JP6644318B1 - Method for suppressing ammonia and the like generated during cooking such as thawing and / or heat treatment of (processed) frozen food of fish meat - Google Patents

Abstract

An object of the present invention is to carry out an alkali treatment for processing fish meat after frozen storage and cooking into a soft texture, while detecting the meat during cooking such as thawing and / or heat treatment due to the alkali treatment. To provide a method for significantly suppressing an increase in volatile basic nitrogen such as ammonia. A method for reducing the amount of volatile basic nitrogen detected during thawing and / or cooking of fish processed (processed) frozen food produced by a method for producing fish processed (processed) frozen food including alkali treatment. And a step of adsorbing volatile basic nitrogen to a porous adsorbent after the alkali treatment in the production method. ) Method of producing frozen food. [Selection diagram] None

Description

  The present invention relates to a method for producing (processed) frozen food of fish meat, particularly when a (processed) frozen food of fish meat produced by a production method including an alkali treatment is cooked by thawing and / or heat treatment. The present invention relates to a method for suppressing (reducing) the amount of volatile basic nitrogen such as ammonia, which is a factor of fish odor, and a method for producing (processed) frozen food of fish meat including the method for reducing the amount.

  Presence of frozen food can be said to act as a business for a restaurant or the like or for cooking in a home kitchen. In other words, the number of menu items can be increased or the cooking time can be shortened at home or a business, and stable quality can be maintained regardless of who cooks. Furthermore, by harvesting and processing frozen foods at the "season" time, the most nutritious and delicious foods can be provided to consumers and businesses at low cost.

  Furthermore, an excellent feature of frozen foods is that they do not rot, which means that foods can be used effectively without wasting and wasting food waste. Leads to a reduction. Furthermore, since the portion of the frozen food that cannot be eaten at the stage of “pre-treatment” is excluded, the amount of garbage generated at the stage of cooking can be reduced.

  As described above, since frozen foods have many excellent characteristics, processed and frozen fish meat is widely manufactured and distributed, so that it can be stored for a long period of time, and can be thawed properly. It has become possible to easily cook a fish dish having a taste and appearance comparable to fresh fish.

  On the other hand, bones, smells, and flares have been cited as causes of lower fish eating rates, and in the fisheries industry, bone removal, masking of smells, Frozen fish meat (processed) foods such as frozen fish fillets that have been subjected to secondary processing such as “soft texture” after thawing cooking have come to market.

  Background of the demand for “soft texture” in (processed) frozen food of fish meat is to respond to the decline in chewing and swallowing functions and mass cooking due to the increase in the number of welfare facilities users due to the declining birthrate and aging of Japan. It has become essential to take measures against drought resistance by storage in a warm storage room.

  In processing such a "soft texture", in the following conventional techniques, an alkali treatment is performed in the process of producing (processed) frozen food of fish meat.

  For example, Patent Literature 1 discloses a method for producing a frozen fish in which the flavor and texture are maintained more favorably, with an alkali having a pH of 11.6 to 12.6 containing trisodium phosphate, an organic acid salt, and a saccharide. There is described a method for producing a frozen fish, in which a fish body is immersed in an aqueous solution for 10 minutes or more, alkali-treated, and then frozen. In addition, the alkali treatment effectively dissolves and reduces the fish odor component caused by ammonia and amines such as trimethylamine and dimethylamine contained in the fish, and reduces the fish odor component. Is described as being able to be reduced.

  Further, as shown in Patent Document 2, as a method for treating fish to have a soft texture, a raw fish is immersed in an aqueous alkaline solution having a pH of 8.0 to 12.5 at atmospheric pressure and room temperature for 30 minutes or more. The alkali-treated fish is placed in a heat treatment space as a semi-open space including a part of a transport line surrounded by a partition plate, and the temperature of the heat treatment space is set to 90 ° C. to 300 ° C. in a range of 5 ° C. to 5 ° C. Either normal pressure superheated steam or saturated steam is supplied from a number of nozzle injection ports of the heating device so as to be maintained for 60 minutes, thereby heat-sterilizing the fish, and heat-sterilizing the fish at -18 ° C. A method for producing a semi-material frozen fish that is rapidly frozen to the following temperatures is shown.

