JP2022117244A - Seasoned boiled shell egg and production method thereof - Google Patents

Abstract

To provide a production method of a seasoned boiled shell egg easy to remove a shell and capable of suppressing sulfidation black discoloration even when using a raw material egg with increased pH after a prescribed time of storage, and also to provide a seasoned boiled shell egg.SOLUTION: A production method of a seasoned boiled shell egg includes: a heat treatment process; and a hydrogen peroxide treatment process of immersion after the heat treatment process into a hydrogen peroxide-containing liquid, being a seasoning liquid containing a salt, with a hydrogen peroxide concentration of 300 ppm or more and less than 10,000 ppm so that a resultant seasoned boiled shell egg has a salt concentration of 0.8 to 2.0 wt.%, inclusive.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a flavored boiled egg with shell and a method for producing the same.

When fresh eggs are used for the production of boiled eggs, the egg white after heating becomes brittle and the eggshell membrane is difficult to peel off, making it very difficult to peel off the shell when eating. However, after a few days have passed since the eggs were laid, carbon dioxide (carbon dioxide gas) in the egg white gradually decreases due to the release over time. will be able to For this reason, a method of storing raw material eggs for a certain period of time to reduce carbon dioxide (carbon dioxide gas) in the albumen is generally adopted.

On the other hand, when a boiled egg is heated, the hydrogen sulfide generated from the egg white and the iron contained in the yolk combine to form ferrous sulfide, which may cause a black discoloration, so-called sulfide blackening. It is known that this discoloration tends to occur when the pH is high. When raw eggs are stored for a certain period of time in order to improve shell peeling, there is a problem that pH increases as carbon dioxide (carbon dioxide gas) in the egg white decreases, and sulfidation blackening tends to occur. Boiled eggs with black discoloration from sulfide do not affect health by eating them, but because they are unappealing and cause a drop in product value, raw eggs should be stored for a long period of time and carbon dioxide (carbon dioxide) should be excessively added. is not preferred. In addition, since raw eggs have individual differences in egg collection date, size, and shell thickness, it is difficult to control all eggs in a uniform state. ing.

As a method for reducing the occurrence of sulfidation black discoloration, a method of storing the processed egg product in a container in an atmosphere reinforced with oxygen is known (Patent Documents 1 and 2). In addition, a method of immersing shelled eggs in a seasoning liquid with a low pH using an organic acid such as vinegar or a pH adjuster has also been practiced.

However, in Patent Documents 1 and 2, as methods for preventing sulfidation blackening, a method of storing an egg processed product in an oxygen-reinforcing container after filling an oxygen-permeable packaging material, (2) include a method of reinforcing and sealing oxygen together with the seasoning liquid, and a method of pressurizing by reinforcing the atmosphere or inside using either an oxygen-permeable or non-permeable packaging material. However, in order to eliminate the sulfide blackening by these methods, even shelled boiled eggs need to be treated for about one day. There was a problem that processing time longer than one day was required. In addition, there are problems such as equipment installation costs, which increases the production cost of boiled eggs, and the danger of ignition and oxygen poisoning due to the use of 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 produces a unique flavor such as a sour taste, resulting in poor taste, and the egg white becomes hard and loses its texture. There was a problem that it could not be used for boiled eggs with shells because it would become mushy.

JP-A-11-299456 JP-A-11-299457

Therefore, the present invention has been made in view of these problems, and even when using raw eggs that have been stored for a certain period of time and have a high pH, the shell is easy to peel and the sulfide blackening is suppressed. To provide a method for producing a boiled egg with shell and flavored boiled egg with shell.

In order to achieve the above object, the present invention employs the following means.

The method for producing flavored boiled eggs with shells of the present invention includes:
In the method for producing flavored boiled eggs with shell,
a heat treatment step;
A hydrogen peroxide treatment step of immersing in a hydrogen peroxide-containing liquid;
characterized by comprising

In the method for producing flavored boiled eggs with shell according to the present invention,
The hydrogen peroxide treatment step may be characterized by being performed after the heat treatment step.

Furthermore, in the method for producing flavored boiled eggs with shell according to the present invention,
The hydrogen peroxide-containing liquid may be a seasoning liquid containing salt.

