JP4744162B2 - A method for preventing blackening of crustaceans and a crustacean package in which blackening is prevented. - Google Patents

Description

The present invention relates to a crustacean blackening prevention method and a crustacean package in which blackening is prevented. More specifically, a method for preventing blackening of crustaceans by keeping the crustaceans sealed in an atmosphere containing carbon dioxide and, if necessary, oxygen, or the crustaceans are sealed in such an atmosphere to prevent blackening. Related to the shellfish shell.
Further, the present invention provides a shelled shell that prevents blackening by removing the blackened shellfish from the package and repackaged in a normal plastic container, or stores and distributes it. The present invention relates to a method for preserving and distributing crustaceans that prevent blackening.

  Crustaceans such as shrimps and crabs have the problem that their bodies or joints turn black after a while. This is because one of the amino acids contained in shrimps and crabs, tyrosine, melanin, a brown substance, is produced by enzymatic reaction in the presence of oxygen. Shrimp and crabs that have turned black have a poor appearance, and therefore the product value is almost lost.Therefore, it is very important to prevent the shrimp and crabs from blackening and maintain their quality. is important. In order to prevent the blackening of crustaceans, it is important to prevent the influence of oxygen as much as possible, so far, various techniques have been studied to prevent this blackening. For example, a method for preventing crustacean blackening due to oxygen by using an antioxidant such as sodium sulfite, sodium bisulfite (Non-patent Document 1) or ascorbic acid has been used. However, in order to use such an antioxidant, it is necessary to comply with the usage standard (0.10 g / kg), so that there is a problem that it does not necessarily reach an effective amount that can prevent blackening. In addition, when sodium sulfite or sodium hydrogen sulfite is used, there is a problem that formaldehyde which is a toxic substance is generated, and the crustacean meat has an off-flavor and a bad odor, resulting in a bad flavor.

  Furthermore, ferulic acid (3-methoxy-4-hydroxycinnamic acid) (patent document 1), enokitake extract (patent document 2), seaweed extract such as chlorella, antioxidant and chelating agent (patent document 3), Sugar millet extract, sugar millet-derived sucrose, or cellobiose (Patent Document 4), white water soluble extract (Patent Document 5), solution containing a proteolytic extract enzymatically degraded with an enzyme proteolytic enzyme (Patent Document 6) In addition, edible proteolytic enzyme inhibitors (plasma proteins such as cows and pigs) (Patent Document 7) are added to shellfish, or shellfish such as shrimp and crab are immersed in these solutions. It is known to prevent blackening that occurs during storage. However, in addition to the above-mentioned problems, since these are used after processing natural products, there are problems such as that the effect is not constant or the effect is not sufficiently produced.

In addition, the use of oxygen scavengers as one of the methods for preventing blackening of crustaceans has been carried out, but the use of oxygen scavengers requires a certain period of time before the effect of oxygen scavenging in the container or package is obtained. The problem is that blackening occurs due to oxygen that is required and not removed during that time.
In addition, crusts such as crabs, shrimps, shellfish, etc. are filled in cans without using liquid juice in a living state, and nitrogen can be injected to seal the cans. Crustacean canned food manufacturing method (Patent Document 8), shellfish is covered with a packaging film before it is alive or the fiber texture of the fleshy part is hardened, and frozen shellfish packaged food is manufactured In this case, the packaged frozen food for crustaceans consists of keeping the inside of the packaging film in a degassed state of oxygen or air and rapidly freezing the shellfish alive or before the flesh structure of the fleshy part is stiffened. A manufacturing method (Patent Document 9) is known.
However, these have to be packaged by evacuating or removing oxygen under strict conditions while raw crustaceans are alive or immediately before death, and the process also requires complicated steps.

The frozen shrimp that has been quickly frozen is individually stored in a gas-tight sachet filled with nitrogen gas, and a plurality of these sachets are stored in a gas-tight bag together with gas. A method is known in which shrimp legs are lost due to impact and quality deterioration due to shrimp oxidation is prevented (Patent Document 10).
In addition, foods such as hair follicles are shaped and primary packaged in an extensible high molecular weight polyethylene film having shrink properties, heated to a predetermined temperature to shrink the high molecular weight polyethylene film, and then immersed in liquid nitrogen. When the shellfish are stored and packaged in a container filled with a buffer material (Patent Document 11), a porous material is mixed with the buffer material to produce a fresh shellfish waste product, etc. A method for removing harmful gases such as ammonia (Patent Document 12) is known.
However, rather than preventing the blackening that occurs during storage of crustaceans, they are preserved and distributed by retaining their shape during storage and distribution of crustaceans or by removing harmful gases such as ammonia. It was to keep the freshness inside.
Furthermore, as a method of preventing blackening of crustaceans due to oxygen, the thawed shrimp is stored in a packaging bag made of a sheet that completely blocks air permeability, and nitrogen gas or argon gas is injected into the packaging bag for packaging. A method of sealing by replacing with air in a bag is disclosed (Patent Document 13). However, in this method, if the replacement effect of nitrogen gas or argon gas in the packaging bag is insufficient, oxygen remains in the packaging bag, and as a result, blackening of shrimp occurs.

