CA2079072A1 - Packed frozen food of the crustacea and method of manufacturing the same - Google Patents
Packed frozen food of the crustacea and method of manufacturing the sameInfo
- Publication number
- CA2079072A1 CA2079072A1 CA002079072A CA2079072A CA2079072A1 CA 2079072 A1 CA2079072 A1 CA 2079072A1 CA 002079072 A CA002079072 A CA 002079072A CA 2079072 A CA2079072 A CA 2079072A CA 2079072 A1 CA2079072 A1 CA 2079072A1
- Authority
- CA
- Canada
- Prior art keywords
- crustacea
- freezing
- packed
- inner space
- frozen
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23B—PRESERVATION OF FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES; CHEMICAL RIPENING OF FRUIT OR VEGETABLES
- A23B4/00—Preservation of meat, sausages, fish or fish products
- A23B4/06—Freezing; Subsequent thawing; Cooling
- A23B4/066—Freezing; Subsequent thawing; Cooling the materials not being transported through or in the apparatus with or without shaping, e.g. in the form of powder, granules or flakes
- A23B4/068—Freezing; Subsequent thawing; Cooling the materials not being transported through or in the apparatus with or without shaping, e.g. in the form of powder, granules or flakes with packages or with shaping in the form of blocks or portions
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23B—PRESERVATION OF FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES; CHEMICAL RIPENING OF FRUIT OR VEGETABLES
- A23B4/00—Preservation of meat, sausages, fish or fish products
- A23B4/14—Preserving with chemicals not covered by groups A23B4/02 or A23B4/12
- A23B4/16—Preserving with chemicals not covered by groups A23B4/02 or A23B4/12 in the form of gases, e.g. fumigation; Compositions or apparatus therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
- B65D81/18—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient
- B65D81/20—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas
- B65D81/2069—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas in a special atmosphere
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Zoology (AREA)
- Wood Science & Technology (AREA)
- Food Science & Technology (AREA)
- Polymers & Plastics (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Mechanical Engineering (AREA)
- Meat, Egg Or Seafood Products (AREA)
- Farming Of Fish And Shellfish (AREA)
- Food Preservation Except Freezing, Refrigeration, And Drying (AREA)
- Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)
- Packages (AREA)
Abstract
ABSTRACT
This invention is related to packed frozen foods of the crustacea and a method of manufacturing the same, in which the packed frozen foods are manufactured by steps comprising wrapping the crustacea in the living state thereof with a wrapping film, pressure reducing an inner space surrounded by the film, and rapidly freezing the crustacea at a reduced pressure prevailing in the inner space.
This invention is related to packed frozen foods of the crustacea and a method of manufacturing the same, in which the packed frozen foods are manufactured by steps comprising wrapping the crustacea in the living state thereof with a wrapping film, pressure reducing an inner space surrounded by the film, and rapidly freezing the crustacea at a reduced pressure prevailing in the inner space.
Description
2~79~
S P E C I F I C A T I O N
TITLE OF THE INVENTION
PACKED FROZEN FOOD OF THE CRUSTACEA
AND METHOD OF MANUFACTURING THE SAME
FIELD OF THE INVENTION
This invention relates to packed frozen foods of the Crustacea and a method of manufacturing the same andg more particularly, to packed frozen foodsy which are obtained by steps comprisiny tight packin~ the crustacea, such as crabs~
lobsters, etc,~ in the living state or a state substantiaily equivalsn~ thereto and in sequence rapidly freezing the resultant packed crustacea, and a method of manufacturing the packed frozen foods of the crustacea with the meat portion substantially similar to one in the living state thereof.
PRI~R ART
Heretofore, a freezing process is effective in use of frozen storage of Crustacea~ fish and other marine products~
without spoiling the quality thereof. These marine products are frozen at a low te~perature of -180 C or below so as to deform their water content into ice crystals, thus permitting a long time preserrvation of the marine products. There are many freezing processes which are effective in practical use, They are usually divided into freezing processes, such as a process, using an air blast, a process using a water pouring technique and a process using a brine liquid.
The freezing process using an air blast is brought into effect in a ware house employing a pipe filled with a cooling - . . ~ ; .
.
. . ...
.. ..
~-. . . i.
; . . -., ,. . ~ ~
,,:,: . .. : ;. : ;.
2 ~ 2 liquid9 and a fan for causing forced a circulation of a cold air cooled by the cooling liquid~ This process has a problem that the marine product is dried during freezing them.
The freezing process using the water pouring technique is one in which the marine product is accommodated and in sequence frozen in a vessel filled with pure water. This process has an advantage that the marine product is free from drying of the product during a frozen storage thereof~ Thus~
it is effective for long preservation and is particularly suited for the Crustacea without need of grazing effect~ The grazing effect is that a formation of a thin ice film on the frozen fish using a pure water shower makes it possible to prevent the fish from drying~ In this process, fish is dipped and frozen in pure water~ Therefore3 pure water that is introduced into the interstices be~ween adjoining fishs amounts to a considerable weight~ For example~ in the case of freezing crabs by using water pouring technique7 10 kg of spring water is required for ~ kg of crab~ thus leading to increase of the transportation and preservation costs, and in addition, an extension of a period required for freezing the crab into a frozen state~ Further, the crab is in-directiy frozen via pure water cooled by a cooling medium, withou~
direct contact of the crab with the cooling medium~ Therefore, the crab temperature can not be lowered rapidly, and thus ~5 the freezing process using water pouring technique requires long time. Consequent~y, this freezing process9 has such advantage that it is effective in long time preservation of the crab in the frozen state, but it provides a deterioration of the quality of the crab meat portion during the cource of freezing the crab.
The freezing process using the brine liquid is a process comprising steps, the such as colling the brine liquid, such as a solution concentration of sodium chloride~ calcium ~, ~790~
chloride, etc~, passing the crustacea through the cooled brine liquid ,and freezing the crustacea in the frozen state~
In this process,the cooled brine liquid is put into as much as it can be held between every interstice of the crustacea~
Thus7 the process has ~he best freezing efficiency among the various freezing processes~ Further, by an option of some brine liquid9it is possible to provide high rapid freezing at a super-low temperature, and it has been proved theoretically that cooling to a temperature of -200 C can be obtained by utilizing some brine liquid~ For an example, a frozen ~
goldfish, which has fro2en in the living state by using the braine liquid, turns to swim again when releasing the fro~en goldfish from a frozen state~ Thus, this process has a tendency of eliminating any damage to the meat portion and is suitable ~or the freezing of high grade curstacea, such as crabs and lobste~sn However, this process has a demerit~
such that the taste and smell of the brine liquid are transferred to the crustacea because of direct contact between the brine liquid and the crustacea~
The cruastacea, such as crab~ shrimp and lobster, have cons~ructions thereof dif~erent from those of other fish~
The constructions are formed in a manner7 such that the crustacea are provided at the surface thereoF with a hard shell having penetrating pores and at a position surrounded by the shell with fibrous muscle tissues comprising fibrous elements align each other~ Consequently, when the freezing process using the brine liquid is utillized in the case that the living crustacea,such as the crab~ lobster and shrimp is frozen and stored into the frozen state, the frozen crustacea provides a generation of considerable amount of ice crystals at a position adjacent to the fibrous muscle tissues thereof, thereby resulted in a separation of fibrous elements due to a pressure applied by the ice crystals, a generation of pours 2 ~ r3~ 9 ~ ~7 2 in a the fibrous muscle tissues and a change of colour into black at least one portions of fibrous elernents, at the time of releasing the frozen crustacea from the frozen state~
Therefore, an application of the brine liquid freezing process in the case of freezing living crustacea leads to a deterioration in quality of the fibrous muscle tissues and a consequent decrease in taste~ sense of taste and flavour, Additionally, during the course of freezing the crustacea by using the brine liquid freezing process, there rise problems, such that the taste and the flavour of the brine liquid are transferred into the crustacea9 that the crustacea have an instinctive tendency of cutting off legs thereof by themselves at the time of facing the pains of death and that the breakage of legs and the shape deformation happen during the course of transportation of the crustacea.
