JP2003265100A - Method for preserving flesh - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for preserving flesh of a fruit by which the flavor and the color of the flesh are prevented from being reduced, and the lightening of a container, and the reduction of a waste and a noncombustible are achieved by the substitution of a metal can. <P>SOLUTION: The flesh is sealed in an oxygen-absorbing container obtained by using, at least at a part, an oxygen-absorbing multilayer film comprising a sealant layer composed of a thermoplastic resin, an oxygen-absorbing layer composed of a thermoplastic resin composition obtained by compounding a deoxidizer, and a barrier layer composed of a gas-barrier material, arranged in order from the inside. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preserving pulp for a long period of time by preventing flavor deterioration and color change of sealed pulp. 2. Description of the Related Art There is a technique in which pulp such as tangerines, chestnuts, cherries, peaches, apples, pineapples and the like is filled in a metal can such as a can and stored, but the metal can is incombustible waste. Due to the problem of material processing and the demand for lighter packaging containers, transfer to plastic containers such as barrier bags and barrier trays has been performed. Further, the metal can also has a problem that the metal component dissolves into the contents. [0003] However, when the pulp is stored in a barrier container such as an ordinary barrier bag, no matter how much the gas replacement operation is performed, the pulp is dissolved in the syrup filled with the trace amount of oxygen remaining in the packaging container or the pulp. It is inevitable that the flavor of the pulp will be reduced or browned due to the trace amount of oxygen. On the other hand, as a method for improving the preservability of food and preventing a change in flavor, there is a packaging technique using an oxygen scavenger, which is used in various foods. The oxygen scavenger packaging technology is a technology for preventing food quality deterioration due to the presence of oxygen by keeping the inside of a packaging container enclosing food to be preserved in an anaerobic state using an oxygen scavenger. In recent years, as one of the deoxygenation packaging technologies, containers are composed of a multilayer material having an oxygen absorbing layer made of an oxygen absorbing resin composition in which an oxygen absorbent is blended with a thermoplastic resin, and the gas barrier properties of the container have been improved. At the same time, a packaging container having an oxygen absorbing function added to the container itself is being developed. Of these, the oxygen-absorbing multilayer having a small total thickness, the so-called oxygen-absorbing multilayer film, is a multilayer obtained by laminating a heat-sealing layer, an oxygen-absorbing layer which is a thermoplastic resin layer in which an oxygen absorbent is dispersed, and a gas barrier layer. It is a film, which is used as a function of preventing oxygen permeation from the outside of the container and adding a function of absorbing oxygen in the container, using a conventionally known manufacturing method such as extrusion lamination, co-extrusion lamination, and dry lamination. Being manufactured. SUMMARY OF THE INVENTION The object of the present invention is to provide a method for preserving pulp for a long period of time by replacing metal cans without impairing the flavor, texture and color of the pulp. And Means for Solving the Problems The inventors of the present invention have conducted intensive studies on a method for improving the preservability by maintaining the flavor, texture and color tone of the pulp, and as a result, the present invention has been completed. . That is, the present invention relates to an oxygen-absorbing multilayer comprising a pulp, a sealant layer made of a thermoplastic resin from the inside, an oxygen-absorbing layer made of a thermoplastic resin composition containing an oxygen scavenger, and a barrier layer made of a gas-barrier substance. A method for preserving pulp, characterized in that the pulp is sealed in an oxygen-absorbing container at least partially using a film. The pulp in the present invention is not limited, and includes cherry, mandarin orange, grapefruit, apple, strawberry, pineapple, peach, grape, none, cucumber, watermelon, banana and the like. A mixture of pulp and syrup or other ingredients is acceptable. In the present invention, the pulp is treated with a sealant layer made of a thermoplastic resin from the inside, an oxygen absorbing layer made of a thermoplastic resin composition containing an oxygen scavenger, and an oxygen layer made of a barrier layer made of a gas barrier substance. The absorbent multilayer film is sealed in an oxygen-absorbing container at least partially used. The sealant layer constituting the oxygen-absorbing multilayer film of the present invention is a portion that becomes a sealant when the oxygen-absorbing multilayer film of the present invention is used for a part or all of a packaging container. It has a role as an isolating layer for isolating the oxygen absorbing layer and a role as an oxygen permeable layer for efficiently transmitting oxygen because oxygen in the packaging container is quickly absorbed by the oxygen absorbing agent in the oxygen absorbing layer. [0010] The sealant layer constituting the oxygen-absorbing multilayer film of the present invention can play the role described above.
Any thermoplastic resin having oxygen permeability can be used without limitation. For example, low-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene, various polyethylenes such as polyethylene with a metallocene catalyst, ethylene-vinyl acetate copolymer, ionomer, ethylene-methyl acrylate copolymer, ethylene-
Ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, propylene homopolymer,
Propylene-ethylene block copolymer, propylene-
Examples include ethylene random copolymers, various polypropylenes such as metallocene-catalyzed polypropylenes, polymethylpentene, and thermoplastic elastomers, and these can be used alone or in combination. Among these, polypropylenes such as propylene homopolymer, propylene-ethylene block copolymer and propylene-ethylene random copolymer, low density polyethylene, linear low density polyethylene,
Various polyethylenes such as ultra low density polyethylene and metallocene catalyzed polyethylene are preferred. The sealant layer contains coloring pigments such as titanium oxide, additives such as antioxidants, slip agents, antistatic agents and stabilizers, fillers such as calcium carbonate, clay, mica and silica, and deodorants. It may be added. The thickness of the heat sealing layer constituting the oxygen-absorbing multilayer film of the present invention is preferably from 10 to 100 μm, more preferably from 20 to 60 μm.
If the thickness of the heat seal layer is less than 10 μm, the oxygen absorbent of the oxygen absorption layer is exposed on the surface and the heat seal strength is undesirably reduced. On the other hand, if the thickness of the heat seal layer is more than 100 μm, it is not preferable because lamination becomes difficult, the oxygen permeability decreases, the oxygen absorption performance of the film decreases, and there is a problem in cost. The oxygen-absorbing layer constituting the oxygen-absorbing multilayer film of the present invention is obtained by dispersing an oxygen scavenger in a thermoplastic resin. The oxygen-absorbing layer has a role of absorbing oxygen dissolved in the container or the stored article, and a role of absorbing a small amount of oxygen entering from the outside of the barrier layer and preventing oxygen from permeating into the container. As the thermoplastic resin constituting the oxygen absorbing layer of the present invention, the same resins as those mentioned above as the resin used for the heat sealing layer are used, but in consideration of the compatibility with the heat sealing layer. It is appropriately selected. As the oxygen-absorbing agent dispersed in the oxygen-absorbing layer constituting the oxygen-absorbing multilayer film of the present invention, an iron-based oxygen absorber composition comprising iron powder and a metal halide is preferably used. Iron powder, which is a main component of the iron-based oxygen absorbent composition, can be used without any particular limitation on purity and the like as long as it can cause an oxygen absorption reaction.For example, a part of the surface is already oxidized. And may contain another metal. The iron powder is preferably granular, for example, reduced iron powder, sprayed iron powder, iron powder such as electrolytic iron powder,
Pulverized or ground products of various irons such as cast iron and steel are used. The average particle size is from 1 to 10 in consideration of handleability, reducing the thickness of the oxygen absorbing layer, and minimizing the unevenness of the oxygen absorbent appearing on the film appearance.
0 μm, preferably 1 to 80 μm
It is preferable to set it in the range. As the metal halide which is an auxiliary agent of the iron-based oxygen absorbent, for example, chloride, bromide or iodide of an alkali metal or alkaline earth metal is used, and lithium, sodium, potassium, magnesium, calcium or Barium chloride or iodide is preferably used. The compounding amount of the metal halide is preferably from 0.1 to 20 parts by weight, particularly preferably from 0.1 to 5 parts by weight, per 100 parts by weight of the iron powder. The metal halide is preferably mixed and added in advance so that the metal halide adheres to the iron powder and is not easily separated. For example, a method of mixing a metal halide and iron powder using a ball mill, a speed mill, or the like, a method of embedding a metal halide in unevenness on the surface of the iron powder, a method of attaching the metal halide to the surface of the iron powder using a binder Alternatively, a method in which an aqueous metal halide solution and iron powder are mixed and then dried to adhere the metal halide to the surface of the iron powder can be employed. A preferred oxygen absorbent is an iron powder-based composition containing iron powder and a metal halide, and particularly preferably a metal halide-coated iron powder composition in which a metal halide is attached to iron powder. The compounding amount of the oxygen absorbent in the oxygen absorbing layer constituting the oxygen absorbing multilayer film of the present invention is 10 to 7
It is preferably in the range of 0% by weight, more preferably in the range of 10 to 60% by weight. When the amount of the oxygen absorbent is less than 10% by weight, the oxygen absorbing ability is insufficient, which is not preferable. When the amount is more than 70% by weight, it is difficult to form the oxygen absorbing layer. The thickness of the oxygen-absorbing layer constituting the oxygen-absorbing multilayer film of the present invention is 10 to 10 regardless of the constituent materials.
It is preferably in the range of 0 μm, particularly preferably 2 μm.
The range is from 0 to 80 μm. Oxygen absorption layer thickness is 10μ
If the thickness is smaller than m, film formation becomes difficult, or the amount of oxygen absorbent per unit area of the film becomes small, so that sufficient oxygen absorption performance cannot be obtained. If the thickness is more than 100 μm,
The total thickness of the film is increased, which may cause inconvenience in handling, or cause a problem in cost. In the oxygen absorbing layer of the present invention, if necessary, coloring pigments such as titanium oxide, various additives such as antioxidants, slip agents, antistatic agents, stabilizers, clay, mica, silica Fillers such as calcium carbonate, calcium sulfate, barium sulfate, deodorants, adsorbents such as activated carbon and zeolite, and defoamers such as calcium oxide and magnesium oxide may be added. In the present invention, the gas barrier layer is a layer that blocks oxygen entering from the outside of the container when the container is made into a packaging container. For example, a metal foil such as an aluminum foil, polyvinylidene chloride, ethylene-vinyl acetate copolymer, etc. Combined saponified materials, gas barrier resins such as nylon 6, nylon 6,6, nylon MXD6, and polyethylene terephthalate, and vapor-deposited films such as aluminum-deposited films and silica-deposited films can be used alone or in combination. The oxygen-absorbing multilayer film constituting the oxygen-absorbing container of the present invention comprises a sealant layer made of a thermoplastic resin from the inside, an oxygen-absorbing layer in which a deoxidizer is mixed with the thermoplastic resin, and a gas barrier substance. It consists of at least three barrier layers, but other layers can be added. For example, it is preferable to provide a protective layer made of a thermoplastic resin outside the barrier layer in order to prevent damage to the gas barrier layer and pinholes. Examples of the resin used for the protective layer include polyethylenes such as high-density polyethylene, polypropylenes such as propylene homopolymer, propylene-ethylene random copolymer, and propylene-ethylene block copolymer, nylon 6, nylon 6,6.
And the like, further, polyesters such as polyethylene terephthalate and combinations thereof. The pulp comprises at least part of an oxygen-absorbing multilayer film comprising a sealant layer made of a thermoplastic resin from the inside, an oxygen-absorbing layer in which an oxygen absorbent is dispersed in the thermoplastic resin, and a barrier layer made of a gas-barrier substance. Seal and store in the resulting oxygen-absorbing container. The oxygen-absorbing container may be a container composed entirely of the oxygen-absorbing multilayer film, but may be a container composed of the oxygen-absorbing multilayer film on one side and a general gas barrier film on one side. An oxygen-absorbing container in which the oxygen-absorbing multilayer film is used in a part may be used. In particular, using the oxygen-absorbing multilayer film on one side and a transparent gas barrier film on the other side,
An oxygen-absorbing container capable of visually confirming the contents of the container can be provided. In this case, the transparent gas barrier film preferably has an oxygen permeability at 23 ° C. and 60% RH of 20 cc / m ² · atm · day or less, more preferably 10 cc / m ² · atm · day or less, and still more preferably A gas barrier material having a transparency of 5 cc / m ² · atm · day or less can be used. Specifically, vapor-deposited films such as silica-deposited films and alumina-deposited films, MX nylon films, stretched nylon films, stretched EVOH films, acrylic acid-based gas barrier polymers (poly (meth) acrylic acid and polyhydric alcohol compounds such as PVA) And a film coated with a poly (meth) acrylic acid-based polymer because of high oxygen permeability. There is no limitation on the shape of the oxygen-absorbing container, and examples include a tray shape, a cup shape, a bag shape, and a freestanding bag shape. There is no limitation on the shape of the oxygen-absorbing multilayer film, and examples include a tray shape, a cup shape, a lid shape, a plug shape, and a liner shape. The filling of the pulp into the oxygen-absorbing container can be carried out by a known method for producing cans or bags. After filling the pulp into the container, boil sterilization, retort sterilization, microwave heating sterilization, ultraviolet sterilization or radiation sterilization can also be performed. The pulp preserved in the present invention is not stored at low temperature such as freezing or refrigeration. It can be distributed at room temperature in the same manner as metal cans such as cans. EXAMPLES The present invention will be described in more detail with reference to examples. Note that the present invention is not necessarily limited to the embodiments. Example 1 Iron powder 10 having an average particle size of 30 μm
00 kg into a vacuum dryer with a heating jacket,
While mixing at 140 ° C. under a reduced pressure of 10 mmHg, 50 kg of a 50% by weight aqueous solution of calcium chloride was sprayed, dried and then sieved to remove coarse particles to obtain an iron-based oxygen absorbent having an average particle size of 30 μm. Next, using a vented twin-screw extruder, an ethylene-propylene random copolymer (nitrogen
While extruding (trade name: F8090, manufactured by Co., Ltd.), an iron-based oxygen absorbent and calcium oxide were supplied by side feed, and an ethylene-propylene copolymer: iron-based oxygen absorbent:
Calcium oxide = 58: 40: 2 weight ratio,
After kneading and extruding from a strand die, the mixture was cooled and pelletized with a pelletizer to obtain an oxygen-absorbing resin composition A. Then, using a tandem extrusion laminator device comprising two single-screw extruders, a T-die, a cooling roll, a slitter and a winder, an unstretched polypropylene film 60 μm fed out (trade name, manufactured by Toray Gosei Co., Ltd.) ZK
93FM) as an oxygen-absorbing layer.
Was extruded and laminated at a thickness of 30 μm to obtain a laminate film in which the oxygen absorbing layer surface was subjected to corona discharge treatment. An aluminum foil having a thickness of 7 μm, a nylon film having a thickness of 15 μm, and a PET film having a thickness of 12 μm were sequentially dry-laminated on the surface of the oxygen absorbing layer to obtain an oxygen absorbing film. The composition of the obtained oxygen-absorbing multilayer film is as follows.
0 μm / oxygen absorption layer 30 μm / aluminum foil 7 μm / nylon 15 μm / PET 12 μm. The surfaces of the sealant layers of the oxygen-absorbing multilayer film were heat-sealed with each other to produce a three-side sealed 150 mm × 200 mm oxygen-absorbing bag. In the created bag,
A mixture of 100 g of oranges and 100 g of syrup was sealed, heated at 95 ° C. for 40 minutes, and then stored at 25 ° C. On the 30th day of storage, the color tone and flavor of the oranges were evaluated.
As a result, the color tone and flavor of the oranges were favorably maintained. Comparative Example 1 The procedure was the same as in Example 1 except that the film bag without the oxygen absorbing layer of Example 1 was used. As a result, the oranges were browned and the flavor was reduced. Example 2 A barrier layer of the oxygen-absorbing film prepared in Example 1 was coated with an alumina-deposited polyethylene terephthalate film 12 μm (trade name, manufactured by Toppan Printing Co., Ltd.).
GL), non-stretched polypropylene 60 μm / oxygen absorbing layer 30 μm / nylon 15 printing / alumina-deposited polyethylene terephthalate film 12 on one side and alumina-deposited polyethylene terephthalate film 12 μm on the other side (manufactured by Toppan Printing Co., Ltd. Example 1 except that a bag made using a transparent barrier film composed of GL) / nylon 15 μm / unstretched polypropylene 70 μm was filled with 100 g of apricot tofu and 100 g of syrup juice containing peach, cherry and pine pulp. Heated and stored in the same manner. On the 30th day of storage, the color tone and flavor of each pulp were evaluated. As a result, the color tone and flavor of peach, cherry, and pine were well maintained. Example 3 A self-supporting bag (size: 130 mm wide × 1 vertical) composed of two side films and one bottom film
85mm x bottom width 35mm)
PET 13 μm coated with acrylic acid gas barrier polymer on one sheet and bottom film (Kureha Chemical Co., Ltd.
Oxygen prepared in Example 1 on another side film using a transparent gas-barrier laminated film consisting of trade name Besela) / nylon 15 μm / linear low-density polyethylene 60 μm (manufactured by Tocelo Co., Ltd., HC). Polypropylene of the oxygen-absorbing resin composition of the absorbent multilayer film was replaced with linear low-density polyethylene (trade name: Kernel 580, manufactured by Nippon Polychem Co., Ltd.)
S), 60 μm of unstretched polypropylene was converted to a linear low-density polyethylene film (manufactured by Tocelo Co., Ltd .; HC) 50 μm.
A self-supporting bag was prepared by heat sealing using the film having a thickness of m. The bag was filled with 100 g of peach and 50 g of syrup, and sealed with 4 cc of air by heat sealing.
Boil treatment at 90 ° C for 40 minutes, 15-30 ° C
In the room. On the 30th and 60th days of storage, the bag was observed from the outside of the side surface of the gas barrier laminate film, and it was confirmed that the color tone of peach was well maintained.
It was opened on the 90th day of storage, and it was confirmed that the color tone and flavor of the peach were good. According to the method of the present invention, pulp, which may contain syrup and the like, is filled into a bag made of an oxygen-absorbing film, thereby preventing the flavor and color tone of the pulp from lowering. In addition, instead of using metal cans, it is possible to reduce the weight of containers and reduce waste and incombustibles. The method of the present invention does not require special equipment and equipment, and can extend the shelf life of the filled pulp at low cost and safely and easily.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Yoshiki Ito             5-6-2 Higashi-Hachiman, Hiratsuka-shi, Kanagawa 3             Ryogas Chemical Co., Ltd. Hiratsuka Laboratory (72) Inventor Tomotaka Wada             5-6-2 Higashi-Hachiman, Hiratsuka-shi, Kanagawa 3             Ryogas Chemical Co., Ltd. Hiratsuka Laboratory (72) Inventor Satoshi Okada             5-6-2 Higashi-Hachiman, Hiratsuka-shi, Kanagawa 3             Ryogas Chemical Co., Ltd. Hiratsuka Laboratory F term (reference) 4B069 AB04 HA11 KA02 KB07 KC12                       KD06 KD07 KD08

Claims (1)

Claims: 1. A sealant layer made of a thermoplastic resin from the inside of a pulp, an oxygen absorbing layer made of a thermoplastic resin composition containing an oxygen scavenger, and a barrier layer made of a gas barrier substance. A method for preserving pulp, characterized in that the pulp is sealed in an oxygen-absorbing container at least partially using an oxygen-absorbing multilayer film comprising