JP7735448B2 - Frozen scallops - Google Patents

Description

(1) Hybrid Lab Co., Ltd. published the frozen seafood manufacturing method, frozen seafood manufacturing system, and frozen seafood invented by Keiichiro Mochizuki on a mailing list from February 4 to February 5, 2022. (2) Luckland Co., Ltd. published the frozen seafood manufacturing method, frozen seafood manufacturing system, and frozen seafood invented by Keiichiro Mochizuki on February 8, 2022, on its website https://www.luckland.co.jp/company/news/index.html, https://www.luckland.co.jp/company/news/2022/0208_line.html, https://www.luckland.co.jp/company/news/2022/0208_line.html, https://www.luckland.co.jp/company/news/2022/0208_line.html. (3) On February 8, 2022, PR TIMES Co., Ltd. published a frozen seafood production method, a frozen seafood production system, and frozen seafood invented by Keiichiro Mochizuki on its website https://prtimes.jp/main/html/rd/p/000000198.000000669.html. (4) On February 8, 2022, Japan Exchange Group, Inc. published on its website https://www.jpx.co.jp/listing/co-search/index.html and https://www2.jpx.co.jp/disc/96120/140120220208583133.pdf the frozen seafood production method, frozen seafood production system, and frozen seafood invented by Keiichiro Mochizuki.

The present invention relates to frozen scallop adductor muscle .

A conventional method for producing frozen seafood is the frozen scallop production method (Patent Document 1). This method involves discarding one half of the scallop shell, removing the roe from the flesh adhering to the other half, separating the flesh from the other half, washing the peeled flesh and soaking it in seawater for several hours, soaking one half of the shell in chlorine water followed by rinsing under running water and draining, soaking the peeled flesh and the other half of the shell in chlorine water to sterilize them again, placing the peeled flesh on top of the other half of the shell to combine them, flash-freezing the scallops using a refrigerant such as liquid nitrogen, glazing them, and storing them frozen at -30°C or below.

Japanese Patent Application Publication No. 3-254632

However, the method described in Patent Document 1 requires many steps before freezing, such as washing the peeled meat and one half of the shell separately and then placing the peeled meat on top of the other half of the shell to combine them, which makes it difficult to maintain freshness during this process.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide frozen scallops that are superior in freshness to conventional frozen seafood.

[Method for producing frozen seafood]
The frozen seafood production method of the present application is a method for producing frozen seafood by freezing seafood, and includes the steps of raising the seafood, packaging the edible portions of the seafood after raising, and freezing the packaged edible portions together with the packaging material using saturated salt water.

In this application, "marine products" refers to plants and animals that live in the sea, including shellfish, fish, and seaweed. "Landing" refers to the short-term cultivation of landed seafood in tanks such as fish preserves (landing tanks).

[Frozen seafood production system]
The frozen seafood production system in this application is a frozen seafood production system that produces frozen seafood, and is equipped with a farm tank for farming seafood, a packaging machine for packaging the farmed seafood, and a freezer for freezing the packaged seafood together with the packaging material.

[Frozen scallops ]
The frozen adductor muscle of the present invention is a seafood product in which the edible portion is frozen, and the K value of the edible portion after thawing, as measured by high performance liquid chromatography, is 20% or less.

The frozen seafood production method and frozen seafood production system of the present application can reproduce ATP, which affects the freshness of seafood, by raising seafood, and can produce highly fresh frozen seafood by freezing seafood using saturated salt water without destroying the seafood cells.Furthermore, the frozen scallop adductor muscle of the present invention has superior freshness compared to conventional frozen seafood.

1 is a flowchart showing an example of a method for producing frozen seafood according to the present application. 1 is a schematic diagram showing an example of a frozen seafood production system according to the present application;

(Embodiment of frozen seafood production method)
An example of an embodiment of the frozen seafood production method of the present application will be described with reference to the drawings. For convenience of explanation, the following example will be described in which the seafood is scallops and the edible part is their adductor muscle. The following description will use the symbols shown in Figure 2, but this is for convenience only and does not mean that the system for implementing the frozen seafood production method of the present application is limited to the frozen seafood production system shown in Figure 2.