~ eneral rule is that the water contents included in the marine product~ such as crustecea and fish, are frozened and in sequence transformed into ice crystals, thereby enabling to preserve the marine product for long period. Furthermore, the marine product is provided with an genaration of ice crystals at some places thereof varied according to the quality or freshness of the marine product~
In details, when the marine product is frozen immediately after its death~ during the period from its death to beginning of its hardening, or during the course of its hardening, it is provided in frbrous muscle tissues thereof with a generation of many ice crystals~ On the contrary, when the marine product is frozen after its hardening following its death, it is provided at a position outside the fibrous muscle tissues thereof with a generation of considerable ice crystals, and in fibrous muscle tissues with only a little ice crystals having rod-like shape or bar-like shape~ Thus generation of ice crystals outside the fibrous ,~ ;
~. :
'. ~.
~7~7~
muscle tissues or ice crystals having rod-like shape leads to a transformation of fibrous muscle tissues into those in the state different from the living state thereof~ Particularly, the ice crystals outside the fibrous muscle tissues constitute a main cause of the sponging of the meat partiand therefore the taste and sense of taste of the meat portion in the living state are greatly lost~
The Crustacea such as the crab or lobster have a structural feature that it has a hard shell thereona Its inner meat portion is cooled via this surface shel!~
Therefore, the cooling of the meat portion is inevitably indirect cooling~ Thereforey in the air blast freezing process~ it is difficult to obtain a cooling effect immediately reaching the meat portion,and it is practically impossible to complete the freezing of the meat part before hardening thereof9 especially, at least during the course of the hardening thereof. More specifically7 in the case of the air blast freezing of the meat portion first a superficial part is frozen~ then an inner intermediate part after a certain period of timel and finally a central part after a considerable period of time after the completion of freezin~
of the intermediate part~ In the case of the air blast freezing of fish among the marine product, if the fish is in a living state? the freezing of superficial and inner intermediate parts of the meat portion can be completed before or during the hardening of the fibrous tissues~
However, with crabs7 lobsters and so forth, having the structural feature that they have a hard shell thereon, if they are frozen in a living state by using the air blast freezing, there may be cases of failure of freezing of even a superficial part of the meat portion during the course of the hardening thereof~ Therefore, with frozen food of crabs and lobsters which are presentiy commercially available as high .; , 2 ~
grade products9 considerable generation of comparatively large ice crystals outside the fibrous muscle tissues of the meat portion is recognized. In addition~ the ice crystals generating inside the tissues are considerably coarse, At any rate, only food with greatly spoiled meat are available.
By the brine liquid freezing of crabs and lobsters in a living state, superior meat quality to that obtainable by using air blast freezing can be obtained~ In this case, however, since the meat directly touches the brine liquid, problems are posed in the taste and smell~
Accordingly, for preserving crabs and lobsters in the living state, it is in practice to store and transport crabs and lobsters by packing the same in a vessel together with sawdust or like wood particles as a buffering material, as disclosed in, for instance, Japanese Patent Application Laid -Open No~ 155732/1991. In this method~ however, the meat portion is held in the living state for transportation, Therefore~ although the method is suited for storage and transportation For shor~ period of time, its purpose can not be attained in case of transportation for long distance or storage for long time~
DISCLOSURE OF THE INVENTION
An object of the invention, which is intended to solve the above problems~ is to provide a packed frozen food of the Crustacea, particularly the crab and the lobster, which has its meat portion frozen for preservation and the tissue struct~re of its meat portion held in a living state or a state substantially close thereto and can provide the meat portion after unfreezing with the taste and sense of the taste substantially identical with or close to those in a living state,and a method of manufacturing said packed frozen 2~0~2 food~
According to the invention~ there is provided a packed frozen food of the Crustacea packed in a packing film and frozen therewith, the inside of the packing film being oxygen - or air-purged, the Crustacea being quickly frozen in a living state or a state before the hardenin~ of the fibrous structure of the meat part thereof~
Also, in the manufacture of this packed frozen food~ the Crustacea is packed in the living state in the packing film and quickly frozen under a pressure, under which the shell is not broken~
BEST MODE ~F CARRYING OUT THE INVENTION
According to the invention1 the Crustacea such as the crab, shrimp and the obster~ to be frozen is wrapped and sealed in its living state or a state before the hardening of the fibrous muscle tissues of its meat part portion9 by using a wrapping film~ The crustacea wrappedwith the film is rapidly frozen for a few period~ In other words, the Crustacea is held in the living state or a state before the hardening of the fibrous muscle tissues of its meat portion following its death.
~xygen or air is purged out from the inner portion of the film surrounding the crustacea~ The inner portion of the film is thus held in a purged state~ That is, the Crustacea is packed in the living state or a state before the hardening of the fibrous muscle tissues. The rapidly freezing is effected by dipping the crustacea with wrapping FiIm in a super-low temperature liquid. For example, the rapidly freezing is subjected to a formation of the super-low temperature liquid having a temperature of -40 C, by coolin~
such a brine liquid as ethyl alcohol, polyethylene glycol and ~' ~ , ', , .;
.- ~ , .
