Eel processing method

Abstract

Provided are an eel processing method and processed eel such that, even if the temperature of the processed eel decreases after the eel has been cooked by heating, the collagen contained in the eel skin is less likely to become hard. 【Solution means】 The eel processing method of the present invention includes a pre-baking step of baking the dressed eel, a boiling step of boiling the baked eel at a temperature at which collagen undergoes heat denaturation for 5 to 50 minutes, and a main baking step of baking the boiled eel.

Description

Technical Field

[0001] The present invention relates to a method for processing eels and eels processed by this method. More specifically, the present invention relates to a method for processing grilled eels including a step of boiling eels and eels processed by this method.

Background Art

[0002] Currently, the processing methods (cooking methods) for grilled eels are roughly divided into two main types: a method of opening raw eels and steaming them in a steamer for several tens of minutes (Kanto style: Edo steaming), and a method of opening raw eels and directly grilling them over gas or charcoal (Kansai style).

[0003] The specific processing method for kabayaki of eels is as follows. An eel that has been split open, either along the back or the belly, is skewered. The skewered eel is grilled over charcoal until the fire passes through and the skin has fine wrinkles to make it a white grilled eel. The white grilled eel is steamed (Kanto style) or not steamed (Kansai style) and then marinated in sauce, taken out of the sauce and grilled again to make kabayaki of eels (Patent Document 1, last line of column 1 to line 6 of column 2).

[0004] Non-Patent Document 1 also describes a processing method similar to that of Patent Document 1 (pages 202 to 206). Further, Non-Patent Document 1 states that eels contain a large amount of collagen, and when heated, the collagen changes into gelatin. Therefore, the higher the collagen content, the softer and juicier the eel becomes (3 lines from the bottom of page 204 to line 1 of page 205).

[0005] As a processing method for eels, "Goroemon steaming" is known. "Goroemon steaming" is a cooking method in which eels are boiled for a short time (less than 3 to 5 minutes) and then grilled.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Non-Patent Documents

[0007] [Non-Patent Document 1] Katsumi Tsukamoto, "The Science of Eels", Asakura Shoten, published in June 2019 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] When eating processed eels such as eel kabayaki immediately after cooking in a restaurant, the hardness due to the eel's skin (the collagen on the skin surface) is not a concern. However, in the case of takeout or delivery, after heat cooking, when a certain amount of time (for example, 30 minutes or more) has passed, the temperature of the processed eel such as eel kabayaki drops to room temperature, the entire skin becomes hard, the collagen contained in the skin also hardens, and the texture deteriorates. Furthermore, when the processed eel is refrigerated, the skin may become so hard that it cannot be bitten.

[0009] Therefore, an object of the present invention is to provide a method for processing eels and processed eels in which the skin of the eel does not easily become hard even when the temperature of the heat-cooked processed eel drops. [Means for Solving the Problems]

[0010] An exemplary embodiment of the present invention is as follows. (Exemplary Embodiment 1) A method for processing eels, comprising: A pre-baking step of baking the dressed eel, and A boiling step of boiling the eel baked in the pre-baking step for a predetermined time until the collagen is irreversibly denatured. (Exemplary Embodiment 2) The method for processing eels according to Exemplary Embodiment 1, wherein The predetermined time in the boiling step is 5 minutes to 50 minutes. (Exemplary Embodiment 3) The method for processing eels according to Exemplary Embodiment 1, wherein The predetermined time in the boiling step is 10 minutes to 45 minutes.

[0011] (Embodiment Example 4) The method for processing eel according to Embodiment Example 1, wherein in the boiling step, the eel is boiled using the boiled dashi stock, the method for processing eel. (Embodiment Example 5) The method for processing eel according to Embodiment Example 1, wherein the eel is an eel skewered on a skewer, the method for processing eel. (Embodiment Example 6) The method for processing eel according to Embodiment Example 1, wherein it includes a main grilling step of grilling the eel boiled in the boiling step, the method for processing eel.

[0012] (Embodiment Example 7) The method for processing eel according to Embodiment Example 6, wherein in the main grilling step, the eel is grilled with sauce or without sauce, the method for processing eel. (Embodiment Example 8) The method for processing eel according to Embodiment Example 1, wherein before the pre - grilling step, it includes a gutting step of gutting the eel, the method for processing eel. (Embodiment Example 9) The boiled eel, wherein the average weighted value (skin side) by the penetration test for the boiled eel is 1.00 N or less.

[0013] (Embodiment Example 10) In the boiled eel according to Embodiment Example 9, the boiled eel, wherein the average weighted value (flesh side) by the penetration test for the boiled eel is 0.40 N or less. (Embodiment Example 11) In the boiled eel according to Embodiment Example 9, the boiled eel, wherein the boiled eel has irreversibly denatured collagen. (Embodiment Example 12) The grilled eel obtained by grilling the boiled eel according to any one of Embodiments Examples 9 to 11. [Advantages of the Invention]

[0014] The eel processing method of the present invention can provide an eel with excellent texture, in which the skin of the eel does not harden even when the temperature drops after processing.