  According to Patent Document 3, as a method for producing a frozen fish which is delicious even when cooked frozen, has no fishy smell, has no curd, and saves the trouble of cooking, the fish body is adjusted to pH 7.1 or more and 11.5 or less. There is disclosed a method of immersing a fish in an alkaline aqueous solution at room temperature under an atmospheric pressure for a predetermined time and freezing the alkali-treated fish. Furthermore, it describes that a fish body is immersed in an aqueous solution containing 0.1 to 20% by mass of a chlorella extract for a predetermined time for the purpose of deodorizing volatile basic nitrogen.

  Also in Patent Document 4, it is possible to heat-cook in a frozen state, suppress the occurrence of curd generated on the surface of the fish during cooking, reduce the odor peculiar to fish, harden the body, and make it difficult for the fish to stick. As a frozen fillet having a taste and a plump texture and being delicious even when cooled, an alkaline aqueous solution having a pH of 9 to 13 was injected and permeated to adjust the pH to a 0.1 to 1.5 alkaline side. A production method by a process of using an intermediate material is shown.

  Patent Literature 5 discloses a method for suppressing the occurrence of quality deterioration due to the decomposition of trimethylamine-N-oxide (TMAO), which is a precursor of trimethylamine, which proceeds during frozen storage of fish meat. The adjustment method and the like have been disclosed above. The pH is adjusted using an alkaline seasoning solution which is an aqueous alkaline solution such as sodium hydrogen carbonate, sodium carbonate and sodium hydroxide.

Patent No. 4616409 Patent No. 6389939 Patent No. 4282746 specification Patent No. 5044036 JP 2005-269960 A

  However, surprisingly, in the prior art as described above, the flavor and texture such as the “soft texture” after the thawing and cooking of (processed) frozen food of fish meat, and the odor peculiar to fish are improved. By various "alkaline treatments" (immersion of fish meat in alkaline aqueous solution, injection of alkaline aqueous solution into fish meat, etc.) performed to reduce (trimethylamine), rather than thawing (processing) frozen food of fish meat and / or Alternatively, it has been found that the amount of ammonia detected during cooking such as heat treatment increases.

  Trimethylamine is a substance that causes fish-specific odor caused by the decomposition (reduction) of trimethylamine-N-oxide (TMAO), which is contained in fish as an osmotic pressure adjusting component, in the process of decay of fish. One. Ammonia is produced by further decomposition of trimethylamine. These are generally included in volatile basic nitrogens which are indicators of spoilage of protein foods such as fishery products and meat. Ammonia and trimethylamine, together with mercaptan and hydrogen sulfide, are also commonly referred to as "four major malodors", and are included in the 22 components designated as "specific malodorous substances" by the Malodor Control Law.

  Therefore, an object of the present invention is to solve the problems in the prior art relating to the production of such (processed) frozen food of fish meat and to carry out an alkali treatment for processing the fish meat after frozen storage and cooking into a soft texture. On the other hand, on the other hand, there is provided a method for significantly suppressing an increase in volatile basic nitrogen such as ammonia detected during cooking such as thawing and / or heat treatment due to the alkali treatment.

  The present inventor performs an adsorption step for volatile basic nitrogen with a porous adsorbent after an alkali treatment in the production of (processed) frozen food, so that the frozen food can be thawed and / or cooked by heat treatment or the like. The present inventors have found that the amount of volatile basic nitrogen such as ammonia detected in the above can be significantly reduced or suppressed, and completed the present invention.