As shown in Figure 1, the main processes of the frozen seafood production method of this embodiment include a process of raising scallops (raising process) S001, a process of removing the shells from the raised scallops (shelling process) S002, a process of vacuum-packaging the adductor muscles (edible parts) of the removed scallops (vacuum packaging process) S006, and a process of freezing the vacuum-packaged adductor muscles together with the packaging (freezing process) S007.

Between the shelling process S002 and the vacuum packaging process S006, the process of washing the adductor muscle (first washing process) S003, the process of sorting the adductor muscle according to size, etc. (sorting process) S004, and the process of draining the water adhering to the adductor muscle (draining process) S005 are carried out.

Furthermore, after the freezing step S007, there are steps to remove salt water adhering to the adductor muscle (second washing step) S008, remove water droplets adhering to the adductor muscle (water removal step) S009, check the frozen state and finished packaging (inspection step) S010, attach a label to the packaging (labeling step) S011, and freeze and store the packaged adductor muscle (hereinafter referred to as "packaged adductor muscle") (frozen storage step) S012. Each of these steps is explained below.

[Livestock farming process]
The stocking step S1 is a step of stocking the shelled scallops, from which any extraneous matter has been removed after landing, in a stocking tank 11. Stocking is carried out by placing cages containing the scallops in the stocking tank 11.

When raising scallops, the same cages used for transporting them from fishing ports, etc. can be used as they are. This eliminates the need to switch to cages specifically for raising scallops, and also prevents damage to the scallops during the switch.

There are no particular restrictions on the size of the culture tank 11, but it is preferable to use a container large enough to fit multiple baskets lined up vertically and horizontally. In this case, by using a culture tank 11 large enough to accommodate multiple layers (for example, two layers) of baskets, the amount that can be cultured at one time can be increased.

In this embodiment, seawater is used for farming. The seawater can be cooled seawater from the habitat of the farmed scallops. During farming, the seawater temperature is kept within a preset temperature range suitable for farming (hereinafter referred to as the "farming temperature range").

Seawater can be stored in a water storage tank 15 installed near the farm tank 11, and the seawater can be supplied into the farm tank 11 using a supply hose (supply means) 18.

In this embodiment, a bubble generator 12 attached to the end of a supply hose 18 is submerged in the aquaculture tank 11, and the bubbles generated by this bubble generator 12 cause the amount of dissolved oxygen in the seawater to exceed a preset threshold value (hereinafter referred to as the "dissolved oxygen reference value").

In this embodiment, a device that generates microbubbles is used as the bubble generator 12. The bubble generator 12 may be a device that generates microbubbles, or may be a device that generates various types of bubbles, such as nanobubbles or ultrafine bubbles. One or more bubble generators 12 may be installed depending on the capacity of the farm tank 11, etc.

In this embodiment, the action of microbubbles allows the adhesions on the scallops and waste products discharged from the scallops to be discharged outside the tank 11. Specifically, the amount of seawater in the tank 11 is increased and allowed to overflow from the tank 11, thereby discharging the adhesions and waste products outside the tank 11. The adhesions and waste products can be discharged outside the tank 11 using a wiper or the like, or they can be collected using a net or the like and discharged outside the tank 11.

[Shelling process]
The shelling step S002 is a step of removing the shells from the scallops. In this embodiment, the shells of the scallops are manually removed after farming, and the adductor muscle, uro, string, and shell are separated. For the shelling, an existing or new spatula can be used.

[First cleaning step]
The first washing step S003 is a step of washing the seawater adhering to the adductor muscle removed in the shelling step S002 with a washing liquid to remove foreign matter such as small shells. The washing liquid may be, for example, sterilized and cooled seawater (sterilized cooled seawater) or other liquids.

Cleaning can be done by spraying the cleaning solution onto the adductor muscle, or by immersing the adductor muscle in the cleaning solution. When spraying the cleaning solution onto the adductor muscle, it is preferable to spray the cleaning solution with a water pressure that is low enough not to damage the adductor muscle.

[Sorting process]
The sorting step S004 is a step of sorting the adductor muscles by size and removing any defective ones. In this embodiment, an operator visually checks the size of the washed adductor muscles and manually sorts them by size. If any defective ones are found, they are removed.

[Draining process]
The draining step S005 is a step of removing water adhering to the adductor muscle. This step can be performed by, for example, blowing air onto the washed adductor muscle placed in a basket, rotating the basket containing the washed adductor muscle, or by other methods.

[Vacuum packaging process]
The vacuum packaging step S006 is a step of vacuum-packaging the adductor muscle that has been subjected to the above steps. In this embodiment, the adductor muscle is vacuum-packaged by so-called skin pack packaging, which involves thermocompression bonding so that no gaps form between the film and the adductor muscle.

This vacuum-sealed packaging prevents moisture from escaping from the scallops, preserving their freshness. However, the packaging method shown here is just one example, and scallops can also be packaged in other ways.

In this embodiment, multiple adductor muscles are vacuum-packaged with the adductor muscles arranged at equal intervals between the films. A resin film with a thickness of approximately 0.1 mm to 0.5 mm can be used for the film. The film thickness and material are examples, and other thicknesses and materials may also be used.

[Freezing process]
The freezing step S007 is a step of freezing the packaged scallops together with the packaging material. In this embodiment, the packaged scallops are frozen by the so-called hybrid ice method, which uses a high-concentration salt solution (saturated salt water) at a temperature of −21.3° C. and a salt concentration of 23.5%.

For freezing using the hybrid ice method, an existing freezer 17, such as a hybrid ice freezer, can be used. When using a hybrid ice freezer, the packaged scallops are immersed in sludgy ice flowing at a predetermined flow rate for a predetermined period of time, and then the packaged scallops are frozen.

There is no particular limit to the time for immersion in the ice cream mud, but it is preferable to immerse the scallops until the core temperature drops below -5°C, which is the lower limit of the maximum ice crystal formation zone.

Freezing using the hybrid ice method allows the scallops to pass through the maximum ice crystal formation temperature range of -1°C to -5°C in a short period of time, which has the advantage of preventing the cells of the adductor muscle from breaking down and making it easier to maintain the umami compounds and ATP (adenosine triphosphate) contained in the adductor muscle.

In this embodiment, high-concentration saline solution at -21.3°C is used, but the temperature of the high-concentration saline solution may be other than this, and can be set appropriately within the range of, for example, approximately -21.3°C to -20.0°C.

[Second cleaning step]
The second washing step S008 is a step of washing away salt that has adhered to the film (packaging material) during freezing in the freezing step S007. This step can be performed, for example, by immersing the packaged adductor muscle in fresh water stored in a container, by spraying fresh water onto the packaged adductor muscle, or by other methods.

[Water removal process]
The water removal step S009 is a step of removing water adhering to the surface of the packaging material. This step can be performed, for example, by spraying jet air onto the packaged scallops or by other methods. An existing water remover can be used for the water removal.

[Inspection process]
The inspection step S010 is a step of inspecting whether there are any problems with the freezing state of the packaged scallops or the finish of the packaging (whether it meets predetermined standards). Packaged scallops that do not meet the predetermined standards are rejected in this step.

[Labeling process]
The labeling step S011 is a step of attaching a product label or the like to the packaged adductor muscle. An existing device can be used for the labeling step. The labeling step S011 can also be performed manually.

[Frozen storage process]
The frozen storage step S012 is a step of storing the packaged scallops with product labels and the like attached in a frozen state together with the packaging. For the frozen storage, an existing freezer or the like can be used.

The frozen scallops (frozen seafood) produced through the farming process S001, the shelling process S002, the vacuum packaging process S006, and the freezing process S007 of this embodiment had a K value of 20% or less and a yield stress of 0.003 kgf/mm2 or ^more when measured by high performance liquid chromatography (HPLC).

The K value is a numerical value that indicates the freshness of seafood (especially seafood such as fish and shellfish), with a lower value indicating higher freshness. A K value of 20% or less is approximately one-third the value of frozen scallops produced using conventional methods. As shown in Table 1 below, seafood with a K value of 20% or less is considered suitable for eating raw as sashimi.

The yield stress is a numerical value that indicates the elasticity of seafood, and a higher value indicates higher elasticity (more chewy). A yield stress of 0.003 kgf/mm2 or ^more is about 1.4 times that of frozen scallops produced by conventional general production methods.

(Other embodiments of the frozen seafood production method)
In the above embodiment, the seafood is scallops as an example, but the frozen seafood production method of the present application can be used as a frozen seafood production method using seafood other than scallops, for example, various bivalve shells such as oysters, surf clams, clams, and manila clams, squid, octopus, and edible jellyfish.

In the above embodiment, an example is shown in which seawater stored in a water storage tank 15 installed near the aquaculture tank 11 is supplied to the aquaculture tank 11 via a supply hose 18, but seawater can also be supplied directly to the aquaculture tank 11 from a water truck or the like. Furthermore, if the processing facility is located near a fishing port or aquaculture farm, seawater can also be supplied directly to the aquaculture tank 11 using a pump or the like.

In the above embodiment, marine products are cultivated in seawater as an example, but they can also be cultivated in liquids other than seawater. For example, liquids similar to seawater components artificially created using water and salt can be used.

Although not explained in the above embodiment, the frozen seafood production method of the present application is not limited to use with wild seafood, but can also be used as a method for producing frozen seafood from farmed seafood.

In the above embodiment, an example is given in which all steps from the livestock rearing step S001 to the frozen storage step S012 are carried out as a single series of steps, but not all of the steps in the above embodiment are essential, and unnecessary steps can be omitted as appropriate.

In the above embodiment, an example is given in which each step from the livestock rearing step S001 to the frozen storage step S012 is carried out in the specified order, but the steps in the above embodiment do not always have to be carried out in that order, and the order can be changed as necessary.

The configuration of the above embodiment is an example, and the frozen seafood production method of the present application is not limited to this configuration. The frozen seafood production method of the present application can be modified, such as by adding, omitting, or replacing components, as long as the intended purpose can be achieved.

The frozen seafood production method of this application can be implemented, for example, using the frozen seafood production system described below or other systems.

(Embodiment of frozen seafood production system)
An example of an embodiment of a frozen seafood production system according to the present invention will be described with reference to the drawings. The frozen seafood production system shown in Fig. 2 includes a culture tank 11, a bubble generator 12, a measuring device 13, a control means 14, a water storage tank 15, a packaging machine 16, and a freezer 17.

The aquaculture tank 11 is a tank for raising marine products. An existing fish pen or the like can be used as the aquaculture tank 11. The size and shape of the fish pen can be determined appropriately depending on the size, shape, and quantity of the marine products to be raised. In this embodiment, a tank with a capacity large enough to hold two stacked cages containing marine products is used.

In this embodiment, the culture tank 11 is equipped with a temperature control function, so that the seawater temperature in the culture tank 11 is maintained within the culture temperature range.

The bubble generator 12 is a device for supplying bubbles into the farm tank 11. In this embodiment, a microbubble generator 12 that generates microbubbles is used as the bubble generator 12. The bubble generator 12 may also be a device other than a microbubble generator, such as a nanobubble generator 12 that generates nanobubbles.

In this embodiment, seawater stored in the water storage tank 15 can be supplied to the aquaculture tank 11 using a supply hose 18, and a microbubble generator is attached to the tip of the supply hose 18. The microbubble generator is submerged in the seawater in the aquaculture tank 11 so that microbubbles can be supplied into the seawater.

The measuring device 13 is a device for measuring the amount of dissolved oxygen in the seawater in the culture tank 11. An existing dissolved oxygen meter can be used as the measuring device 13. The measuring device 13 may be provided as needed, and can be omitted if not required. When the measuring device 13 is provided, the measurement results from the measuring device 13 can be transmitted to the control means 14.

In this case, the control means 14 determines from the transmitted numerical value whether the amount of dissolved oxygen in the seawater in the culture tank 11 is equal to or greater than the dissolved oxygen standard value, and if the dissolved oxygen level is less than the standard value, the output of the bubble generator 12 can be controlled so that the dissolved oxygen level in the seawater is equal to or greater than the dissolved oxygen standard value.

Measurement by the measuring device 13 and control of the bubble generator 12 by the control means 14 are repeated to ensure that the amount of dissolved oxygen in the seawater in the culture tank 11 is always above the dissolved oxygen reference value. This control can be performed as needed, and can be omitted if not required.

The control means 14 starts and stops the supply of seawater based on control signals from a switch (not shown), and also adjusts the seawater temperature in the culture tank 11 based on control signals from a temperature regulator (not shown). The control means 14 also controls the operation of the valve generator 12, among other things.

The water storage tank 15 is a tank for storing seawater used for farming. In this embodiment, the water storage tank 15 is equipped with a cooling means 15a for maintaining the stored seawater at a constant temperature and a stirring means 15b for stirring the stored seawater. The capacity of the water storage tank 15 can be determined appropriately depending on the size, shape, and quantity of the seafood to be farmed.

In this embodiment, the temperature of the seawater stored in the water storage tank 15 is set to be the same as or lower than the temperature of the seawater in the aquaculture tank 11. In this case, if the seawater temperature in the aquaculture tank 11 rises during the aquaculture process, the advantage is that the seawater temperature in the aquaculture tank 11 can be lowered by supplying seawater from the water storage tank 15 into the aquaculture tank 11.

The water storage tank 15 is provided with a supply hose 18 that supplies the stored seawater into the aquaculture tank 11. As mentioned above, a bubble generator 12 is attached to the end of the supply hose 18. The end of the supply hose 18 to which the bubble generator 12 is attached is submerged in the liquid in the aquaculture tank 11.

The packaging machine 16 is a device for packaging seafood after farming. In this embodiment, a vacuum seal packaging machine is used as the packaging machine 16, which seals the seafood in film and vacuum packages it. Using a vacuum seal packaging machine has the advantage that the cells of the scallop adductor muscle to be packaged are not destroyed, making it easier to maintain freshness.

The freezer 17 is a device for freezing packaged seafood together with the packaging. In this embodiment, the freezer 17 is a hybrid ice freezer equipped with a freezing tank 17a that contains saturated salt water and a flow means 17b that circulates the saturated salt water in the freezing tank 17a.

The hybrid ice freezer of this embodiment is equipped with a cooling means 17c that maintains the temperature of the saturated salt water in the freezing tank 17a at approximately -21.3°C, and a speed control means 17d that controls the flow rate of the saturated salt water in the freezing tank 17a.

Seafood cells are easily destroyed when passing through the maximum ice crystal formation zone, between -1°C and -5°C. However, as in this embodiment, by immersing the packaged seafood in its packaging in saturated saltwater maintained at approximately -21.3°C, the maximum ice crystal formation zone can be passed through in a short time. As a result, the adductor muscle cells are less likely to be destroyed, and the umami compounds and ATP (adenosine triphosphate) contained in the adductor muscle can be maintained.

(Other embodiments of the frozen seafood production system)
In the above embodiment, an example is given in which one water storage tank 15 is provided, but it is also possible to provide two or more water storage tanks 15. For example, if two water storage tanks 15 are provided, one can store seawater at a higher temperature than the seawater in the culture tank 11, and the other can store seawater at a lower temperature than the seawater in the culture tank 11.

By doing this, if the seawater temperature in the culture tank 11 rises during the culture process, the advantage is that the seawater temperature in the culture tank 11 can be lowered simply by supplying seawater with a lower temperature than the seawater in the culture tank 11.

On the other hand, if the seawater temperature in the culture tank 11 drops during the culture process, there is the advantage that the seawater temperature in the culture tank 11 can be raised simply by supplying seawater with a higher temperature than the seawater in the culture tank 11. In either case, it is easy to adjust the seawater temperature in the culture tank 11.

The frozen seafood production system of the above embodiment does not include any of the steps included in the frozen seafood production method that are performed manually, such as the shelling process and sorting process, but if these steps can be performed using equipment, the system can also be configured to include this equipment.

The configuration of the above embodiment is an example, and the frozen seafood production system of the present application is not limited to the above configuration. The frozen seafood production system of the present application can be modified, such as by adding, omitting, or replacing components, as appropriate, to the extent that the intended purpose can be achieved.

(component analysis)
In order to demonstrate the effectiveness of the method for producing frozen seafood of the present application, the applicant conducted a component analysis of the adductor muscle of a scallop processed by the method for producing frozen seafood of the present application.

Component analysis included analysis of the K value and the elements used to calculate the K value: ATP (adenosine triphosphate), ADP (adenosine diphosphate), AMP (adenosine monophosphate), IMP (inosinic acid), HxR (inosine), and Hx (hypoxanthine).

As mentioned above, the K value is an index that represents the freshness of seafood and is calculated using the following formula 1.
[Formula 1]

After seafood dies, ATP is not regenerated, but changes to ADP → AMP → HxR → Hx. The ATP in the adductor muscle immediately after shelling affects the K value, and the higher the amounts of ATP, ADP, and AMP, the better the K value.

Although there are differences depending on the type of seafood, generally, the lower the K value, the higher the freshness, and it is evaluated as shown in Table 1 below (Journal of the Japanese Society of Fisheries Science, Vol. 24 (9) (Tsuneyuki Saito, Noriyuki Enomoto, Minoru Matsuyoshi, Japanese Society of Fisheries Science, 1959, pp. 749-750).

The results of this component analysis are shown in Table 2.

This component analysis confirmed that the frozen seafood production method described in this application can produce frozen scallops with a K value of 20% or less.

(Compression test)
The present applicant conducted a compression test to measure the elasticity of the frozen seafood obtained by the frozen seafood production method of the present application. In this compression test, the force required to crush the adductor muscle to 10 mm was measured. The compression test was conducted on the adductor muscle used in the component analysis. A conventional rheometer was used for the compression test.

The results of this compression test are shown in Table 3.

This compression test confirmed that the method for producing frozen seafood of the present invention can produce frozen scallops with a yield stress of 0.003 kgf/ ^mm2 or more.

The frozen seafood production method and frozen seafood production system of the present application can be used as a method and system for producing frozen seafood from various seafood. Furthermore, the frozen scallops of the present invention can be produced and sold as an independent commercial product.

REFERENCE SIGNS LIST 11 Stock tank 12 Bubble generator 13 Measuring instrument 14 Control means 15 Water storage tank 15a Cooling means 15b Stirring means 16 Packaging machine 17 Freezer 17a Freezing tank 17b Flow means 17c Cooling means 17d Speed control means 18 Supply hose (supply means)

Claims (1)

In frozen scallops ,
The K value of the thawed adductor muscle is 20% or less as measured by high performance liquid chromatography, and the yield stress of the thawed adductor muscle is 0.003 kgf/ ^mm2 or more as measured by a compression test that measures the force required to crush the adductor muscle 10 mm .
1. A frozen scallop characterized by: