JP2002360223A - Fresh fish-treating liquid, method of treatment by using the same, and treated fresh fish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fresh fish-treating liquid for returning the body surfaces of berry parts of samon and trout of which economical values are damaged by a blackening of the berry part body surfaces after their landing, to a color in their living time so as not to damage their economical values. SOLUTION: This fresh fish-treating liquid is a solution for returning the fresh fishes of which berry part body surfaces are blackened after death, especially blackened samon and trout, to the color in their living time, and consists of a mixed solution of a potassium compound and a surfactant. The method for treating the fresh fishes aims at the fresh fishes of which berry part body surfaces are blackened, specially the blackened samon and trout as subjects, and immersing the fresh fishes in the above fresh fish-treating liquid at >=7 deg.C water temperature for returning the berry part body surfaces to the color in their living time. Also, in the method, the fishes are immersed in an aqueous acid solution for removing excessive viscous liquid after returning the body berry part surfaces to the color of their living time. The fresh fishes treated with the above method, especially the fresh samon and trout and their frozen products are also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing solution for fresh fish, in particular, a processing of fresh salmon and trout fish, a processing method using the same, and a processed fresh fish. More specifically, the present invention relates to the abdominal body of a fresh fish whose salmon trout after landing has a darkened abdominal body surface and has no problem in quality, but has a poor economical value due to unfavorable appearance. The present invention relates to a technique for returning a table to its original color so as not to lose its economic value.

[0002]

2. Description of the Related Art The change in coloration of a fish body is controlled by the behavior of pigment granules of pigment cells. The blackening of the color of the abdominal body after the landing of salmon trout is due to the diffusion of pigment granules (melanosomes) of the black pigment cells among the pigment cells. In the salmon trout after landing, the surface of the abdomen may be blackened, and these fresh fish have no problem in quality, but their appearance is unfavorable and their economic value has been reduced.

The Journal of the Fisheries Society of Japan 64, 280-285,
1998, Shigeru Hayashi, Hideki Ushio, Toshiaki Oshima, Hideaki Yamanaka, Chiaki Koizumi "The synergistic effect of temperature on potassium agglomeration of cultured red sea bream pigment pigments" includes a viable cultured red sea bream under a low temperature such as 0 ° C at 300 mmol / l potassium. It is reported that immersion in an ionic solution could prevent the body color from blackening. Prevention of blackening of the color of fresh fish is an important solution in the industry.

[0004]

Accordingly, the present invention restores the abdominal surface of salmon and trout fresh fish, whose economic value is impaired by the blackening of the abdominal body surface after landing, and the economic value is impaired. The purpose is not to be. The present invention restores the abdominal body surface to its fresh color while maintaining its freshness only for fresh fish of good freshness after landing, particularly salmon trout whose abdominal body surface is blackened, and is economical. The goal is to ensure that value is not compromised. That is,
The purpose of the present invention is to provide a method that can be used only in a state of extremely good freshness after landing, and not to provide a method in which only the appearance is favorable even if the freshness is deteriorated.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, by mixing a surfactant such as saponin with a potassium ion solution, melanosomes are easily aggregated. The present inventors have found that in salmon trout, melanosomes tend to aggregate at a temperature higher than the environmental water temperature, not at a low temperature, which is reported to be easier for melanosomes to aggregate in red sea bream, and completed the present invention.

[0006] The present invention is a solution for returning fresh fish whose abdominal body surface has blackened after death, more specifically, fresh salmon and trout fish, to a fresh color, which comprises a mixed solution of a potassium compound and a surfactant. It is a fresh fish treatment liquid characterized in that:

The present invention is also directed to fresh fish whose abdominal body surface has blackened after death, more specifically, fresh salmon and trout fish, wherein the fresh fish is prepared from a mixed solution of a potassium compound and a surfactant having a water temperature of 7 ° C. or higher. A fresh fish processing method characterized by returning the abdominal body surface to its original color by immersion in a fresh fish processing solution.

[0008] It is characterized in that, after the abdominal body surface is returned to its original color, it is immersed in an acidic aqueous solution to remove excess mucus. In this case, the present invention is characterized in that the abdominal body surface is blackened after death. For fresh fish, more specifically, fresh salmon trout fish, the fresh fish is immersed in a fresh fish treatment solution consisting of a mixed solution of a potassium compound and a surfactant at a water temperature of 7 ° C. or higher to return the abdominal body surface to its fresh color. And then immersing in an acidic aqueous solution to remove excess mucus.

Further, the present invention provides a fresh fish in which a blackened abdominal body surface is restored to its original color by immersion in a mixed solution of a potassium compound and a surfactant, preferably at a water temperature of 7 ° C. or more. And more specifically, fresh salmon and trout fish.