Brief Description of the Drawings

[0015]

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Modes for Carrying Out the Invention

[0016] The eel processing method and the processed eel according to the embodiment of the present invention will be described. In the following embodiments, the processing method of eel grilled eel in the Kanto style (with bottom grilling) will be described as an example, but it is not limited thereto, and the processing method of eel grilled eel in the Kansai style (without bottom grilling) can also be used.

[0017] <Cutting step: Cutting a live eel> First, in the cutting step, a live eel (katsuman: a live eel) is cut with a kitchen knife and the body is cut into 2 to 4 equal parts (the number of cuts varies depending on the size of the eel). Three to five bamboo skewers are inserted into the cut body.

[0018] <Grilling process: Grilling the eels that have been processed> In the grilling process (the white grilling process), the eels that have been processed and skewered on bamboo skewers are placed on a grilling stand and grilled over charcoal or gas for about 3 to 15 minutes. In the grilling process, the eels are grilled without adding flavor. The grilling temperature is preferably 600°C to 750°C. Remove the eels from the grilling stand and arrange them, and remove the rough heat from the grilled eels.

[0019] <Boiling process: Boiling the grilled eels in a pot> The boiling process will be described. Fill a pot (for example, with a diameter of 40 to 60 cm and a capacity of 20 to 50 L) with water up to seven-tenths and boil it until it boils. Put the grilled eels skewered on skewers into the pot all at once in an amount that fills the surface of the pot.

[0020] After putting the eels into the pot, cover the pot and bring the boiling liquid in the pot (preferably dashi) to a boil. Boil the eels for a predetermined time after it starts boiling. The predetermined time can preferably be 5 to 50 minutes, more preferably 10 to 45 minutes, and even more preferably 16 to 22 minutes. The predetermined time varies depending on the type and size of the eels.

[0021] For the boiling liquid, use the one obtained by boiling water with kelp and sugar in a cooking pot for 2 to 3 days. The surface temperature of the boiling liquid is 95°C to 99°C, and the central temperature of the eels put in is 75°C to 90°C. The salt concentration of the boiling liquid was 0.3% or less (the minimum value of the measuring instrument. No salt was added).

[0022] After the predetermined time has passed, since the boiled eels have become sufficiently soft, take out the eels from the hot water with a spatula so that the flesh of the eels does not fall off. Check the elasticity by pressing with a finger to see if the central part of the skin surface of the eels has become soft. When it is confirmed that the elasticity of the central part of the skin surface has become loose, lift it out of the pot.

[0023] <Final grilling process> Take out the boiled eels from the pot, turn off the hot water, and grill them again over a charcoal or gas grilling stand for 3 to 15 minutes. At this time, if it is grilled eel with sauce, add the sauce and grill. When it is grilled to completion, it is finished.

[0024] <Investigation> In the case of the conventional cooking methods of eels (steaming or directly grilling) without boiling, the collagen attached inside the skin surface of the central part of the eel skin (so-called the back part of the eel) softens (gels) once by heating, but it is considered that when it returns to room temperature, it hardens again and becomes a hard skin, making it difficult to eat as food. In the eel processing method (the so-called "Yabee Goroemon Steaming") according to the embodiment of the present invention, the eel is boiled for a predetermined time until the collagen is irreversibly denatured, so that the softened (gelled) state is maintained even at room temperature. The irreversible denaturation of collagen is considered to occur when the collagen fragments in hot water and gelatinization and / or peptidization (generation of collagen peptides) occur.

[0025] By boiling the eel for a predetermined time, the boiling hot water penetrates into the inside of the eel skin, and an appropriate temperature can be maintained even in the interior that is difficult to reach by the normal cooking method of non-boiled eels. By maintaining the temperature with the hot water entering the interior in this way, when taken out of the pot, the central temperature of the eel body rises to 75°C to 90°C, and it is considered that the collagen is gelatinized and / or peptidized by this heating.

[0026] <Differences from the conventional example, features and merits of this embodiment> In the conventional "Goroemon Steaming" that is said to have originated around Inba-numa in Chiba Prefecture since the late Edo period, the pre-roasted eel is boiled. However, the boiling time is as short as about several minutes after the water boils, preferably less than 3 to 5 minutes.