7 ~
calcium chloride and a consequent dipping of the wrapped crustacea into the super-low temper~ture liquid~ The crab or lobster in the living state or in a state before the hardening of the fibrous muscle tissues, which is wrapped with the packing film in an air-proof state, is dipped in the super-low temperature brine liquidu In this way, the living Crustacea is killed9 and the freezing of the fibrous muscle tissues is comple~ed before the hardening of the fibrous muscle tissues. When the rapidly freezing is done in this way, ice crystais generated in the meat portion of the Crustacea mostly are located in the fibrous muscle tissue and become finer and round~ Also, a generation of ice crystals outside at a position adjacent to the tissue cells is prevented.Even if ice crystals are g&nerated slightly outside the tissue cells, they become finer, and they mostly become round~ Thus the degree of rupture of the fibrous muscle tissues is very low compared to that with the rad-like or pillar-like ice crystals in the prior art~
More specifically, when freezing the Crustacea such as the crab and the lobster in the living state or a nearly living state~ it is very important to determine the timing of killing the Crustacea in relation to the instant of completion of the freezing. If the timing is inadequate so that the freezing is continued beyond the fibrous muscle tissue hardening period after the death9 even by the rapidly freezing at the super-low temperature as abovey it is difficult to prevent a generation of rod-like or pillar-like ice crystals outside the fibrous muscle tissue at the csnter of the meat portion and obtain a freezing effect in a manner~
such that ice crystals generated in the meat portion are made finer~ Accordingly~ the living Grustacea, with a difficulty of handling them is set to ;ts natural form by folding or closing its legs in a manner, such that it will not cut off ~ .
.
2~07~
its legs by itself9 and in this form it is quickly packed in a wrapping film. Then, after effecting predetermined air purging, the crustacea wrapped with the film is dipped in the super-low temperature li~uid for momentarily killing the Crustacea and completing the freezing thereof before the hardening of the fibrous muscle tissue in the meat portion~
By carrying out the rapidly freezing in this way~ the generation of rod-like or pillar-like ice crystals outside the tissue is prevented over the entire meat portion~ The ice crystals that are generated are mostly inside the tissue and are made fine~ Thus, when the meat portion is released from the frozen state, a fibrous muscle tissue in the living state or a nearly living state can be obtained~ It is thus possible to obtain a taste and a sense of taste in the living state~
From the above, it has been shown as one example that living crabs or lobsters wrapped with the film and rapidiy frozen. This invention can be applied to the crustacea without reaching the commencement of the hardening of the fibrous muscle tissue.
Further, as much oxygen or air as possible is purged from an inner space surrounded by the wrapping film~ and the rapidly freezing is effected in the air-proof state~ One of the reasons for holding the air-proof state is to prevent oxidization of the meat portion during the preservation in the frozen state and also to avoid the phenomenon of blackening the meat portion. More specifically, the shell of the Crustacea has a considerably large number of penetrated pores~ Through these pores, air or oxygen enter the meat portion via the shell.Thus, oxidization is caused to proceed, thus resulting in drying by freezing or generation of the phenomenon of blackening~According to the invention, the Crustacea are wrapped with the wrapping fiIm so as to close _ g _ .
.
~7~72 the penetrated pores of the shell~ thus achieving perfectly sealing of the meat portion. Thus, oxidization substan~ially does not take place during the preservation in the frozen state~ and it is possible to substantially perfectly prevent drying by freezing or a change of color of the meat portion.
Another reason for the air purging is to maintain at desirable level the cooling performance o~ the the brine liquid or the like. A layer of air or oxygenJ which is present between the Crustacea to be wrapped and the wrapping film, has a heat-insulating effect and thus makes a decrease in the cooling performance of the brine liquid. In this case, when the crustacea with air or oxigen film is dipped in the super-low temperature li~uid as noted above~ the freezing of the meat portion does not proceed rapidly. In detail, although the superficial part of the meat portion may be completely frozen before or during the hardening of the fibrous muscle tissue, the intermediate and central parts are not completely frozen at the end of the hardening o~ the ~ibrous muscle tissue, thus resulting in the spoiling thereof~
A further reason ~or the air purging is to ensure perfectly close contact oF the wrapping film with the Crustacea.This is because the shell surface of the Crustacea7 particularly crabs and lobsters, has sharp irregularities~
Therefore, a large amount of air of oxygen present between the wrapping fiIm and the crustacea constitutes a resistance to prevent pefectly close contact of the packing film with the shell surface.
A still further reason for air purging is to reduce the pressure prevailing at the inner space surrounded by the wrapping film upto a pressure below the external atmospheric pressure (760 mm Hg)~ The reduced pressure is about 20 to 120 mm Hg~ and enable to promot that the ice crystals generated by the rapidly freezing are made finer and also . , ~ : , . ., ,, - ~i . ~ ~. ,;
2 ~
round with the reduced pressure state~
Further, among all of ice crystals generated in the meat portion, ice crystals within fibrous muscle tissue are ~ormed as finer preferable particles the particles of the ice crystals within fibrous muscle tissue decrease in ;ize as small as possible~ Particularly, their grain size is suitably 100 microns or below. If ice crystals generated in the fibrous muscle tissue have a grain size greater than 100 microns, they are readily liable to break the fibrous structure of the meat portion~ and the fibrous muscle tissue obtained at the time of releasing from the frozen state is greatly different from that in the living state, thus greatly deteriorating the sense o~ taste and taste~
Further~ the crab or lobster in t~e ~iving state or a state close thereto is frozen via the wrapping film7 and hence the crab or lobster to be frozen does not touch the brine liquid and air during the course o~ freezing and preversation thereof. Thus, drying of the surface in the ~rozen state does not proceed and the transition of flavour of the brine liquid to the crab is prevented~ Particularly, it is possible to prevent weaken;ng of legs due to otherwise possible progress of drying~ and legs or the like are not damaged during transportation of the crab or the like, The wrapping film in use has to have such a mechanical strength that no pin hole is formed when Pierced by a projection of the shell sur~ace o~ the crab or lobster~
Particularly, it has to have a moisture-proof property and a sealing property, and specifically a stringent gas barrier property~ In terms of the gas permeability, a value of 10 to 50 cm3/m~ by 24 h.catoms, 23C, 50 % RHa To fully provi~e these properties, a laminate film may be usedO For example, it is possible to use a laminate film having an overall thickness ranging between 50 and 150 microns, which may be '~
' ' obtained from rolled nylon or extended nylon imparted with moisture-proof and gas barrier properties (for instance in two layers each with a thickness ranging hetween 10 and 50 microns) and straight chain low density polyethylene or low density polyethylene (~or instance in a layer with a thickness ranging between 30 and 100 microns)"
Further, as noted above~ the pressure prevailing at an inner space surrounded by the wrapping fiim is reduced only down to about ~0 to 120 mm Hg~ If the pressure is reduced beyond this range, the shell and legs of the crab or lobster are ruptured by this reduced pressure~ thus causing damage to the meat portion as well~
To reduce the pressure to the extent as noted above, air is purged using a vacuum wrapping device a~ter the crab 1~ or lobster is wrapped with the wrapping film. Thereby~ the inner pressure can be reduced from the atmospheric pressure oF 760 mm Hg down to around 20 to 120 mm Hg, for instance~
However, when the pressure reduction is effected only to this extent, slight air remains in the inner space surrounded by ~0 the wrapping film and may cause the phenomenon of blackening of the meat portion if a certain period of time is involved before the commencement of the rapidly freezing. The phenomenon of blakening of the meat portion if a certain period of time is involved before the commencement of the ~5 rapidly freezing.