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

Furthermore, in the method for producing flavored boiled eggs with shell according to the present invention,
A step of immersing the flavored boiled egg in the shell in a hydrogen peroxide-containing liquid having a hydrogen peroxide concentration of 1,000 ppm or more and less than 8,000 ppm so that the salt concentration 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 shell according to the present invention is
In the flavored boiled egg with shell produced by the method for producing flavored boiled egg with shell described above,
(1) Sulfurization blackness is less than 5%, (2) Hydrogen peroxide is 0.3 ppm or less, and (3) Salt concentration is 0.8% by weight or more and 2.0% by weight or less. .

According to the flavored boiled egg with shell and the method for producing the same according to the present invention, in the process of producing the flavored boiled egg with shell, by performing hydrogen peroxide treatment, the shell is easily peeled and blackening due to sulfide is suppressed. You can get flavored boiled eggs.

FIG. 1 is a flow chart showing steps of a method for producing a flavored boiled egg with shell according to an embodiment. FIG. 2 is a table showing evaluation results of Examples. FIG. 3 is a photograph of a cross-sectional portion of a flavored boiled egg with a shell cut into two halves in the longitudinal direction of the shell-peeled boiled egg. FIG. 4 is a diagram showing an example of sulfide blackness analysis of boiled eggs.

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

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

The method for producing flavored boiled eggs with shell according to the present invention mainly includes 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 easier 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 arbitrarily selected, and there is no problem even if this step is omitted. Since boiled eggs tend to be blackened by sulfidation when stored for a longer period of time, the present invention contributes to a higher effect of improving appearance in such cases.

(2) Heat treatment step The heat treatment step is a step of producing boiled eggs from raw eggs, and the method is not particularly limited as long as it is a method that can produce boiled eggs by heating such as boiling or steam heating. do not have. The degree of heating is also not particularly limited, and may be appropriately selected according to need, from those in which the inside of the yolk is thick and liquid to those in which the inside of the yolk is completely solidified and boiled.

(3) Hydrogen peroxide treatment step The hydrogen peroxide treatment step is a step of immersing eggs in an immersion liquid containing hydrogen peroxide. This is a step performed to suppress sulfide blackening of eggs. The timing of the hydrogen peroxide treatment may be before the heat treatment step described above or after the heat treatment step, but it is particularly preferable to perform the treatment after the heat treatment. Examples of the immersion liquid used for the hydrogen peroxide treatment include hydrogen peroxide-containing water and a hydrogen peroxide-containing seasoning liquid containing a seasoning such as salt. The concentration of hydrogen peroxide should be 300 ppm or more and less than 10,000 ppm, and 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 black discoloration due to sulfide will be reduced. On the other hand, if the hydrogen peroxide solution or the hydrogen peroxide-containing seasoning liquid has a concentration of 10,000 ppm or more, although the effect of suppressing sulfidation blackening can be obtained, the flavor of the boiled egg is affected and the residue in the final product. This is because there is a problem

In this process, hydrogen peroxide penetrates into the inside of the flavored boiled egg with shell, and two reactions occur to prevent the occurrence of sulfidation blackening and to eliminate the sulfidation blackening that has already occurred. It is believed that a flavored boiled egg with a shell free of sulfide blackening is obtained. In the first reaction, egg white protein is denatured by heating inside a flavored boiled egg with shell, and hydrogen sulfide released from sulfur-containing amino acids such as methionine and cysteine is oxidized by hydrogen peroxide and decomposed into sulfur and water. be. This is thought to prevent the formation of ferrous sulfide by combining hydrogen sulfide and iron in the egg yolk, thereby preventing black discoloration due to sulfide. In the second reaction, ferrous sulfide, which is the cause of sulfide blackening, is oxidatively decomposed by hydrogen peroxide, and the sulfide blackening is thought to disappear.

A flavored boiled egg in the shell is required to have the edible portion inside the egg shell seasoned with salts, which is the commercial value. Salts such as table salt and amino acid salts are mainly used for seasoning in many cases. Sulfide blackening occurs even in a state where salts have not permeated, depending on the state of raw eggs and heating conditions. It is known that sulfide black discoloration tends to occur remarkably under the The reason why the presence of salts promotes sulfide blackening has not been elucidated so far, but it is known that the structural stability of proteins generally varies depending on the type and concentration of salts in addition to pH. there is In addition, as mentioned above, it is also known that heat denaturation of egg white protein causes sulfidation black discoloration. It is considered that this further accelerates the occurrence of sulfide black discoloration. The present invention can suppress sulfidation blackening even in seasoned boiled eggs in the shell, which contain salts and are prone to sulfidation blackening.

