Meat storage bag

Abstract

To provide a storage bag for meat that can package meats so that they are red in color and has good packaging workability.SOLUTION: A storage bag for meat includes: a bottom film that is deep drawn to store meats; and a lid film that is deposited to the bottom film. The bottom film and the lid film are made of polyolefin material, and any one of the films has an oxygen permeability of 2,000 cc / m2 atm day (under conditions of 23°C and 65%RH) or higher, and another film has an oxygen permeability of 1,000 cc / m2 atm day (under conditions of 23°C and 65%RH) or higher.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a packaging bag for packaging meat such as beef. [Background technology]

[0002] Beef generally contains a large amount of the pigment protein myoglobin. When exposed to little or no oxygen, this myoglobin becomes reduced deoxymyoglobin, which is purple in color, and when exposed to a large amount of oxygen, it becomes oxygenated oxymyoglobin, which is bright red. On the other hand, when a small amount of oxygen is present, myoglobin is oxidized to become oxidized metmyoglobin, which is brown in color.

[0003] Among these, the oxygen-type oxymyoglobin has a beautiful red color that stimulates the appetite of those who see it, which has the effect of increasing consumer desire to purchase. For this reason, when retailing beef in supermarkets, etc., it is placed on plastic trays, covered with plastic wrap, and packaged as aerated, so that it is displayed in a state where it comes into contact with a large amount of oxygen (tray packaging).

[0004] Conventionally, before the meat is packaged in trays, it goes through multiple packaging steps: (1) butchering and processing the meat, followed by primary packaging (vacuum packaging), (2) distributing it in the primary packaging and transporting it to retailers, and (3) opening the primary packaging, transferring it to tray packaging, and displaying and selling it. These multiple packaging steps are necessary because the packaging bags used in the primary packaging block the supply of oxygen to the beef, causing it to turn into the aforementioned deoxymyoglobin or metmyoglobin state and turn purple or brown. Therefore, retailers open the primary packaging and repackage it into aerated tray packaging, which reacts with oxygen to increase the oxymyoglobin content and produce a red color.

[0005] Although it is possible to consider the method of distributing the product while it is still in the tray packaging, the wrap used for the tray has problems such as low sealing performance and weak puncture strength, which may cause problems such as leakage of the drip liquid generated from the beef, attachment of miscellaneous bacteria during transportation, and the occurrence of holes due to the load during transportation.

[0006] In view of the above circumstances, Patent Document 1 discloses a packaging bag that can distribute and sell beef in a degassed state. This packaging bag has a two-layer structure in which an inner film and an outer film are laminated. The inner film uses low-density polyethylene (LLDPE), and the outer film uses oriented polypropylene (OPP). In this case, the oxygen permeability of the inner film is 1000 - 6000 cc / m 2 / 24hr·atm under the conditions of 20°C and 90% RH, and the oxygen permeability of the outer film is 5000 - 8500 cc / m 2 / 24hr·atm under the condition of 20°C is used.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] Since the above-mentioned packaging bag uses oriented polypropylene (OPP) for the outer film, the stretchability of the film is poor. Therefore, a packaging bag made of such a two-layer film structure must be supplied as a bag product pre-processed into a flat bag shape. In order to enclose the beef inside, an operator needs to manually fill the beef and seal the packaging material by heat sealing. That is, when such a two-layer film structure is used as a packaging material for red meat, the working efficiency is poor.

[0009] In Japan, beef is rarely sold in vacuum packaging, and most cases are tray-packaged and colored red. Furthermore, in retail stores for imported foods, etc., although beef is occasionally sold in vacuum packaging, oxygen is blocked by the film used, resulting in a purple or brown color development.

[0010] The present invention has been made by paying attention to the above-described problems, and an object thereof is to provide a meat storage bag that can package meat so as to exhibit a red color and has good packaging workability.

Means for Solving the Problems

[0011] In order to achieve the above object, the present invention is a meat storage bag including a bottom film that is deep-drawn and houses meat, and a lid film that is adhered to the bottom film, wherein the bottom film and the lid film are made of a polyolefin material, and one of the films has an oxygen permeability of 2000 cc / m 2 ·atm·day (under the conditions of 23°C and 65% RH) or more, and the other film has an oxygen permeability of 1000 cc / m 2 ·atm·day (under the conditions of 23°C and 65% RH) or more.

[0012] The meat storage bag having the above-described configuration includes a bottom film that is deep-drawn and houses meat, and a lid film that is adhered to the bottom film. These films are made of a polyolefin material with a simple molecular structure and good oxygen permeability. In this case, one of the films has an oxygen permeability of 2000 cc / m 2 ·atm·day (under the conditions of 23°C and 65% RH) or more, and the other film has an oxygen permeability of 1000 cc / m 2 ·atm·day (under the conditions of 23°C and 65% RH) or more. When enclosing meat using a deep-drawing machine during primary packaging, the content of oxymyoglobin increases and it comes to exhibit a red color. Therefore, since it exhibits a red color while being housed in the deep-drawing machine, the work of transferring to a tray package becomes unnecessary in a retail store or the like, and the work efficiency is improved.

Advantages of the Invention

[0013] According to the present invention, meat can be packaged to exhibit red color, and a meat storage bag with good packaging workability can be obtained.

Embodiments for Carrying Out the Invention

[0014] The present invention is characterized in that it is a storage bag for containing meat (in this embodiment, beef) using a deep drawing machine. As described above, in Japan, meat storage bags are not formed using a deep drawing machine and arranged in retail stores as they are, but are tray-packaged in retail stores. Also, among imported products, there are some that enclose meat in a storage bag made by a deep drawing machine, but they are similar to vacuum packaging (using a film sheet with low oxygen permeability), and their color development shows a brownish or purple color, and they do not look good.

[0015] The inventor conducted an evaluation test on the oxygen permeability and the color development property of beef for a meat storage bag formed by a deep drawing machine so that it can exhibit red color like tray packaging and be arranged on the store shelf as it is. In this case, the film sheet disclosed in Patent Document 1 described above has a two-layer structure, and the inner film that is difficult to permeate oxygen has a value of 1000 - 6000 cc / m 2 24hr·atm under the conditions of 20°C and 90% RH. Therefore, in the present invention, for the film sheet, a film sheet approximating the minimum oxygen permeability within the above range is used as the minimum oxygen permeability for the test. That is, considering the disclosure content of Patent Document 1, if the oxygen permeability is 1000 cc / m 2 24hr·atm or less, it is considered that sufficient red color will not be developed, and if it is higher than that, the tendency to exhibit red color becomes stronger. Also, since the film sheet of the present invention is premised on being conveyed to a deep drawing machine for processing, a two-layer structure is used that has a minimum strength and is low in cost.

[0016] First, regarding oxygen permeability and the storage bag, several film sheets were prepared as samples. With the sample sheets stacked, processed beef was enclosed and welded, and a test was conducted to evaluate the state of the meat (the state of red color development) after a certain period (24 hours later) of refrigerated storage. As described above, the present invention considers packaging meat using a deep drawing machine. However, in the evaluation test, instead of using a deep drawing machine, a packaging bag was created by heat-welding the periphery with a plurality of sample sheets enclosing beef.

[0017] Regarding the sample sheets, two sheets of a general-purpose L-LDPE sheet were stacked, and by changing the total thickness of the two sheets, those with oxygen permeabilities within four ranges (a) to (e) were created for the lid film and the bottom film, respectively. In this case, the two sheets are in a two-layer structure by dry lamination.

[0018] However, with only one packaging bag, the state of the enclosed meat is different, and it is not appropriate to accurately evaluate. Also, for a plurality of sample sheets, it is difficult to accurately match the oxygen permeability due to variations in PE molecular weight, crystal structure, etc. Therefore, for the lid film and the bottom film, 20 sheets each within four ranges (a) to (e) were created.

[0019] That is, the evaluation shown in Table 1 below shows the results of comprehensively evaluating the color development situation with beef slices enclosed after creating five packaging bag samples for the lid film and the bottom film, respectively. Regarding the sample sheet to be the bottom film, it was vacuum-pressed using a vacuum pump onto a mold for deep drawing molding so as to be in the same situation as when packaging using a deep drawing machine.

[0020]

Table 1

[0021] According to the above results, it is considered that good or very good color development can be obtained if at least one of the lid film and the bottom film has an oxygen permeability of 2000 cc / m 2 ·atm·day or more. That is, if the condition is set such that either one has an oxygen permeability of 1500 cc / m 2 ·atm·day or more, in some cases, purple or brownish - red color tones may appear. Therefore, in the present invention, regarding the lid film and the bottom film of each two - layer structure, at least one of them has an oxygen permeability of 2000 cc / m 2 ·atm·day or more, which is a characteristic feature. In this case, for the bottom film, although the contact area with the enclosed meat becomes large, due to deep - drawing molding, it is easily deformed. Considering that it has a certain degree of tensile elongation, etc., the film thickness is preferably 100 μm or more. For this reason, it is preferable to increase the oxygen permeability on the lid film side.

[0022] As described above, in the present invention, for the bottom film and the lid film conveyed to the deep - drawing machine, a polyolefin material with a simple molecular structure and good gas permeability is used. One of the films has an oxygen permeability of 2000 cc / m 2 ·atm·day (under the conditions of 23°C and 65% RH) or more, and the other film has an oxygen permeability of 1000 cc / m 2 ·atm·day (under the conditions of 23°C and 65% RH) or more. Also, regarding the bottom film, it is characterized by a two - layer structure in which the outer and inner sides are made of low - density polyethylene (L - LDPE) with different wall thicknesses, and these are bonded by dry lamination or non - solvent lamination.

[0023] As a specific configuration that satisfies the above requirements, for the lid film (lid material), it is possible to use a two-layer structure of OPP 20μm / / L-LDPE 40μm. These film sheets have OPP on the outside and L-LDPE on the inside, and are laminated by dry lamination or non-solar lamination to form a roll stock. That is, for the outer film sheet, it is preferable to use an olefin material that allows oxygen to permeate. Since it will not have sufficient strength without being a biaxially stretched film (to have both oxygen permeability and strength), it is preferable to use an OPP material. Also, for the inner film sheet, as a material with good oxygen permeability and good heat sealability (it may also have easy peelability), it is preferable to use an L-LDPE material.

[0024] As described above, for the lid material, it is preferable to have a two-layer structure so as to obtain a desired oxygen permeability, low cost, and desired strength. However, as long as the above-mentioned oxygen permeability is obtained, the number of layers and thickness are not limited. In the following examples, PORO-FL2 manufactured by Futamura Chemical is used as the outer film sheet, and LL-XLTN manufactured by Futamura Chemical is used as the inner film sheet, and a structure with a two-layer structure is used.

[0025] Also, for the bottom film, in order to cope with deep drawing molding, it is preferable to use a material with a tensile elongation of 200% or more as measured in accordance with JIS K 7161 in either the machine flow direction (MD direction) or the direction perpendicular to the flow direction (TD direction).

[0026] Regarding the specific configuration of the bottom film (bottom material) that satisfies the above requirements, it is possible to use a two-layer structure of L-LDPE 30μm / / L-LDPE 100μm so as to obtain a desired oxygen permeability and low cost. These film sheets are laminated by dry lamination or non-solar lamination to form a roll stock. In the following examples, as the 30-μm L-LDPE film sheet, L Smart C-1 manufactured by Mitsui Chemicals Toagosei Co., Ltd. (which is preferably biaxially stretched among polyethylene and has a firm feeling while maintaining the tensile elongation) is used, and as the 100-μm L-LDPE film sheet, UB-106T manufactured by Tamapoly Co., Ltd. is used, and a two-layer structure using these is employed. Note that this two-layer structure sheet has a configuration that satisfies the above-mentioned tensile elongation of 200% or more.

[0027] As described above, regarding the lid material and the bottom material, it is preferable to form a two-layer structure so that a desired oxygen permeability, desired strength, and elongation can be obtained and cost reduction can be achieved. However, as long as at least the above-mentioned oxygen permeability is obtained, the number of layers, thickness, and constituent materials are not limited.

Example

[0028] Hereinafter, an example of the meat storage bag (packaging bag filled with meat) according to the present invention will be described while comparing it with a meat storage bag made using a general film sheet material (a general-purpose film sheet material conventionally used for deep drawing machines).

[0029] The example and the general-purpose film sheet for deep drawing packaging are composed of laminating the materials shown in Table 2 below.

[0030]

Table 2

[0031] As shown in Table 2, in this example (the product developed by our company), the film on the lid material side has an oxygen permeability of 2711.0 cc / m 2 ·atm·day (under the conditions of 23°C and 65% RH) or more, and the film on the bottom material side has an oxygen permeability of 1158.0 cc / m 2 ·atm·day (under the conditions of 23°C and 65% RH) or more, which is 1000 cc / m 2 ·atm·day (under the conditions of 23°C and 65% RH) or more. 2·It was configured to have an oxygen permeability of ·atm·day (under the conditions of 23°C and 65% RH).

[0032] These lid sheets and bottom sheets were wound in a raw material roll form, and under the trial production conditions shown in Table 3 below, a packaging bag was created using known trial production equipment. In this case, the dimensions of the packaging material were 250 mm in width and 300 mm in length. Domestic beef thigh steak meat was used as the meat to be enclosed, and the packaging form was vacuum packaging.

[0033]

Table 3

[0034] In the above-mentioned deep drawing equipment, it was confirmed that it could be formed according to the mold at a general-purpose molding temperature of 90°C. Also, regarding the line suitability, the bottom film with the above-mentioned two-layer structure had no problems such as meandering or feeding defects on the production line, and the line suitability was good. Then, meat storage bags were created under the above-mentioned conditions, and a storage test was conducted for each sample. Regarding the evaluation items, as shown in Table 4 below, a sensory test and a myoglobin composition were carried out.

[0035]

Table 4

[0036] Also, as the evaluation schedule, it was frozen and stored for 7 days including the start date of storage in a freezer, and on the 8th day, the storage location was moved to a refrigerator and stored for another 7 days in refrigerated storage, for a total of 15 days of storage (refer to Table 5 below for the specific evaluation schedule).

[0037]

Table 5

[0038] When a sensory test was conducted on the example (the product developed by our company) and general-purpose deep drawing packaging according to the evaluation schedule shown in Table 5, the results shown in Table 6 below were obtained.

[0039]

Table 6

[0040] In the examples, even after the 8th day from the start of thawing, no change was observed in the color (good color was maintained), but in general-purpose deep-drawn packaging, browning was observed after the 8th day. This is presumably due to the fact that sufficient oxygen permeability was not obtained as described above.

[0041] To verify this, the myoglobin composition of the examples (products developed by our company) and general-purpose deep-drawn packaging was examined according to the evaluation schedule shown in Table 5.

[0042] Regarding the myoglobin composition, as described above, it becomes reduced deoxymyoglobin (Deoxy Mb) and exhibits a purple color, and when it comes into contact with a large amount of oxygen, it becomes oxygenated oxymyoglobin (Mb O2) and exhibits a vivid red color. Also, when myoglobin is oxidized, metmyoglobin (Met Mb) is produced and it comes to exhibit a brown color. That is, even if the storage period is long, if the proportion of oxygenated oxymyoglobin (Mb O2) is large, the red color development will be maintained. Here, the proportion of oxygenated oxymyoglobin (Mb O2) was examined on the 1st day, 8th day, 10th day, 12th day, and 15th day, and the results shown in the following Table 7 were obtained.

[0043]

Table 7

[0044] As shown in this table, in the example, the proportion of oxymyoglobin (Mb O2) on the first day was 55.9%, and even on the 15th day, it maintained 46.9%, confirming that sufficient red color was developed. In contrast, for general-purpose deep-drawn packaging, the proportion of oxymyoglobin (Mb O2) on the first day was 63.3%, but it became 26.9% on the 8th day and decreased to 22.6% on the 15th day, showing a brownish appearance after the 8th day. That is, compared with the conventional deep-drawn packaging, the result was obtained that the color development of beef was better in this example.

[0045] As verified in the above examples, compared with the conventional degassing packaging, it is possible to provide a packaging bag that keeps the beef fresh in color and taste. In addition, continuous production by deep-drawn packaging is possible, and there is no need for repacking work in retail stores, so it is possible to provide a packaging bag with excellent production efficiency.

[0046] Regarding the oxygen permeability of the lid material and the bottom material, since the bottom material has a problem with tensile elongation as described above, it is preferable to increase the oxygen permeability of the lid.

Claims

1. A meat storage bag comprising a bottom film that is deep-drawn to accommodate meat and a lid film adhered to the bottom film, wherein The bottom film and the lid film are made of polyolefin material, and one of the films has an oxygen permeability of 2000 cc / m ２ ·atm·day (under the conditions of 23°C and 65% RH) or more, and the other film has an oxygen permeability of 1000 cc / m ２ ·atm·day (under the conditions of 23°C and 65% RH) or more, the bottom film has a two-layer structure in which the outer and inner sides are made of low-density polyethylene with different wall thicknesses and are laminated by dry lamination or non-sol lamination. The meat storage bag is characterized by this.

2. The lid film has an oxygen permeability of 2000 cc / m ２ ·atm·day (under the conditions of 23°C and 65% RH) or more, and the meat storage bag according to claim 1 is characterized in that it has such an oxygen permeability.

3. The bottom film has a tensile elongation of 200% or more as measured in accordance with JIS K 7161 in either the flow direction (MD direction) of the deep-drawing processing machine or the direction perpendicular to the flow direction (TD direction). The meat storage bag according to claim 1 or 2 is characterized by this.

4. The lid film has a two-layer structure in which the outer side is OPP and the inner side is L-LLDPE, and these are laminated by dry lamination or non-sol lamination. The meat storage bag according to any one of claims 1 to 3 is characterized by this.

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