JP2019068769A - Method of producing frozen bivalve - Google Patents

Abstract

To provide a method of producing frozen bivalve whose smell can be suppressed and whose sweetness can be tasted.SOLUTION: A method of producing frozen bivalve of this invention includes: a heating step for heating bivalve so that the center temperature reaches 45-65°C; a refrigerating step for refrigerating the bivalve after the heating step; and a freezing step for freezing the bivalve after the refrigerating step.SELECTED DRAWING: None

Description

  The present invention relates to a method of producing frozen bivalve shells.

  As bivalves distributed in the market, there are refrigerated distribution products and frozen distribution products. As a refrigerated distribution product, for example, it is distributed as a fresh product in a raw shelled state or in a peeled state. For example, in the state of the frozen processed material that has been heated and processed by heating in the traditional manner, it is distributed as a heated product.

  Perishables have a short shelf life, and many bivalves have a limited fishing period, so the distribution period is also limited, and market prices fluctuate significantly. There was a problem that stable supply could not be done together.

  The cooked products have a problem that the texture and the color are obviously changed as compared with the fresh products. In addition, freezing and thawing unheated bivalve shells made it loose, so it was difficult to adopt unheated items as frozen circulating products. For example, even if the bivalve shellfish (sulmy mochi) is frozen by the existing method, when it is thawed, it looses itself and loses its crispy texture peculiar to perishables, resulting in a significant loss of commercial value. was there.

  Non-Patent Document 1 describes a method for cryopreservation of clams, and it is reported that heat treatment with a central temperature of clams of 50 ° C. or more for 1 minute or more does not cause deterioration even after cryopreservation. In addition, Non-Patent Document 1 describes the color tone by heat treatment performed for 2 minutes at a water temperature of 60 ° C. and heating by residual heat in a small size clam and heat treatment performed at a water temperature of 60 ° C. for 3 minutes in a large size clam. It is reported that the texture does not deteriorate, the raw odor disappears, and it does not deteriorate even after frozen storage. Furthermore, although heat treatment at a water temperature of 60 ° C for 5 minutes or more increases sweetness, it is reported that the texture decreases. ing.

Fukushima Fisheries Research Institute Fisheries Research Institute Environment Division 1999 Fisheries Research Institute Business Report Classification Code 19-03-55000000

  An object of the present invention is to provide a method for producing frozen bivalve molluscs in which the smell is suppressed and sweetness is felt when thawed in order to stably supply bivalves in a state of high commercial value to the market.

  As a result of extensive investigations on the method for solving the above-mentioned problems, the present inventor manufactures frozen bivalves in which smell is suppressed and sweetness is felt when thawed by a specific heating step, cooling step and freezing step. It has been found that it is possible to complete the present invention.

The present invention relates to, for example, the following [1] to [6].
[1] A heating step of heating the bivalves at a temperature at which the center temperature reaches 45 to 65 ° C., a cooling step of cooling the bivalves performed after the heating step, and a freezing of the bivalves performed after the cooling step The manufacturing method of the frozen bivalve shellfish which has a process.
[2] The method for producing a frozen bivalve shellfish according to [1], wherein the cooling step is a step of setting the center temperature of the bivalve shellfish to 10 ° C. or less within 30 minutes after the end of the heating step.
[3] The method for producing bivalve shellfish according to [1] or [2], wherein the heating step is a step of heating the bivalve shellfish using a 50 to 70 ° C. solution as a heat source.
[4] The refrigeration according to any one of [1] to [3], wherein the freezing step is a freezing step in which the central temperature of bivalves passes through a temperature range of -1 to -5 ° C within 30 minutes. How to make bivalves.
[5] The frozen bivalve according to any one of [1] to [4], wherein the freezing step is a freezing step in which the central temperature of bivalves reaches -30 ° C. or less within 1 hour from the initiation of freezing. Manufacturing method.
[6] The method for producing a frozen bivalve according to any one of [1] to [5], wherein the bivalve is a snail.

  ADVANTAGE OF THE INVENTION According to this invention, when it thaws, the smell can be suppressed and the frozen bivalve shellfish which sweetness can be felt can be manufactured.

It is a comparative example and the free amino acid amount analysis result of the thin-skinned snail of the Example. It is a scheme which shows the manufacturing method of the frozen bivalve in the comparative example 3, an Example.

