JPH03289475A - Package of fishery product for refrigeration and method of packaging same - Google Patents

Abstract

PURPOSE:To prevent quality deterioration due to drip by a means wherein a water-absorbing sheet for wrapping fishery products for refrigeration consists of a water-permeable sheet, a water-permeable or water-impermeable sheet and a high water-absorbing resin interposed between these two sheets and a gas-barrier bag-like wrapping material for forming the outer covering of the aforesaid water-absorbing sheet is made heat sealable. CONSTITUTION:To package fishery products for refrigeration, such fishery products are wrapped in a water-absorbing sheet consisting of a water-permeable sheet adapted to be disposed on the fishery product side, a water-permeable or water-impermeable sheet and a high water-absorbing resin interposed between these two sheets, placed into a heat sealable gas-barrier bag-like wrapping material and heat sealed under reduced pressure to vacuum pack the fishery products for the subsequent refrigeration thereof. Nonwoven fabric, paper, etc., are used as the water-permeable sheet. It is preferable to use the gas-barrier bag-like wrapping film or laminated films having an oxygen permeability of at most 200cc/m<2>.24 hours.atm.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a package for frozen seafood and a packaging method, and in particular to a package for frozen seafood for vacuum packaging that can prevent deterioration of quality due to dripping. and packaging methods.

[Problems to be solved by conventional techniques and inventions] Conventionally,
Frozen seafood products such as tuna, yellowtail, shrimp, crab, octopus, and squid are placed in plastic bags in their raw state, then vacuum-packed, and then frozen before storage, distribution, or sale. I am forced to do so.

In this packaging method, when seafood is frozen, water in the tissue turns into ice crystals, causing tissue destruction.
When frozen seafood is thawed, a large amount of drips occur. This causes the following problems.

(1) In the case of red-fleshed fish such as tuna, the color of the flesh changes due to prolonged contact with drippings.

(2) At the time of sale, drips remaining in the tissue ooze out, spoiling the appearance.

(3) The texture of the area that comes into contact with the drip becomes soggy, which impairs the texture.

(4) As the water activity of the area in contact with the drip increases, microorganisms are more likely to propagate and cause microbial contamination.

(5) Easy to cause microbial contamination in the drip.

Therefore, an object of the present invention is to provide a package for frozen seafood and a packaging method that can prevent deterioration in quality due to dripping.

[Means to solve the problem]

As a result of intensive research in view of the above objectives, the present inventors have found that if seafood for freezing is first covered with a water-absorbing sheet, then covered with a plastic bag, vacuum-packaged, and then frozen,
The inventors have discovered that deterioration due to drips after thawing can be prevented, thereby achieving the above object, and have conceived the present invention.

That is, the packaging body for frozen seafood of the present invention consists of a water-absorbent sheet that covers the frozen seafood and a gas barrier bag-like body that covers the outside of the water-absorbent sheet, and the water-absorbent sheet covers the frozen seafood. The gas barrier bag-like body is composed of a water-permeable sheet located on the seafood side, a water-permeable sheet or a water-impermeable sheet, and a superabsorbent resin sandwiched between the two sheets, and the gas barrier bag-like body has heat sealability. It is characterized in that seafood for freezing can be vacuum packaged by heat-sealing under reduced pressure after coating, and then frozen.

Furthermore, the method for packaging frozen seafood of the present invention includes a water permeable sheet located on the side of the frozen seafood, a water permeable sheet or a non-water permeable sheet, and a super absorbent resin sandwiched between the two sheets. The seafood for freezing is covered with a water-absorbing sheet consisting of the above, and then placed in a gas barrier bag-like body having heat-sealing properties, vacuum-packaged by heat-sealing under reduced pressure, and then frozen. .

The present invention will be explained in detail below.

In the present invention, the water-absorbing sheet is composed of a water-permeable sheet located on the seafood side for freezing, a water-permeable sheet or a water-impermeable sheet, and a superabsorbent resin sandwiched between the two sheets.

Examples of the superabsorbent resin include starch/acrylate graft copolymer, carboxymethylcellulose crosslinked product, vinyl alcohol/acrylate copolymer, polyacrylonitrile hydrolyzate, crosslinked polyacrylate, and modified polyvinyl alcohol. , acrylate polymer, acrylate/acrylamide copolymer, isobutylene/
Examples include maleic anhydride copolymers.

Usually, the above super absorbent resin has a water content of 500 to 1500 c in pure water.
It has a water absorption capacity of c/g.

In addition, these super absorbent resins may be used alone or in combination of two or more kinds.

The amount of such super absorbent resin is 1 ml of water absorbent sheet.
1 to 200 g per serving is preferred. The amount of super absorbent resin is Ig
With the droplets, sufficient water absorption cannot be exhibited, and even if it exceeds 200 g, it will only increase the cost and is meaningless. A particularly preferable amount of the superabsorbent resin is 10 to 100 g/m''.The shape of the superabsorbent resin is preferably a powder granule, and the particle size can be from 0.1 to several thousand meters.

In the present invention, an antibacterial agent can be added to the superabsorbent resin for the purpose of preventing the proliferation of various bacteria in drips generated when frozen seafood is thawed. As the above-mentioned antibacterial agent, zeolite (hereinafter referred to as antibacterial zeolite) which retains metal ions having an antibacterial effect through ion exchange is preferable from the viewpoint of stability and hygiene. Examples of such antibacterial zeolites include natural or synthetic zeolites made of aluminosilicate that retain metal ions with antibacterial activity in the ion-exchangeable portion, as disclosed in JP-A-58-7361. It will be done.

Examples of the metal ions having an antibacterial effect include ions of silver, copper, zinc, tin, lead, bismuth, and the like. As the metal ion, silver, copper, and zinc are particularly preferred. Note that the above metal ions may be used alone or in combination of two or more.

In addition, zeolite is generally an aluminosilicate having a three-dimensionally developed skeleton structure, and based on Aj2.03, the following general formula: % formula %) (where M is an ion-exchangeable normal value or It is a divalent metal ion, n is the valence of the metal ion, X is a coefficient indicating the proportion of metal oxide, y is a coefficient indicating the proportion of silica, and 2 is the coefficient of crystal water. It is a coefficient indicating the ratio.)

Such zeolite is preferably one whose solid particles have a specific surface area of 150 m'/g or more (based on anhydrous zeolite). In addition, its constituent components Si0□ and M
The molar ratio with 2O3 (SiO3/Aj2203) is usually 1
It is 4 or less, preferably 11 or less.

The shape of the above-mentioned zeolite is preferably in the form of powder particles, and the particle size is not particularly limited, but is usually 0.1 to several 100 particles.

By using a zeolite having such characteristics, the amount of the antibacterial metal ions retained can be arbitrarily adjusted by an ion exchange method to prepare an antibacterial zeolite having desired antibacterial properties.

The amount of the metal having bactericidal properties is 0.1% by weight to saturation amount based on the entire antibacterial zeolite. Here, the saturated amount is the saturated value of the ion exchange capacity of the zeolite used. A metal content lower than 0.1% by weight does not provide sufficient antibacterial action. The preferred metal content is 0.3 to 10% by weight.

The amount of such antibacterial zeolite added is
0.1 to 100 g per m' is preferable, especially 0°2
~10g is preferred. The amount of antibacterial zeolite added is 0.1
If it is less than 1 g/m', sufficient antibacterial properties cannot be exhibited;
There is no point in exceeding 00 g/m'.

Further, in the present invention, a deodorizing agent can be added for the purpose of reducing the fishy odor peculiar to frozen seafood.

The deodorizing agent is not particularly limited, but the following materials can be used, for example.

■Physical deodorizers such as neutral activated carbon, fibrous carbon adsorbent, zeolite, activated alumina, acid clay, etc.

■Chemical deodorant Acidic agents, alkaline agents, oxidizing agents, reducing agents, etc.

■Physical/chemical deodorizers Alkaline or acidic impregnated activated carbon, zeolite adsorbed with plant essential oils, etc.