The present invention relates to the following aspects.
[Aspect 1]
A method for reducing the amount of volatile basic nitrogen detected at the time of thawing and / or cooking fish meat (processed) frozen food produced by the method for producing fish processed (processed) frozen food including alkali treatment, comprising: The above-mentioned reduction method, wherein a step of adsorbing volatile basic nitrogen to the porous adsorbent is performed after the alkali treatment in the production method.
[Aspect 2]
The reduction method according to embodiment 1, wherein at least a part of the volatile basic nitrogen is newly generated from the fish meat by an alkali treatment.
[Aspect 3]
3. The reduction method according to aspect 1 or 2, wherein the alkali treatment comprises immersing the fish meat in an aqueous alkaline solution having a pH of 7.1 to 12.6.
[Aspect 4]
The reduction method according to any one of aspects 1 to 3, wherein the volatile basic nitrogen generated from fish meat is adsorbed on the porous adsorbent by immersing fish meat in an aqueous solution containing a porous adsorbent.
[Aspect 5]
The reduction method according to any one of aspects 1 to 4, wherein the porous solid adsorbent contains activated carbon and / or zeolite as an active ingredient.
[Aspect 6]
The reduction method according to any one of claims 1 to 5, wherein the volatile basic nitrogen is ammonia.
[Aspect 7]
A method for producing (processed) frozen fish meat, comprising the steps of:
1. Pretreatment including the method for reducing the amount of volatile basic nitrogen according to any one of Embodiments 1 to 6;
2. 2. washing; Packaging.
[Aspect 8]
The pretreatment step is further characterized in that it includes one or more steps selected from the group consisting of a raw material thawing step, a processing step, an X-ray residual bone inspection step, a washing step, and a dewatering step. The manufacturing method according to aspect 7.

The (processed) frozen food of fish meat is provided to food through various cooking means such as heat treatment, if necessary, after thawing or in a frozen state.
In the method of the present invention, the amount of volatile basic nitrogen detected at the time of thawing and / or cooking of the (processed) frozen food obtained by the conventional method for producing (processed) frozen food of fish meat including alkali treatment After the alkali treatment, a volatile adsorbent such as ammonia, which is generated from fish meat (caused by spoilage of fish meat and alkali treatment in the production method), is adsorbed and removed by a porous adsorbent. By providing an economical treatment means, it is possible to significantly reduce (suppress).

  Fish meat, which is a frozen food produced by the method of the present invention, need not contain additives other than the additives used in the prior art for suppressing freeze denaturation. As a result, for example, the sodium content in the frozen food does not increase as compared with the prior art.

[Requirements for frozen foods]
According to the Japan Frozen Food Association, the following four voluntary standards (processes) must be met for the production and storage of "frozen foods".
1. Pre-treatment: pre-treatment, edible parts only;
2. Freezing: Quick freezing and maintaining quality;
3. 3. Packaging: Properly packaging to prevent quality deterioration; Storage and distribution: Store and distribute below -18 ° C.

[General method of producing frozen foods]
A general method for producing frozen food mainly includes the following steps.
1. Pre-processing "Pre-processing" is the first stage of cooking, excluding portions that cannot be eaten. For example, if a fish is peeled, it is not edible, such as removing scales, removing heads, internal organs, and fins into three pieces. This corresponds to a preparatory process that is usually performed before heating cooking, for example, excluding portions.

  In general, the pretreatment step includes, for example, a raw material thawing step, a processing step such as “three grated” and “bone removal”, a residual bone inspection step using X-rays, a water washing (immersion or running water washing, etc.) step, One or more steps selected from the group consisting of a (draining) step and a UV irradiation step (such as sterilization and umami amplification) can be included as appropriate. The water washing process is a process mainly performed to remove dirt and the like attached to fish meat, and a dehydration (drainage) process performed thereafter removes water and moisture absorbed and adsorbed to the fish meat in the water washing process and the like. Remove.

2. Freezing In order to maintain the quality of the food, it is necessary to freeze it at a speed appropriate for the material (rapid freezing). In general, the term “rapid freezing (rapid freezing) refers to a method of rapidly freezing food at a speed at which the food passes through a maximum ice crystal formation temperature range (−5 to −1 ° C.) within 30 minutes and cooling the food to −18 ° C. or less. ) ". As a result, the size of the ice particles formed in the food becomes smaller, and the ice particles do not spread or damage the space of cells or tissues, so that the influence on the food can be minimized.

There are the following four types of quick freezing, and some types may be combined. Each method has advantages and disadvantages, and foods suitable for the freezing method are also different. Therefore, an optimal quick freezing method for the target food is selected.
(1) Pneumatic freezing (air blast method)
There is a batch method or a continuous method in which cold air is applied to food to freeze it.
(2) Liquid freezing (brine method)
A method of soaking food in a low-temperature liquid. The low-temperature liquid is called brine, and a salt solution or alcohol is used.
(3) Contact freezing (contact method)
In a method of freezing by contacting with a low-temperature freezing plate, for example, sandwiching and applying pressure to increase efficiency.
(4) Liquefied gas freezing method
It is a method of spraying liquid nitrogen or liquefied carbon dioxide gas.

3. Packaging Frozen foods should be properly packaged to fit the food, prevent quality changes due to drying during storage and distribution, and maintain hygiene. Further, the packaging is provided with a “display” that conveys information on the product such as the name of the product, the standard, what the raw materials are, and the cooking method. In addition, in the case of frozen fish meat, a "cutting process" for cutting the fish meat or the like into an appropriate size is often included before packaging. Further, for example, the odor generated from the frozen fish meat can be removed by enclosing an adsorbent such as zeolite and the like in a package, thereby adsorbing volatile basic nitrogen and the like generated during storage.

4. Storage and distribution Usually, store and distribute at -18 ° C or lower. Generally, microorganisms do not grow below -15 ° C, and the storage temperature of frozen foods is defined as “-15 ° C or lower” according to the standards of the Food Sanitation Law. Therefore, usually, rot does not occur at -15 ° C or lower, but the flavor and taste may change. Therefore, the industry's voluntary standard is set at -18 ° C or lower, which is 3 ° C lower than that.

[Method of the present invention]
Hereinafter, embodiments of the present invention will be described in detail.
The present invention includes ammonia, dimethylamine, trimethylamine, and the like, which are detected during thawing and / or cooking of fish processed (processed) frozen food produced by a method for producing fish processed (processed) frozen food including an alkali treatment. The present invention relates to a method for reducing the amount of volatile basic nitrogen, which comprises a step of adsorbing volatile basic nitrogen to a porous adsorbent after an alkali treatment in the production method.

  As shown in the following examples, by providing an alkali treatment in the process of producing (processed) frozen food of fish meat, a volatile base detected during thawing and / or cooking of (processed) frozen food of fish meat. Since the amount of nitrogen is increased, at least a part of the volatile basic nitrogen adsorbed by the porous adsorbent in the adsorption step of the present invention is not caused by normal fish meat spoilage in the production step, but is caused by the alkali treatment. It is considered that this newly generated from the fish meat (due to the alkali treatment). However, in the method for producing (processed) frozen food of fish meat, the step of generating (or causing) volatile basic nitrogen does not need to be limited or specified. Further, the step of adsorbing the volatile basic nitrogen on the porous adsorbent can be carried out before the alkali treatment, as appropriate, in addition to after the alkali treatment.

  In the present invention, “fish meat” generally means meat derived from fish and shellfish. There is no particular limitation on the type, form, shape, size, etc. As described above, “pretreatment” means a series of treatment steps performed before a freezing (frozen) step in the method for producing (processed) frozen food of fish meat. The present invention is characterized in that in such a pretreatment, a cleaning (immersion) step is performed using a porous adsorbent.

  In the present invention, "alkaline treatment" refers to the improvement and improvement of the flavor and texture of frozen fish and the volatility of trimethylamine and the like contained in fish bodies in the process of producing (processed) frozen food of fish meat. This step is carried out for various purposes such as reducing the fishy odor of fish meat after frozen storage by reducing fishy odor components caused by basic nitrogen, and can be carried out in any mode known to those skilled in the art.

  For example, alkali treatment is performed by immersing fish meat in an alkaline aqueous solution having a pH of 7.1 to 12.6 at a low temperature to room temperature (for example, in a range of 0 ° C to 20 ° C) for about 10 minutes to several hours. Can be implemented. Incidentally, the aqueous solution may contain appropriate compounds such as organic acid salts and saccharides in addition to the buffer component. The specific conditions of the alkali treatment include the pH and composition of an aqueous alkali solution as described in Patent Documents 1 to 5, especially Patent Document 1 or Patent Document 3 (sodium bicarbonate used as a buffering agent). PH adjusters such as sodium carbonate, trisodium citrate, and trisodium phosphate, and the compounding ratio of other compounds such as organic acid salts and saccharides), and the immersion time in an alkaline aqueous solution. However, those skilled in the art can appropriately set the values.

