JPS59142917A - Method of packing fresh meat and package of meat - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fresh meat packages and methods for packaging fresh meat. As used herein, the term "fresh meat" includes frozen fresh meat, ground meat and meat products, all uncooked.

Fresh meat that is cut and packaged for the purpose of self-service retail sales has a significantly shorter shelf life on the shelves because the red oxymyoglobin pigment in the meat part of the pack is lost. This pigment turns brown through autoxidation, and hemolin p' (llaem
The ions on ring ) are oxidized from the ferrous state to the ferric state. The rate of autoxidation is controlled by a number of factors, including:

1 Partial pressure of oxygen on the surface of meat.

2. Atmospheric temperature.

3. Adjust the pH of the meat.

4. Microbial activity.

Factors 1 and 2 can be controlled by selecting the packaging system and subsequent processing methods.

Processes are already being used to extend the shelf life of meat by packaging it within highly impermeable barrier materials that enclose a controlled and cool atmosphere.

This controlled atmosphere is typically high in oxygen and carbon dioxide (q is 75 parts and C02 is 25 parts), and the high oxygen levels allow oxymyoglobin to form deeper into the meat. is promoted. This method suffers from high costs, large encapsulation atmospheres, bulkiness, unnatural appearance of the product, and the risk of leakage (i.e., indirect "explosive" contamination by ivy and microorganisms) when the consumer removes the pack from all points of sale. It has many problems, including difficulty in detection.

In contrast to what was previously proposed, the Applicant has discovered that the presently available packaging is prepared by two polymeric membranes that are oxygen permeable and transparent.

According to one aspect of the invention, fresh meat is vacuum processed and first
Packed under reduced pressure between the layer of material and the layer of second material.
, at least one of said layers of material is permeable to oxygen to a sufficient extent that oxygen can flow into the package under the influence of partial pressure, and at least one of said layers of material is transparent. A meat package is provided that looks like this. The oxygen flowing inside the package under the influence of the partial pressure is converted to carbon dioxide by the meat to a certain extent. Carbon dioxide has a higher diffusion rate than oxygen (about 5 times) and can also be dissolved in meat.

Carbon dioxide leaves the pack faster than oxygen enters.
This explanation helps maintain the appearance of the vacuum packaging-1 in a stretched state.

According to another aspect of the invention, a first web of material is formed into a body receiving fresh meat; the meat is placed within the body;
Uke is a method of packaging fresh meat by sealing it with a second web of somatic material. Uke is a method of packaging fresh meat by sealing it with a second web of somatic material. In Uke, the meat that has entered the body undergoes vacuum treatment and is sealed under reduced pressure to create the entire package. and further characterized in that at least one of said webs is made of a material permeable to oxygen under the influence of partial pressure, and at least one of said webs is transparent. provided.

The effect of the vacuum cycle is to remove permanent gases from the meat. These gases are then replaced with oxygen by a controlled partial release of the vacuum during the processing cycle of the machine, and this replacement brings the oxygenated layer deeper into the inner circle, creating the "critical oxygen" (see proc of Burtsuknu et al., RoySac, B 1932)
, which occurs during the unstable stage before passing through the frozen storage, while ensuring that it is treated with a heating stage of shrinkage and sealing. The second feature of this vacuum release is the reduction of atmospheric pressure acting on the meat and the minimization of pressure effects (no drip seepage).
It is.

As an alternative, fresh meat may be packaged in anaerobic packaging under vacuum or in an inert gas atmosphere in a "master pack" until needed, so that the fresh meat is packaged in anaerobic packaging. Controlled partial release of the vacuum can be performed with nitrogen or other inert gas.

After opening the "Master Pack" and exposing the individual packages to the air, "Bloomink (btComiry)"
That is, reoxygenation of the respiratory pigments of the meat takes place.

Web IJ1 such that the package consists of a single transparent membrane of oxygen-permeable polymer that shrinks around the fresh meat supported on a base, more rigid, and possibly contrasting polymeric layer. Preferably, one of the layers is transparent and permeable to oxygen.

The level of oxygen permeability to the packaging material depends on the selection of the polymer and the formation of a thin film of the polycarbonate on the vacuum packaging machine itself by a hot or cold drawing process. ing. This method of cold or hot drawing not only makes the material thinner and more permeable to oxygen, but it can also be used during or after the edge heat sealing of the thermoformed web to the non-thermoformed web. Depending on the subsequent heat treatment, the entire bag or a portion thereof may be heated to a temperature of 70°C to 100°C (optimally 75°C to 80°C).
Alternatively, the vines may be immersed in water vapor at elevated temperatures in a sealed chamber, or the vines may be passed through a thermal tunnel to generate shrinkage energy to maintain a rigid pack.