In addition the pressure reduction at the inner space surrounded by the wrapping film is preferably carried out by staps comprising purging ~he air existing in the inner space to an extent such that vacuum conditions may be substantially formed in the inner space, and sequently introducing the innert gas into the inner space~ thereby forming in the inner space the innert gas surroundings with a pressure ranging From 20 mm Hg to 120mm ~Ig.
`
2 ~ 2 Thus formation of the innert gas surroundings enables to prevent the meat portion of crab, shrimp and lobster from blacking out thereof and to promote a formation of precise ice crystals within fibrous muscle tissues of the meat portion and at a position surrounded with fibrous muscle tissues.
Namely, non-existence of the innert gas surroundings at the inn~r space surround0d with the wrapping film permits a penetration of the brine liquid through pores exis~ing in the wrapping film and the shell of the crab or the like, and a consequent transference of the brine liquid flavour into the meat portion of the crab or the like.
On the contrary~ the crab or the like packed and frozen according to this invention is provided with the inner gas surroundings enveloping the crab or the like~ The inner surroundings prevent an immersion of the brine iiquid into the meat portion of the crab or the like.
Furthermore, the existence of the innert ~as surroundings releases ths meat portion of the crab or the like from an oxidation by air or oxygen.
Additionally, the existence of the innert gas surroundings provides a buffer zone reducing shock due to plunging the crab or the like into the brine liquid. in detail7this shock provides a water separation in the fibrous muscle tissues of the meat portion and at a position surrounded by the fibrous muscle tissues~ The separated water during the course of rapid freezing is frozen and converted into ice crystals, among which ice crystals existing in the fibrous muscle tissues have an increase in size.
In contrast to this, according to this invention, the innert gas enveloping the meat portion of the crab or the like forms the buffer zone, by which a shock due to the brine .
2~7~72 liquid is reduced~ Consequentl y9 in the Fibrous muscle tissues, does not occur a water-separation and a consequent formation of precise ice crystals~ without a formation oF
coarse ice crystals with increase in size~
Example 1 A crab in the living state thereoF was bound by using a rope, in a manner such that it does not cut off its legs by itself~ The binding crab was wrapped with a laminate film with a thickness of 130 microns, which comprises two oriented nylon films each with a thickness oF 25 microns and a low density polyethylen film with a thickness of 80 microns~ The crab wrapped with the film was subjected in sequence to steps comprising a pressure reducing of inner pressure prevailing at an inner portion surrounded by the film in a manner that the inner pressure falls down to around 80 mm Hg~ and a dipping for about 15 minules into a brine liquid at a temperature -40~, which iiquid was prepared with an ethyl alcohol~ thereby resulted in rapidly freezing the crabu Thereafter7 we had comparative observation using a microscope between the fibrous muscle tissues of the resultant rapidly freezed crab and those of the crab in the living state, As a result, the two fibrous muscle tissues were found to resemble each other such that they may be hardly distinguished each otherO
Further, after releasing the frozen crab from the frozen state thereof~ the leg meat portion could be eaten as meat slice~During the cource of freezing, the crab9 the crab had not a direct contact with the brine liquid~ and ethyl alcohol adhering to the surface of the wrapping film was completely evaporated and scattered until the crab was unfrozen~
,' . .
2~7~2 Further, surroundings with a pressure of about 80mm Hg was formed mainiy in an inner space surrounded with the laminate film~ As a result, there happened no drying due to freezing~ Furthermore, there happened no quality deterioration even after preservation for lon9 time (i~ea, for 11 months). Further, the frozen crab cou~d be packed in a box without joining adjacent crabs each other by a binder of ice formed at freezing the crab~
The living crab was wrapped by a manner same as shown in Example la Thereafter~ the inner portion surrounded by the laminate film was subjected in sequence to a air purging step to an extent such as to produce a vacuum ambience of Omm Hg, and a nitrogen gas introduction step with producing innert gas surroundings having a pressure of 80mm Hg.
Thereafter, the wrapped crab with the innert gas surroundings was rapidly frozerl by a manner shown in Example 1~
The resultant frozen crab wrapped wi~h the film was subjected to a preservation for long time, i.e~, one year or more after which the frozen crab was prevented from black colour change phenomenon~
As described in detail in the above, according to this invention~ the crustacea in the living state thereof or in a state substantialiy equal to the living state thereof is subjected to a packing step with a wrapping film, a pressure reduction step of tha inner space within the wrapping film, and a rapid freezing step~ Consequently, in the fibrous muscle tissues, are formed ice crystals comprising fine particles with a round shape~
Accordingly, the frozen crustacea has not a decrease in qualityy during the cource of preserving it~ In addition, 287~7~
without use of anti-oxidization ayent or the like, it is possible to eliminate the blackening of the Crustacea3 Further, at the time of unfreezing the frozen crustacea, a muscle tissue maintaining the living state thereof can be ob~ained.
Further, since the Crustacea is wrapped with the wrapping film~ it can be rapidly frozen by using brine liquid without a direct contact with any brine liquid. Thus, ice crystals formed in the meat portion at the time of freezing ~he meat portion can be readily made round and finer, and there.~akes place no drying in frozen state. It is ~hus possible to maintain high freshness~ Further~ the packed frozen food can be packed in a box or the like without possibility of secure~ant of adjacent pieces of Crustac0a to each other by ice,and thus can be handled very easiIy~
.:
, , . ..
..
S P E C I F I C A T I O N
TITLE OF THE INVENTION
PACKED FROZEN FOOD OF THE CRUSTACEA
AND METHOD OF MANUFACTURING THE SAME
FIELD OF THE INVENTION
This invention relates to packed frozen foods of the Crustacea and a method of manufacturing the same andg more particularly, to packed frozen foodsy which are obtained by steps comprisiny tight packin~ the crustacea, such as crabs~
lobsters, etc,~ in the living state or a state substantiaily equivalsn~ thereto and in sequence rapidly freezing the resultant packed crustacea, and a method of manufacturing the packed frozen foods of the crustacea with the meat portion substantially similar to one in the living state thereof.
PRI~R ART
Heretofore, a freezing process is effective in use of frozen storage of Crustacea~ fish and other marine products~
without spoiling the quality thereof. These marine products are frozen at a low te~perature of -180 C or below so as to deform their water content into ice crystals, thus permitting a long time preserrvation of the marine products. There are many freezing processes which are effective in practical use, They are usually divided into freezing processes, such as a process, using an air blast, a process using a water pouring technique and a process using a brine liquid.
The freezing process using an air blast is brought into effect in a ware house employing a pipe filled with a cooling - . . ~ ; .
.
. . ...
.. ..
~-. . . i.
; . . -., ,. . ~ ~
,,:,: . .. : ;. : ;.
2 ~ 2 liquid9 and a fan for causing forced a circulation of a cold air cooled by the cooling liquid~ This process has a problem that the marine product is dried during freezing them.