[0010] It is further characterized in that excess mucus is removed by immersion in an acidic aqueous solution.
The present invention provides a mixed solution of a potassium compound and a surfactant, preferably, immersed in the mixed solution having a water temperature of 7 ° C. or more to return the blackened abdominal body surface to a fresh color, and then immersed in an acidic aqueous solution. Fresh fish from which excess mucus has been removed, more specifically salmon trout fresh fish. Further, the present invention is a frozen product of the above fresh fish, more specifically, a fresh salmon trout fish.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is directed to a fresh fish in which blackening of the surface of the abdominal body is observed, the quality of which is reduced only by appearance problems, despite the fact that there are no physical problems. . The method of the present invention is a method applicable only to fresh fish of extremely high freshness in which the melanosome remains responsive to external stimuli, and cannot change the body color of low-freshness salmon trout. In other words, the present invention is a fresh fish of extremely high freshness in which the melanosome remains responsive to stimuli from the outside world, and although there is no problem in terms of meat quality, the quality rank is only due to appearance problems. The target is an individual whose blackened abdominal body surface is observed to be lowered. Salmon trout is exemplified as a fresh fish in which blackening of the abdominal body surface is observed. Examples of salmon trout include cultured fish such as coho salmon, rainbow trout, Atlantic salmon, and king salmon.

The potassium compound which is a component of the mixed solution constituting the fresh fish processing solution of the present invention includes potassium dihydrogen citrate, potassium acetate, potassium carbonate, potassium monohydrogen carbonate, potassium chloride, potassium phosphate, and monophosphate. Examples thereof include potassium hydrogen and potassium dihydrogen phosphate.

[0013] Surfactants which are other components of the mixed solution include saponins such as soybean saponin and tea seed saponin;
Various emulsifiers of food additives are exemplified.

The acid of the acidic solution used to remove excess mucus by immersing the abdominal body surface after returning it to its fresh color is various organic acids such as ascorbic acid, citric acid, malic acid and acetic acid. Is exemplified.

In the treatment method of the present invention, a fresh salmon trout fish whose abdomen body surface has blackened after death is immersed in a mixed solution of a potassium compound and a surfactant at a water temperature of 7 ° C. or higher to give the abdomen body surface a fresh color. The method is characterized in that, if necessary, thereafter, excess mucus is removed by immersion in an acidic aqueous solution.

The fresh fish of the present invention has a blackened abdominal body surface which has been immersed in a mixed solution of a potassium compound and a surfactant to return to its original color, preferably a potassium compound having a water temperature of 7 ° C. or higher and a surfactant. Is a fresh fish of salmon trout, especially salmon trout, in which the blackened abdominal body surface has been restored to its original color by immersion in a mixed solution of, and then, if necessary, immersed in an acidic aqueous solution to remove excess mucus.

[0017]

The present invention is intended for fresh fish in which blackening of the surface of the abdomen is observed, although the quality of the abdomen is reduced only by the appearance problem, despite the fact that there is no problem in terms of meat quality.
The responsiveness of the melanosome to the remaining external stimuli can be exploited. It is not a blackening prevention method that alters the body color of low-freshness salmon trout to confuse consumers, but can be applied only to fresh fish of extremely high freshness in which the melanosome remains responsive to external stimuli. Therefore, by a simple processing method such as immersion in a mixed solution of a potassium compound and a surfactant, it is possible to return the color to the original color while maintaining its freshness, and in the case of trout salmon, return the blackened abdomen to silver It is possible to improve the quality rank and increase profits. In addition, fresh fishing, particularly fresh trout salmon fishing, can be returned to its original hue, and no return to blackening of the body surface is observed even when frozen. It is presumed that the melanophore died by freezing and the movement of the pigment granules stopped.

[0018]

The present invention will be described more specifically with reference to the following examples. The present invention is not limited by these examples.

Example 1 Melanosome agglutination test of aqueous solution of potassium compound to which saponin was added Method: In order to eliminate as many individual differences as possible and to carry out as many tests as possible, a test was carried out using rainbow trout epidermis pieces. After killing the rainbow trout immediately, the rainbow trout was wholesaled into three pieces, the skin was peeled off and cut into strips. The cut sections were adhered to a plastic dish and used for the test.

It was examined whether treatment of the epidermis with a surfactant increases the permeability of potassium ions into the melanophore and enhances the melanosome aggregation action. As a surfactant, saponin which is a component such as green tea or soybean was used, and 0.05% (w / w) was added to a 0.01 N aqueous potassium solution. K ₂ CO ₃ and K ₂ HPO ₄ were used as potassium compounds, and the treatment temperature was 7 ° C. The determination of the melanosome aggregation action was performed visually.