  The method for producing a frozen bivalve shellfish of the present invention comprises a heating step of heating the bivalve shellfish at a temperature at which the center temperature reaches 45 to 65 ° C., a cooling step of cooling the bivalve shellfish performed after the heating step, and a row after the cooling step. It has a freezing step of freezing bivalves.

(clams)
The method for producing a frozen bivalve shellfish of the present invention may be any shellfish belonging to the bivalve shellfish. For example, scallops of the snail family, scallops, snails, scallops, snails, mussels, mussels of the snails, snails of the snails, snails of the snails, snails of the snails, snails of the snails, scallops, snails, snails of the snails , Clams, clams, clams, and mussels of the clam family.

The frozen bivalves obtained by the production method of the present invention have a texture similar to that of fresh products when thawed. For this reason, the production method of the present invention is preferably used for bivalve molluscs where the texture is greatly impaired when frozen without being heated and thawed, and more specifically, the mussels, mussels, mussels, mussels Preferably, mussel is more preferred.
In addition, the Uvagai of the Bakagai family is called by its common name Hokigai.

  The state of the bivalve shellfish is fresh, unheated and may be shelled or peeled prior to the heating step. Further, the bivalve shellfish used in the heating step may be a bivalve shell shell formed by wrapping a shellfished or peeled shellfish with a plastic film or the like before the heating step.

The peeling process is a process of removing the shell from the shell and removing the viscera, mantle and scallops.
In the production method of the present invention, it is preferable to use the bivalve shell-treated after the heating step or the bivalve shell-packaged after the peel treatment, in view of the ease of heating.

(Heating process)
The method for producing a frozen bivalve shellfish of the present invention has a heating step of heating at a temperature at which the center temperature of the bivalve shell shell reaches 45 to 65 ° C.

  As a center temperature of a bivalve, 47-62 degreeC is preferable and 50-60 degreeC is more preferable. Heating until the center temperature of bivalves reaches the above-mentioned range is preferable because the texture upon thawing the frozen bivalves obtained is particularly close to that of a fresh food and less discoloration due to heating.

  By performing the heating step at a specific temperature, when the frozen bivalve shellfish obtained by the production method of the present invention is thawed, the color tone of the bivalve shellfish, the change in texture and the odor can be suppressed and the sweet taste can be increased. We estimated that.

The bivalves used in the heating step may be bivalves which are shelled and peeled as described above, or bivalves which are shelled or peeled.
The heating method is not particularly limited as long as the center temperature of the bivalve reaches 45 to 65 ° C. Immersion in a heated liquid, exposure to heated air or steam, infrared irradiation, electromagnetic wave irradiation, steam convection, Electric heating etc. are mentioned. For example, a heating method by immersion in a heated solution can be used because there is little denaturation by heating of the outer part of the bivalve shellfish at the time of heating. In this case, it is preferable to use a solution of 50 to 70 ° C. as a heat source because it can be heated promptly, and it is particularly preferable to use a solution of 60 to 65 ° C. The solution may be, for example, water or water containing other components. Examples of water containing other components include water containing sodium chloride (NaCl). When water containing sodium chloride is used, the sodium chloride concentration is preferably 1 to 4% by mass.

The other components may contain at least one component selected from potassium chloride, a seasoning, a bactericidal component and the like together with or in place of the common salt.
When using the said solution as a heat source, it is preferable to use 1-1000 times the mass of a bivalve, and it is more preferable to use 3-500 times. The use of a large amount of heat source stabilizes the temperature of the heat source, but since the apparatus becomes large, the above range is preferable from the viewpoint of balance. When using the solution within the said range, it is possible to implement this invention appropriately and the smell of a bivalve can be suppressed.

The heating is performed until the central temperature of the clam reaches a predetermined temperature in the range of 45 to 65 ° C., and it is usually 2 to 8 minutes, preferably 3 to 7 minutes.
Moreover, it is preferable to shift to a cooling process immediately after the completion of heating. Specifically, when the center temperature of the bivalve shellfish reaches a predetermined temperature (50.degree. C. or 60.degree. C. in the example) within the range of 45-65.degree. C., the heating is immediately stopped, and the center temperature is 45-65.degree. It is preferable to move to the cooling step within 5 minutes, preferably within 3 minutes, more preferably within 1 minute after reaching the predetermined temperature within the range of. There is no particular limitation on the lower limit of the time to shift to the cooling step, but it is usually 1 second or more.

