Manufacturing method of shellfish specimen

Abstract

The invention discloses a manufacturing method of a shellfish specimen. The preparation method comprises the following steps: S1, running water treatment: filling microorganism balls containing compound bacteria into shellfish without shellfish meat, and soaking the shellfish in a water body in which running water continuously flows; s2, degreasing: soaking the shellfish subjected to flowing water treatment in the step S1 in a degreasing agent, and cleaning after soaking; s3, dehydrating: soaking the shellfish cleaned in the step S2 in a dehydrating agent for dehydrating; s4, preservation: putting the shellfish dehydrated in the step S3 into a preservation solution for soaking, and drying to obtain the shellfish specimen. By means of the manufacturing method, the integrity, the color and the gloss of the shellfish specimen are guaranteed, and the manufactured shellfish specimen is clear in texture and free of odor.

Description

Technical Field

[0001] The invention belongs to the technical field of shellfish preservation, and more specifically, relates to a method for preparing shellfish specimens. Background Art

[0002] Shells are the mantles of mollusks that live near water. They are calcified substances formed by the secretion of a special glandular cell of the mollusks to protect the soft parts of the body. As an important component of marine life, shells have unique shapes and beautiful textures. Compared with natural calcium carbonate minerals in nature, shells have a unique multi-scale, multi-level "brick-mud" assembly structure, and because of their multi-level layered structure, they have excellent properties such as good toughness and high strength.

[0003] The collection and preparation of specimens are the premise and foundation of marine shellfish research. Marine shellfish specimens include their external genitalia, radula, jaws, shells, etc., which can be used as the basis for identification. Before specimen preparation, the shell and meat of shellfish need to be separated. The current existing shellfish shell and meat classification methods include, for example, quickly inserting a knife between the bivalve shells, shaving off the adductor muscle, opening the bivalve, and then scraping off the meat with a knife; or, for example, gastropod shellfish are generally soaked in fresh water and then boiled, and then the meat is pulled out with tweezers or clamps, but steaming will damage the shell to a certain extent and affect the color of the shell itself.

[0004] For the preservation of shells, 5% formalin solution is used for fixation for 10 hours and then transferred to 70% ethanol for long-term storage, or directly fixed and preserved with 70% ethanol. Patent publication number CN111557299A discloses a method for preparing specimens, which first immerses the specimen in formalin solution and then freezes it; then the specimen is cut, the midsagittal section is dehydrated and defatted, vacuum impregnated and hardened, and then assembled and bonded, and the specimen is prepared.

[0005] However, traditional methods of preparing shell specimens often make it difficult to fully preserve the original shape, color and texture of the shells, resulting in reduced ornamental and research value of the specimens. Summary of the invention

[0006] In view of the above-mentioned existing technical problems, the primary purpose of the present invention is to provide a method for making shellfish specimens, which can maintain the original shape and color of the shells to the greatest extent, and avoid problems such as damage, fading, and odor of the shells during the production process.

[0007] The second purpose of the present invention is to provide a method for preparing a shellfish specimen and obtain the shellfish specimen.

[0008] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0009] The present invention claims protection for a method for preparing a shellfish specimen, comprising the following steps:

[0010] S1. Flowing water treatment: The microbial balls containing the composite bacteria are stuffed into the shellfish from which the shellfish meat has been removed, and the shellfish are immersed in a continuously flowing water body;

[0011] S2. Degreasing: The shellfish treated with running water in step S1 is immersed in a degreasing agent and then washed;

[0012] S3 dehydration: Step S2 after the cleaned shellfish soaked in a dehydrating agent for dehydration;

[0013] S4 preservation: After step S3, the shellfish is dehydrated and immersed in a preservative solution and dried to obtain a shellfish specimen;

[0014] According to weight percentage, the fresh-keeping liquid comprises: 70 to 80 parts of varnish, 5 to 10 parts of sodium dehydroacetate, 3 to 7 parts of eugenol, 3 to 5 parts of rosmarinic acid, 1 to 3 parts of osthole, and 1 to 3 parts of magnolol.