[0027] In contrast, the method for processing eels according to the present embodiment includes a step of boiling the eels for a predetermined time of, for example, 20 minutes or more. By the step of boiling for a predetermined time, uneven heating such as baking is eliminated from the collagen (gelatinous substance) between the skin surface and the body, and uniform heating becomes possible, so that when eaten, the body and skin of the eel become soft enough to melt smoothly. Furthermore, in the case of eels steamed with steam as in the conventional method, after the grilling step, the skin is soft for 20 to 30 minutes, but when the time elapses and the temperature drops to room temperature, the skin becomes hard. In contrast, in the "Habe Etaemon Steaming" method for processing eels according to the present embodiment, even when the time elapses and the temperature drops, as shown in the examples, the skin surface continues to maintain softness, so it can be used for takeout and eating outside the store.

[0028] In the method for processing eels including the conventional steaming step with steam, even after the grilling step, the peculiar smell of eels (the collagen between the skin and the inside of the skin, the smell of fat) inevitably remains. In contrast, in the "Habe Etaemon Steaming" method for processing eels according to the present embodiment, the peculiar smell of eels has almost disappeared.

[0029] In the conventional steaming step with steam, in order to confirm whether the heat has been transferred to the body of the eel, it is necessary to open the lid of the steamer, and since the temperature and amount of steam vary depending on the height of the basket stage of the steamer and even in the baskets on the same stage, unevenness is likely to occur. In contrast, in the "Habe Etaemon Steaming" method for processing eels according to the present embodiment, by opening the lid of the pot, it is possible to visually confirm and touch with fingers the degree of heat transfer to each slice of eel to check its softness.

[0030] The effects and functions of the method for processing eels according to the present embodiment are summarized as follows. · The body is easily loosened, the skin also becomes soft, and the peculiar fishy smell of eels is no longer felt. · Even for eels with a lot of fat, the extra fat content drops during the boiling process, resulting in a refreshing and non-greasy taste. · Even when it cools down, the body does not harden and remains soft and jelly-like.

[0031] By using the eel processing method (Hatcho Goroemon steaming method) according to this embodiment, it is possible to provide eel that remains soft even when cooled to room temperature. As a result, new value is created for eel kabayaki products that have low evaluations in refrigerated and frozen products, which will also have a positive impact on the sales of the entire eel industry.

Example

[0032] Regarding the eel obtained by the eel processing method of this embodiment, it was confirmed by experiment whether the skin and the elasticity of the skin surface of the eel kabayaki remain soft even at room temperature. In addition to comparing with other steaming cooking methods, the superiority of the eel processing method according to this embodiment was confirmed by comparing with the conventional Goroemon steaming method with a short boiling time.

[0033] <Test target sample> Regarding the following Comparative Example A, Comparative Example B, and Example C, the hardness was measured. Comparative Example A (Edo steaming) is a grilled eel that has been opened and subjected to a pre-roasting process and a steaming process of steaming for 10 minutes as has been conventionally done. The pre-roasting process was performed under the same conditions for Comparative Example A, Comparative Example B, and Example C. Specifically, the pre-roasting process was performed with charcoal fire at 550 to 650 °C for a total of 2 minutes of pre-roasting on the side of the flesh for 1 minute and on the side of the skin for 1 minute.

[0034] Comparative Example B (Goroemon steaming) is a grilled eel that has been opened and subjected to a pre-roasting process and a boiling process, and the boiling time of the boiling process was 2 minutes and 15 seconds. Example C (Hatcho Goroemon steaming) is a grilled eel processed by the processing method of this embodiment, and the boiling time of the boiling process was 18 minutes and 40 seconds.

[0035] Measurement samples were prepared as follows for each of the eels of Comparative Example A, B, and Example C. For each of the above eels, four blocks each with a size of about 30 mm square were cut out from the head side (Figure 1) and used as measurement samples (identification symbols: Al, A2, Bl, B2). Also, measurement samples (identification symbols: A3, A4, B3, B4) were cut out from the tail side in the same manner for each of the above eels. Each of the above eels was tested in a state of being at room temperature.

[0036] <Hardness measurement test> The hardness measurement test was carried out using a creep testing machine (RHEONERII RE2-33005C: Yamaden Co., Ltd.) for a penetration test. In the penetration test, a 20N load cell was used, and a cylindrical plunger (diameter: 2 mm) was penetrated vertically from the side of each measurement sample under the conditions of a measurement speed of 10 mm / sec and a strain rate of 170% (a stage movement distance 1.7 times the thickness of the measurement sample) to measure the load value. When performing multiple measurements within the same block, the penetration site of the plunger was changed. The state of the penetration test by the creep testing machine is shown in Figure 2.

[0037] <Test results> The load-displacement curve of Comparative Example A "Edo steamed (head side)" is shown in Figure 3. Also, the load values at the peak tops of the side and the skin side are shown in Table 1. For "Edo steamed (head side)-1" shown in Table 1, the average thickness was 11.0 mm, the average peak load (side) was 0.51 N, and the average peak load (skin side) was 1.68 N. For "Edo steamed (head side)-2" shown in Table 1, the average thickness was 10.8 mm, the average peak load (side) of the side was 0.54 N, and the average peak load (skin side) was 1.25 N.