  The present inventors speculate that by stopping heating immediately and moving to a cooling process, hardening of the texture of bivalve mollusks and excessive discoloration by heating such as heating due to residual heat may be suppressed. In addition, since it is possible to suppress the enzyme reaction in bivalve tissue or to suppress the growth of various bacteria, it is presumed that deterioration in eating quality may be prevented.

(Cooling process)
The method for producing a frozen bivalve shellfish of the present invention has a cooling step of cooling the bivalve shellfish, which is performed after the heating step.

  The cooling method is not particularly limited, and examples thereof include cold liquid, ice water (for example, sherbet ice), refrigeration, freezing, cooling using cold air, vaporization cooling by warm air, and the like. It is preferable to use sherbet-like ice obtained by freezing about 20 to 50% of the liquid because it can be cooled quickly. As the sherbet-like ice, a material obtained by freezing about 20 to 50% of water containing sodium chloride, such as seawater with adjusted salinity, water to which salt is added, is preferable. That is, the cooling step is preferably a step of cooling bivalve shells in sherbet ice. The water containing sodium chloride preferably has a salinity (NaCl) concentration of 1 to 4% by mass, and more preferably 2 to 3.5% by mass.

The other components may contain at least one component selected from potassium chloride, a seasoning, a bactericidal component and the like together with or in place of the common salt.
It is preferable that a cooling process is a process which sets the center temperature of a bivalve to 10 degrees C or less within 30 minutes after completion | finish of a heating process. The end of the heating step means that the center temperature of bivalves reaches a predetermined temperature in the range of 45 to 65 ° C. and the heating is ended, and in the present invention, preferably within 30 minutes after the end of the heating step. Preferably, within 15 minutes after completion of the heating step, the clams are cooled so that the center temperature of the clams is 10 ° C. or less. In addition, when heating is completed, when heating is performed by being immersed in a heated liquid, for example, it is a time of taking out from a heated liquid.

  In the cooling step, it is preferable to cool the central temperature of the clam to -2 to 10 ° C, preferably 0 to 4 ° C. The cooling step is a step which is completed usually within 35 minutes, preferably within 30 minutes after the heating step. The lower limit of the time for completing the cooling step is not particularly limited, but is usually one minute or more after the heating step is completed.

  The cooling step may be performed integrally with the subsequent freezing step. For example, after the end of heating, the cooling process can be immediately performed using a freezing apparatus, and the process can proceed to the freezing process using the freezing apparatus as it is.

(Freezing process)
The method for producing a frozen bivalve shellfish of the present invention comprises a step of heating the bivalve shellfish and a step of freezing the bivalve shellfish, which is performed after the step of cooling.

  As the bivalve shellfish used in the freezing step, the bivalve shellfish subjected to the cooling step may be used as it is. In the case where the cooling step is performed on bivalve shells, it may be used in the freezing step after being peeled off prior to the freezing step. When the cooling step is performed on an unpackaged bivalve shellfish, it may be packaged in a plastic film or the like before the freezing step and then used for the freezing step. When the cooling step is performed on the packaged clams, it may be taken out from the package before the freezing step, or may be repackaged in a desired size and then used for the freezing step.

  The freezing method is preferably a rapid freezing method, such as a gas contact freezing method (air blast freezing method), a solid contact freezing method (contact freezing method), a liquefied gas spray freezing method, a liquid immersion freezing method, etc. Can be mentioned. For example, a gas contact freezing method may be used in which freezing is performed by blowing air at about -35 to -45 ° C.

  In the freezing step, the central temperature of bivalve shellfish passes through the temperature zone of -1 to -5 ° C, which is the maximum ice crystal formation temperature zone, preferably within 30 minutes, more preferably 1 to 20 minutes. Moreover, as a freezing process, center temperature of bivalves reaches -30 degrees C or less within preferably less than 1 hour, more preferably 1 to 40 minutes from a freezing start.