■Other iron phthalocyanine derivatives, salts with desulfurization properties such as zinc oxide, mixtures of iron (n) compounds, L-ascorbic acid, alum, etc.

The content of the deodorizing agent is preferably 0.1 to 100 g per ml of sheet in order to have sufficient deodorizing ability.
In particular, 0.2 to 50 g is preferable. The amount of deodorizer added is 0.
If it is less than 1 g/m', sufficient deodorizing properties cannot be exhibited, and if it exceeds 100 g/m', there is no point.

Note that the above deodorizing agents may be used alone or in combination.

To add the antibacterial zeolite and/or deodorizer to the superabsorbent resin, a commonly used method may be used. For example, super absorbent resin powder and antibacterial agent and/or deodorizer powder are uniformly sprinkled on a sheet, and another sheet is placed on top of that and then heat-pressed, or super absorbent resin powder is applied. A suitable method is to add antibacterial zeolite and/or a deodorizing agent during preparation.

In addition, other additives that do not pose a hindrance to food hygiene may be appropriately added to the superabsorbent resin for the purpose of modifying the superabsorbent resin. In that case, the addition method may be the same as in the case of the antibacterial zeolite and deodorizer described above.

Further, in the present invention, the sheet used to sandwich the superabsorbent resin must have water permeability, at least on the seafood side for freezing. Examples of the water-permeable sheet include nonwoven fabric and paper. In addition, the water-permeable sheet does not need to be composed of a single sheet of paper or nonwoven fabric, and can vary depending on the shape of the packaged object.
Depending on the size, etc., paper sheets, nonwoven fabrics, or two or more sheets of paper and nonwoven fabrics may be used in combination as appropriate. In particular, a combination of two membranes is preferred, with paper on the superabsorbent resin side and nonwoven fabric on the frozen seafood side. Note that the thickness and the like may be appropriately set depending on the shape, size, etc. of the packaged object.

Further, the outer side of the water-absorbing sheet does not need to be a water-permeable sheet, and may be a water-impermeable sheet.

As the water-impermeable sheet, various synthetic resin films such as polyolefin, polyester, polyamide, etc. can be used. Note that a combination of the above-mentioned water-impermeable sheet and a water-permeable sheet made of nonwoven fabric, paper, or the like can also be used.

A water absorbent sheet made of such two sheets and a super absorbent resin can be prepared by spraying, for example, super absorbent resin powder and, if necessary, antibacterial zeolite and/or deodorant powder onto one sheet. It can be obtained by covering the upper part of the sheet with the other sheet and then heat-pressing the sheet. On this occasion,
When the sheet is made up of two or more films, each film is also heat-pressed at the same time. Incidentally, in order to improve the adhesion between the two sheets and the superabsorbent resin, it is preferable to add an appropriate binder to the superabsorbent resin powder.

Examples of the binder include thermoplastic resins such as polyolefin and polyesternope polyamide. The amount of binder added is 0.1 to 1 m' of water-absorbing seawater.
10 g/m', preferably 0.5-5 g/m'. Further, the addition method may be such that it is sprinkled on the sheet at the same time as or before or after the scattering of the super absorbent resin powder.

In the present invention, the gas barrier bag-like body is made of a gas barrier film or a bonded body of gas barrier films, and can be used in normal vacuum packaging.

The above gas barrier film includes polyolefin,
Materials such as polyester and polyamide can be used. In the case of a laminate, the combination is not particularly limited, but examples include nylon/polypropylene, nylon/low-density polyethylene, nylon/linear low-density polyethylene, nylon/ethylene-vinyl acetate copolymer (EVA)
, nylon/ethylene-vinyl alcohol copolymer (I
EVO)l)/Polypropylene, nylon/EVOH
/Low density polyethylene, nylon/EVOH/Linear low density polyethylene, nylon/EVOH/BVA
, nylon/polyvinylidene chloride (PVDC)/polypropylene, nylon/PVDC/low-density polyethylene, nylon/PVDC/linear low-density polyethylene,
Combinations such as nylon/PVDC/εVA are preferred.

Note that the above-mentioned nylon film also includes a shrinkable nylon film or a film coated with vinylidene chloride.