The freezing process using the water pouring technique is one in which the marine product is accommodated and in sequence frozen in a vessel filled with pure water. This process has an advantage that the marine product is free from drying of the product during a frozen storage thereof~ Thus~
it is effective for long preservation and is particularly suited for the Crustacea without need of grazing effect~ The grazing effect is that a formation of a thin ice film on the frozen fish using a pure water shower makes it possible to prevent the fish from drying~ In this process, fish is dipped and frozen in pure water~ Therefore3 pure water that is introduced into the interstices be~ween adjoining fishs amounts to a considerable weight~ For example~ in the case of freezing crabs by using water pouring technique7 10 kg of spring water is required for ~ kg of crab~ thus leading to increase of the transportation and preservation costs, and in addition, an extension of a period required for freezing the crab into a frozen state~ Further, the crab is in-directiy frozen via pure water cooled by a cooling medium, withou~
direct contact of the crab with the cooling medium~ Therefore, the crab temperature can not be lowered rapidly, and thus ~5 the freezing process using water pouring technique requires long time. Consequent~y, this freezing process9 has such advantage that it is effective in long time preservation of the crab in the frozen state, but it provides a deterioration of the quality of the crab meat portion during the cource of freezing the crab.
The freezing process using the brine liquid is a process comprising steps, the such as colling the brine liquid, such as a solution concentration of sodium chloride~ calcium ~, ~790~
chloride, etc~, passing the crustacea through the cooled brine liquid ,and freezing the crustacea in the frozen state~
In this process,the cooled brine liquid is put into as much as it can be held between every interstice of the crustacea~
Thus7 the process has ~he best freezing efficiency among the various freezing processes~ Further, by an option of some brine liquid9it is possible to provide high rapid freezing at a super-low temperature, and it has been proved theoretically that cooling to a temperature of -200 C can be obtained by utilizing some brine liquid~ For an example, a frozen ~
goldfish, which has fro2en in the living state by using the braine liquid, turns to swim again when releasing the fro~en goldfish from a frozen state~ Thus, this process has a tendency of eliminating any damage to the meat portion and is suitable ~or the freezing of high grade curstacea, such as crabs and lobste~sn However, this process has a demerit~
such that the taste and smell of the brine liquid are transferred to the crustacea because of direct contact between the brine liquid and the crustacea~
The cruastacea, such as crab~ shrimp and lobster, have cons~ructions thereof dif~erent from those of other fish~
The constructions are formed in a manner7 such that the crustacea are provided at the surface thereoF with a hard shell having penetrating pores and at a position surrounded by the shell with fibrous muscle tissues comprising fibrous elements align each other~ Consequently, when the freezing process using the brine liquid is utillized in the case that the living crustacea,such as the crab~ lobster and shrimp is frozen and stored into the frozen state, the frozen crustacea provides a generation of considerable amount of ice crystals at a position adjacent to the fibrous muscle tissues thereof, thereby resulted in a separation of fibrous elements due to a pressure applied by the ice crystals, a generation of pours 2 ~ r3~ 9 ~ ~7 2 in a the fibrous muscle tissues and a change of colour into black at least one portions of fibrous elernents, at the time of releasing the frozen crustacea from the frozen state~
Therefore, an application of the brine liquid freezing process in the case of freezing living crustacea leads to a deterioration in quality of the fibrous muscle tissues and a consequent decrease in taste~ sense of taste and flavour, Additionally, during the course of freezing the crustacea by using the brine liquid freezing process, there rise problems, such that the taste and the flavour of the brine liquid are transferred into the crustacea9 that the crustacea have an instinctive tendency of cutting off legs thereof by themselves at the time of facing the pains of death and that the breakage of legs and the shape deformation happen during the course of transportation of the crustacea.
~ eneral rule is that the water contents included in the marine product~ such as crustecea and fish, are frozened and in sequence transformed into ice crystals, thereby enabling to preserve the marine product for long period. Furthermore, the marine product is provided with an genaration of ice crystals at some places thereof varied according to the quality or freshness of the marine product~
In details, when the marine product is frozen immediately after its death~ during the period from its death to beginning of its hardening, or during the course of its hardening, it is provided in frbrous muscle tissues thereof with a generation of many ice crystals~ On the contrary, when the marine product is frozen after its hardening following its death, it is provided at a position outside the fibrous muscle tissues thereof with a generation of considerable ice crystals, and in fibrous muscle tissues with only a little ice crystals having rod-like shape or bar-like shape~ Thus generation of ice crystals outside the fibrous ,~ ;
~. :
'. ~.
~7~7~
muscle tissues or ice crystals having rod-like shape leads to a transformation of fibrous muscle tissues into those in the state different from the living state thereof~ Particularly, the ice crystals outside the fibrous muscle tissues constitute a main cause of the sponging of the meat partiand therefore the taste and sense of taste of the meat portion in the living state are greatly lost~
The Crustacea such as the crab or lobster have a structural feature that it has a hard shell thereona Its inner meat portion is cooled via this surface shel!~
Therefore, the cooling of the meat portion is inevitably indirect cooling~ Thereforey in the air blast freezing process~ it is difficult to obtain a cooling effect immediately reaching the meat portion,and it is practically impossible to complete the freezing of the meat part before hardening thereof9 especially, at least during the course of the hardening thereof. More specifically7 in the case of the air blast freezing of the meat portion first a superficial part is frozen~ then an inner intermediate part after a certain period of timel and finally a central part after a considerable period of time after the completion of freezin~
of the intermediate part~ In the case of the air blast freezing of fish among the marine product, if the fish is in a living state? the freezing of superficial and inner intermediate parts of the meat portion can be completed before or during the hardening of the fibrous tissues~
However, with crabs7 lobsters and so forth, having the structural feature that they have a hard shell thereon, if they are frozen in a living state by using the air blast freezing, there may be cases of failure of freezing of even a superficial part of the meat portion during the course of the hardening thereof~ Therefore, with frozen food of crabs and lobsters which are presentiy commercially available as high .; , 2 ~
grade products9 considerable generation of comparatively large ice crystals outside the fibrous muscle tissues of the meat portion is recognized. In addition~ the ice crystals generating inside the tissues are considerably coarse, At any rate, only food with greatly spoiled meat are available.
By the brine liquid freezing of crabs and lobsters in a living state, superior meat quality to that obtainable by using air blast freezing can be obtained~ In this case, however, since the meat directly touches the brine liquid, problems are posed in the taste and smell~
Accordingly, for preserving crabs and lobsters in the living state, it is in practice to store and transport crabs and lobsters by packing the same in a vessel together with sawdust or like wood particles as a buffering material, as disclosed in, for instance, Japanese Patent Application Laid -Open No~ 155732/1991. In this method~ however, the meat portion is held in the living state for transportation, Therefore~ although the method is suited for storage and transportation For shor~ period of time, its purpose can not be attained in case of transportation for long distance or storage for long time~
DISCLOSURE OF THE INVENTION
An object of the invention, which is intended to solve the above problems~ is to provide a packed frozen food of the Crustacea, particularly the crab and the lobster, which has its meat portion frozen for preservation and the tissue struct~re of its meat portion held in a living state or a state substantially close thereto and can provide the meat portion after unfreezing with the taste and sense of the taste substantially identical with or close to those in a living state,and a method of manufacturing said packed frozen 2~0~2 food~
According to the invention~ there is provided a packed frozen food of the Crustacea packed in a packing film and frozen therewith, the inside of the packing film being oxygen - or air-purged, the Crustacea being quickly frozen in a living state or a state before the hardenin~ of the fibrous structure of the meat part thereof~
Also, in the manufacture of this packed frozen food~ the Crustacea is packed in the living state in the packing film and quickly frozen under a pressure, under which the shell is not broken~
BEST MODE ~F CARRYING OUT THE INVENTION
According to the invention1 the Crustacea such as the crab, shrimp and the obster~ to be frozen is wrapped and sealed in its living state or a state before the hardening of the fibrous muscle tissues of its meat part portion9 by using a wrapping film~ The crustacea wrappedwith the film is rapidly frozen for a few period~ In other words, the Crustacea is held in the living state or a state before the hardening of the fibrous muscle tissues of its meat portion following its death.
~xygen or air is purged out from the inner portion of the film surrounding the crustacea~ The inner portion of the film is thus held in a purged state~ That is, the Crustacea is packed in the living state or a state before the hardening of the fibrous muscle tissues. The rapidly freezing is effected by dipping the crustacea with wrapping FiIm in a super-low temperature liquid. For example, the rapidly freezing is subjected to a formation of the super-low temperature liquid having a temperature of -40 C, by coolin~
such a brine liquid as ethyl alcohol, polyethylene glycol and ~' ~ , ', , .;
.- ~ , .
7 ~
calcium chloride and a consequent dipping of the wrapped crustacea into the super-low temper~ture liquid~ The crab or lobster in the living state or in a state before the hardening of the fibrous muscle tissues, which is wrapped with the packing film in an air-proof state, is dipped in the super-low temperature brine liquidu In this way, the living Crustacea is killed9 and the freezing of the fibrous muscle tissues is comple~ed before the hardening of the fibrous muscle tissues. When the rapidly freezing is done in this way, ice crystais generated in the meat portion of the Crustacea mostly are located in the fibrous muscle tissue and become finer and round~ Also, a generation of ice crystals outside at a position adjacent to the tissue cells is prevented.Even if ice crystals are g&nerated slightly outside the tissue cells, they become finer, and they mostly become round~ Thus the degree of rupture of the fibrous muscle tissues is very low compared to that with the rad-like or pillar-like ice crystals in the prior art~
More specifically, when freezing the Crustacea such as the crab and the lobster in the living state or a nearly living state~ it is very important to determine the timing of killing the Crustacea in relation to the instant of completion of the freezing. If the timing is inadequate so that the freezing is continued beyond the fibrous muscle tissue hardening period after the death9 even by the rapidly freezing at the super-low temperature as abovey it is difficult to prevent a generation of rod-like or pillar-like ice crystals outside the fibrous muscle tissue at the csnter of the meat portion and obtain a freezing effect in a manner~
such that ice crystals generated in the meat portion are made finer~ Accordingly~ the living Grustacea, with a difficulty of handling them is set to ;ts natural form by folding or closing its legs in a manner, such that it will not cut off ~ .
.
2~07~
its legs by itself9 and in this form it is quickly packed in a wrapping film. Then, after effecting predetermined air purging, the crustacea wrapped with the film is dipped in the super-low temperature li~uid for momentarily killing the Crustacea and completing the freezing thereof before the hardening of the fibrous muscle tissue in the meat portion~
By carrying out the rapidly freezing in this way~ the generation of rod-like or pillar-like ice crystals outside the tissue is prevented over the entire meat portion~ The ice crystals that are generated are mostly inside the tissue and are made fine~ Thus, when the meat portion is released from the frozen state, a fibrous muscle tissue in the living state or a nearly living state can be obtained~ It is thus possible to obtain a taste and a sense of taste in the living state~
From the above, it has been shown as one example that living crabs or lobsters wrapped with the film and rapidiy frozen. This invention can be applied to the crustacea without reaching the commencement of the hardening of the fibrous muscle tissue.
Further, as much oxygen or air as possible is purged from an inner space surrounded by the wrapping film~ and the rapidly freezing is effected in the air-proof state~ One of the reasons for holding the air-proof state is to prevent oxidization of the meat portion during the preservation in the frozen state and also to avoid the phenomenon of blackening the meat portion. More specifically, the shell of the Crustacea has a considerably large number of penetrated pores~ Through these pores, air or oxygen enter the meat portion via the shell.Thus, oxidization is caused to proceed, thus resulting in drying by freezing or generation of the phenomenon of blackening~According to the invention, the Crustacea are wrapped with the wrapping fiIm so as to close _ g _ .
.
~7~72 the penetrated pores of the shell~ thus achieving perfectly sealing of the meat portion. Thus, oxidization substan~ially does not take place during the preservation in the frozen state~ and it is possible to substantially perfectly prevent drying by freezing or a change of color of the meat portion.
Another reason for the air purging is to maintain at desirable level the cooling performance o~ the the brine liquid or the like. A layer of air or oxygenJ which is present between the Crustacea to be wrapped and the wrapping film, has a heat-insulating effect and thus makes a decrease in the cooling performance of the brine liquid. In this case, when the crustacea with air or oxigen film is dipped in the super-low temperature li~uid as noted above~ the freezing of the meat portion does not proceed rapidly. In detail, although the superficial part of the meat portion may be completely frozen before or during the hardening of the fibrous muscle tissue, the intermediate and central parts are not completely frozen at the end of the hardening o~ the ~ibrous muscle tissue, thus resulting in the spoiling thereof~
A further reason ~or the air purging is to ensure perfectly close contact oF the wrapping film with the Crustacea.This is because the shell surface of the Crustacea7 particularly crabs and lobsters, has sharp irregularities~
Therefore, a large amount of air of oxygen present between the wrapping fiIm and the crustacea constitutes a resistance to prevent pefectly close contact of the packing film with the shell surface.