(Others)
The frozen bivalve shellfish obtained by the production method of the present invention is preferably packaged at the time of its distribution. The packaging can be performed at any stage of the manufacturing method, for example, before the heating step, between the cooling step and the freezing step, or after the freezing step. The package is preferably a vacuum package from the viewpoint of a small volume after packaging and capable of preventing oxidation and drying.

  Furthermore, it may have things other than the above-mentioned process. For example, removal of non-food parts such as outer covering film and uro, washing may be performed, and after the heating step or after the cooling step, the peel may be cut and sliced into any size.

  The frozen bivalves produced by the present invention can be thawed by methods such as low temperature thaw, natural thaw, ice water thaw, water thaw, and thaw using a microwave oven. For example, low temperature thawing performed in a refrigeration temperature zone of 10 ° C. or lower and ice water thawing are preferable because they are less likely to damage the quality.

  Measurement of free amino acids can be mentioned as a method of quantitatively evaluating the taste when the frozen bivalves produced in the present invention are thawed by the above method. Free amino acids are considered to contribute greatly to the taste of bivalves, for example, to evaluate the amount of sweetness, alanine, glycine, umami aspartic acid, glutamic acid, and bitter arginine to evaluate the taste it can. In particular, alanine has a strong sweet taste, and since the threshold value is as low as 0.06 mass%, the present inventors speculate that even a small amount has a large effect on taste.

  EXAMPLES The present invention will next be described in more detail by way of examples, which should not be construed as limiting the invention thereto. In the examples,% means% by mass unless otherwise noted.

  As the mussels used in Examples and Comparative Examples, commercially available Nemurodon-produced edible mussels were used. The shelled Uva mussel was peeled off with a knife, and the non-food parts such as the outer capsular membrane and the viscera (uro) were removed to use as a peeled Uva mussel in Examples and Comparative Examples.

The measurement of the central temperature of the peeled umbilical point was carried out by inserting a thermometer into a part called "foot" of the umbilical point.
As a freezing method, a gas contact freezing method (air blast freezing method) was used.
Thawing was performed by thawing ice water.

<Evaluation method>
(sensory test)
A sensory test was carried out on the peeled fleshy snails obtained in Examples and Comparative Examples. In addition, about the Example and Comparative Examples 2 and 3, after thawing the obtained frozen Uva mussel, a sensory test was performed.
In the sensory test, five persons examined and evaluated the color tone, the amount of drip after thawing, the texture, the smell and the sweetness based on the following inspection criteria.
Color tone · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · It is desirable that there is no color change on the basis of a non-frozen peeled thin-shell (Comparative Example 1).
After thawing drips ... it is better to be less.
The texture of the texture ... frozen non Me Bare Spisula sachalinensis (Comparative Example 1) and moderate (reference), soft ones and hard ones are not good.
Smell ・ ・ ・ Less is better.
Sweetness · · · · · · · · · · · · · · · · · · · · frozen non-free skinned lobster (comparative example 1) as normal (standard), it is good to be strong.

(Measurement of free amino acid content)
The amount of free amino acids was measured by the following method for the peeled fleshy snails obtained in Examples and Comparative Examples. In Examples and Comparative Examples 2 and 3, the obtained frozen clams were stored at -60 ° C for one week, and after thawing with ice water, the amount of free amino acids was measured. In Comparative Example 1, the free amino acid amount was immediately measured after the peeling treatment.

The sample was used after quantifying what peeled about 2 g of the tip part of "feet" among peeled bodies. The sample and about 50 mL of 5% by mass trichloroacetic acid previously cooled in a refrigerator were mixed and ground in an ice-cooled mortar. Thereafter, the mixture was treated with a centrifuge at 10000 ° C. for 10 minutes at 4 ° C. to precipitate solid content. The supernatant was filtered and then made up to 100 mL and subjected to HPLC for quantification. The analysis conditions are as follows.
Detector: Fluorescence detector (RF-10AXL) (manufactured by Shimadzu Corporation)
Column: Shim-Pack Amino-Li (manufactured by Shimadzu Corporation)
・ Column temperature: 39 ° C
The analysis was performed on four samples, and the average value was calculated to be an analysis value.
The analytical value is shown as the amount of free amino acid in 100 g of sample.

Comparative Example 1
With respect to peeled fleshy snails, raw sensory test and measurement of free amino acid content were performed. The results are shown in Table 1 as perishables.