Such a gas barrier bag film or film bond has an oxygen permeability of 200 c c / m
'·24 hr-atm or less is preferable. If the oxygen permeability exceeds 200 cc/m'·24 hr·atm, the seafood for freezing becomes easily oxidized by oxygen entering the packaging system after packaging, which is not preferable.

In order to package frozen seafood using such a water-absorbing sheet and gas barrier bag, first, the area around the frozen seafood is covered with the above-mentioned water-absorbing sheet. At this time, the surface of the water-permeable base material is the side of the seafood for freezing. Thereafter, the coated seafood for freezing may be placed in the above-mentioned bag-like body and vacuum-packaged by heat-sealing under reduced pressure. The reduced pressure conditions during the vacuum packaging are preferably 0 to 100 mmHg.

Subsequently, freezing is performed, and conditions such as freezing temperature and time may be appropriately set depending on the type, shape, storage period, etc. of the packaged object. For example, the packaged object may be sufficiently cooled with cooling water at -2 to 5°C, and then cooled at -80 to -20°C in a refrigerator.

Note that the thawing conditions may be appropriately set depending on the type, shape, storage period, etc. of the packaged object. For example, the above-mentioned frozen product may be thawed by immersing it in cooling water at -5 to 10°C.

By packaging the frozen seafood in this way, the drip that oozes out when the frozen seafood is thawed is absorbed by the water-absorbent sheet. Therefore, not only can the appearance of frozen seafood be maintained well, but also problems such as deterioration of flavor due to dripping, increase in water activity, proliferation of various bacteria, and swelling of tissue can be solved.

[For production]

According to the packaging method of the present invention, not only the appearance of frozen seafood is maintained well, but also deterioration of flavor due to dripping, increase in water activity, proliferation of various bacteria, etc. are suppressed.

The reason for this effect is that it consists of a water-permeable sheet located on the seafood side for freezing, a water-permeable sheet or a non-water-permeable sheet, and a superabsorbent resin sandwiched between the two sheets. After directly coating seafood for freezing with a water-absorbing sheet, vacuum packaging is performed by covering it with a gas barrier bag. Because there is no going back,
This is thought to be due to the fact that even if a large amount of drips ooze out compared to frozen seafood, it does not remain in the bag.

〔Example〕

Example 1 A super water-absorbent resin (Aqua Keep 1, manufactured by Sumitomo Seika Chemical Co., Ltd.) was placed on paper with a basis weight of 25 g/m' (MSP25, manufactured by Maetel).
0SIIP) at 40 g/m' and a binder (East Flank Chemit R272S) at 2 g/m', cover this with the aforementioned paper with a basis weight of 25 g/m', and heat at 80°C. They were sandwiched and integrated using heated embossing rolls.

This sheet was cut to 590 mm x 390 mm, and a nonwoven fabric (manufactured by Kuraray ■ NA240JP209
6) Place it on top and fold the lower nonwoven fabric into the side of the base paper. Furthermore, a nonwoven fabric was fed from the top, and the side portions were heat-sealed at 120°C using a gear roll. The end portions were heat-sealed at 130°C using a seal bar, and the whole was then passed through a heated embossing roll to be sandwiched and integrated at 80°C. After integration, 600 mm x 4 at the end
A water-absorbing sheet was prepared by cutting the sheet to a length of 0.00 mm and sandwiching the superabsorbent resin layer between two upper layers and two lower layers of laminated materials.

After covering a 3 kg block of tuna with the water-absorbent sheet obtained in this way, a nonouchi made of shrinkable nylon/linear low-density polyethylene (width 250 m
After vacuum packaging at a reduced pressure of 53 mmHg, warm air at 60° C. was blown to completely adhere the film to the tuna meat. Next (1), after showering with 3℃ cold water to lower the surface temperature of the tuna meat,
The packaged tuna meat was stored in a refrigerator at -40°C for 48 hours.

This frozen tuna meat packaging pouch was immersed in cold water at 3° C. for 48 hours, thawed, the tuna meat was removed, and the amount of drip remaining in the pouch was measured.