A still further reason for air purging is to reduce the pressure prevailing at the inner space surrounded by the wrapping film upto a pressure below the external atmospheric pressure (760 mm Hg)~ The reduced pressure is about 20 to 120 mm Hg~ and enable to promot that the ice crystals generated by the rapidly freezing are made finer and also . , ~ : , . ., ,, - ~i . ~ ~. ,;
2 ~
round with the reduced pressure state~
Further, among all of ice crystals generated in the meat portion, ice crystals within fibrous muscle tissue are ~ormed as finer preferable particles the particles of the ice crystals within fibrous muscle tissue decrease in ;ize as small as possible~ Particularly, their grain size is suitably 100 microns or below. If ice crystals generated in the fibrous muscle tissue have a grain size greater than 100 microns, they are readily liable to break the fibrous structure of the meat portion~ and the fibrous muscle tissue obtained at the time of releasing from the frozen state is greatly different from that in the living state, thus greatly deteriorating the sense o~ taste and taste~
Further~ the crab or lobster in t~e ~iving state or a state close thereto is frozen via the wrapping film7 and hence the crab or lobster to be frozen does not touch the brine liquid and air during the course o~ freezing and preversation thereof. Thus, drying of the surface in the ~rozen state does not proceed and the transition of flavour of the brine liquid to the crab is prevented~ Particularly, it is possible to prevent weaken;ng of legs due to otherwise possible progress of drying~ and legs or the like are not damaged during transportation of the crab or the like, The wrapping film in use has to have such a mechanical strength that no pin hole is formed when Pierced by a projection of the shell sur~ace o~ the crab or lobster~
Particularly, it has to have a moisture-proof property and a sealing property, and specifically a stringent gas barrier property~ In terms of the gas permeability, a value of 10 to 50 cm3/m~ by 24 h.catoms, 23C, 50 % RHa To fully provi~e these properties, a laminate film may be usedO For example, it is possible to use a laminate film having an overall thickness ranging between 50 and 150 microns, which may be '~
' ' obtained from rolled nylon or extended nylon imparted with moisture-proof and gas barrier properties (for instance in two layers each with a thickness ranging hetween 10 and 50 microns) and straight chain low density polyethylene or low density polyethylene (~or instance in a layer with a thickness ranging between 30 and 100 microns)"
Further, as noted above~ the pressure prevailing at an inner space surrounded by the wrapping fiim is reduced only down to about ~0 to 120 mm Hg~ If the pressure is reduced beyond this range, the shell and legs of the crab or lobster are ruptured by this reduced pressure~ thus causing damage to the meat portion as well~
To reduce the pressure to the extent as noted above, air is purged using a vacuum wrapping device a~ter the crab 1~ or lobster is wrapped with the wrapping film. Thereby~ the inner pressure can be reduced from the atmospheric pressure oF 760 mm Hg down to around 20 to 120 mm Hg, for instance~
However, when the pressure reduction is effected only to this extent, slight air remains in the inner space surrounded by ~0 the wrapping film and may cause the phenomenon of blackening of the meat portion if a certain period of time is involved before the commencement of the rapidly freezing. The phenomenon of blakening of the meat portion if a certain period of time is involved before the commencement of the ~5 rapidly freezing.
In addition the pressure reduction at the inner space surrounded by the wrapping film is preferably carried out by staps comprising purging ~he air existing in the inner space to an extent such that vacuum conditions may be substantially formed in the inner space, and sequently introducing the innert gas into the inner space~ thereby forming in the inner space the innert gas surroundings with a pressure ranging From 20 mm Hg to 120mm ~Ig.
`
2 ~ 2 Thus formation of the innert gas surroundings enables to prevent the meat portion of crab, shrimp and lobster from blacking out thereof and to promote a formation of precise ice crystals within fibrous muscle tissues of the meat portion and at a position surrounded with fibrous muscle tissues.
Namely, non-existence of the innert gas surroundings at the inn~r space surround0d with the wrapping film permits a penetration of the brine liquid through pores exis~ing in the wrapping film and the shell of the crab or the like, and a consequent transference of the brine liquid flavour into the meat portion of the crab or the like.
On the contrary~ the crab or the like packed and frozen according to this invention is provided with the inner gas surroundings enveloping the crab or the like~ The inner surroundings prevent an immersion of the brine iiquid into the meat portion of the crab or the like.
Furthermore, the existence of the innert ~as surroundings releases ths meat portion of the crab or the like from an oxidation by air or oxygen.
Additionally, the existence of the innert gas surroundings provides a buffer zone reducing shock due to plunging the crab or the like into the brine liquid. in detail7this shock provides a water separation in the fibrous muscle tissues of the meat portion and at a position surrounded by the fibrous muscle tissues~ The separated water during the course of rapid freezing is frozen and converted into ice crystals, among which ice crystals existing in the fibrous muscle tissues have an increase in size.
In contrast to this, according to this invention, the innert gas enveloping the meat portion of the crab or the like forms the buffer zone, by which a shock due to the brine .
2~7~72 liquid is reduced~ Consequentl y9 in the Fibrous muscle tissues, does not occur a water-separation and a consequent formation of precise ice crystals~ without a formation oF
coarse ice crystals with increase in size~
Example 1 A crab in the living state thereoF was bound by using a rope, in a manner such that it does not cut off its legs by itself~ The binding crab was wrapped with a laminate film with a thickness of 130 microns, which comprises two oriented nylon films each with a thickness oF 25 microns and a low density polyethylen film with a thickness of 80 microns~ The crab wrapped with the film was subjected in sequence to steps comprising a pressure reducing of inner pressure prevailing at an inner portion surrounded by the film in a manner that the inner pressure falls down to around 80 mm Hg~ and a dipping for about 15 minules into a brine liquid at a temperature -40~, which iiquid was prepared with an ethyl alcohol~ thereby resulted in rapidly freezing the crabu Thereafter7 we had comparative observation using a microscope between the fibrous muscle tissues of the resultant rapidly freezed crab and those of the crab in the living state, As a result, the two fibrous muscle tissues were found to resemble each other such that they may be hardly distinguished each otherO
Further, after releasing the frozen crab from the frozen state thereof~ the leg meat portion could be eaten as meat slice~During the cource of freezing, the crab9 the crab had not a direct contact with the brine liquid~ and ethyl alcohol adhering to the surface of the wrapping film was completely evaporated and scattered until the crab was unfrozen~
,' . .
2~7~2 Further, surroundings with a pressure of about 80mm Hg was formed mainiy in an inner space surrounded with the laminate film~ As a result, there happened no drying due to freezing~ Furthermore, there happened no quality deterioration even after preservation for lon9 time (i~ea, for 11 months). Further, the frozen crab cou~d be packed in a box without joining adjacent crabs each other by a binder of ice formed at freezing the crab~
The living crab was wrapped by a manner same as shown in Example la Thereafter~ the inner portion surrounded by the laminate film was subjected in sequence to a air purging step to an extent such as to produce a vacuum ambience of Omm Hg, and a nitrogen gas introduction step with producing innert gas surroundings having a pressure of 80mm Hg.
Thereafter, the wrapped crab with the innert gas surroundings was rapidly frozerl by a manner shown in Example 1~
The resultant frozen crab wrapped wi~h the film was subjected to a preservation for long time, i.e~, one year or more after which the frozen crab was prevented from black colour change phenomenon~
As described in detail in the above, according to this invention~ the crustacea in the living state thereof or in a state substantialiy equal to the living state thereof is subjected to a packing step with a wrapping film, a pressure reduction step of tha inner space within the wrapping film, and a rapid freezing step~ Consequently, in the fibrous muscle tissues, are formed ice crystals comprising fine particles with a round shape~
Accordingly, the frozen crustacea has not a decrease in qualityy during the cource of preserving it~ In addition, 287~7~
without use of anti-oxidization ayent or the like, it is possible to eliminate the blackening of the Crustacea3 Further, at the time of unfreezing the frozen crustacea, a muscle tissue maintaining the living state thereof can be ob~ained.