[0015] In the present invention, the shellfish meat removed from the shellfish is first treated with composite bacteria, and the composite bacteria form a small material decomposition system. Through synergistic action, each of the composite bacteria exerts its specific metabolic and decomposition functions, jointly accelerates the decomposition process of the snail meat, realizes the transformation and recycling of organic matter, and avoids the odor caused by the residual snail meat. By using microbial balls containing composite bacteria, the decomposition of the residual shellfish meat can be accelerated, and the continuous water flow can take away the decomposed meat in time to avoid the specimen from generating odor. In addition, compared with the existing treatment methods of boiling or drying, the continuous flow of water can ensure the integrity and clear texture of the shellfish shells, maintain the luster and color of the shells, and inhibit the generation of odor.

[0016] Furthermore, the shellfish treated with running water are successively defatted and dehydrated, and the defatting treatment can remove lipid substances and water on the surface of the shellfish to avoid the generation of odor. Furthermore, the treatment with the preservative liquid can play an antioxidant, antiseptic, anti-deterioration and antibacterial role. Sodium dehydroacetate has a good inhibitory effect on various molds and bacteria, which can extend the storage period of the specimens and avoid mold loss; eugenol, rosmarinic acid and osthole have a wide antibacterial spectrum and antioxidant properties; magnolol can significantly reduce the survival of pathogens and play a significant antibacterial role. Through the treatment of the above-mentioned preservative liquid, the color and gloss of the shellfish specimens can be maintained.

[0017] The present invention ensures the integrity, color and gloss of the shellfish specimens through the above-mentioned water treatment, degreasing, dehydration and preservation steps, so that the shellfish specimens present a natural and beautiful appearance and have great ornamental value. The prepared shellfish specimens have clear textures, bright colors, strong gloss, and no odor. The above-mentioned preparation method of the present invention is simple and easy to implement, and reduces the difficulty and complexity of specimen preparation.

[0018] Preferably, in step S1, carnivorous snails are used to remove shellfish meat. Specifically, the carnivorous snails are selected from one or more of the group consisting of Dongfeng Snail, Red Snail, Horn Snail, Jade Snail, Litchi Snail, and Fragrant Snail.

[0019] Preferably, in step S1, the composite bacteria include Bacillus licheniformis, Bacillus subtilis, Enterococcus faecium, Lactobacillus casei, red yeast, denitrifying bacteria and nitrifying bacteria. The above-mentioned Bacillus licheniformis, Bacillus subtilis, Enterococcus faecium, Lactobacillus casei, red yeast, denitrifying bacteria and nitrifying bacteria can be conventionally used in the art.

[0020] More preferably, the mass ratio of Bacillus licheniformis, Bacillus subtilis, Enterococcus faecium, Lactobacillus casei, red yeast, denitrifying bacteria and nitrifying bacteria is 1-2:1-2:2-3:1-2:1-2:1-3:1-3.

[0021] More specifically, the functions of each strain in the method of the present invention are as follows:

[0022] Bacillus licheniformis: It has a strong ability to secrete proteases, which can decompose the protein in snail meat and convert it into small molecule peptides and amino acids. It can also produce some antibacterial substances, inhibit the growth of harmful microorganisms, and create a favorable decomposition environment for other beneficial microorganisms.

[0023] Bacillus subtilis: It can secrete a variety of enzymes, such as protease, amylase and lipase. Protease can break down the protein in snail meat, amylase can break down the carbohydrates, and lipase can break down fat, accelerating the overall decomposition process of snail meat.

[0024] Enterococcus faecalis: Participates in the fermentation process of organic matter, converts complex organic matter into simpler substances, and at the same time produces some organic acids, lowers the pH value of the environment, and creates conditions conducive to decomposition.

[0025] Lactobacillus casei: It can produce organic acids such as lactic acid, lower the pH value of the environment, and inhibit the growth of some spoilage bacteria. At the same time, it can also decompose some carbohydrates and proteins and promote the transformation of organic matter.

[0026] Red yeast: It can use the organic matter in snail meat to grow and reproduce, decompose organic matter during metabolism, and produce some enzymes to assist other microorganisms in the decomposition process.

[0027] Denitrifying bacteria: convert nitrogen compounds such as nitrates into nitrogen gas, reduce nitrogen accumulation, promote nitrogen cycle, and help decompose and transform nitrogen-containing organic matter in snail meat.

[0028] Nitrifying bacteria: Under aerobic conditions, they convert ammonia nitrogen into nitrates, participate in the nitrogen cycle, provide nitrogen sources for other microorganisms, and promote overall decomposition and material circulation.