Results: Table 1 shows the results of the melanosome test of the aqueous potassium compound solution to which saponin was added. The untreated epidermal pieces that were not immersed in the aqueous potassium compound solution showed no change even 30 minutes after the preparation of the epidermal pieces, and the melanosomes remained diffused. Slight aggregation of melanosomes was observed in the epidermis pieces immersed in a 0.01 N aqueous solution of K ₂ CO ₃ and K ₂ HPO ₄ . On the other hand, when saponin was added to these potassium aqueous solutions, aggregation of melanosomes was further observed.

[0022]

[Table 1] ───────────────────────── After 30 minutes ────────────────── ─────── Untreated-K ₂ CO ₃ + Saponin + K ₂ CO ₃ ++ K ₂ HPO ₄ + Saponin + K ₂ HPO ₄ ++ ──────────────────カ リ ウ ム Potassium solution soaked in rainbow trout epidermis for 30 minutes is 0.01N, saponin is 0.05%. ++: Effective, +: Slightly effective,-: No effect

Example 2 Effect of Temperature on Melanosome Aggregation Method: The effect of temperature on melanosome aggregation was examined using 0.05% saponin + 0.01N K ₂ CO ₃ and K ₂ HPO ₄ aqueous solution. Temperature of processing solution is 0 ℃, 7 ℃, 17 ℃
The untreated pieces of epidermis were stored at 7 ° C. The breeding water temperature of the rainbow trout from which the epidermis pieces were collected was 9 ° C. The determination of melanosome aggregation was visually determined.

Results: Table 2 shows the effect of temperature on melanosome aggregation. When the treatment liquid was set at 0 ° C., melanosomes did not aggregate as in the case without treatment, despite the presence of saponin and potassium ions. In contrast,
When treated at a temperature higher than the breeding water temperature, the melanosomes aggregated significantly more than when treated at a temperature close to the breeding water temperature.

[0025]

[Table 2] ３０ 30 minutes later ──────────────────── ─── Untreated-0 ° C -7 ° C ++ 17 ° C ++ サ 0.05% saponin + 0.01N K ₂ CO ₃ Breeding water temperature 9 ℃ +++: Extremely effective, ++: Effective,-: No effect

Example 3 Melanosome aggregation test using rainbow trout individuals Method: The results obtained in the test using epidermis pieces were examined in rainbow trout individuals. For the test, a round of rainbow trout whose body surface was blackened one hour after immediate killing was used.

0.05% saponi at a temperature higher than the breeding water temperature
+ 0.01 N K_TwoCO_ThreeOr K _TwoHPO_FourD in aqueous solution
Melanosomes in melanophores by treating dimas individuals
Was shown to cause strong aggregation. Therefore, on
The treatment liquid is effective not only on the epidermis but also on individuals.
Rukoto has been shown. However, these treatments
Of mucus from the epidermis is secreted,
The effect of ascorbic acid was examined.

Results: Table 3 shows the mucus removing effect of the ascorbic acid aqueous solution. P of 0.05% saponin + 0.01N K ₂ CO ₃ aqueous solution
H is about 10-11, 0.05% saponin + 0.01N
The pH of the K ₂ HPO ₄ aqueous solution was about 7 to 8 and all were alkaline. Rainbow trout after immersion in the treatment liquid for 30 minutes secreted a large amount of mucus, but the mucus could be removed by immersion in a 0.05% ascorbic acid aqueous solution (pH 4) for 15 minutes.

[0029]

[Table 3] 効果 Mucus removal effect ─────────────── ───────────── Untreated +++ 0.05% ascorbic acid aqueous solution ± ────────────────────────── ── The rainbow trout round was immersed in 0.05% saponin + 0.01N K ₂ CO ₃ for 30 minutes and then immersed in a 0.05% ascorbic acid aqueous solution for 15 minutes. +++: Large amount of mucus, ±: Almost no mucus

Example 4 Demonstration test using trout (seawater-cultured rainbow trout) Purpose: The test was performed for the following purposes. 1) Saponin 0.05% at 15 ° C and potassium carbonate (K ₂
The effect of immersion for one hour in the combined use of CO ₃ ) 0.02N is confirmed. 2) Observe the return of the abdominal body surface to blackening by leaving it at room temperature after immersion. 3) Consider the effect of suppressing the blackening return by freezing. 4) Consider how much the effect of improving body color is reflected on the quality rank.