  The conditions for the step of adsorbing volatile basic nitrogen to the porous adsorbent in the present invention are determined by those skilled in the art according to various conditions such as the type of fish meat and porous solid adsorbent, the processing form and shape of fish meat, and the type of pretreatment. Can be set as appropriate. As a specific embodiment, for example, it is carried out by immersing fish meat in a suitable solution (for example, an aqueous solution) containing 5 to 20% of a porous adsorbent. In general, at a relatively low temperature (for example, 0 ° C. to 20 ° C.), it is carried out in a short time (for example, 1 to 25 minutes), particularly, in a case where immersion treatment is performed, in several tens seconds to several minutes. Is preferred.

  Alternatively, for example, in a dehydration (draining) step performed after a water washing (immersion or running water washing) step, the surface of the fish meat and And / or volatile and basic nitrogen such as ammonia can be quickly and sufficiently adsorbed and removed from the inside with a porous solid adsorbent. In this step, the specific method and means for bringing the fish meat into contact with the porous solid adsorbent are not particularly limited or limited, and can be carried out by any appropriate method and means known to those skilled in the art. From a sanitary point of view, it is preferred that the fish meat and the porous solid adsorbent are indirectly contacted via a suitable water-permeable substance known to those skilled in the art, such as a cloth or a non-woven fabric. For this purpose, for example, a cloth or a nonwoven fabric can be spread on a plate-shaped porous solid adsorbent, and fish meat can be placed on the cloth or the like to perform dehydration (liquid drainage). Alternatively, for example, a bag made of a cloth or a nonwoven fabric containing a porous solid adsorbent in the form of pellets, round granules, and crushed particles is prepared, and these are appropriately spread, and then dehydrated by placing fish meat thereon (liquid). Cutting) can be performed efficiently.

The active ingredient contained in the porous adsorbent used in the present invention may be any substance known to those skilled in the art, for example, diatomaceous earth (a sediment consisting of empty fossil diatoms, also called "diatomite", ), Zeolite (a silicate mineral mainly composed of zeolite, a kind of aluminosilicate), and any other natural substances known to those skilled in the art, artificially synthesized products thereof, and others. And processed products obtained through various processes such as baking and curing under high temperature and high pressure, and organic materials such as synthetic resins in addition to inorganic materials such as various metal oxides such as silica and alumina. Substances can be mentioned. Each of them is characterized by containing a large number of micropores (several μm to several angstrom) inside a solid and having a large surface area (several hundreds to several thousand m ² / g).

  The form, shape, and particle size of the porous adsorbent are not particularly limited, and may be, for example, pellet, round, crushed, powder, and plate (board) by appropriate methods and means known to those skilled in the art. ), Etc., can be formed into any form known to those skilled in the art. Note that the porous solid adsorbent may contain several types of active ingredients.

Further, the present invention relates to a method for producing (processed) frozen food of fish meat, which includes the following steps.
1. Pretreatment including the method for reducing the amount of volatile basic nitrogen of the present invention;
2. 2. washing; Packaging.

  Unless otherwise described herein, each step included in pretreatment, washing and packaging may be appropriately performed by those skilled in the art according to any method, means, or condition known in the art as described above. Can be set. Further, in the manufacturing method of the present invention, steps other than the above steps can be included in any stage.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the following examples.

    Frozen food of fish meat produced by the production method of the present invention (Example) and (processed) frozen food of fish meat produced by a method including an alkali treatment as described in the prior art cited above as a comparative example ( Comparative Example), the amount of ammonia odor generated when the frozen food was thawed and / or cooked was measured by an inspection method known to those skilled in the art, and the texture and the like of the thawed and / or cooked frozen food were measured. Were compared. By the way, the golden meat was used as the fish meat.

[Example: Production method according to the present invention]
Frozen fish meat products (Examples 1 to 3) were produced by a production method comprising the steps shown in Tables 1 to 3 below. In the methods of Tables 1 and 2, immersion in a zeolite-containing solution was performed as a “step of adsorbing volatile basic nitrogen to the porous adsorbent”. In the production methods described in Tables 1 and 2, the pH and the composition of the alkaline aqueous solution, that is, the content (% by weight) of each component in the solution, the immersion time in the alkaline aqueous solution, and the zeolite content are different. On the other hand, in the production method described in Table 3, in the dehydration (draining) step performed after washing with running water, the adsorption step was performed by bringing zeolite into direct contact with fish meat.