Further, the frozen tuna meat packaging pouch was immersed in cold water at 3°C for 48 hours, thawed, and then aged at 10°C for 24 hours. The number of viable bacteria was measured at the contact area (contact area with the water-absorbent sheet) between the aged tuna meat and the house.

The results of these measurements are shown in Table 1.

Example 2 Paper of 125 g/m' (MSP25 manufactured by Maetel)
), super absorbent resin (manufactured by Sumitomo Seika ■, Aqua Keep 10SHP) at 40 g/m', antibacterial zeolite (Kanebo Flank Bacter Killer BM5 (11A) 2 g/m', binder (manufactured by Toshi ■, Chem.) ) R272S) Ig,/m
Spread it evenly with the amount of
g/m' paper and sandwiched with a heated embossing roll at 80°C. .

This sheet was cut to 590 mm x 390 mm, and a nonwoven fabric (manufactured by Kuraray ■ NA240JP209
6) Place it on top and fold the lower nonwoven fabric into the side of the base paper. Further, a nonwoven fabric was fed from the top, and the side portions were heat-sealed at 120° C. using a gear roll. Further, the end portions were heat-sealed at 130°C using a seal bar, and the whole was passed through a heated embossing roll to be sandwiched and integrated at 80°C. After integration, 600 mm x 40 at the end
A water absorbent sheet was prepared by cutting the sheet to 0 mm and sandwiching the above super absorbent resin layer between two upper layers and two lower layers of laminated material.

After covering a 3 kg block of tuna with the water-absorbent sheet obtained in this way, it was placed in a shrinkable nylon/linear low-density polyethylene pouch (width 250 mm).
, length 300 mm), vacuum-packaged at a vacuum degree of 50 mm) Ig, and then 60°C warm air was blown to completely adhere the film to the tuna meat. After showering with 3°C cold water to lower the surface temperature of the tuna meat, the packaged tuna meat was placed in a refrigerator and stored at 40°C for 48 hours.

The drip amount of this frozen tuna meat packaging pouch after thawing and the number of viable bacteria after aging at 10° C. for 24 hours after thawing were measured in the same manner as in Example 1.

The results are also shown in Table 1.

Comparative Example 1 In Example 1, tuna meat was placed directly into a shrinkable nylon/linear low-density polyethylene pouch (width 250 mm, length 300 mm) without using a water absorbent sheet, and
After vacuum packaging at a reduced pressure of mmHg, warm air at 60°C was blown to completely adhere the film to the tuna meat. Next, after showering with 3℃ cold water to lower the surface temperature of the tuna meat, place the packaged tuna meat in the refrigerator and heat it at -40℃.
It was stored for 48 hours.

Drip amount and 1 of this tuna meat packaging pouch after thawing
The number of viable bacteria after aging at 0°C for 24 hours was measured in the same manner as in Example 1.

The results are also shown in Table 1.

As is clear from Table 1, both of the frozen tuna meat packaging pouches produced by the packaging method of the present invention had a drip amount of Occ after thawing. On the other hand, the frozen tuna meat packaging pouch of Comparative Example 1 had a dripping amount of 31% after being left at 10°C for 6 hours.
It was a large amount of 0cc.

Regarding the number of viable bacteria, the number of viable bacteria in the frozen tuna meat packaging pouches of Examples 1 and 2 was one-tenth or less of that of Comparative Example 1. In particular, it can be seen that the product in which antibacterial zeolite is added together with the superabsorbent resin has an extremely excellent bacterial growth inhibiting effect, which is about 1/100 of that of Comparative Example 1.

〔Effect of the invention〕

As detailed above, according to the method for packaging frozen seafood of the present invention, a water-permeable sheet located on the side of the frozen seafood, a water-permeable sheet or a non-water-permeable sheet, and the sandwiched between the two sheets. Seafood for freezing is covered with a water-absorbent sheet made of super absorbent resin, and then placed in a gas-barrier bag-like body having heat-sealing properties, and vacuum-packaged by heat-sealing under reduced pressure. Since it is then frozen,
Drips are completely absorbed, and not only can the appearance of frozen seafood after thawing be maintained well, but also deterioration of flavor, increase in water activity, and proliferation of various bacteria due to drips can be suppressed.