JP 2000-325015 A JP 2003-70450 A JP 2000-139434 JP-A-6-311842 Japanese Unexamined Patent Publication No. 2000-23615 JP-A-77-147890 Japanese Patent Laid-Open No. 6-25690 JP-A-8-275725 JP-A-5-84038 JP 2001-314151 A Japanese Patent Laid-Open No. 2-20242 Japanese Patent Laid-Open No. 3-155732 Japanese Patent Laid-Open No. 2003-72858 September 25, 1985 “Food Industry”, page 796

The present invention has been made for the purpose of solving these problems. In particular, regardless of the state of crustacean raw materials, and without the use of blackening inhibitors, the purpose is to obtain crustaceans that prevent blackening and maintain quality without strict deoxidation. It is a thing. More specifically, the present invention preserves crustaceans such as shrimp and crabs in a space where carbon dioxide exists, so that oxygen is not strictly removed, and even if there is some oxygen, crustacean blackening due to oxygen occurs. The object of the present invention is to provide a crustacean blackening prevention method and a crustacean packaging body in which blackening is prevented, which can effectively control the quality and maintain the quality.
Furthermore, the present invention has found that even when the crustacean package is opened and repackaged in a normal plastic package, blackening does not proceed and can be prevented. Accordingly, an object of the present invention is to provide a method for preserving and distributing crustaceans using the packaging body and the repackaging body.

As a result of diligent efforts to solve the above-mentioned problems, the present inventors have carried out crustacean fresh products (including the living state), refrigerated products or frozen products in a sealed atmosphere under an atmosphere containing carbon dioxide. It has been found that blackening that occurs specifically during storage of crustaceans can be prevented.
And, if this carbon dioxide gas concentration is 23% or more, especially this gas concentration is the carbon dioxide gas concentration at the end of hermetically sealed storage (immediately before opening the sealed space), the crustaceans are gas of this carbon dioxide for most of the preservation period. It was found that this blackening prevention can be effectively achieved in practice. Furthermore, in this case, not only can the blackening be prevented even if oxygen gas is present in an amount of 35% or less, but also the effect of suppressing the growth of obligate anaerobic bacteria such as Clostridium botulinum due to the presence of a small amount of oxygen gas. Can also be expected.
That is, the present invention relates to a crustacean blackening prevention method and a crustacean package in which blackening is prevented as follows. The present invention also relates to a method for preserving and distributing crustaceans as follows.
(1) Prevention of blackening of crustaceans, characterized by storing crustaceans in a closed space with an atmosphere of carbon dioxide concentration of 23% or more and oxygen concentration of 35% or less immediately before opening the sealed space Method.
(2) The method for preventing blackening of crustaceans according to (1) above, wherein the atmosphere having a carbon dioxide concentration of 23% or more immediately before opening the sealed space is made of dry ice.
(3) The crustacean according to (1) or (2) above, wherein the crustacean is a fresh product of one of shrimp, crab, hermit crab or giant clam Blackening prevention method.
(4) The blackening of the crustacean according to any one of (1) to (3) above, wherein the sealed space is in a sealed room, a sealed container, or a sealed package. Prevention method.
(5) The method for preventing blackening of crustaceans according to (4) above, wherein the sealed container or the sealed package is made of a plastic packaging material.
(6) Blackening that is hermetically packaged in a sealed container or sealed package having an atmosphere in which the carbon dioxide concentration is 23% or more and the oxygen concentration is 35% or less immediately before opening the sealed space is prevented. Crustacean packaging.
(7) The atmosphere with a carbon dioxide concentration of 23% or more immediately before opening the sealed space is made of dry ice and is hermetically packaged in a sealed container or sealed package having an atmosphere with an oxygen concentration of 35% or less. Crustacean packaging that prevents blackening.
(8) A crustacean package in which blackening is prevented by re-packaging the shellfish into a plastic container after opening the package according to (6) or (7) .
(9) A method for preserving and distributing crustaceans that prevents blackening, characterized by preserving and distributing crustaceans repackaged in a plastic container after opening the package according to (8) .