When molding the receiver body, the hemispherical mold allows for bidirectional orientation of the polymeric film to create a uniform thickness, which results in uniform oxygen permeability and subsequent shrinkage. It is particularly useful to utilize molds. In practice, the hemispherical offset at the periphery of the mold must be slight to ensure that there is no localization of stress when sealing the molded membrane to the other webs.

Ionomeric polymers are suitable for use as oxygen permeable materials forming the molded bodies of the present invention. These polymers are copolymerized sodium or zinc salts of ethylene-acrylic acid or ethylene-methacrylic acid. These polymers are highly transparent, have the ability to prevent contamination, and have high oxygen permeability in thin sections. The bridge can use a single web of ionomer having a thickness of 25 to 250 microns as the web from which the body is formed, and the other web from which the body is formed has a rigidity to provide the desired rigidity. Permeable composites include cardboard/ionomer, oriented polystyrene/ionomer and polymethyl pentene/ionomer, and semipermeable composites are composite lidding materials made with an ionomer web reinforced with a membrane. There are oriented polypropylene/ionomers, and impermeable composites include non-plastic polyvinyl chloride/ionomers. If burst resistance is desired, a layer of polymethyl pentene may be added to the paperboard/ionomer composite to provide a paperboard/polymethylpentene/ionomer composite. This composite material can be coated with white pigment to provide an attractive base for display purposes. Oriented polystyrene/ionomer and polymethyl pentene/ionomer are preferred board materials when it is necessary to maintain full oxygen permeability "all over the place."

The method of the present invention loses significant advantages over the previously described methods of controlling the atmosphere. The method of the present invention is less expensive because the impermeable boundary multilayer is replaced with a simpler structure. In addition, it requires a special atmosphere, which increases costs in terms of production and control, but when displaying the pack, it creates a greenhouse effect. Incident light rays increase the temperature inside the pack as it cannot be dissipated. Vacuum packaged products are more compact for transportation and storage. The stretched/squeezed appearance is attractive and Therefore, leaking packages can be easily identified, and in any case, the chances of the package leaking are limited due to the contour retention provided by the skin pack.Since there is no abnormal atmosphere, the storage period can be extended. Even after cleaning, there is just the usual dirt.

Another potential feature of the packaging method of the invention is its application to products where rupture of the overlying web results in l:t) loss of packaging. In particular, bones within the product, such as offal or thick cuts of meat with sharp cartilage, are susceptible to ionomer membrane failure, especially in the presence of high vacuum. These membranes are capable of pulling down around a sharp point, and such pulling down can occur until the pressure exerted at that point causes physical failure at the thinnest IIψ. This failure can be prevented by combining the ionomer with a substantially non-extensible layer or layers that limit the progressive thinning of the ionomer.

Such combinations can be created by conventional methods of pressing and extruding the ionomer and the appropriate polymeric material together. It is clear that this cannot be achieved unless a layer with sufficiently high oxygen permeability is used. The most preferred material is an unstretched grade of polymethyl-pentene that can have a total thickness of up to 300 microns, preferably 100 to 200 microns, while maintaining adequate gas permeability within the composite. Another method is to use rigid, flexible or extensible plastic nets, such as [IVet
ton) J) using two or more layers of ionomer with reinforcing mesh. This multilayer structure provides excellent masking resistance and limits the gradual stretching and thinning of the ionomer to the extent that the mesh is present.

However, two layers of polymethyl pentene can be used to improve the overall heat seal provided that a suitable seal can be achieved between the two layers by high temperature heat sealing or lacquer coating.

In order to make the invention easier to understand, one example of the invention will now be described in more detail.

In this example, packages of fresh meat, such as beef steaks, roast cuts, ground meat, or offal, are to be formed on a conventional vacuum packaging-gas delivery machine. A web of ionomer having a thickness in the range of 25 microns to 250 microns to meet the desired forming thickness is fed into the machine, and the web is heated at 60°C before reaching either the vacuum forming station or the pressure forming station. or 7
The web is heated to 0 DEG C. and at that station a retractable, telescopic receptacle is formed into the body having a suitable thickness to provide the desired permeability. Meat that is packaged and made into products
Put it inside the body. The receiver then contacts the generally non-extensible composite web under tension. The two webs are either ionomer/cardboard (opaque structure) or ionomer/
A composite material, which can be constructed from polymethyl pentene (transparent), is bonded in a vacuum chamber to cover the eye area of the body. The layer of ionomer is ideally less than 20 [72
It should be 5 microns thick. In the opaque parts of the structure, the ionomer can be colored white to provide a suitable background for display. The package is then placed inside the chamber structure (J
The high vacuum is removed. After the edge of the box is sealed, a vacuum is created by supplying oxygen or a rich mixture of oxygen (e.g. 80% 02 + 20% C'(J2)f) and changing the pressure inside the package to 80% of atmospheric pressure. The package is subjected to a heating step combined with a heat seal for secondary sealing and shrinkage on the machine.