[0029] Preferably, in step S1, the flow rate of the running water is 500-1000 mL / min. At this flow rate, the shellfish meat can be prevented from stinking.

[0030] Preferably, the microbial ball comprises, by weight, 7 to 16 parts of a porous filler carrier and 1 to 2 parts of composite bacteria. In the present invention, the microbial ball is composed of a porous filler carrier and composite bacteria. The porous filler carrier is conducive to the attachment and fixation of the composite bacteria thereon, and also has the function of adsorbing and removing odors. Other materials such as medical stone, perlite, vermiculite, etc. can also be used as materials for the porous filler carrier.

[0031] Further preferably, the porous filler carrier comprises: 2 to 5 parts of volcanic rock biological filler, 3 to 6 parts of diatomaceous earth and 2 to 5 parts of coral.

[0032] In some embodiments, the preparation method of the microbial ball is: volcanic rock biological filler, diatomaceous earth, coral, composite bacteria and solvent are mixed to form a sphere, and the solvent is removed by drying to obtain the microbial ball. More specifically, the particle size of the microbial ball is 0.5 to 2 mm.

[0033] Preferably, the drying is: drying with cold air at 25-30°C for 12-24 hours, and after drying, the microbial balls are obtained.

[0034] Preferably, in step S2, the degreasing agent is selected from one or more of sodium alkyl sulfonate, trichloroethylene, and petroleum ether. More specifically, the sodium alkyl sulfonate is sodium sulfonate having 8 to 14 carbon atoms.

[0035] Preferably, in step S3, the dehydrating agent is anhydrous ethanol.

[0036] Preferably, in steps S1 to S4, at least one of the following (a) to (d) is selected:

[0037] (a) In step S1, the continuous water flow time is ≥ 2 days;

[0038] (b) In step S2, the soaking time is 5 to 10 minutes;

[0039] (c) In step S3, the soaking time is 10 to 15 minutes;

[0040] (d) In step S4, the soaking time is 1 to 5 minutes.

[0041] Preferably, in the step S3, grinding is further performed after drying.

[0042] Furthermore, the present invention seeks protection for a shellfish specimen obtained by a production method.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] (1) The method for preparing shellfish specimens provided by the present invention can maintain the color and luster of the shellfish specimens to the greatest extent, without generating any odor, and the specimens have clear and complete textures. The preparation method avoids the problems of deformation, fading, odor, etc. of the shellfish specimens during the preparation process, so that the shellfish specimens present a natural and beautiful appearance, which is of great ornamental value.

[0045] (2) The preparation method provided by the present invention is simple and easy to operate, reducing the difficulty and complexity of specimen preparation.

[0046] (3) The preparation method provided by the present invention enhances the stability of the specimen, enabling it to be preserved for a long time without being damaged, which is conducive to collection and display.

[0047] (4) The production method provided by the present invention reduces excessive reliance on chemical agents, reduces potential harm to the environment, and is more environmentally friendly and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is the Babylonia conch with residual shellfish meat before being processed in Example 1.

[0049] Figure 2 This is the Babylonia snail treated with running water and microbial balls in Example 1.

[0050] Figure 3 The baby cones are preserved and dried in Example 1.

[0051] Figure 4 This is the Dongfeng snail of comparative example 1 that has cracks and a lighter shell color with dark edges after being exposed to the sun.

[0052] Figure 5 This is the Dongfeng snail of comparative example 2 that cracked after being boiled in water and had a lighter shell color and darker edges. DETAILED DESCRIPTION

[0053] The present invention is further described below in conjunction with the accompanying drawings and specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0054] Embodiment 1 A method for preparing shellfish specimens

[0055] (1) Material preparation: Select brightly colored, intact, and undamaged Babylonia square-spottedii. Use a knife to remove the organisms attached to the surface of the Babylonia square-spottedii. Use a soft-bristled brush to gently scrub the surface of the Babylonia square-spottedii to remove impurities and dirt.

[0056] (2) Meat removal and disposal: Figure 1 As shown in the figure, the snails are placed in a tank where carnivorous snails are mixed, so that the flesh of the snails is scraped clean (the snails with residual flesh are as shown in Figure 1 shown).