[Comparative example: manufacturing method in the prior art]
Comparative Examples 1 and 2 are different from the methods of Tables 1 and 2 only in that the “zeolite-containing solution immersion” step (corresponding to the “volatile volatile nitrogen adsorption step” in the present invention) is not performed. The methods shown in Tables 4 and 5 below were respectively performed.

[Testing method for ammonia odor]
It carried out by the well-known test | inspection method using a sampler as follows.
・ Sample weight: 60-65g / 1 bag (95-99% deaerated packaging)
Heating conditions: One bag of a sample (frozen fish meat) was put in boiling water and boiled for 7 minutes after re-boiling.
・ Gas sampling: 100 cm gas was sampled with a sampling device (GASTEC: 8-8-6 Fukayanaka, Ayase City, Ayase City, Kanagawa Prefecture, 252-1195, Japan).
・ Target gas: Ammonia

As is clear from the results in Table 6, the (processed) frozen food (comparative example) obtained by the conventional method for producing (processed) frozen food of fish meat including the alkali treatment was detected during thawing and / or cooking. (Comparative Example 1 (Table 4): about 180 ppm, Comparative Example 2 (Table 5): about 40 ppm) can be obtained by the conventional method for producing (processed) frozen food of fish meat without alkali treatment. Processing) It was found that the amount increased considerably compared to the amount of ammonia detected during thawing and / or cooking of the frozen food (control: below the detection limit).
On the other hand, in the method of the present invention, ammonia which is considered to be caused by the alkali treatment as detected in the comparative example is simply and economically treated by adsorbing and removing the ammonia using the porous adsorbent provided after the alkali treatment. As a result of adsorption by means, the amount of ammonia detected during thawing and / or cooking of (processed) frozen food (Example 1 (Table 1): about 50 ppm, Example 2 (Table 2): below detection limit) Was significantly reduced (suppressed).

[Panel test (sensory test)]
Example 1 and Comparative Example 1 prepared as specimens by the above method were tasted by the following panelists, and their texture and the like were compared.

  As is clear from the results in Table 7, the cooked fish meat (processed) frozen food (Example 1) obtained by the production method of the present invention was compared with Comparative Example 1 in terms of “softness” and “softness”. It was shown to be excellent in both points of "odor" and "deliciousness".

The production method of the present invention has excellent flavor and texture such as "softness", and is produced as a by-product in the conventional method of producing (processed) frozen food of fish meat by alkali treatment. We succeeded in reducing volatile basic nitrogen such as ammonia.
As a result, it is possible to eliminate the causes of the decrease in the eating rate of fish such as "bone", "odor", and "flavor", and to contribute to the revival of Japanese fish eating culture.

Claims (7)

A method for reducing the amount of volatile basic nitrogen detected at the time of thawing and / or cooking fish meat (processed) frozen food produced by the method for producing fish processed (processed) frozen food including alkali treatment, comprising: after in alkali treatment in the production method, by immersing the fish in an aqueous solution of 5 to 20 wt% of zeolite, which comprises carrying out the step of adsorbing the volatile base nitrogen generated from fish zeolite, The reduction method. The method according to claim 1, wherein the fish meat is immersed in the aqueous solution of the zeolite for 30 seconds to 90 seconds . 3. The method according to claim 1, wherein at least a part of the volatile basic nitrogen is newly generated from the fish meat by an alkali treatment. The method according to any one of claims 1 to 3, wherein the alkali treatment comprises immersing the fish meat in an aqueous alkaline solution having a pH of 7.1 to 12.6. The method according to any one of claims 1 to 4, wherein the volatile basic nitrogen is ammonia. A method for producing (processed) frozen fish meat, comprising the steps of:
1. Pretreatment including the method for reducing the amount of volatile basic nitrogen according to any one of claims 1 to 5;
2. Washing;
3. 3. a freezing step ; Packaging. The pretreatment step is further selected from the group consisting of a raw material thawing step, a processing step including a bone removal step by complete removal , an X-ray residual bone inspection step, a washing step, and a dewatering step, and one or more of the following. 7. The method according to claim 6, comprising the steps of: