JP6944738B1 - Boiled eggs with shells and how to make them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a shell-flavored boiled egg having good shell peeling and suppressed blackening of sulfide even when a raw egg having a high pH after being stored for a certain period of time is used, and a shell-flavored boiled egg. I will provide a. SOLUTION: After a heat treatment step and the heat treatment step, a hydrogen peroxide-containing liquid having a hydrogen peroxide concentration of 300 ppm or more and less than 10,000 ppm and containing salt is added to a boiled egg with a shell. A method for producing a boiled egg with a shell, which comprises a hydrogen peroxide treatment step of immersing the egg so that the salt concentration is 0.8% by weight or more and 2.0% by weight or less. [Selection diagram] Fig. 1

Description

The present invention relates to a shelled flavored boiled egg and a method for producing the same.

When fresh eggs are used in the production of boiled eggs, the heated egg whites are brittle and the eggshell membranes are difficult to peel off, making it very difficult to peel off the shells when eating. However, as the number of days elapses from spawning, carbon dioxide (carbon dioxide) in the egg white gradually decreases due to release over time, and the heated egg white becomes elastic and the eggshell membrane is easily peeled off, so the shell is easily peeled off. Will be able to. Therefore, a method is generally adopted in which raw egg is stored for a certain period of time to reduce carbon dioxide (carbon dioxide) in egg white.

On the other hand, when a boiled egg is heated, hydrogen sulfide generated from the egg white and iron contained in the yolk combine to form ferrous sulfide, which may cause discoloration to black, so-called black sulfide. It is known that this discoloration is likely to occur at high pH. When the raw egg is stored for a certain period of time in order to improve the shell peeling, there is a problem that the pH rises as the carbon dioxide (carbon dioxide gas) in the egg white decreases, and blackening of sulfide is likely to occur. Boiled eggs with blackening sulfide do not affect the health of eating, but they cause a decrease in commercial value in terms of appearance. Therefore, raw eggs are stored for a long period of time and carbon dioxide (carbon dioxide) is excessive. It is not preferable to reduce it to. In addition, since raw egg has individual differences such as egg collection date, size, and shell thickness, it is difficult to control all of them in a uniform state, and stable quality is an issue especially in commercial mass production. ing.

As a method for reducing the occurrence of blackening of sulfide, a method of storing the inside of a container containing a processed egg product in an atmosphere reinforced with oxygen (Patent Document 1 and Patent Document 2) is known. In addition, a method of immersing eggs after shelling in a seasoning liquid having a low pH using an organic acid such as vinegar or a pH adjuster has also been used.

However, in Patent Document 1 and Patent Document 2, as a method of preventing blackening of sulfide, a method of filling a processed egg product in an oxygen-permeable packaging material and then storing it in an oxygen-reinforced container, in an oxygen-impermeable packaging material There are a method of reinforcing and sealing oxygen together with a seasoning liquid, and a method of reinforcing and pressurizing oxygen in the atmosphere or inside by using either an oxygen permeable or impermeable packaging material. However, with these methods, even shell-peeled boiled eggs require treatment for about one day in order to eliminate blackening of sulfide, and those with eggshells such as shell-flavored boiled eggs are even less effective. There was a problem that a processing time longer than one day was required. In addition, there are problems that equipment introduction cost is incurred, the production cost of boiled eggs is high, and it is necessary to consider the risk of ignition and oxygen toxicity by using high concentration oxygen. From the above, it is considered that the method of reinforcing oxygen is not practical.

In addition, the method using an organic acid or a pH adjuster has a problem that the taste is deteriorated due to a unique flavor such as acidity, the egg white becomes hard and the texture is impaired, and an acidic substance dissolves the eggshell. There was a problem that it could not be used for boiled eggs with shells because it would end up.

Japanese Unexamined Patent Publication No. 11-299456 Japanese Unexamined Patent Publication No. 11-299457

Therefore, the present invention has been made in view of these problems, and even when a raw egg having a high pH after being stored for a certain period of time is used, the shell has good peeling and the blackening of sulfide is suppressed. It is an object of the method of producing a boiled egg with a shell and providing a boiled egg with a shell.

The present invention has adopted the following means in order to achieve the above-mentioned object.

The method for producing a flavored boiled egg with a shell of the present invention is:
In the method of producing boiled eggs with shells
Heat treatment process and
The hydrogen peroxide treatment process of immersing in a hydrogen peroxide-containing liquid and
It is characterized by including.

Further, in the method for producing a flavored boiled egg with a shell according to the present invention,
The hydrogen peroxide treatment step may be characterized in that it is performed after the heat treatment step.

Further, in the method for producing a flavored boiled egg with a shell according to the present invention,
The hydrogen peroxide-containing liquid may be characterized in that it is a seasoning liquid containing salt.

Further, in the method for producing a flavored boiled egg with a shell according to the present invention,
Includes a step of immersing a shelled boiled egg in a hydrogen peroxide-containing solution having a hydrogen peroxide concentration of 300 ppm or more and less than 10,000 ppm so that the salt concentration of the boiled egg is 0.8% by weight or more and 2.0% by weight or less. It may be characterized in that.

Further, in the method for producing a flavored boiled egg with a shell according to the present invention,
A step of immersing a shelled boiled egg in a hydrogen peroxide-containing solution having a hydrogen peroxide concentration of 1,000 ppm or more and less than 8,000 ppm so that the salt concentration of the boiled egg is 0.8% by weight or more and 2.0% by weight or less. It may be characterized by including.

In addition, the flavored boiled egg with a shell according to the present invention
In the shell-flavored boiled egg produced by the method for producing a shell-flavored boiled egg described above,
It is characterized in that (1) the blackness sulfide variation is less than 5%, (2) hydrogen peroxide is 0.3 ppm or less, and (3) the salt concentration is 0.8% by weight or more and 2.0% by weight or less. ..

According to the shell-flavored boiled egg and the method for producing the shell-flavored boiled egg according to the present invention, in the process of producing the shell-flavored boiled egg, the shell is peeled off well and the blackening of sulfide is suppressed by performing the hydrogen peroxide treatment. You can get a flavored boiled egg.

FIG. 1 is a flowchart showing a process of a method for producing a flavored boiled egg with a shell according to an embodiment. FIG. 2 is a table showing the evaluation results of the examples. FIG. 3 is a photograph of a boiled egg with a shelled flavor, which has been peeled and cut into two equal parts in the long axis direction, and a cross-sectional portion thereof is photographed. FIG. 4 is a diagram showing an example of analysis of blackness sulfide variation of a boiled egg.

Hereinafter, a method for producing a shell-flavored boiled egg and a form for carrying out the shell-flavored boiled egg according to the present invention will be described in detail.

The method for producing a shelled boiled egg and the egg used for the shelled flavored boiled egg according to the present invention are not particularly limited as long as they are edible. For example, eggs such as chicken, quail, duck, and duck can be used.

The method for producing a flavored boiled egg with a shell according to the present invention mainly comprises a carbon dioxide release step (S1), a heat treatment step (S2), a hydrogen peroxide treatment step (S3), and a secondary heating step (S4). include.

(1) Carbon dioxide release step (S1)
The carbon dioxide release step is a step for ensuring the elasticity of the egg white after heating and making it easy to peel off the eggshell membrane, and is a step for releasing carbon dioxide (carbon dioxide gas) from the egg by storing it for a predetermined period of time. .. It can be selected arbitrarily, and there is no problem even if this step is omitted. When the boiled egg is stored for a longer period of time, blackening of the boiled egg is likely to occur. Therefore, in the present invention, it contributes to a higher effect of improving the appearance in such a case.

(2) Heat treatment step The heat treatment step is a step of producing a boiled egg from a raw egg, and the method is not particularly limited as long as it is a method capable of producing a boiled egg by heating such as boiling or steam heating. No. The degree of heating is not particularly limited, and an appropriate selection may be made as needed, from a liquid state in which the inside of the yolk is thick to a boiled state in which the inside of the yolk is completely solidified.

(3) Hydrogen Peroxide Treatment Step The hydrogen peroxide treatment step is a step of immersing an egg in a dipping solution containing hydrogen peroxide. This is a step performed to suppress blackening of sulfide of eggs. The timing of the hydrogen peroxide treatment may be before the above-mentioned heat treatment step or after the heat treatment step, but it is particularly preferable to carry out the hydrogen peroxide treatment after the heat treatment. Examples of the immersion liquid used for the hydrogen peroxide treatment include hydrogen peroxide-containing water, hydrogen peroxide-containing seasoning liquid containing a seasoning such as salt, and the like. The concentration of hydrogen peroxide may be 300 ppm or more and less than 10,000 ppm, more preferably 1,000 ppm or more and less than 8,000 ppm. If the concentration of hydrogen peroxide is less than 300 ppm, the effect of suppressing blackening of sulfide is reduced. On the other hand, if a hydrogen peroxide solution or a hydrogen peroxide-containing seasoning solution having a concentration of 10,000 ppm or more is used, the effect of suppressing blackening of sulfurization can be obtained, but the effect on the flavor of the boiled egg and the residue in the final product are obtained. Because there is a problem.

In this step, hydrogen peroxide permeates the inside of a boiled egg with a shell, causing two reactions, one that prevents the occurrence of blackening sulfide and the other that eliminates the blackening sulfide that has already occurred. It is thought that a boiled egg with a shell and no blackening of sulfide can be obtained. In the first reaction, the egg white protein is denatured by heating inside the shelled boiled egg, and hydrogen sulfide liberated from sulfur-containing amino acids such as methionine and cysteine is oxidized by hydrogen sulfide and decomposed into sulfur and water. NS. It is considered that this prevents hydrogen sulfide and iron in egg yolk from binding to ferrous sulfide in advance to prevent the occurrence of blackening of sulfide. In the second reaction, ferrous sulfide, which is the cause of blackening sulfide, is oxidatively decomposed by hydrogen peroxide, and it is considered that the blackening sulfide disappears.

Boiled eggs with shells are required to be seasoned with salts in the edible part inside with the eggshells attached, which is the commercial value. In many cases, salts such as salt and amino acid salts are mainly used for seasoning. Blackening of sulfide occurs depending on the condition of raw eggs and heating conditions even when salts are not infiltrated, but especially in eggs with shells, the frequency and degree of blackening of sulfide differs depending on the presence or absence of salts, and the presence of salts It is known that blackening of sulfide is remarkably likely to occur below. The reason why the presence of salts promotes blackening of sulfide has not been clarified so far, but it is generally known that proteins have different structural stability depending on the type and concentration of salts as well as pH. There is. In addition, as described above, it is also known that the occurrence of blackening of sulfide is due to heat denaturation of egg white protein, and by performing seasoning and heating together with salts such as salt, denaturation of egg white protein and the resulting denaturation It is considered that the occurrence of blackening sulfide is further promoted. According to the present invention, blackening of sulfide can be suppressed even in a boiled egg with a shell that contains salts and is prone to blackening of sulfide.

When a hydrogen peroxide-containing seasoning solution containing a seasoning containing salts such as salt is used in the hydrogen peroxide treatment step, the final salt concentration of the shelled boiled egg is 0. The immersion concentration and immersion time of the immersion liquid may be adjusted so as to be 8% by weight or more and 2.0% by weight or less. This is because if it is less than 0.8% by weight, the saltiness is light, and if it exceeds 2.0% by weight, the saltiness is too strong and it is not suitable as a commercial product. The salt concentration referred to here refers to the salt concentration in the edible portion of the boiled egg with a shell, excluding the shell.

(4) Secondary heating step The secondary heating step is a step of accelerating the decomposition of hydrogen peroxide. Hydrogen peroxide is highly reactive and reacts with organic substances and is naturally decomposed into harmless oxygen and water. However, by performing a secondary heat treatment after the hydrogen peroxide treatment, the decomposition of hydrogen peroxide is further promoted. Can be made to. The conditions for the secondary heat treatment are not particularly specified, but it is preferable to carry out the treatment at 91 ° C. × 2 minutes to 62 ° C. × 40 minutes. After the secondary heating, cool it with a blower or the like and store it in the refrigerator.

By the above steps, a flavored boiled egg with a shell in which blackening of sulfide is suppressed can be obtained.

In the following examples, each step was performed under the following conditions.
First, in order to improve shell peeling, a carbon dioxide release step was carried out in which the raw egg was stored in a refrigerator at 10 ° C. for 30 days from the day of egg collection so that the pH of the raw egg was 9.0 or higher. After performing the primary heat treatment step of boiling the stored eggs with boiling water, the hydrogen peroxide concentration was 300 ppm (Examples 1-1 to 1-3), 500 ppm (Example 2), 1,000 ppm (Implementation). Example 3), 2,500 ppm (Examples 4-1 to 4-4), 4,000 ppm (Example 5), 8,000 ppm (Examples 6-1 to 6-3). A hydrogen peroxide treatment step of immersing the prepared salt water in the refrigerator overnight was performed (Examples 1 to 6). The salt concentration of the shell-flavored boiled egg was 1.4% by weight in Example 1-1, Example 2, Example 3, Example 4-1 and Example 5, and Example 6-1. -2, Example 4-2, Example 6-2 is 0.8% by weight, Example 1-3, Example 4-3, Example 6-3 is 2.0% by weight, Example 4-4 Was immersed so as to be 0.3% by weight.

