JPH04267771A - Packing of dressed meat - Google Patents

Abstract

PURPOSE:To maintain the freshness of dressed meat and retain the scarlet color of the meat for a long period of time by a method wherein the air in a pack is replaced with carbon dioxide and nitrogen in a specific proportion and the pack is sealed with film and thereafter heated to shrink the film so as to effect a close packing thereof. CONSTITUTION:In wrapping a pack having dressed meat received therein in the film which is formed by coating a stretchable film containing a cross-linked or linear, low-density polyethylene with a copolymer latex consisting mainly of vinylidene chloride and drying the same at a low temperature, the air in the pack is replaced with 60-90% oxygen, 40-10% carbon dioxide and 0-30% nitrogen and the pack is sealed with the film and thereafter heated to shrink the film so as to effect a close packing thereof. In other words, a container 2 having dressed meat 4 received therein is wrapped in the film 1 coated with latex and, after the gas replacement it is sealed with seals 3. As a method of heating and shrinking the packing film, the packed container is made to pass through a hot air tunnel.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for packaging meat, and more particularly to a method for packaging meat that maintains the freshness of meat and provides freshness to consumers.

0002

[Prior Art] Currently, meat for consumers is packaged in such a way that the meat is stored in a container such as a plastic tray, and the container containing the meat is entirely wrapped in a stretch film made of vinyl chloride. . In addition, as a packaging method in which the inside of the container is replaced with gas, there is a tofu pack method in which a hard barrier film is used and the flange of the barrier container is heat-sealed.

0003

[Problems to be Solved by the Invention] However, products packaged with vinyl chloride stretch film do not have barrier properties or heat-sealing properties, so gas replacement is not required. The effect will not occur. In addition, since the tofu pack method heat-seals the flange of the container, it is necessary to change the heat-seal tray of the packaging machine each time the size of the barrier container is changed, and in reality, it is necessary to change the heat-seal tray of the packaging machine. The machine can only wrap containers of one size, and this method requires that there be no wrinkles at the flange, so only hard film can be used, and the meat may bulge out of the container. There was a problem in that items stored in this condition could not be packaged and had no effect on display to consumers.

The object of the present invention is to provide a method for packaging meat that is free from the above-mentioned problems.

[0005]

[Means for Solving the Problems] As a result of various studies on packaging methods for meat, the present inventor has developed a method for packaging meat using a copolymer mainly composed of polyvinylidene chloride in a cross-linked polyethylene film or a linear low-density polyethylene stretched film. A barrier film coated with latex and dried at low temperature has excellent transparency, stable heat-sealing properties, and high heat-shrinkability. The present invention was completed based on the discovery that it is possible to tightly package the meat, keep the freshness of the meat, and keep the bright red color of the meat for a long time.

That is, the present invention provides a method for packaging meat by gas displacement, in which a container containing meat is made of a stretched film containing cross-linked polyethylene or a stretched film containing linear low-density polyethylene, and a copolymer mainly composed of vinylidene chloride. When packaging with a film coated with polymer latex and dried at low temperature, the air inside the packaging is 60-90% oxygen and 4% carbon dioxide.
This is a meat packaging method in which the packaging is airtight by sealing the film after purging with 0 to 10% nitrogen and 0 to 30% nitrogen, and then heating the packaging to shrink the film and tightly package it.

The stretched film containing crosslinked polyethylene used in the present invention refers to polyethylene of various densities, or ethylene and propylene with a polyethylene content of 50% by weight or more,
A copolymer with an α-olefin such as 1-butene or 1-pentene, or a vinyl monomer such as vinyl acetate, acrylic acid, acrylic ester, or vinyl chloride, which is one or two of the polyethylene resins. A film made of a mixture of at least one of these resins, a film made of one or two or more layers of these resins, irradiated with ionizing radiation and then stretched in at least one axis, or a film that was irradiated with ionizing radiation and stretched in at least one axis. It is a film laminated with another film such as a polyethylene film. Among these, a film crosslinked by irradiation with ionizing radiation is preferred.