Method: The following three test plots were set. a Washing after immersion for 1 hour, freezing immediately, then thawing b Washing after immersion for 1 hour, leaving at room temperature for 1 hour, then freezing, then thawing c (control group without immersion) After leaving at room temperature for about 2 hours, Freezing and then thawing In sections a and b, a mixed solution of saponin 0.05% + potassium carbonate (K ₂ CO ₃ ) 0.02N was prepared (starting water temperature 15.8 ° C., room temperature 14.5 ° C.) Three trout after the primary processing (the gills and internal organs were removed and cleaned) in which the abdominal body surface was blackened were immersed. At the end of the immersion, the surface of the abdominal body was visually observed. At the start, at the end of immersion, etc., the L ^* value of the left and right abdomen of the trout was measured with a colorimeter and the average value was calculated. In the abdomen at the time of raw high L ^* value, L ^* value is low in the abdomen, which was blackened in reverse. That is, an increase in the L ^* value indicates an improvement in body color. An air bra freezer was used for freezing. After storage at −25 ° C. for 2 days, it was thawed. The quality rank was evaluated visually by three to four quality control personnel at the factory. The results of the experiment are shown in Tables 4 and 5.

<< Results and Discussion >> 1) Changes before and after immersion In section a and section b immersed in the solution for 1 hour, a clear abdominal body color improvement effect was confirmed by visual observation, and the L ^* value also increased (see Table 1). 4). As a result, the quality rank rose from B or C to Premium or A (Table 5). On the other hand, in the section c which was left in the air at room temperature, no large difference was observed in the quality rank and L ^* value. 2) Change before and after leaving for 1 hour In section b where the container was left for 1 hour at room temperature after immersion, a return to blackening of the body surface was observed. As a result, the L ^* value was reduced, and the quality rank was lowered in two out of three individuals. On the other hand, no change was observed in section c, which was left in the air at room temperature. 3) Changes before and after freezing In section a, the whiteness of the abdomen was maintained even after thawing, and Premium with the highest quality rank was maintained. In section b and section c, no significant difference was observed before and after freezing. In section b, as described above, although blackening was observed during standing for 1 hour, no change was observed in sections a and b after freezing and thawing. This was presumably because the melanophore died due to freezing and the movement of the pigment granules stopped.

[0033]

[Table 4]

[0034]

[Table 5]

Example 5 The optimum concentration of potassium carbonate is examined. << Method >> Saponin and potassium carbonate were diluted with ordinary fresh water and warm water obtained by heating the same to prepare an aqueous solution shown in Table 6 at about 15 ° C. (starting water temperature 15.1 ° C., ending water temperature 15.2 ° C.). 2 ° C). Two trout after the primary processing in which the abdominal body surface was blackened were immersed in each of them, and after 30 minutes and 1 hour, the body color of the abdomen was visually observed.

<< Results and Discussion >> Table 6 shows the observation results. In all the test groups, the effect was higher than that of the control freshwater group, and the effect of the combined use of saponin and potassium carbonate could be reproduced by setting the water temperature of the solution at around 15 ° C. Among the test plots, the black pigment granules were most strongly aggregated in the saponin 0.05% + potassium carbonate 0.02N plots, indicating that the effect was the strongest. Therefore, the optimum concentration of potassium carbonate was estimated to be about 0.02N. Table 6 shows the observation results.

[0037]

[Table 6] After 30 minutes 60 minutes after test ─────────────────────────────────── Saponin 0.05% + potassium carbonate 0.04N 0, 12, 2, 3 Effective Saponin 0.05% + Potassium Carbonate 0.02N 0, 12, 2-3 Strong Effect Saponin 0.05% + Potassium Carbonate 0.01N 0, 0-12, 2-3 Effective Saponin 0.05% + Potassium Carbonate 0.005N 0 11, 0 2, 1〜2 Effective Saponin 0.05% + potassium carbonate 0.0025N 0, 0〜1 1-2, 2-3 Effective Fresh water 0, 0 1, 0 ─────────────────────────── Evaluation value 0: No change 1: Slightly white 2: Pretty white 3: Completely white

Example 6 The optimum concentration of saponin in the combined use of saponin and potassium carbonate (K ₂ CO ₃ ) is examined. << Method >> Saponin and potassium carbonate were diluted with ordinary fresh water and warmed warm water to prepare an aqueous solution shown in Table 7 at about 15 ° C. (starting water temperature 15.1 ° C., ending water temperature 14.). 8 ° C). Since the high-concentration saponin solution foams violently, the concentration was set to 0.1% or less. The concentration of potassium carbonate was set to 0.02N, which is assumed to be the most effective. Two trout after the primary processing in which the abdominal body surface was blackened were immersed in each of the prepared solutions, and after 30 minutes and 1 hour, the body color of the abdomen was visually observed. What was left in the air at room temperature without immersion was used as a control.