[0057] (3) Flow operation: Take out the remaining Dongfeng snail shells, fill them with microbial balls containing composite bacteria, and place them in water for 2 days or more. The water flow rate is controlled at 600 ml per minute. During this period, the water needs to flow continuously. Figure 2 shown.

[0058] The steps for making microbial balls are as follows:

[0059] ① According to the mass ratio, the composite bacteria include Bacillus licheniformis BLCC1-0238, Bacillus subtilis BS-168, Enterococcus faecium EF08, Lactobacillus casei LC-01, marine red yeast, denitrifying bacteria Halomonas sp.HRL-11, and Nitrobacter (the above strains are all from the China Marine Microbial Culture Collection Center), which are mixed and prepared in the ratio of 1:1:2:1:1:3:3 respectively;

[0060] ② Mix 3 parts of volcanic rock biological filler, 4 parts of diatomaceous earth, 5 parts of coral and 2 parts of compound bacteria by weight, add distilled water to dissolve into a viscous state, and use the mixed material to make small balls of about 1 mm through a mold; ③ Carry out cold air drying in an oven at 25°C for 24 hours. After drying, microbial balls are made.

[0061] (4) Degreasing process: Soak the shells of the baby snails in sodium dodecyl sulfate for 5 minutes to remove the oil contained in the shells of the baby snails.

[0062] (5) Dehydration: Wash off the residual degreasing agent with distilled water, soak in anhydrous ethanol for disinfection and dehydration, take out after 10 minutes, place in a well-ventilated place, and wait for the ethanol to evaporate naturally.

[0063] (6) Preservation operation: Place the shells of the Dongfeng snails in the preservative solution, ensuring that they are fully immersed in all directions without dead corners. After soaking for 1 minute, take out the shells of the Dongfeng snails and place them in a well-ventilated place again to allow them to dry naturally (such as Figure 3 shown).

[0064] Calculated by weight, the preservative liquid includes: 76 parts of varnish (varnish, source: Guangzhou Fumeo Paint Co., Ltd.), 8 parts of sodium dehydroacetate, 6 parts of eugenol, 4 parts of rosmarinic acid, 3 parts of osthole, and 3 parts of magnolol.

[0065] (7) Polishing: Use sandpaper to gently polish the shell surface of the conch to remove surface flaws and enhance glossiness.

[0066] Embodiment 2 A method for preparing shellfish specimens

[0067] The difference between this embodiment and embodiment 1 is that:

[0068] Bacillus licheniformis, Bacillus subtilis, Enterococcus faecalis, Lactobacillus casei, red yeast, denitrifying bacteria, and nitrifying bacteria are mixed in the ratio of 2:2:2:1:1:2:2 respectively.

[0069] Calculated by weight, the fresh-keeping liquid comprises: 70 parts of varnish, 10 parts of sodium dehydroacetate, 3 parts of eugenol, 5 parts of rosmarinic acid, 1 part of osthole, and 3 parts of magnolol.

[0070] Embodiment 3 A method for preparing shellfish specimens

[0071] The difference between this embodiment and embodiment 1 is that:

[0072] Bacillus licheniformis, Bacillus subtilis, Enterococcus faecalis, Lactobacillus casei, red yeast, denitrifying bacteria, and nitrifying bacteria are mixed in the ratio of 2:2:3:2:2:1:1 respectively.

[0073] Calculated by weight, the fresh-keeping liquid comprises: 80 parts of varnish, 5 parts of sodium dehydroacetate, 7 parts of eugenol, 3 parts of rosmarinic acid, 3 parts of osthole, and 1 part of magnolol.

[0074] Comparative Example 1

[0075] This comparative example differs from Example 1 in that:

[0076] The Dongfeng conch shells processed in step (2) of Example 1 are placed in the sun for drying, replacing the flow line operation step of step (3) of Example 1, and then steps (4) to (7) are carried out.

[0077] The specific operation of the drying treatment is as follows: Step (2) Rinse the treated baby conch shells with clean water, and then place them on a towel to drain the water. Choose a sunny and well-ventilated place for drying. During the drying process, the baby conch shells can be turned over appropriately to ensure that they are evenly dried.

[0078] Comparative Example 1: Figure 4 As shown by Figure 4 It can be seen that cracks appeared on the Dongfeng snail specimen after one day of drying, the texture was unclear, the shell color lost its luster and became dull, and the specimen had a bad smell.