[0038] The peak load is the value immediately before the plunger penetrates the body or the skin. It can be understood that the greater the peak load, the harder it is. Therefore, the smaller the value of the peak load, the softer the texture.

[0039]

Table 1

[0040] The load - distortion curves of Comparative Example A "Edo - style steaming (tail side)" are shown in Fig. 4. Also, the load values at the peak tops on the flesh side and the skin side are shown in Table 2. For "Edo - style steaming (tail side) - 1" shown in Table 2, the average thickness was 11.0 mm, the average load at the peak top on the flesh side was 0.63 N, and the average load at the peak top on the skin side was 1.59 N. For "Edo - style steaming (head side) - 2" shown in Table 2, the average thickness was 11.0 mm, the average load at the peak top on the flesh side was 0.67 N, and the average load at the peak top on the skin side was 1.33 N.

[0041]

Table 2

[0042] The load - distortion curves of Comparative Example A "Edo - style steaming (head side)" are shown in Fig. 5. Also, the load values at the peak tops on the flesh side and the skin side are shown in Table 3. For "Gozu - monogatari - style steaming (head side) - 1" shown in Table 3, the average thickness was 11.2 mm, the average load at the peak top on the flesh side was 0.63 N, and the average load at the peak top on the skin side was 1.59 N. For "Gozu - monogatari - style steaming (head side) - 2" shown in Table 3, the average thickness was 12.1 mm, the average load at the peak top on the flesh side was 0.67 N, and the average load at the peak top on the skin side was 1.33 N.

[0043]

Table 3

[0044] The load - distortion curves of Comparative Example B "Gozu - monogatari - style steaming (tail side)" are shown in Fig. 6. Also, the load values at the peak tops on the flesh side and the skin side are shown in Table 4. For "Gozu - monogatari - style steaming (tail side) - 1" shown in Table 4, the average thickness was 11.1 mm, the average load at the peak top on the flesh side was 0.70 N, and the average load at the peak top on the skin side was 2.70 N. For "Gozu - monogatari - style steaming (tail side) - 2" shown in Table 4, the average thickness was 10.6 mm, the average load at the peak top on the flesh side was 0.81 N, and the average load at the peak top on the skin side was 3.04 N.

[0045]

Table 4

[0046] The load - distortion curve of Example C "Yabee Goroemon Steamed (head side)" is shown in Fig. 7. Also, the load values at the peak tops on the body side and the skin side are shown in Table 5. For "Yabee Goroemon Steamed (head side)-1" shown in Table 5, the average thickness was 11.3 mm, the average peak top load (body side) was 0.35 N, and the average peak top load (skin side) was 0.74 N. For "Yabee Goroemon Steamed (head side)-2" shown in Table 5, the average thickness was 10.6 mm, the average peak top load (body side) was 0.39 N, and the average peak top load (skin side) was 0.90 N.

[0047]

Table 5

[0048] The load - distortion curve of Example C "Yabee Goroemon Steamed (tail side)" is shown in Fig. 8. Also, the load values at the peak tops on the body side and the skin side are shown in Table 6. For "Yabee Goroemon Steamed (tail side)-1" shown in Table 6, the average thickness was 10.4 mm, the average peak top load (body side) was 0.30 N, and the average peak top load (skin side) was 0.60 N. For "Yabee Goroemon Steamed (tail side)-2" shown in Table 6, the average thickness was 10.8 mm, the average peak top load (body side) was 0.39 N, and the average peak top load (skin side) was 0.74 N.

[0049]

Table 6

[0050] <Summary> Table 7 summarizes the average values of Tables 1 to 6. As is clear from Table 7, it can be understood that the average load value of Example C is significantly lower than that of Comparative Examples A and B. Based on Example C, the eel obtained by the eel processing method according to this embodiment has an average load value (skin side) of 1.00 or less, preferably in the range of 0.90 to 0.70, and an average load value (flesh side) of 0.40 or less, preferably in the range of 0.40 to 0.30.

[0051]

Table 7

Claims

1. A method for processing eels, comprising: A pre-roasting step of roasting the dressed eel; A boiling step of boiling the eel roasted in the pre-roasting step in soup stock for 10 to 45 minutes from when the soup stock starts to boil until the collagen in the eel irreversibly denatures; A final roasting step of roasting the eel boiled in the boiling step.

2. The method for processing eels according to Claim 1, wherein in the boiling step, the eel roasted in the pre-roasting step is boiled for 16 to 22 minutes.

3. The method for processing eels according to Claim 1, wherein the eel is an eel skewered on a stick.

4. The method for processing eels according to Claim 1, wherein in the final roasting step, the eel is roasted with or without sauce.

5. The method for processing eels according to Claim 1, further comprising a dressing step of dressing the eel before the pre-roasting step.

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