After the hydrogen peroxide treatment, the salt remaining on the surface of the egg is flushed with water, then the secondary heat treatment is performed by heating with boiling water, and then the egg is cooled and dried with a blower until the rough heat and the water on the surface are removed. To obtain a boiled egg with a shell.

In Example 7, after performing a primary heat treatment in which shelled chicken eggs are boiled in boiling water, they are immersed in salt water adjusted to have a hydrogen peroxide concentration of 2,500 ppm under a pressure of 0.2 MPa and boiled. Hydrogen peroxide treatment was performed so that the salt concentration of the eggs was 1.4% by weight. After the hydrogen peroxide treatment, the salt remaining on the surface of the egg is flushed with water in the same manner as in Examples 1 to 6, and then a secondary heat treatment is performed in which the egg is heated with boiling water. The eggs were cooled and dried until the water was removed, and boiled eggs with shells were obtained.

Further, as Comparative Examples 1 to 5, the hydrogen peroxide concentration was 0 ppm (without addition) (Comparative Example 1-1, Comparative Example 1-2), 100 ppm (Comparative Example 2), 200 ppm (Comparative Example 3), 10,000 ppm. (Comparative Example 4) Using salt water adjusted to 20,000 ppm (Comparative Example 5), except for Comparative Example 1-2, soaked so that the salt concentration of the boiled egg was 1.4% by weight. Then, in Comparative Example 1-2, the mixture was immersed so as to have a concentration of 0.3% by weight. After the hydrogen peroxide treatment, the salt remaining on the surface of the egg is flushed with water in the same manner as in Examples 1 to 6, and then a secondary heat treatment is performed in which the egg is heated with boiling water. The eggs were cooled and dried until the water was removed, and boiled eggs with shells were obtained.

The shell-flavored boiled eggs produced under the above conditions were evaluated for "sulfide blackening inhibitory effect", "hydrogen peroxide residue", and "egg flavor" by the following methods. The evaluation results are shown in FIG.

In Example 1-1, Example 1-2, Example 1-3, and Example 2, the "blackening sulfide effect" was evaluated as Δ, the "hydrogen peroxide residue", and the "egg flavor" were evaluated as ○. became. In Example 3, Example 4-1 and Example 4-2, Example 4-3, Example 4-4, Example 5 and Example 7, "effect of suppressing blackening of sulfide" and "residual hydrogen peroxide". , "Egg flavor" were all evaluated as ○. In Examples 6-1 and 6-2, and 6-3, the "blackening sulfide effect" and "hydrogen peroxide residue" were evaluated as ○, and the “egg flavor” was evaluated as Δ. .. On the other hand, in Comparative Example 1-1, Comparative Example 2 and Comparative Example 3, "hydrogen peroxide residue" and "egg flavor" were evaluated as ○, but “sulfide blackening suppressing effect” was evaluated as ×. .. In Comparative Example 4, "effect of suppressing blackening of sulfide" and "residual hydrogen peroxide" were evaluated as ◯, but "flavor of egg" was evaluated as x. In Comparative Example 5, the "blackening sulfide effect" was evaluated as ◯, the "hydrogen peroxide residue" was evaluated as Δ, but the "egg flavor" was evaluated as ×. In Comparative Example 1-2 (boiled egg salt concentration 0.3%), blackening of sulfide was not observed, whereas in Comparative Example 1-1 (boiled egg salt concentration 1.4%), blackening of sulfide was observed. From the occurrence, it can be seen that the presence of salts has a profound effect on the occurrence of sulfide blackening. Further, from Example 2, Example 3, Comparative Example 1-1, Comparative Example 2 and Comparative Example 3, when immersed in salt water having a hydrogen peroxide concentration of 1000 ppm or more, a higher effect of suppressing blackening of sulfide can be obtained. Recognize. The shelled boiled egg with shells obtained in Example 4-1 and Comparative Example 1-1 and Comparative Example 1-2 was cut into two equal parts in the long axis direction, and a cross-sectional portion was photographed. The photograph taken is shown in FIG. From this photograph, it can be understood that the hydrogen peroxide treatment has a high effect of suppressing blackening of sulfurization.

As shown in FIG. 4, the effect of suppressing sulfide blackening was evaluated as follows. Peel the shell of a flavored boiled egg with a shell, cut it in half so that it is horizontal to the long axis of the egg, measure the "black sulfide variation", and measure the black sulfide change suppression effect from the average of 20 samples in 3 stages. It was evaluated by (○, △, ×).
○ ・ ・ ・ No blackening of sulfide is observed (blackening of sulfide less than 1%)
Δ: Almost no blackening of sulfide is observed (blackening of sulfide of 1% or more and less than 5%).
×: Blackening of sulfide is observed (blackening of sulfide of 5% or more)
* Calculation method of "black sulfide variation" The boiled egg with the shell peeled off is cut into two equal parts in the long axis direction, and the cross section is photographed.
The "blackening sulfide area" and the "total area of egg yolk" were measured with Image-J on the image of the cross-sectional portion, and the blackening sulfide degree was calculated by the following formula.
Black sulfide variation = "black sulfide area" / "total egg yolk area" x 100
-In the Image-J analysis procedure "blackened area", the threshold value of the image is set in the range of 0 to 160 (adjustment range: 0 to 255) in the "red" channel of the cross-sectional image of the boiled egg yolk. The area of the selected portion in the cross section of the yolk was calculated.
The "total area of egg yolk" is selected in the cross section of the yolk by adjusting the threshold value of the image to the range of 0 to 80 (adjustment range: 0 to 255) in the "blue" channel of the cross section image of the boiled egg yolk. The area of the egg yolk was calculated.
-Camera used for shooting: "Canon EOS Kiss X8i"
-Shooting conditions: Horizontal illuminance of 450 to 480 Lux under fluorescent lighting
Distance from the target surface to the camera 50-55 cm
-Horizontal plane illuminance measuring device: "Testo540 (Test Co., Ltd.)"

The residual hydrogen peroxide was evaluated by measuring the residual concentration of hydrogen peroxide in the final product by the oxygen electrode method and using the following criteria.
○ ・ ・ ・ Less than 0.3ppm is “no residue”
× ・ ・ ・ 0.3ppm or more “residual”

The flavor of the egg was evaluated according to the following criteria after confirming the flavor of the final product after peeling.
○ ・ ・ ・ Egg flavor can be felt △ ・ ・ ・ Egg flavor is not so much felt × ・ ・ ・ Offensive odor can be felt

The present invention is not limited to the above-described embodiment, and can be implemented in various embodiments as long as it belongs to the technical scope of the present invention.

As shown in the above-described embodiment, it is mainly industrially applicable as a method for producing a shelled flavored boiled egg.

S1 ... Carbon dioxide release step, S2 ... Heat treatment step, S3 ... Hydrogen peroxide treatment step, S4 ... Secondary heating step (S4)

Claims (4)

In the method of producing boiled eggs with shells
Heat treatment process and
The salt concentration of a boiled egg with shells is 0.8% by weight or more and 2.0 in a hydrogen peroxide-containing solution containing a seasoning containing salts and a hydrogen peroxide concentration of 300 ppm or more and less than 10,000 ppm. A hydrogen peroxide treatment step of immersing so as to be less than% by weight , and
Secondary heat treatment process to promote decomposition of hydrogen peroxide,
A method for producing a flavored boiled egg with a shell, which comprises. The method for producing a flavored boiled egg with a shell according to claim 1, wherein the hydrogen peroxide treatment step is performed after the heat treatment step. Immerse in the hydrogen peroxide-containing solution having a hydrogen peroxide concentration of 1,000 ppm or more and less than 8,000 ppm so that the salt concentration of the shelled boiled egg is 0.8% by weight or more and 2.0% by weight or less. The method for producing a shelled flavored boiled egg according to claim 1 or 2, which comprises a step. In the method for producing a flavored boiled egg with a shell according to any one of claims 1 to 3.
(1) A method for producing a shelled boiled egg having a black sulfide variation of less than 5% and (2) hydrogen peroxide of 0.3 ppm or less.

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