Comparative Example 2
<Frozen and thawed product>
The peeled umbilical cord was packaged in a zippered sealed bag without heating, frozen and then thawed.
Freezing is rapid freezing, and the air blast freezing method is performed so that the central temperature of the peeled flatfish passes through the temperature range of -1 ° C to -5 ° C within 20 minutes and reaches -30 ° C or less within 40 minutes. Frozen using

  The above frozen peeled fleshy snail was thawed at a refrigeration temperature of 10 ° C. or less. The thawing was performed by immersing in ice water, and was terminated when the center temperature reached 0 ° C. or higher, and a sensory test and measurement of the amount of free amino acid were performed. The results are shown in Table 1.

[Examples 1-2, Comparative Example 3]
<Heating, cooling, freezing, thawing product>
Peel the fleshy Uva mussel, put in 2% saline kept at 63 to 65 ° C, for 1 to 3 minutes (Comparative Example 3), 3 to 5 minutes (Example 1), 4 to 7 minutes (Example 2) The mixture was heated with intermittent stirring. The 2% saline solution was prepared to be about 3 times the mass of peeled bare metal.

  Immediately after raising the temperature to 40 ° C., 50 ° C., and 60 ° C., the center temperature of the peeled umbilical cactus was measured, and then immediately introduced into a sherbet-like 2% saline solution and cooled. Cooling was done to reach 0 ° C. within 10 minutes.

  After cooling, it was drained to remove stains on the surface of the black pigment part of Uva mussel, and remaining edible parts such as outer membrane and uro. It was then washed, packaged in a zippered closed bag and flash frozen. The freezing and thawing process, the sensory test and the measurement of the amount of free amino acid were performed in the same manner as in Comparative Example 2 above.

Table 1 shows the results of sensory test and measurement of the amount of free amino acid in Examples and Comparative Examples.
In Example 1, compared to Comparative Example 1, there was no change in color tone and texture. The best results were obtained because the drip after thawing was almost nonexistent, odorless and sweet.

In Example 2, although there was a change in color tone as compared to Comparative Example 1, there was no change in texture, and there was almost no drip after thawing, no odor and strong sweetness, so good results were obtained. Was obtained.
In Comparative Examples 2 and 3, as compared with Comparative Example 1, the change in texture of the peeled flatfish after thawing can not be suppressed and it is soft and has a smell.
The examples were superior to Comparative Examples 1 and 2 in terms of odor, sweetness, texture and drip.

Moreover, in Examples 1 and 2, it is surmised that alanine which is a free amino acid which exhibits sweetness increases among free amino acids, and sweetness came to be felt strongly.
FIG. 1 shows the results of quantification of free amino acids of peeled umbilicalus. It can be seen that the amount of alanine is increased in Example 1 and Example 2. Based on the threshold of alanine being 0.06% by mass, it is presumed that sweetness can be felt to be increasing.
In FIG. 2, the outline of the manufacturing method of the frozen bivalve shell of the comparative example 3 and the Example was shown. The steps of the solid line show essential steps in the present invention, and the steps of the dotted line show optional steps.

Claims (6)

Heating the bivalve molluscs at a temperature at which the center temperature reaches 45-65 ° C.,
A method for producing a frozen bivalve shellfish, comprising a cooling step of cooling bivalve shells, which is performed after the heating step, and a freezing step of freezing bivalve shells, which is performed after the cooling step.   The manufacturing method of the frozen bivalve shellfish according to claim 1, wherein the cooling step is a step of setting the central temperature of the bivalve shell shell to 10 ° C or less within 30 minutes after the end of the heating step.   The method for producing bivalve shells according to claim 1 or 2, wherein the heating step is a step of heating the bivalve shells using a solution at 50 to 70 ° C as a heat source.   The manufacturing method of the frozen bivalve according to any one of claims 1 to 3, wherein the freezing step is a step of passing the temperature range in which the center temperature of the bivalve is -1 to -5 ° C within 30 minutes.   The manufacturing method of the frozen bivalve according to any one of claims 1 to 4, wherein the freezing step is a freezing step in which the central temperature of the bivalve reaches -30 ° C or less within one hour from the start of freezing.   The method for producing a frozen bivalve according to any one of claims 1 to 5, wherein the bivalve is a snail.