8 applicants Dai Nippon Printing Co., Ltd.

Claims (15)

[Claims] (1) A packaging body for frozen seafood that is composed of a water-absorbent sheet that covers the frozen seafood and a gas barrier bag-like body that covers the outside thereof, wherein the water-absorbent sheet is placed on the frozen seafood side. It consists of a water-permeable sheet, a water-permeable sheet or a non-water-permeable sheet, and a superabsorbent resin sandwiched between the two sheets, and the gas barrier bag-like body has heat-sealability and is coated with a water-permeable sheet. 1. A package for frozen fish and shellfish, characterized in that the fish and shellfish for freezing can be vacuum packaged by heat-sealing under reduced pressure, and then frozen. (2) The package for frozen seafood according to claim 1, wherein the water-permeable sheet is made of paper and/or nonwoven fabric. (3) In the frozen seafood package according to claim 1 or 2, the gas barrier bag-like body has a gas barrier capacity of 200 cc/m^.
A package for frozen seafood, characterized by having an oxygen permeability of 2.24 hr.atm or less. (4) A water-absorbent sheet consisting of a water-permeable sheet located on the seafood side for freezing, a water-permeable sheet or a non-water-permeable sheet, and a superabsorbent resin sandwiched between the two sheets,
A method for packaging seafood for freezing, which comprises coating seafood for freezing, then placing it in a gas barrier bag-like body having heat-sealing properties, vacuum packaging by heat-sealing under reduced pressure, and then freezing. (5) The method according to claim 4, wherein the gas barrier bag-like body has an oxygen permeability of 200 cc/m^2.24 hr.atm or less. (6) In the method according to claim 4 or 5, the water-permeable sheet is composed of two or more membranes of paper and/or nonwoven fabric, and the two or more membranes are bonded together by heat-pressing. A distinctive method of packaging seafood for freezing. (7) A method for packaging seafood for freezing according to claim 6, wherein the water-permeable sheet is a laminate of paper located on the superabsorbent resin side and a nonwoven fabric. (8) A method for packaging seafood for freezing according to any one of claims 4 to 7, characterized in that an antibacterial agent and/or a deodorizing agent are added to the superabsorbent resin. (9) In the method according to claim 8, the antibacterial agent retains metal ions having an antibacterial effect through ion exchange, has a specific surface area of 150 m^2/g or more, and has a specific surface area of 150 m^2/g or more.
and Al_2O_3 (SiO_2/Al_2O
A method for packaging seafood for freezing, characterized in that _3) is zeolite solid particles of 14 or less. (10) In the method according to claim 9, the zeolite solid particles are A-type zeolite, X-type zeolite, Y-type zeolite,
A packaging method for seafood for freezing, characterized in that the packaging method comprises one or more types selected from type zeolite and mordenite. (11) The method according to claim 9 or 10, wherein the metal ion having an antibacterial effect is one or more metal ions selected from silver, copper, and zinc. types of packaging methods. (12) The method according to claim 8, wherein the amount of the antibacterial agent and/or deodorizing agent added is 0.1 to 100 g per 1 m^2 of the water absorbent sheet. Packaging method. (13) The method according to any one of claims 4 to 12, wherein the superabsorbent resin is a starch/acrylate graft copolymer, a carboxymethyl cellulose crosslinked product, a vinyl alcohol/acrylate copolymer, One or more selected from polyacrylonitrile hydrolyzate, crosslinked polyacrylate, modified polyvinyl alcohol, acrylate polymer, acrylate/acrylamide copolymer, isobutylene/maleic anhydride copolymer. A method for packaging seafood for freezing, characterized by: (14) A method for packaging seafood for freezing according to any one of claims 4 to 13, characterized in that the amount of the super absorbent resin is 10 to 200 g per 1 m^2 of the water absorbent sheet. (15) The method for packaging seafood for freezing according to any one of claims 4 to 13, wherein the freezing temperature is -80 to -5°C.