This results in a particularly effective retention of the drops and extracted juices, especially by sealing the two membrane webs together. Alternatively, shrinkage/secondary sealing can be performed with hot water at 70°C to 80°C.

The package is then made ready for sale with the substantially rigid composite coating serving as the base on which the package rests.

Instead of using a single web of ionomer as one of the materials from which the package is made, it is possible to use a composite formed of layers of polymethyl pentene and extensible grades of ionomer extruded together. Such a composite material can be used as either or both of the first and second materials or webs.

The composite material can be comprised of a web of polymethyl pentene having a thickness of 25 to 900 microns laminated to a web of ionomer having a thickness of 15 to 250 microns. This material can be hot-drawn or cold-drawn to form a body in which fresh meat is placed and covered with a lid of the same material. The gas permeability of the ionomer component of the composite material is suitable for the requirements of fresh meat packaging and is at least 5
rl, / m2 / 24 hours / atmospheric pressure difference.

When polymethyl pentene is used as the material component, polymethyl pentene is 16 times more permeable to oxygen than the ionomer, making it considerably thicker than if the material were a single film of the ionomer. Therefore, it can be made stronger and more rupture resistant1, thus making the package mechanically stronger and more resistant to bone rupture.

When such composite materials are used in packaging equipment, the minimum thickness of the ionomer layer is determined by the need to obtain a suitable thermal seal of the material at the tube edge of the body, and this minimum thickness is approximately 15 microns. . However, as the receiver forms a body, the ionomer layer becomes proportionately thinner (due to the tensile action of the body), so that a thin, highly elastic membrane of ionomer with an extremely low gas permeability rate forms the body of the receiver. However, a predetermined minimum thickness of 15 microns required for adequate thermal sealing at the periphery can be maintained. For example, if the area of the tensile region increases by a factor of 3 due to the formation of a body, the gas permeation rate of the resulting 5 micron layer of ionomer will be 250,007 nt/min.
lr? /24 hours/ Atmospheric pressure difference.

Due to the strong and resilient nature of the composite material and the fact that it can be made thicker than a single ionomer membrane, the receiver is equipped with gripper fingers or chains to hold and transport the body during unfilling and subsequent filling with fresh meat. It becomes easy to use composite materials in packaging machines.

The receiver can be made of ionomer/polymethyl pentene composite material for the body and lid material, but especially if the lid material is to be colored to provide an attractive background for display purposes, cardboard/polymethyl pentene can be used. Preferably, it is made from a single chair of a three-layer ionomer composite material or other hard composite materials mentioned above.

It is particularly useful when packaged as a composite ionomer/polymethyl pentene package and pressure reduced with nitrogen instead of oxygen.

The present invention will now be further illustrated by the following strands.

EXAMPLE A composite material consisting of a 50 micron thick extensible grade layer of polymethyl pentene laminated by co-extrusion with a 25 micron thick layer of ionomer in a conventional manner was tension processed. The receiver is fitted with a wall thickness of 25 microns at its edges where the heat sealing to the lidding material takes place. As a result, the thickness of the ionomer at the base of Uke's body is 15,000 ml/door/24 hours/
The gas permeability at atmospheric pressure is 8 microns.

After filling with fresh meat, the body is heat sealed with the hole paper/ionomer lid material in the manner described above.

Example 2 A composite material consisting of a 300 micron thick extensibility grade layer of laminated polymethyl pentene over a 25 micron thick ionomer layer with a 65 micron wall thickness at its base in tension. 1.25000rnt shield/2
A gas permeation rate of 4 hours/atmospheric pressure forms in the body. After filling the whole body with fresh meat, wrap the body in cardboard/
The receiver, along with the polymethyl pentene/ionomer composite material, thermally seals the body and creates a high degree of thermal puncture resistance in the package.

Adjacent to the cardboard base (or other composite structure resembling cardboard) are packaging accessories (e.g. expanded polystyrene plates or trays, foil plate structures or other presentation surface structures). Alternative constructions are also possible, such as to provide a rigid base for the package when the package is inverted at the point of sale. The excess membrane is drawn off midway through the vacuum/sealing station and continues to contract and shrink, allowing a wide range of sizes and shapes of cut meat to be machined within the critical dimensions of the cavity in the mold/sealing mold. It can be adapted. In the case of meat products containing cuts or bones that are susceptible to bursting, the base-forming web may be made of non-stretchable grades of ionomers and polymethyl pentene to provide the burst resistance required in these cases. Can be made from extruded composite materials.

Unlike in the case of non-shrink laminates, the shape and contour of the mold are less important; in the case of conventional non-shrink laminates, these fit together loosely without wrinkles or excess membrane material. The packaging body sound must be set as accurately as possible.

Meat at the slaughterhouse, freezer, preparation and cutting stage (especially in relation to temperature) exactly 1! ! Treated as 2, then -0.2
Holding at 5°C [31.5°F] provides a substantial shelf life that approaches that of controlled atmosphere packaged products.

The pack can also serve a dual role and purpose as a frozen meat package. In this case, the meat is generally packaged fresh and the resulting packs are frozen for storage. Importantly when used as frozen meat packaging, freezing burn does not occur due to the film packaging effect.

The packs of the present invention are also effective when the animal from which the meat is obtained is treated with a tenderizing agent, such as a Pavin type meat tenderizer, prior to slaughter. In the absence of such a tenderizing process, the meat is typically vacuum packaged and the tenderizing of the meat is carried out in the vacuum pack for three weeks or more. However, by packaging tenderized meat in the pack of the present invention, tender meat can be obtained in a shorter period of time than the three weeks required for unprocessed meat.

Participant Transparent Paper LLC Agent Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto Patent Attorney Akira Matsumoto

Claims (19)

[Claims] (1) A method for packaging fresh meat, the method comprising: forming a first web of material in a receptacle for receiving fresh meat; placing the fresh meat inside the receptacle; controlling and partially releasing the vacuum; contacting the mouth of the body with a second web of material; and forming a closed package containing the fresh meat. sealing the second web to the first web under reduced pressure, at least one of the webs being made of a material permeable to oxygen under the influence of partial pressure;
A method of packaging fresh meat, wherein at least one of said webs is transparent. (2) The packaging method according to claim 1, wherein one of the webs is transparent and permeable to oxygen. (3) One of the webs is flexible and the other web is more rigid.
) The packaging method described in section 2. (4) The packaging method according to claim (3), wherein the pigment is separate from the more rigid web. (5) One of the webs comprises an oxygen permeable ionomer polymer selected from the group consisting of sodium and zinc salts of copolymers of ethylene-acrylic acid and ethylene-methacrylic acid. The packaging method described in range 1m. (6) Claim 5 in which the web of ionomer polymer is combined with a substantially non-stretchable coating or layer.
Packaging method as described in section. (7) The ionomer polymer web is polymethyl
A packaging method as claimed in claim 6 in combination with an oxygen permeable layer of substantially non-extensible grade of benzone. 8. The packaging method of claim 5, wherein the ionomeric polymer web is combined with an oxygen permeable layer of extensible grade of polymethylpentene. (9) The thickness of the web is 25 to 250 microns, and the thickness of the polymethyl pentene layer is 25 to 900 microns.
The packaging method according to claim 5, which focuses on microns. (10) Oriented polystyrene with a more rigid web in the form of a plate;
Claim 3 is an oxygen permeable composite web comprising an ionomeric polymer in combination with an oxygen permeable material selected from the group consisting of polymethyl pentene, unplasticized polyvinyl vinyl and oriented polypropylene. Packaging method as described. (11) A method of packaging according to claim 1, wherein the controlled partial release of the vacuum is carried out with an oxygen-enriched gas, so that the package contains an oxygen-enriched gas at sub-atmospheric pressure. . (12) The packaging method according to claim (12), wherein the controlled partial release of vacuum is carried out in a mixture containing 80% oxygen and 20% carbon dioxide. (13) Anaerobic packaging in which controlled partial expulsion of vacuum is carried out with nitrogen or other inert gas, and which can be stored under vacuum conditions or under an atmosphere of inert gas if <1-7 A packaging method according to claim (1), which provides a packaging method according to claim (1). (14) Contains whole fresh meat that has been vacuum treated and packaged under reduced pressure between a layer of the first material and a layer of the second material, at least one of said layers being packaged under the influence of partial pressure; A meat package which is permeable to oxygen to the extent of light to permit oxygen to flow into the body, and wherein at least one of said layers is transparent. (15) The package according to claim (14), wherein one of the layers is transparent and permeable to oxygen. (16) One of the layers is fiJ flexible and the other layer is more rigid.
1. The package according to 1. (17) One of the layers comprises an oxygen permeable ionomer polymer selected from Group J consisting of sodium and zinc salts of copolymers of ethylene-acrylic acid and ethylene-methacrylic acid. Range number (
The package according to item 14). (18) A package according to claim (I7), wherein said layer is made of an ionomeric polymer in combination with a layer of polymethylpentene. (19) The rigid web is permeable to oxygen and is made of an oxygen permeable material selected from the group consisting of plate-like oriented polystyrene, polymethyl pentene, unplasticized polyvinyl chloride, and oriented polypropylene. A package according to claim 16, which is a composite web comprising a combination of ionomer polymers.