According to the present invention, by storing crustaceans in a closed space having an atmosphere with a carbon dioxide concentration of 23% or more, the blackening of the crustaceans is more effective even under conditions where oxygen remains in the space. The quality can be suppressed. In the present invention, the oxygen concentration may be 35% or less, particularly 20% or less. In the present invention, the carbon dioxide concentration may be a high initial concentration such as 50% or more, the oxygen concentration may be 20% or less, the carbon dioxide concentration at the end of storage may be 23% or more, and the oxygen concentration may be 20% or less. The higher the carbon dioxide content, the better the effect of preventing blackening. Further, if the oxygen is 20% or less, blackening can be sufficiently prevented, but a smaller amount is preferable. In addition, when the ratio of carbon dioxide and oxygen does not reach 100%, an inert gas such as nitrogen or argon may be added. In addition, the percentage of these gas concentrations shows the volume% of gas composition.
In the present invention, as the crustacean, one selected from shrimp, crab, hermit crab and giant clam is preferably used.
In order to store the crustaceans in the present invention in a sealed space having an atmosphere of carbon dioxide and, if necessary, oxygen gas, even if dry ice is put in the packaging space in which the crustaceans are packaged, carbon dioxide gas alone or carbon dioxide A mixed gas of nitrogen and oxygen may be added.
These crustaceans may be fresh, refrigerated or frozen.
Further, the method for preventing crustacean blackening in the present invention is preferably carried out in a sealed room, a sealed container or a sealed package as the space.
Furthermore, in the present invention, the container or package is preferably a sealed container or a sealed package made of a plastic packaging material.
Further, the present invention may be a crustacean package in which blackening is prevented by sealing and packaging the crustaceans in such a package having a carbon dioxide concentration of 23% or more and an oxygen concentration of 35% or less.
Furthermore, in the present invention, the shellfish is packaged hermetically in a package having an atmosphere with a carbon dioxide concentration of 23% or more and an oxygen concentration of 35% or less. It may be repackaged in a plastic container or the repackaged crustaceans may be stored and distributed.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The method for preventing blackening of crustaceans according to the present invention is characterized in that the crustaceans are hermetically packaged in a space having a carbon dioxide concentration of 23% or more and, if necessary, an oxygen concentration of 35% or less.
Here, the carbon dioxide concentration is preferably 23% or more, more preferably 60% or more, and further preferably 80% or more. When the carbon dioxide concentration is 60% or more, blackening is remarkably suppressed as compared with when the carbon dioxide concentration is 23% or more and less than 60%. Furthermore, if it is 80% or more, in addition to the blackening prevention effect at the time of unopening, the blackening prevention effect after opening will become more remarkable. On the other hand, if the carbon dioxide concentration is less than 23%, the blackening reaction due to oxygen proceeds and the quality retention effect cannot be obtained.
Further, when the oxygen concentration in the space is 35% or less, the effects of the present invention are more apparent and preferable, but the more preferable oxygen concentration is 25% or less, and more preferably 0.5% or more and 20% or less. . Most preferably, it is 1% or more and 20% or less. There are no particular restrictions on the type of gas other than carbon dioxide and oxygen, but nitrogen, argon, helium, or the like can be used. In addition, the oxygen concentration is 0.5% or more and 20% or less, more preferably 1% or more and 20% or less, so that an appropriate amount of oxygen is contained in the package, and obligate anaerobic bacteria such as Clostridium botulinum. The effect of suppressing the growth of can be expected. When the oxygen concentration in the air exceeds 35%, even if the carbon dioxide concentration is 23% or more, it is difficult to obtain a quality maintaining effect by preventing blackening of the crustaceans due to the high oxygen concentration.

As a method of realizing an atmosphere with a carbon dioxide concentration in the space of 23% or more and an oxygen concentration of 35% or less, a gas flash type or vacuum packaging machine that blows carbon dioxide alone or a mixed gas of carbon dioxide and oxygen into the space, etc. In addition to the method of using carbon dioxide and oxygen in the gas state, such as a chamber type that replaces in the chamber, dry ice is allowed to stand in the space, and the dry ice itself sublimates to make the carbon dioxide concentration 23 There is also a method of adjusting to more than%.
When the sum of carbon dioxide and oxygen concentration does not reach 100%, an inert gas such as nitrogen or argon is added to make the gas concentration 100%. As a method for adding the inert gas, a gas flash method or a chamber method is used as in the method for adjusting the carbon dioxide and oxygen concentrations.
Here, the gas concentration in the space can be measured by collecting the gas in the space with an airtight syringe and injecting the gas into a gas chromatography or injecting it into a gas concentration measuring device.
Furthermore, as a method for realizing the atmosphere of carbon dioxide, a method of directly introducing carbon dioxide gas from a carbon dioxide cylinder or the like into the space, or a gas in a space (packaging) containing carbon dioxide using a gas replacement packaging machine or the like There is a method of replacing with gas. Any of them is an effective method for realizing the conditions of the present invention, but a simpler method includes dry ice filling. The dry ice sealing method is a method of sealing crustaceans and dry ice in the same space. For example, the dry ice-sealed packaging has an advantage that it can be implemented simply and at low cost as long as there is a packaging material whose inner surface is thermally weldable, dry ice, and a heat-sealing machine for sealing. Furthermore, if there is a deaeration chamber in addition to these materials and equipment, the headspace can be set by appropriately setting the weight or volume of crustaceans, the pressure gauge value during deaeration and sealing, and the weight of dry ice. It is also possible to obtain a sealed package having a certain level of carbon dioxide concentration. For example, dry ice with a different weight is added to 825 g of frozen sweet shrimp and degassed and sealed (gauge pressure value when degassed and sealed: atmospheric pressure 600 mmHg, package head space 1600 cm ³ , degassed When the relationship between the carbon dioxide concentration in the package and the amount of enclosed dry ice when the head space was 200 cm ³ ) was found, a high correlation was observed between the two as shown in Table 1 and FIG. In the case of the above conditions, if it is desired to manufacture a crustacean package having a carbon dioxide concentration of about 40%, 3.6 g of dry ice may be sealed from the regression equation of FIG. There are no particular restrictions on the shape of the dry ice, and it can be divided into general block-shaped dry ice, finer flakes, or powdered dry ice produced by injecting liquefied carbon dioxide from a nozzle. It can be used suitably. As a method of commercializing dry ice-sealed packaging, we measure fresh, refrigerated or frozen crustaceans, and inject liquefied carbon dioxide gas according to their weight or volume into crustaceans (or a certain amount). After the amount of dry ice is charged), a process for promptly sealing and packaging can be proposed. The specific embodiment of the series of steps is not particularly limited. For example, for the packaging step, the shellfish to which weighed dry ice is added is placed in a deep-drawn container and sealed and packaged. Crustaceans can be packaged in plastic bags as they are, or in a metal or plastic (including foamed polystyrene) tray, or simply wrapped with a plastic film, or sealed and packaged, or There is a method of packaging using a pillow packaging machine.

  The crustacean blackening prevention method of the present invention may be any fresh product, refrigerated product or frozen product selected from shrimps, crabs, hermit crabs, and clams. , Crab, crab, hair crab, crab, crab, lobster, tiger shrimp, rice shrimp, pink shrimp, sweet shrimp, shrimp, krill, hermit crab, or clam. Each shape is not particularly limited, but in the case of crabs, there are round (figure), shoulders or sections (joint of feet and roots), feet (shelled or unshelled), shrimp Has a head or tail (head, chest and legs removed). The crustaceans of the present invention may be any of fresh products, refrigerated products, and frozen products. Fresh products are distributed to the market one to two days after catching, and refrigerated / frozen products are stored and distributed at a predetermined temperature for one day or more after catching. The present invention can also be applied as a method for preventing blackening of insect larvae, willows, adults, and the like. For example, salmon pupae used for fishing bait are suitable applications.

  Further, the method for preventing blackening of crustaceans according to the present invention is characterized in that the crustaceans are stored in a space having a carbon dioxide concentration of 23% or more and, if necessary, oxygen 35% or less, and the space is sealed. It is characterized by being in a room, in a container or in a package. Here, there are highly airtight rooms, containers, storages, etc. as sealed rooms, and boxes, bottles, bottles made of metal, glass, paper, plastic, wood, etc. as sealed containers or packages And a bag type.

  A sealed container or a sealed package made of a plastic packaging material is preferably used as the sealed container or package. Here, examples of the plastic that can be suitably used in the present invention include films, sheets, bottles, cups, and the like in which polyolefin, polyamide, polyester, etc. are single or laminated, and the shape of the container or package is single. Or a laminated film, a pouch shape formed using a sheet (the pouch shape includes a bottom seal pouch, a three-side seal pouch, etc.), a deep drawing shape, a pillow shape, a cup shape, a bottle shape, and the like. For the laminated films and sheets, gas barrier materials such as conventionally known ethylene vinyl alcohol copolymers, MXD nylon, polyvinylidene chloride, inorganic vapor deposition films such as silicon oxide and aluminum oxide, and polyacrylic acid coated films The thing containing is preferable.

