PACKAGING OF FOOD
20180222609 ยท 2018-08-09
Inventors
Cpc classification
B65B5/02
PERFORMING OPERATIONS; TRANSPORTING
B65B31/021
PERFORMING OPERATIONS; TRANSPORTING
B65B31/00
PERFORMING OPERATIONS; TRANSPORTING
B65B25/001
PERFORMING OPERATIONS; TRANSPORTING
B65B9/045
PERFORMING OPERATIONS; TRANSPORTING
B65B9/02
PERFORMING OPERATIONS; TRANSPORTING
B65D1/34
PERFORMING OPERATIONS; TRANSPORTING
International classification
B65B9/02
PERFORMING OPERATIONS; TRANSPORTING
B65D1/34
PERFORMING OPERATIONS; TRANSPORTING
B65B5/02
PERFORMING OPERATIONS; TRANSPORTING
B65B25/00
PERFORMING OPERATIONS; TRANSPORTING
B65B31/00
PERFORMING OPERATIONS; TRANSPORTING
B65D75/00
PERFORMING OPERATIONS; TRANSPORTING
B65D81/26
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The invention relates to improvements in or relating to the packaging of food 36 between a first plastic film 16 and a second plastic film 18 using a packaging apparatus 10. A tray 24 is formed from the first plastic film 16, the tray having a floor 33 with at least one channel 32. An absorbent pad 34 is provided on the floor 33 of the tray 24. A portion of food 36 is provided on the floor 33 of the tray 24. The second plastic film 18 is placed on the tray 24 to sandwich the absorbent pad 34 and the portion of food 36 between the plastic films 16, 18. The packaging apparatus 10 is operated to urge the two plastic films 16, 18 together and to create a seal therebetween. At least one duct 76 is formed between said at least one channel 32 and at least one of the second plastic film 18, the absorbent pad 34, and the portion of food 36.
Claims
1. A vacuum package containing a portion of food, the package comprising: a tray, a plastic film and an absorbent pad, the tray having a floor with at least one channel running in a transverse direction along the tray, and at least one channel running in a longitudinal direction along the tray, said channels intersecting each other so that they are in communication with each other, said channels being formed by a plurality of raised portions of the floor, said raised portions being provided as a row or a grid, the raised portions being discrete projections from the floor of the tray, each raised portion having an apex, the absorbent pad and the portion of food being provided on the floor of the tray so that they cover at least one of said channels, the absorbent pad having a smaller area than the portion of food so that it is concealed by the portion of food and so that the portion of food is in contact with the apex of the raised portions of the tray around a perimeter of the absorbent pad to grip the portion of food, the plastic film being vacuum formed onto the tray to urge the plastic film and the tray together and to sandwich the absorbent pad and the portion of food between the plastic film and the tray to create a seal therebetween, wherein a plurality of intersecting ducts are formed between said channels and each of the plastic film, the absorbent pad, and the portion of food to permit liquid to pass to the absorbent pad, wherein at least one of the tray and the plastic film has an adhesive thereon such that an adhesive bond is provided between the plastic film and each apex of the raised portions around the portion of food by said plastic film being vacuum formed onto the tray.
2. A package according to claim 1, wherein the tray has a continuous lip around the portion of food, said channels and the absorbent pad, the lip for providing a continuous seal between the lip and the plastic film.
3. A package according to claim 1, wherein a spacing between adjacent channels is between 0.5 cm and 2.0 cm, and preferably 1.0 cm.
4. A package according to claim 1, wherein each apex has an area of between 0.75 to 2.5 mm.sup.2.
5. A package according to claim 1, wherein each raised portion has at least one face which is concave.
6. A package according to claim 1, each raised portion has a height of between 1.0 mm and 7.0 mm, and preferably 3.6 mm.
7. A package according to claim 1, wherein the tray has a sidewall extending from the floor.
8. A package according to claim 1, wherein the portion of food is fish.
9. A package according to claim 1, wherein the tray is an opaque plastic.
10. A package according to claim 1, wherein at least a part of the plastic film is a see-through plastic film.
11. A package according to claim 1, wherein the floor of the tray has a well in communication with the at least one channel.
12. A package according to claim 1, wherein the plastic film is a breathable film.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] Other features of the invention will be apparent from the following description of preferred embodiments shown by way of example only with reference to the accompanying drawings, in which;
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DETAILED DESCRIPTION
[0063]
[0064] The opaque plastic film 16 and the clear plastic film 18 are comprised of a mixture of food grade plastics including poly styrenic resins. One or both of the two plastic films 16, 18 have a known adhesive coating which is, for example heat-activated or activated by the application of light having a particular wavelength. In one arrangement the plastic film 16 is a gas permeable plastic film.
[0065] The opaque plastic film 16 is fed from the first feed reel 12 onto a mould 22 or forming tool where it is formed into a series of trays 24, which are attached to each other. For example, heat is applied to the opaque plastic film 16 from above as shown by arrow 25, and the mould 22 is moved upwards as shown by arrow 26 to form the trays 24. A partial vacuum or air pressure may be applied to the opaque plastic film 16 during the moulding stage to form the trays 24. The mould 22 has a mould floor 28 with a series of channels 30 which have been machined into it. The channels 30 of the mould 22 produce corresponding channels 32 in a tray floor 33 of the trays 24 when formed. The channels 32 are described in greater detail below with reference to
[0066] Whereas the term tray 24 is used it will be understood that the tray 24 is a container or a receptacle having an open top, and which has a floor and a side wall which extends from the floor and is continuous. In an alternative arrangement the tray 24 does not have side walls and is substantially planar and includes the channels 32.
[0067] The apparatus 10 is arranged to place an absorbent sheet or pad 34 onto the base 28 of each formed tray 24. Alternatively the absorbent sheet 34 may be placed manually onto each tray 24. The apparatus 10 then places a portion of fresh fish 36 onto the absorbent sheet 34 of each tray 24. Alternatively the portion of fresh fish 36 may be placed manually onto each tray 24. The absorbent sheet 34 is of a known kind, and acts to absorb water and other juices/liquid from the portion of fresh fish 36 as described in greater detail below. The absorbent sheet 34 has a smaller area than the portion of fish 36 when viewed from above so that it is concealed by the portion of fish 36. It will be appreciated that the step of forming the tray 24 requires the application of heat 25. The formed tray 24 is required to be sufficiently cool before the portion of fish 36 is placed on it to reduce the possibility of heating or partially cooking it. In this respect the absorbent sheet 34 has the advantage that it may provide an amount of heat insulation between the portion of fish 36 and the tray 24 to reduce or avoid unwanted heating or cooking of the fish 36.
[0068] The apparatus 10 then feeds the clear plastic film 18 from the second feed reel 14 over the trays 24 and the portions of fish 36 having the absorbent sheet 34 underneath them, as shown at 38. A vacuum packaging device 40, 42 then moves over each tray 24 as shown by arrows 44, 46 to apply a partial vacuum below the tray 24 and above and the clear plastic film 18 together with the application of heat to the clear plastic film 18. For example, the clear plastic film 18 may reach a temperature of around 200-210 C. under the application of heat. For example, the partial vacuum may be around 3 to 10 mbar. The region above the clear plastic film 18 film is then vented to atmosphere. This process removes sufficient air between the two plastic films 16, 18. The apparatus applies heat, for example using a heating element of the vacuum packaging device 40, 42, to activate the adhesive on the plastic films 16, 18 to adhesively bond and seal them together at the points where they are in contact with each other. In this manner the portions of fish 36 and the absorbent sheet 34 are hermetically sealed between the two plastic films 16, 18. The two plastic films 16, 18 and the vacuum packaging device 40, 42 are of a known kind whereby the two plastic films 16, 18 are arranged to bond or partially bond to each other during the venting of the region above the clear plastic film 18 to atmospheric pressure and/or heat. One or both of the films 16, 18 may be provided with the adhesive to provide the required bonding therebetween. The apparatus 10 has cutters 48, 50 which move as shown by arrows 52, 54 to consecutively cut each tray 24 so that separate packages 56 containing the fish 36 are produced. As an alternative to using the adhesive, the cutters 48, 50 may partially melt the films 16, 18 together to form the seal therebetween at the points where they are in contact with each other.
[0069] The apparatus 10 produces packages 56 of fish 36 between the two plastic films 16, 18 as a continuous process on the production line of the apparatus 10. Alternatively the apparatus 10 may be arranged to produce packages 56 of fish 36 in batches as a continuous process. Whereas the apparatus 10 has been described above it will be appreciated that it may be constructed from a known apparatus such as a CRYOVAC DARFRESH apparatus available from Sealed Air Corporation, which has been modified according to the embodiments of the invention. With such an apparatus, or using the apparatus 10 described above, the opaque plastic film 16 may be a black film having the technical specification PFIL059, and the clear plastic film 18 may be a multi-layer clear plastic film having a thickness of 400 micrometres and comprised in the majority of styrenic resins. Packages 56 produced using the DARFRESH apparatus or the apparatus 10, may be described as skin packs or skin packages because they have a base tray 24 with a plastic film 18 or a skin which has been formed thereon. Such a way of packaging may be termed skin packaging which is characterised by the use of adhesive between the two films 16, 18, and whereby the upper film is a shrink wrap film so that it stretches around the fish 36.
[0070] The package 56 comprises a moulded tray 24 where the clear plastic film 18 envelops the fish 36 and cooperates with the tray 24 to bond to it. The clear plastic film 18 is a transparent protective film which adheres to the tray 24 while allowing sight of the fish 36 by the consumer.
[0071] Whereas the apparatus 10 shows that the tray 24 is formed by the apparatus 10, it will be appreciated that alternatively the tray 24 may be pre-formed elsewhere and then fed into the apparatus 10. If the tray 24 is pre-formed it may not necessarily be of a thermoforming plastic, and it may be for example expanded foam. The steps of placing the fish 36 and absorbent pad 34 onto the tray 24 and laying the clear plastic film 18 onto the tray 24 prior to applying the partial vacuum and venting to atmospheric pressure can then be performed by the apparatus 10.
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[0076] From the above
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[0078] The method further includes cutting the two films 16, 18 to create a separate package 56 containing the portion of food 36 and the absorbent pad 34, as shown at 90. The method further includes providing the absorbent pad 34 on the floor 33 of the tray 24 so that it at least partially covers at least a part of said at least one channel 32, as shown at 84. The method further includes placing the portion of food 36 on the floor 33 of the tray 24 so that it is at least partially cover a part of said at least one channel 32, as shown at 85. The method further includes placing the portion of food 36 on the floor 33 of the tray 24 so that it is at least partially on the absorbent pad 34, as shown at 85. The method further includes placing the portion of food 36 on the floor 33 of the tray 24 so that it wholly covers the absorbent pad 85.
[0079] The method further includes forming the tray 24 with a continuous lip 64 around the portion of food 36, said at least one channel 32 and the absorbent pad 34, the lip 64 for providing a continuous seal between the plastic films 16, 18. The method further includes forming the floor 33 of the tray 24 with a plurality of channels 32 for providing a plurality of ducts 76 between the plurality of channels 32 and at least one of the second plastic film 18, the absorbent pad 34, and the portion of food 36. The method further includes forming the plurality of channels 32 so that the ducts 76 are in communication with one another, as shown at 82. The method further includes forming said at least one channel 32 using a row or a grid of raised portions 62 of the floor 33 of the tray 24. The method further includes forming the tray 24 with a sidewall 66 extending from the floor 33. The method further includes using the packaging apparatus 10 to urge the two plastic films 16, 18 together by applying a partial vacuum above the clear plastic film 18 and below the opaque plastic film 16, and then venting a region above the clear plastic film 18 to atmospheric pressure. The method further includes using the packaging apparatus 10 to apply heat to at least partially bond the two plastic films 16, 18 together.
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TABLE-US-00001 TABLE 1 Quality Grading Score Sensory Quality 9 Excellent Quality 8 Very Good Quality 7 Good Quality 6 Fairly Good Quality 5 Satisfactory Quality 4 Just Acceptable Quality 3 Poor Quality 2 Very Poor Quality 1 Bad Quality
[0083] A summary of the quality grading score for each package is shown in Table 2 and in
TABLE-US-00002 TABLE 2 Quality Grading Score Product D + 1 D + 6 D + 7 D + 8 Prior art package 8 4 3 Not Assessed Package 56 8 7 6 3
[0084] In
[0085] Whereas the package of the prior art may be able to keep the fish fresh, for example, up to seven days, the package 56 of the above embodiments has been shown in the experiments to keep the fish fresh for up to one or two days longer. Extending the shelf life of the fish 36 by at least one or two days is a highly significant achievement because it may avoid the requirement to discard the fish 36 if it has not been sold by the supermarket, which reduces food waste. The advantage of keeping the fish 36 fresher for longer is due to the fact that the fish 36 rests in less water when in the package 56. In addition, since little or no water pools in the package 56 it provides an improved appearance to the consumer, particularly towards the end of the shelf life.
[0086] The use of an absorbent sheet 34 when packaging fish 36 is expressly not be recommended by packaging suppliers because it may interfere with the seal between the two films 16, 18. Such a recommendation against using absorbent sheet 34 represents a prejudice in the technical field. However, the Applicant has conducted experiments using the embodiments of the invention describe above to show that the problems associated with interfering of the seal between the two films 16, 18 of the package 56 are avoided or at least significantly reduced or minimised to acceptable levels because the tray 24 grips the fish 36 to inhibit it from moving on the tray 24 and because water is absorbed by the absorbent pad 34.
[0087] The packages 56 are suitable for transporting to a supermarket in bulk and for stacking on shelves ready for sale. The packages 56 present the fish 36 to the consumer in an appealing manner because it is visible through the clear plastic film 16 and has a three-dimensional appearance. The packages 56 may also be frozen for transporting long distance. Such freezing may expand the volume of the portion of fish 36. If the package 56 undergoes a controlled thawing process prior to stacking on a supermarket shelf additional water and juices may be released by the portion of fish 36. With the embodiments of the invention the additional water and juices are able to pass more easily to the absorbent sheet 34 due to the ducts 76. When the package 56 undergoes freezing and defrosting the fish 36 is kept fresher for a longer period of time because there is little or no water for the fish 36 to rest in which increases the shelf life.
[0088] Another advantage provided by the tray 24 is that it is relatively rigid due to the raised portions 62 which provide a structure to the tray 24 which stiffens it. This provides the advantage that it is much easier to peel away the clear plastic film 16 from the opaque plastic film 18 to open the package 56. Furthermore, if a small amount of liquid is present in the package 56 it is less likely to spill or splash when the package 56 is opened because the tray 24 is relatively stiff. Furthermore, such a stiffer tray 24 may also allow a lighter weight tray 24 to be used, which may provide a cost and environmental advantage.
[0089] In the above embodiments the channels 32 are shown to have a curved floor between the raised portions 62 where the square bases 68 of each pyramid meet. The curved floor and the pyramid structure mean that the trays 24 can be formed easily by the mould 22, and are readily releasable from the mould 22. It will be appreciated that the raised portions 62 and channels 32 may have any suitable shape that permits the formation of a duct 76 with the clear plastic film 16. It will also be appreciated that the number of channels 32 and orientation relative to the tray 24 may also be varied. In one arrangement the channels 32 are comprised of recessed lettering or writing on the tray floor 33. Such recessed lettering or writing may be used to display instructions or a Trade Mark into the tray 24.
[0090] Whereas the packaging of fish 36 is mentioned above it will be appreciated that the method, package and apparatus may also be used to package other food that may release water or juices such as chicken, pork, beef, seafood, other proteins etc.
[0091] Whereas the above embodiments describe a plurality of channels 32, raised portions 62 and/or ducts 76, it will be appreciated that the embodiments may at least partially provide the desired effect with only one channel 32, raised portion 62 and/or duct 76, with the proviso that the water or other juices from the portion of fish 36 is able to pass to the absorbent sheet 34. Furthermore, whereas the absorbent sheet 34 is shown in the above embodiment to be wholly covered by the portion of fish 36, the desired effect may at least partially be provided by having the portion of fish 36 covering only a part of the absorbent sheet 34. Alternatively the portion of fish 36 and the absorbent sheet 34 may be located away from each other on the tray floor 33 and connected to each other by the duct 76 between the clear plastic film 16 and the opaque plastic film 18.
[0092] Whereas in the above embodiments the fish 36 is in contact with the absorbent pad 34, in an alternative arrangement the fish 36 is not in contact with the absorbent pad 34. With such an arrangement the fish 36 and the pad 34 are located on separate parts of the floor 33, and are in communication with one another by said at least one duct 76.
[0093] Whereas the above embodiments have been described as being able to extend the shelf life of food it will be appreciated that in general such an extension of time may be dependent on many factors including, for example, the particular supermarket or retailer, the manner in which the packages 56 are handled or transported, or the final destination country. Whereas, in general the shelf life may be extended, it will be appreciated that the food may remain fresher for longer over a given shelf life period.
[0094] In one embodiment the clear plastics film 18 is a breathable film, which may be a legal requirement for sale of the package 56 in certain countries, for example the US. Such a breathable film may be of polyethylene, which is porous to oxygen. For example, the breathable film may have a water vapour transmission rate of 2.1 gms/100 sq. in./24 hrs, and may have an oxygen transmission rate of 12,000 cc/m.sup.2/24 hrs. A suitable breathable film is available from Sealed Air Corporation having the product code VF310K. The oxygen permeable film 18 guards against anaerobic conditions being generated within the package 56 that may cause anaerobic bacterial spores, such as Clostridium botulinum, to germinate and produce toxins.
[0095] The Applicant has conducted microbiological experiments using such a breathable film to compare the package 56 and the prior art package. The experiments show that viable colony counts for aerobic bacterial colonies is greatly reduced using the package 56. Table 3 shows results for Salmon using the prior art package. Table 4 shows results for Salmon using the package 56.
TABLE-US-00003 TABLE 3 Aerobic Presumptive Sulphite Listeria spp. Presumptive Coagulase Colony Coliforms Reducing Presumptive Detection Pseudomonas Salmonella spp. Positive Count cfu/g cfu/g Clostridia cfu/g E. coli cfu/g per 25 g spp. Count cfu/g Detection per 25 g Staphylococci P + Day FM0010GL FM0030GL FM0056 FM0160DGL FM0220EGY FM0280GL FM077GY cfu/g FM804GL P + 09 50,000 60 <10 <10 Not 600,000 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND] P + 08 33,000 220 <10 <10 Not 32,000 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND] P + 07 3,000 10 <10 <10 Not 12,000 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND] P + 06 38,000 630 <10 <10 Not 12,000 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND] P + 05 <1000 <10 <10 <10 Not 16,000 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND]
TABLE-US-00004 TABLE 4 Aerobic Presumptive Sulphite Listeria spp. Presumptive Coagulase Colony Coliforms Reducing Presumptive Detection Pseudomonas Salmonella spp. Positive Count cfu/g cfu/g Clostridia cfu/g E. coli cfu/g per 25 g spp. Count cfu/g Detection per 25 g Staphylococci P + Day FM0010GL FM0030GL FM0056 FM0160DGL FM0220EGY FM0280GL FM077GY cfu/g FM804GL P + 09 <1000 <10 <10 <10 Not <20 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND] P + 08 <1000 10 <10 <10 Not <2000 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND] P + 07 1,000 <10 <10 <10 Not <2000 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND] P + 06 <1000 <10 <10 <10 Not <2000 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND] P + 05 <1000 110 <10 <10 Not <2000 Not <20 [100,000] [100] [10] [10] Detected: [1,000,000] Detected: [100] [ND] [ND]
[0096] Accordingly, the package 56 with a breathable film 18 produces an additional benefit of reducing viable bacterial colonies, which is due to the ducts 76 allowing water and other juices from the fish 36 to pass to the absorbent pad 34.