In addition, in the hydrogen peroxide treatment step, when using a hydrogen peroxide-containing seasoning liquid containing seasonings containing salts such as common salt, the salt concentration of the final flavored boiled egg in the shell is 0.5%. It is preferable to adjust the immersion concentration and immersion time of the immersion liquid 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 salty taste is light, and if it exceeds 2.0% by weight, the salty taste is too strong and is not suitable as a commercial product. The salt concentration here refers to the salt concentration in the edible portion of the flavored boiled egg with shell removed.

(4) Secondary Heating Step The secondary heating step is a step of promoting decomposition of hydrogen peroxide. Hydrogen peroxide is highly reactive and naturally decomposes into harmless oxygen and water when it reacts with organic matter. can be made Although the secondary heat treatment conditions are not particularly specified, it is preferable to perform the secondary heat treatment at 91° C.×2 minutes to 62° C.×40 minutes. After secondary heating, cool with an air blower or the like and store in a refrigerator.

By the above steps, a flavored boiled egg with a shell in which black discoloration due to sulfide is suppressed is 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 performed in which the eggs were stored in a refrigerator at 10° C. for 30 days from the date of collection so that the pH of the raw eggs 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 in adjusted salt water overnight in a refrigerator was performed (Examples 1 to 6). The salt concentration of flavored boiled eggs with shell is 1.4% by weight in Examples 1-1, 2, 3, 4-1, 5, and 6-1, and 1.4% by weight in Example 1. -2, Example 4-2, Example 6-2 0.8% by weight, Example 1-3, Example 4-3, Example 6-3 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 washed away with water, and after the secondary heat treatment of heating with boiling water, it is cooled and dried with a blower until the rough heat and moisture on the surface are removed. to obtain flavored boiled eggs with shell.

In Example 7, chicken eggs with shells were subjected to a primary heat treatment of boiling in boiling water, then 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 carried out so that the salinity of the egg was 1.4% by weight. After the hydrogen peroxide treatment, the salt remaining on the surface of the egg was washed away with water in the same manner as in Examples 1 to 6, and then the secondary heat treatment was performed by heating with boiling water. Cooling and drying were carried out until the water content was removed, and flavored boiled eggs with shells were obtained.

Further, as Comparative Examples 1 to 5, the hydrogen peroxide concentration was 0 ppm (no 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), salt water adjusted to 20,000 ppm (Comparative Example 5) was used, and except for Comparative Example 1-2, the boiled eggs were immersed so that the salt concentration was 1.4% by weight. Comparative Example 1-2 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 was washed away with water in the same manner as in Examples 1 to 6, and then the secondary heat treatment was performed by heating with boiling water. Cooling and drying were carried out until the moisture was removed to obtain a flavored boiled egg with a shell.

The flavored boiled eggs with shell produced under the above conditions were evaluated for "sulfide black discoloration inhibitory effect", "residual hydrogen peroxide", 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 "sulfide black discoloration inhibitory effect" was evaluated as △, and the "residual hydrogen peroxide" and "egg flavor" were evaluated as ○. became. In Example 3, Example 4-1, Example 4-2, Example 4-3, Example 4-4, Example 5, and Example 7, "sulfurization black discoloration suppression effect", "remaining hydrogen peroxide and "egg flavor" were all evaluated as ○. In Examples 6-1, 6-2, and 6-3, the "sulfide black discoloration inhibitory effect" and "residual hydrogen peroxide" were evaluated as ◯, and the "egg flavor" was evaluated as △. . On the other hand, in Comparative Examples 1-1, 2 and 3, "remaining hydrogen peroxide" and "egg flavor" were evaluated as ○, but "sulfidation black discoloration inhibitory effect" was evaluated as ×. . In Comparative Example 4, "sulfidation black discoloration inhibitory effect" and "residual hydrogen peroxide" were evaluated as "good", but "egg flavor" was evaluated as "poor". In Comparative Example 5, "sulfidation black discoloration inhibitory effect" was evaluated as ◯, "hydrogen peroxide residue" was evaluated as Δ, but "egg flavor" was evaluated as x. In Comparative Example 1-2 (boiled egg salt concentration 0.3%), no sulfidation black discoloration was observed, whereas in Comparative Example 1-1 (boiled egg salt concentration 1.4%), sulfidation black discoloration occurred. It is understood that the presence of salts has a profound effect on the occurrence of sulfidation black discoloration. In addition, from Example 2, Example 3, Comparative Example 1-1, Comparative Example 2 and Comparative Example 3, it was found that immersion in salt water with a hydrogen peroxide concentration of 1000 ppm or more resulted in a higher sulfidation black discoloration suppressing effect. Recognize. The shelled flavored boiled eggs obtained in Example 4-1, Comparative Example 1-1, and Comparative Example 1-2 were cut into two halves in the longitudinal direction, and the cross-sectional portion was photographed. Fig. 3 shows the photograph taken. From this photograph, it can be understood that the hydrogen peroxide treatment is highly effective in suppressing black discoloration due to sulfuration.

As shown in FIG. 4, the sulfide black discoloration inhibitory effect was evaluated in the following manner. Peel the shelled flavored boiled egg, cut it in half so that it is parallel to the long axis of the egg, measure the "sulfide blackening degree", and use the average of 20 samples to evaluate the sulfidation blackening inhibitory effect in three stages. (○, △, ×) was evaluated.
◯: No black discoloration by sulfidation (degree of black discoloration by sulfide is less than 1%)
Δ: Sulfurization black discoloration is hardly observed (sulfurization black discoloration degree of 1% or more and less than 5%)
×: Sulfurization black discoloration is observed (sulfurization black discoloration of 5% or more)
*Calculation method of "sulfide blackness" Cut the shelled boiled egg into two equal parts in the longitudinal direction and photograph the cross section.
The image of the cross section was measured with Image-J to measure the "sulfide black discoloration area" and the "entire egg yolk area", and the degree of sulfide black discoloration was calculated using the following formula.
Sulfurization blackness = "Sulfurization blackening area" / "Total area of yolk" x 100
・Image-J analysis procedure "Area of blackened part" is set in the range of 0 to 160 (adjustment range: 0 to 255) for the threshold value of the image in the "red" channel of the cross-sectional image of the boiled egg yolk. The area of the selected part in the cross-section of the yolk was calculated.
"Whole yolk area" is selected in the cross section of the boiled egg yolk by adjusting the image threshold in 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. I was asked to calculate the area of that part.
・Camera used: “Canon EOS Kiss X8i”
・Shooting conditions: horizontal illumination of 450 to 480 Lux under fluorescent lighting
50-55 cm distance from the target surface to the camera
・ Horizontal surface illuminance measurement device: “Testo 540 (Test Co., Ltd.)”

The remaining hydrogen peroxide was evaluated by measuring the concentration of residual hydrogen peroxide in the final product by the oxygen electrode method and evaluating it according to the following criteria.
○ ... Less than 0.3 ppm "no residue"
× 0.3 ppm 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 off the shell.
○: You can feel the flavor of the egg △: You can hardly feel the flavor of the egg ×: You can feel the offensive odor

It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented in various forms within the technical scope of the present invention.

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

S1... carbon dioxide release step, S2... heat treatment step, S3... hydrogen peroxide treatment step, S4... secondary heating step (S4)

Claims (6)

In the method for producing flavored boiled eggs with shell,
a heat treatment step;
A hydrogen peroxide treatment step of immersing in a hydrogen peroxide-containing liquid;
A method for producing a flavored boiled egg with a shell, comprising: 2. The method for producing flavored boiled eggs in shell according to claim 1, wherein the hydrogen peroxide treatment step is performed after the heat treatment step. 3. The method for producing flavored boiled eggs in shell according to claim 1 or 2, wherein the hydrogen peroxide-containing liquid is a seasoning liquid containing salt. A step of immersing the seasoned boiled egg with shell in the hydrogen peroxide-containing liquid having a hydrogen peroxide concentration of 300 ppm or more and less than 10,000 ppm so that the salt concentration is 0.8% by weight or more and 2.0% by weight or less. The method for producing a flavored boiled egg with a shell according to any one of claims 1 to 3, characterized by comprising The flavored boiled egg with shell is immersed in the hydrogen peroxide-containing liquid having a hydrogen peroxide concentration of 1,000 ppm or more and less than 8,000 ppm so that the salt concentration is 0.8% by weight or more and 2.0% by weight or less. The method for producing flavored boiled eggs with shell according to any one of claims 1 to 3, characterized by comprising a step. In the flavored boiled egg with shell produced by the method for producing flavored boiled egg with shell according to any one of claims 1 to 5,
(1) Sulfurization blackness is less than 5%, (2) Hydrogen peroxide is 0.3 ppm or less, and (3) Salt concentration is 0.8% by weight or more and 2.0% by weight or less. Seasoned boiled eggs with shell.

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