As an example of the present invention, for example, when fried shrimp is quickly placed on a plastic tray and sealed with a plastic packaging material in a pillow packaging machine, a gas containing carbon dioxide is blown in and sealed with a gas flash method. By making the package, the effect of preventing shrimp blackening can be obtained. As another example, by creating a deep-drawn container using a plastic packaging material in a deep-drawing packaging machine, placing shrimp, and blowing and sealing a gas containing carbon dioxide in the same manner, An effect of preventing blackening can be obtained.
These packagings that can prevent blackening are usually stored and distributed at room temperature (10 ° C to 40 ° C), refrigerated (-2 ° C to 10 ° C), or frozen (-60 ° C to -2 ° C). Is done. Note that the present invention is not limited to these examples.

In addition, most crustaceans in Japan are imported from overseas. As a promising application of the present invention, there is a method in which crustaceans caught overseas are packaged locally by the method of the present invention and used as consumer packs that are imported to Japan and then distributed to the final consumers as they are. Also, a method of using shellfish packaged overseas overseas once opened in Japan, applying simple packaging such as tray wrapping and selling at stores such as supermarkets, so-called the present invention specializing in commercial packaging Is also promising. The latter can be developed as commercial packaging because it is based on the feature that carbon dioxide packaging can suppress blackening even after opening (Example 2), and is a new application obtained for the first time in the present invention. .

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not restrict | limited to a following example.

About 800g of frozen pink shrimp (without antioxidant) in a polystyrene (PS) tray, and put it in a plastic pouch (PET ^1.5 // Ny6 · 66 ⁸ / EVOH ⁵ // LLDPE ²¹ total thickness 38.5μm. , 1.5μm thick polyethylene terephthalate (PET layer), adhesive layer (//), 8μm thick nylon 6 and nylon 66 copolymer (NY6 ・ 66), 5μm thick ethylene / vinyl alcohol copolymer from the left The sample was inserted into an union (EVOH), an adhesive layer (//), and the rightmost line represents a linear low-density polyethylene having a thickness of 21 μm) and used as a sample (packaging volume of about 2800 cm ³ ). For each sample, “(a) Gas replacement packaging with a predetermined gas composition (carbon replacement packaging using a chamber-type vacuum packaging machine so as to have a carbon dioxide, oxygen and optionally nitrogen gas composition”, or “(b) Perform deaeration packaging with a predetermined amount of dry ice pieces (deaeration packaging using a chamber-type packaging machine to reduce the headspace volume of the package by about 50%), and gas immediately after packaging or after sublimation of dry ice After the measurement, the sample was stored in a freezer at −20 ° C. for 4 days and then thawed for 2 days at 5 ° C. After measuring the gas composition again, it was opened and visually evaluated for the degree of blackening of shrimp. Evaluation method is 4 panelists, the content of pink shrimp as content is 0: little or no blackening, 1: slightly recognized 2: slightly recognized (practical), 3 : Admit Is, 4:.. Observed significantly in five stages scored each to calculate the mean point results are shown in Table 2 also shows these tones in FIGS.

  Samples of each package evaluated in Example 1 were opened, five shrimps were placed in a PS tray, overlapped with a polyvinyl chloride (PVC) plastic film, and stored at 5 ° C. for 24 hours. The degree of blackening of shrimp at this time was visually evaluated. Evaluation method is 4 panelists, the content of pink shrimp is 0: little or no blackening, 1: slightly recognized 2: slightly recognized (practical), 3: Acknowledged 4: Scored in 5 stages, markedly recognized, and the average score was calculated. The results are shown in Table 3.

The relationship between the carbon dioxide concentration when dry ice is sealed in a package and the amount of dry ice enclosed is shown. The state of the pink shrimp after storage at 5 ° C. for 2 days in Example 1 is shown (Comparative Examples 1 to 9b). The state of the pink shrimp after storage at 5 ° C. for 2 days in Example 1 is shown (Examples 1b to 11a).

Claims (4)

Of crustaceans that have been sealed and sealed in sealed containers or sealed packages having an atmosphere of carbon dioxide concentration of 23% or more and oxygen concentration of 35% or less immediately before opening the sealed space. A crustacean package in which blackening is prevented by re-packaging crustaceans in a plastic container after opening the package . The shellfish package according to claim 1, wherein the atmosphere having a carbon dioxide concentration of 23% or more immediately before opening the sealed space is made of dry ice. The crustacean package according to claim 1 or 2 , wherein the crustacean is a fresh product, a refrigerated product or a frozen product of any one of shrimp, crab, hermit crab, and clam . 4. A method for preserving and distributing crustaceans that prevents blackening, characterized by storing and distributing crustaceans repackaged in a plastic container after opening the package according to any one of claims 1 to 3. .