packed bunches were chilled to 3 degrees Centigrade for 18 hours and thereafter maintained at 20 degrees Centigrade, the other thus-packed bunches were continuously maintained at 20 degrees Centigrade. One bunch was packaged without ozone treatment and also maintained at 20 degrees Centigrade to act as a reference. After a total of 7 days from the date of packaging the packages were opened and the flowers were put into vases with regular drinking water at room temperature and maintained at room temperature adjacent each other. 3 days later the (vases of) bunches were individually assessed by two test persons regarding appearance and condition of the flowers. The results are presented in the following table:

TABLE-US-00001 TABLE 1 test results of ozone-treated roses Bunch Chilled Warm Quality [nr] [PPM O.sub.3] [PPM O.sub.3] [ranking] 1 200 1 (good) 2 50 2 3 7 3 4 50 4 5 200 5 6 7 6 7 1000 7 8 1000 8 9 0 = reference 9 (bad) 

[0133] Observations and conclusions were that:

[0134] The untreated bunch used as reference was heavily affected with botrytis and mildew and had an unacceptable appearance.

[0135] Afflictions of botrytis and mildew were less for any ozone-condition, already clearly so at 7 ppm ozone.

[0136] The best bunch still had an acceptable appearance for display.

[0137] The chilling step directly after packaging leads, on average, to better results.

[0138] For chilled bunches ozone damage may be identified from 50 ppm ozone, and increasing with increased ozone concentration. For room-temperature bunches ozone damage may be identified from 200 ppm ozone, and increasing with increased ozone concentration.

[0139] The disclosure is not restricted to the above described embodiments which can be varied in a number of ways within the scope of the claims. For instance, the package may be provided with an overpressure relative to the ambient atmosphere. Packages may be supported on a transporter during filling. Packages may be closed by hand. Gas composition sensors may be provided and placed differently and/or be formed as an optical detector. Weighing devices may be added. A (micro)perforator may be absent.

[0140] Elements and aspects discussed for or in relation with a particular embodiment may be suitably combined with elements and aspects of other embodiments, unless explicitly stated otherwise.