<< Results and Discussion >> The observation results are shown in Table 7. The saponin 0.1% and 0.05% groups showed a strong effect, and the optimum concentration was estimated to be 0.05% or more. However, as described above, a high-concentration saponin solution causes problems such as bubbling and bitterness, so 0.05% was considered to be an appropriate concentration.

[0040]

[Table 7] ─────────────────────────────────── Test area 30 minutes and 60 minutes later Remarks ─────────────────────────────────── Saponin 0.1% + potassium carbonate 0.02N 1, 0 2-3, 2-3 Black back side is also missing Saponin 0.05% + potassium carbonate 0.02N 0, 1 2-3, 2-3 Back black side is also missing Saponin 0.025% + Potassium carbonate 0.02N 0, 0 2, 2 Some back side black Saponin 0.0125% + Potassium carbonate 0.02N 0, 12, 2, 3 Backside part black Leave in air 0, 0 0, 0 No change ─────────────────── ──────────────── Evaluation value 0: No change 1: Slightly white 2: Pretty white 3: Completely white

Example 7 Saponin 0.05% and potassium carbonate (K ₂ CO ₃ ) 0.0
Consider the optimal water temperature of the solution when 2N is used in combination. << Method >> Saponin and potassium carbonate were diluted with ordinary fresh water and warm water obtained by heating the same to prepare various water temperature solutions at 10 to 20 ° C. (Table 8). In each of them, two trout after the primary processing in which the abdomen body surface was blackened were immersed two by two, and the body color of the abdomen was visually observed after 30 minutes, 45 minutes, and 1 hour. As a control group, a group which was left in the air at room temperature without immersion was set.

<< Results and Discussion >> In the immersion for 60 minutes, 1
5.0 ° C, 17.5 ° C, 20.0 ° C, 10.0 ° C, 1 ° C
The effect was stronger than that in the 2.5 ° C. section, and no difference in the effect was observed in the preceding three sections. Therefore, from the viewpoint of keeping freshness, it is considered that about 15 ° C. is appropriate for immersion for one hour.

[0043]

[Table 8] 区 Test area Water temperature (℃) of solution * 30 minutes After 45 minutes After 60 minutes Remarks Start time End time ─────────────────────────────────── 10.0 ° C 9.9 10.2 0-1, 0-1 0-1, 1, 1, 2 weak effect 12.5 ℃ 12.4 12.8 0-1, 0-1 10-1, 1, 1, 2 weak effect 15.0 ℃ 15.1 15.4 0-1, 0- 1 1, 2 2, 2-3 Effect 17.5 ℃ 17.4 17.6 2, 0-1 2-3, 22 2-3, 2 Effect 20.0 ℃ 20.0 19.9 2, 1-2 2-3, 2 2-3, 2 2 Effect left in the air 0, 0 0, 0 0, 0 No change ────────────────────────────────── ─ Solution *: Saponin 0.05% + potassium carbonate (K ₂ CO ₃ ) 0.02N Leaving in the air: Room temperature (16.9 at the start, 16.6 at the end) Evaluation value 0: No change 1: Slightly white 2: Pretty white 3 : Completely white

[0044]

According to the present invention, it is possible to provide a fresh fish, particularly a salmon trout fresh fish, which overcomes the blackening of the abdominal body surface after landing and has no loss in economic value due to its appearance.

Claims (8)

[Claims] 1. A fresh fish treatment liquid which is a solution for returning a fresh fish whose abdominal body surface has blackened after death to its original color, which comprises a mixed solution of a potassium compound and a surfactant. 2. The fresh fish treatment liquid according to claim 1, wherein the fresh fish is a salmon trout fresh fish whose abdomen body surface has blackened after death. 3. A method for recovering the abdominal body surface to a fresh color by immersing the fresh fish in the fresh fish treatment solution according to claim 1 having a water temperature of 7 ° C. or higher, for a fresh fish whose abdominal body surface has turned black after death. Characteristic method of processing fresh fish. 4. After returning the body surface of the abdomen to its original color,
4. The method for treating fresh fish according to claim 3, wherein excess mucus is removed by immersion in an acidic aqueous solution. 5. The method for treating fresh fish according to claim 3, wherein said fresh fish is a salmon trout fresh fish whose abdomen body surface has blackened after death. 6. A fresh fish processed by the method of claim 3. 7. The fresh fish according to claim 6, wherein said fresh fish is a fresh salmon trout fish. 8. A frozen product of the fresh fish according to claim 6 or 7.