The stretched film containing linear low density polyethylene used in the present invention is made of a linear copolymer of ethylene and α-olefin and has a density of 0.870 to 0.935. Single layer or multilayer combination, at least uniaxially stretched, or ethylene and α-
Contains at least one layer of a linear copolymer with olefin, which contains 50% or more of polyethylene, and consists of a copolymer of ethylene and a monomer selected from vinyl acetate, acrylic acid, acrylic ester, vinyl chloride, etc. A multi-layered material containing at least one layer is stretched in at least one axis.

[0009] The α-olefin is selected from the group of propylene, 1-butene, 1-pentene, 1-hexene and the like. The method of extruding and stretching these single-layer or multi-layer resins is to perform melt extrusion through a single-layer or multi-layer die, cool and solidify without stretching to create a tubular unstretched sheet, which is then tubular stretched. The tube is stretched by applying pressure to the inside of the tube in a temperature range that allows the tube to be supplied to the device and oriented.

The temperature at which the stretched film used in the present invention starts to shrink depends on the temperature at which stretching is carried out. Therefore, the stretching temperature that can generally be carried out is in the range lower than the melting point of the resin crystals and higher than the glass transition temperature. Therefore, the stretched film starts to shrink in the range of 60 to 80°C. Therefore, in the present invention, the film of the package is provided with gas barrier properties at the same time as the package is heat-shrinked.

The latex made of a copolymer mainly composed of vinylidene chloride used in the present invention is an aqueous emulsion sold as Saran Latex (manufactured by Asahi Kasei Industries, Ltd., trade name). The above-mentioned latex used in the present invention contains a sufficient amount of blocking agent since it is dried at low temperature after being applied to the film, and a large amount of anti-fogging agent is added because anti-fogging properties are required for packaging products. There is a need to. Therefore, the gas barrier properties are inferior to the commonly used vinylidene chloride copolymer latex.

The film coated with latex used in the present invention is prepared by applying an anchor coating agent such as polyurethane, polyethyleneimine, or epoxy to the stretched film, drying at low temperature, and then applying the blocking agent and antifogging agent. It is produced by coating the latex contained therein, for example, with an air knife coater and drying it at a low temperature, that is, below the temperature at which the stretched film shrinks, and at a temperature as high as possible. The thickness of the latex coating is not particularly limited, but is preferably 1 to 10 microns from the viewpoint of gas barrier properties, heat sealability, and the like. Furthermore, the produced film has no wrinkles due to shrinkage and has high oxygen permeability.

[0013] In the present invention, a container containing meat is packaged with a film coated with the latex described above. At that time, the air inside the package is 60-90% oxygen, 40-10% carbon dioxide,
Replace with nitrogen until it becomes 0-30%. Next, the package is sealed to be in an airtight state, and then the package is heated to shrink the film and tightly package the package. In the present invention, the method of wrapping a container containing meat with a film is carried out by a commonly used method. At this time, the inside of the packaged container contains 60-90% oxygen and 40-10% carbon dioxide.
, replace the air in the container until it becomes 0-30% nitrogen. Examples of replacement methods include flushing a mixed gas of oxygen and carbon dioxide inside the vacuum packaging machine or the package, or pressing the package with a sponge or the like to expel the air inside the package and then introducing the gas. method etc.

The gas that replaces the inside of the package is to maintain the freshness of the meat and maintain its bright red color for a long period of time.Oxygen prevents oxymyoglobin from changing into metmyoglobin, and carbon dioxide gas prevents the meat from changing into metmyoglobin. It dissolves in the water inside, lowers the pH, and suppresses the growth of bacteria. The composition of the gas is 60-90% oxygen, 40-1% carbon dioxide.
0%, nitrogen 0-30%. If the gas composition is outside the above range, the gas will escape from the inside of the package due to the gas partial pressure difference, the package will be in a reduced pressure state, and its commercial value will be lost. 70 to 90% oxygen and 30 to 10% carbon dioxide are preferred.

[0015] Also, the method of sealing the gas-exchanged package is carried out by sealing the film with heat sealing, impulse sealing, high frequency sealing, or the like. For example, as shown in FIG. 1, a container 2 containing meat 4 is packaged with a film 1 coated with latex, and the gas-substituted package is sealed 3 to make it airtight. Furthermore, the method of heating the sealed package is carried out by passing the package through a hot air tunnel. For example, as shown in FIG. 2, the film is heated and shrunk until the film 1 comes into close contact with the container 2. At this time, the temperature inside the tunnel needs to be changed depending on the shrinkability of the stretched film, but it is usually carried out at 130 to 150°C. Further, in heat shrinking, a method is preferred in which the bottom film of the package is first heat-shrinked and then the top film of the package is heat-shrinked to remove wrinkles.

[0016]

[Examples] The present invention will be explained below with reference to Examples.

[0017]

[Example and Comparative Example 1] After applying an anchor coating agent to an ionizing radiation irradiated crosslinked polyethylene stretched film (thickness 15 μm) and drying it, polyvinylidene chloride latex (Asahi Kasei Corporation) to which a blocking agent and an antifogging agent were added was added to the film. Co., Ltd., product name: Saran Latex) with a film thickness of 3
After coating the film until it reached μ, a film was prepared by drying at 60°C.

[0018] Next, a container containing beef slices in a polystyrene tray was wrapped with the above film, and the air inside the container was replaced with 80% oxygen and 20% carbon dioxide (sample 1), 70% oxygen, A sample with 30% carbon dioxide gas substituted (Sample 2) and a sample with air as is (Comparative Example 1) were prepared, and airtight packages were prepared by heat sealing on three sides as shown in FIG.

After that, the gas and air inside the package were slightly removed, and the package was passed through a tunnel at 160° C. for 15 seconds to shrink the film and form a tactile package. The three types of packages mentioned above were stored in a refrigerator at 0° C., and the color tone, off-odor, and general viable bacterial count were examined after 7 days. Table 1 shows the results.
Shown below. Note that no reduced pressure was observed in any of the packages.

[0020]

[Comparative Example 2] Thinly sliced pork loin was placed in a PSP plastic tray and wrapped in a polyvinyl chloride stretch film. At this time, two types were prepared: one in which the inside of the container was replaced with 80% oxygen and 20% carbon dioxide (sample 4), and one in which the air was replaced (sample 5).

[0021] These packages were stored in a refrigerator at 0°C,
After 7 days, changes in color tone and abnormal odor were examined. The results are shown in Table 2.

[0022]

[Reference Example] As a reference example, the gas barrier properties of the film used in the present invention were measured before and after the heat shrinking process. Polyvinylidene chloride latex was coated on a crosslinked polyethylene stretched film irradiated with ionizing radiation so that the film had a thin film thickness of 2 μm, and the film was dried at 60° C., and the oxygen gas permeability of the film was measured. The result is 200cc/m2 /24hr
It was an ATM. When this film was passed through a tunnel at 170°C for 15 seconds using the method of Example 1, the result was 35
cc/m2/24hr atm, and good gas barrier properties were imparted by heat treatment of the package.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

[Effect of the invention] The present invention uses a barrier film,
In addition, since the inside of the package is replaced with oxygen and carbon dioxide gas, the freshness of the meat can be maintained for a long period of time, and the bright red color of the meat can be preserved. Further, in the packaging method of the present invention, by using the film as described above, imparting gas barrier properties to the film and heat shrinking can be performed in one step.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the packaging method of the present invention in which a package is in a sealed state.

FIG. 2 is a perspective view of a package manufactured by the packaging method of the present invention.

[Explanation of symbols]

1 Cross-linked polyethylene stretched film 2 Container 3 Seal part 4. Meat

Claims (1)

[Claims] Claim 1: A method for packaging meat by gas displacement, in which a container containing meat is made of a stretched film containing cross-linked polyethylene or a stretched film containing linear low-density polyethylene made of a copolymer mainly composed of vinylidene chloride. When packaging with a film coated with latex and dried at low temperature, the air inside the package is 60-90% oxygen and 40% carbon dioxide.
~10% nitrogen and 0 to 30% nitrogen, seal the film to make the package airtight, and then heat the package to shrink the film and tightly package the meat. Packaging method.