[0079] Comparative Example 2

[0080] This comparative example differs from Example 1 in that:

[0081] The Dongfeng conch shells processed in step (2) of Example 1 are boiled in water, replacing the flow-line operation step of step (3) of Example 1, and then steps (4) to (7) are performed.

[0082] The specific operation of the boiling treatment is as follows: add an appropriate amount of clean water to the pot, heat it to boiling, and put the shells of the baby conch treated in step (2) into the boiling water. During the boiling process, always pay attention to the changes of the baby conch. At the same time, as the impurities are removed, the water becomes turbid. When the boiling time reaches 5 minutes, use a colander to remove the baby conch and immediately put it into the prepared cold water to allow it to cool quickly.

[0083] Comparative Example 2: Figure 5 As shown by Figure 5 It can be seen that cracks appeared on the Dongfeng snail specimens after being dried in the sun, the texture became clearer, the shell color lost its luster and became dull, and the specimen had a bad smell.

[0084] Comparative Example 3

[0085] The difference between this comparative example and Example 1 is that step (6) is not performed.

[0086] Comparative Example 4

[0087] The difference between this comparative example and Example 1 is that step (4) and step (5) are not performed.

[0088] Comparative Example 5

[0089] The difference between this comparative example and Example 1 is that step (3) was not performed.

[0090] Test Case

[0091] The Babylonia specimens prepared in the above-mentioned embodiments and comparative examples were observed for their integrity, texture clarity, color and gloss, and odor (smell). The classification and judgment criteria of each index are shown below, and the results of each index are shown in Table 1 below.

[0092] (1) Integrity

[0093] Level 1, highly complete: without any missing, damaged or deformed, intact;

[0094] Grade 2, Moderately intact: There are some minor flaws, wear or scratches;

[0095] Level 3, less complete: with obvious damage, missing parts or cracks;

[0096] Level 4, Severely Destroyed: Object or system is almost completely destroyed or missing.

[0097] (2) Texture clarity

[0098] Level 1, high definition: The texture is fine and distinct, the lines are smooth, and the direction and details of each texture can be clearly distinguished; even when observed at a close distance or with the help of a magnifying glass of a certain magnification, the texture still maintains a high degree of clarity;

[0099] Level 2, medium clarity: The texture is relatively clear, but the details are not as obvious as level 1. The main texture direction can be easily distinguished, but there will be slight blur or incoherence in some local areas;

[0100] Level 3, low definition: The texture is blurred, and it is difficult to distinguish the specific texture direction and details. The overall look is chaotic, with only some rough outlines or color blocks and no obvious texture structure.

[0101] (3) Color and gloss

[0102] Level 1, bright and vivid: high color saturation, bright colors; strong gloss;

[0103] Level 2, medium color and gloss: The color is relatively soft, with moderate saturation, not too bright or too dull; the gloss is average, not as strong as level 1;

[0104] Level 3, Dull: The color is dull, lacks saturation, and looks dull; the gloss is very low and the surface has a matte or rough texture.

[0105] (4) Odor (smell)

[0106] Level 1, odorless: absolutely no unpleasant odor; even if you sniff it at close range, you can't feel any odor;

[0107] Level 2, slight odor: There is a slight, less obvious odor, but it will not make people feel strongly uncomfortable; it can only be detected when sniffing carefully at a close distance;

[0108] Level 3, obvious odor: There is a relatively strong odor, which is easily noticed by people and may cause a certain degree of discomfort;

[0109] Level 4, stench: extremely strong odor that is unbearable and may even cause harm to human health.

[0110] Table 1

[0111] Completeness Texture clarity Color and Gloss Odor (bad smell) Example 1 Level 1 Level 1 Level 1 Level 1 Example 2 Level 1 Level 1 Level 1 Level 1 Example 3 Level 1 Level 1 Level 1 Level 1 Comparative Example 1 Level 3 Level 3 Level 3 Level 3 Comparative Example 2 Level 2 Level 3 Level 3 Level 3 Comparative Example 3 Level 1 Level 3 Level 3 Level 2 Comparative Example 4 Level 1 Level 2 Level 1 Level 2 Comparative Example 5 Level 1 Level 1 Level 2 Level 3

[0112] From Table 1 above and Figure 3 It can be seen that the shellfish specimen preparation method provided by the present invention can produce a Babylonia specimen with high integrity (reaching level 1), high texture clarity (reaching level 1), high color saturation and strong gloss (reaching level 1), and no odor (reaching level 1).

[0113] It can be seen from Example 1, Comparative Example 1 and Comparative Example 2 that when the baby snail is placed in the sun for drying or boiled, the baby snail specimens produced will be damaged, and the texture of the baby snail specimens will be greatly damaged, and the texture will be unclear as a whole. In addition, the luster of the baby snail specimens disappears, becomes dull and produces a bad smell.

[0114] It can be seen from Example 1 and Comparative Example 3 that the use of preservative liquid to preserve the baby cones can greatly improve the texture clarity of the baby cones specimens, and the texture clarity is improved from level 3 to level 1; in addition, the specimens are also brightly colored and have a strong gloss; the color and gloss are also improved from level 3 to level 1; and no odor is generated.

[0115] It can be seen from Example 1 and Comparative Example 4 that without dehydration and defatting treatment, the texture clarity of the final prepared babylonica specimen deteriorates and an odor occurs.

[0116] It can be seen from Example 1 and Comparative Example 5 that without using the composite bacteria and without subjecting the Babylonia to running water treatment in running water, the Babylonia specimens finally produced have poor color and gloss and have a bad smell.

[0117] The foregoing examples are merely illustrative and are used to explain some features of the method of the present invention. The appended claims are intended to require the widest possible range that can be imagined, and the embodiments presented herein are demonstrated by the applicant's actual test results. Therefore, the applicant's intention is that the appended claims are not limited by the selection of examples that illustrate the features of the present invention. Some numerical ranges used in the claims also include sub-ranges therein, and changes in these ranges should also be interpreted as being covered by the appended claims where possible.

Claims

1. A method for preparing a shellfish specimen, characterized in that: The following steps are involved: S1. Flowing water treatment: The microbial balls containing the composite bacteria are stuffed into the shellfish from which the shellfish meat has been removed, and the shellfish are immersed in a continuously flowing water body; S2. Degreasing: The shellfish treated with running water in step S1 is immersed in a degreasing agent and then washed; S3 dehydration: Step S2 after the cleaned shellfish soaked in a dehydrating agent for dehydration; S4 preservation: After step S3, the shellfish is dehydrated and immersed in a preservative solution and dried to obtain a shellfish specimen; According to weight percentage, the fresh-keeping liquid comprises: 70 to 80 parts of varnish, 5 to 10 parts of sodium dehydroacetate, 3 to 7 parts of eugenol, 3 to 5 parts of rosmarinic acid, 1 to 3 parts of osthole, and 1 to 3 parts of magnolol.

2. The method according to claim 1, characterized in that: In the step S1, carnivorous snails are used to remove the shellfish meat.

3. The method according to claim 1, characterized in that: In the step S1, the composite bacteria include Bacillus licheniformis, Bacillus subtilis, Enterococcus faecium, Lactobacillus casei, red yeast, denitrifying bacteria and nitrifying bacteria.

4. The method according to claim 3, characterized in that: The mass ratio of Bacillus licheniformis, Bacillus subtilis, Enterococcus faecium, Lactobacillus casei, red yeast, denitrifying bacteria and nitrifying bacteria is 1-2:1-2:2-3:1-2:1-2:1-3:1-3.

5. The method according to claim 1, characterized in that: In step S1, the flow rate of the running water is 500-1000 mL / min.

6. The method according to claim 1, characterized in that: In step S2, the degreasing agent is selected from one or more of sodium alkyl sulfonate, trichloroethylene, and petroleum ether.

7. The method according to claim 1, characterized in that: In the step S3, the dehydrating agent is anhydrous ethanol.

8. The method according to claim 1, characterized in that: In the steps S1 to S4, at least one of the following (a) to (d) is selected: (a) In step S1, the continuous water flow time is ≥ 2 days; (b) In step S2, the soaking time is 5 to 10 minutes; (c) In step S3, the soaking time is 10 to 15 minutes; (d) In step S4, the soaking time is 1 to 5 minutes.

9. The method according to any one of claims 1 to 8, characterized in that: The shellfish is the Babylonia spp.

10. A shellfish specimen obtained by the method according to any one of claims 1 to 9.

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