Further, since the Crustacea is wrapped with the wrapping film~ it can be rapidly frozen by using brine liquid without a direct contact with any brine liquid. Thus, ice crystals formed in the meat portion at the time of freezing ~he meat portion can be readily made round and finer, and there.~akes place no drying in frozen state. It is ~hus possible to maintain high freshness~ Further~ the packed frozen food can be packed in a box or the like without possibility of secure~ant of adjacent pieces of Crustac0a to each other by ice,and thus can be handled very easiIy~
.:
, , . ..
..
Claims (7)
1. A packed frozen food of the crustacea comprising a wrapping film, an inner space surrounded by said wrapping film, and a frozen crustacea inserted in said inner space and rapidly frozen in a living state thereof or in a state before the hardening of fibrous muscle tissues of the meat portion thereof,said inner portion being held at a pressure ranging from 20 to 120mm Hg.
2. The packed frozen food of the crustacea according to claim 1, wherein all or most of ice crystals generated in said meat portion have round and fine shapes.
3. The packed frozen food of the crustacea according to claim 13 wherein said crustacea is a crab or a lobster.
4. The packed frozen food according to claim 1, wherein said wrapping film is a synthetic resin film consisting of a single layer or two or more layers and excellent in gas barrier and moisture-proof properties,
5. The packed frozen food according to claim 1, wherein said inner space is formed by innert gas surroundings.
6. A method of manufacturing a packed frozen food of the crustacea, in which said method comprises steps of packing the crustacea in a living state or a state before the hardening of the fibrous muscle tissues of the meat portion thereof, with a wrapping film, purging air existing in an inner space surrounded by said film so as to reduce the pressure in said inner space down to 20 to 120 mm Hg and then rapidly freezing said packed crustacea.
7. A method of manufacturing a packed frozen food of the crustacea, in which said method comprises steps of packing the crustacea in a living state or a state before the hardening of the fibrous muscle tissues of the meat portion thereof, with a wrapping film, existing in an inner space surrounded by said film, introducing an inert gas into said inner space so as to form inert gas surroundings with a pressure of at 20 to 120 mm Hg, and then rapidly freezing the resultant packed crustacea.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3276759A JP3055830B2 (en) | 1991-09-27 | 1991-09-27 | Frozen crab packaged food and method for producing the same |
| JP276759/1991 | 1991-09-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2079072A1 true CA2079072A1 (en) | 1993-03-28 |
Family
ID=17573957
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002079072A Abandoned CA2079072A1 (en) | 1991-09-27 | 1992-09-24 | Packed frozen food of the crustacea and method of manufacturing the same |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP3055830B2 (en) |
| KR (1) | KR100205171B1 (en) |
| CA (1) | CA2079072A1 (en) |
| TW (1) | TW204296B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100515198B1 (en) * | 1997-09-04 | 2005-12-21 | 니프로 가부시키가이샤 | Freezing storage method of biologic tissue |
| US6238716B1 (en) | 1998-11-05 | 2001-05-29 | Packpat B.V. | Conditioned packaging for shellfish or crustaceans |
| JP2008104384A (en) * | 2006-10-24 | 2008-05-08 | Kuoria:Kk | Method for preventing discoloration of fresh food, and fresh-food discoloration inhibitor |
| JP4659799B2 (en) * | 2007-09-07 | 2011-03-30 | 一恭 鎌田 | Method for producing frozen crab pack |
| JP5808186B2 (en) * | 2010-07-29 | 2015-11-10 | 株式会社昭和冷凍プラント | Freezing equipment and freezing method for frozen food production |
| WO2014133200A1 (en) * | 2013-02-26 | 2014-09-04 | Park Jong-Seok | Method for manufacturing individually packaged crabs marinated in soy sauce |
| CA2927207A1 (en) * | 2013-11-06 | 2015-05-14 | The Procter & Gamble Company | Flexible containers for use with short shelf-life products, and methods for accelerating distribution of flexible containers |
| KR102377918B1 (en) * | 2021-04-27 | 2022-03-22 | 허찬영 | Crab packaging method and crab packaging products using the same |
-
1991
- 1991-09-27 JP JP3276759A patent/JP3055830B2/en not_active Expired - Lifetime
- 1991-12-03 TW TW080109500A patent/TW204296B/zh active
-
1992
- 1992-03-03 KR KR1019920003452A patent/KR100205171B1/en not_active Expired - Fee Related
- 1992-09-24 CA CA002079072A patent/CA2079072A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| TW204296B (en) | 1993-04-21 |
| JPH0584038A (en) | 1993-04-06 |
| JP3055830B2 (en) | 2000-06-26 |
| KR100205171B1 (en) | 1999-07-01 |
| KR930005537A (en) | 1993-04-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4396636A (en) | Method for producing frozen-food | |
| CA2079072A1 (en) | Packed frozen food of the crustacea and method of manufacturing the same | |
| Kolbe et al. | Planning for seafood freezing | |
| CN108576559A (en) | A kind of micro- jelly food preservation method and production technology | |
| RU1837785C (en) | Fresh fish storage method | |
| AU2003248790B2 (en) | Method of freezing meat in a marinade | |
| JP7297346B1 (en) | Storage system and storage method for perishables | |
| JPS6291170A (en) | Method for freezing and preservation of food | |
| Magnussen et al. | Freezing of fish | |
| JPS60241877A (en) | Method for freezing hydrous food | |
| US20020106443A1 (en) | Method of freezing salted meat products | |
| KR100353036B1 (en) | Immersion freezing chicken and the method of chicken processing | |
| US2863779A (en) | Method of preparing shrimp in frozen condition | |
| KR102823128B1 (en) | Method of processing crustacean aquatic products with superior flesh texture and moisture retention | |
| JPS62201565A (en) | Method for putting large-sized food in cold storage | |
| JPS59106255A (en) | Preservation of fishes and shellfishes in frozen state | |
| JPS6360989B2 (en) | ||
| JP2002253177A (en) | Heat-treated shrimp and method for producing heat- treated shrimp | |
| JPH0220242A (en) | Production of frozen food | |
| JPH07327587A (en) | Frozen food and its production | |
| JP2024098598A (en) | Lean fish meat processing method and lean fish meat processed by the same | |
| Goulding | Refrigerated transport of frozen tuna | |
| JPH0335753A (en) | Preparation of frozen lobster eatable in raw state | |
| Dassow | Freezing Gulf of Mexico shrimp at sea | |
| JPH01171433A (en) | Preservation of meat of tuna |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |