Shrimp refrigerator keep-alive method based on multi-parameter regulation and control and emptying promotion synergistic effect

Abstract

The invention discloses a shrimp refrigerator keep-alive method based on the synergistic effect of multi-parameter regulation and control and evacuation promotion, and belongs to the technical field of fresh keeping of live shrimps. The keep-alive method comprises the following steps: (1) preparing culture water with the salinity of 25-30% o, soaking lemon slices in the culture water, and taking out the soaked lemon slices to obtain a keep-alive solution; and (2) adding the shrimps into the keep-alive solution, and transferring to an environment of 5-11 DEG C for preservation. According to the method, low-temperature induced dormancy and microenvironment accurate regulation and control are utilized, and metabolism and oxygen requirements of the shrimps are reduced, so that the live shrimps survive for a long time in an oxygen-free environment, the quality of the fresh live shrimps is ensured, and a new technical thought is provided for improving the freshness and taste of food materials.

Description

Technical Field

[0001] The present invention relates to the technical field of live shrimp preservation, and particularly to a method for preserving live shrimp in a refrigerator based on the synergistic effect of multi-parameter regulation and promoting evacuation. Background Art

[0002] With the improvement of the living standards of Chinese people, consumers' demand for fresh and high-quality seafood products, especially live shrimp products, has been continuously increasing. Shrimp is a widely consumed seafood. With the popularity of fitness exercises and the concept of light food in recent years, shrimp meat, as a food material with low calories, low fat, and high nutritional density, has become increasingly popular. However, shrimp is vulnerable to microbial spoilage. After the death of shrimp, it is easily contaminated by the microorganisms carried by itself and external microorganisms, leading to spoilage and deterioration. Nowadays, the increasing demand of consumers for high quality, food safety, and long shelf life has prompted people to pay more and more attention to safe and effective shrimp preservation technologies.

[0003] According to research, the "difficulty in preservation" encountered by many users after purchasing live shrimp is indeed an important pain point, especially the short survival time of live shrimp, which may die within 1-2 hours usually. In this case, users often choose to process and freeze immediately, or put them in the refrigerator for a short time. However, after the frozen shrimp loses its fresh state, its taste and flavor will indeed decline, and it is difficult to maintain the quality when freshly purchased. Through the basic research on the live preservation characteristics of shrimp, systematically studying and optimizing multiple factors affecting the survival rate provides an innovative solution for improving the survival rate of shrimp, and exploring the quality change mechanism of shrimp during the live preservation process in the ecological ice temperature. Through innovative technical means and methods, the goal of temporarily preserving live shrimp in the refrigerator for 12 hours is achieved, providing consumers with more convenient and high-quality live shrimp products. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preserving live shrimp in a refrigerator based on the synergistic effect of multi-parameter regulation and promoting evacuation to solve the problems existing in the above-mentioned prior art. The present invention utilizes low-temperature induced dormancy and precise microenvironment regulation to reduce the metabolism and oxygen demand of shrimp, enabling live shrimp to survive for a long time in an oxygen-free environment, ensuring the quality of fresh live shrimp, and providing a new technical idea for improving the freshness and taste of food materials.

[0005] To achieve the above purpose, the present invention provides the following scheme:

[0006] The present invention provides a method for preserving live shrimp in a refrigerator based on the synergistic effect of multi-parameter regulation and promoting evacuation, including the following steps:

[0007] (1) Prepare a culture water with a salinity of 25-30‰, soak lemon slices in the culture water and then take them out to obtain a preservation solution;

[0008] (2) Put the shrimps into the said live preservation solution and transfer them to a refrigerator at 5-11°C for preservation.

[0009] The research of the present invention finds that when the salinity is 25-30‰, the survival rate of shrimps is significantly improved. After soaking 2 lemon slices in 1L of salt water and then taking them out, the core components in the lemon slices, including citric acid, vitamin C, flavonoids, limonene, citral, etc., can dissolve into the salt water. Citric acid can destroy the cell membrane of pathogenic bacteria, inhibit the proliferation of common aquatic pathogenic bacteria such as Vibrio parahaemolyticus and Aeromonas hydrophila, activate the nerve reflex mechanism mediated by the TRPV1 ion channel in the shrimp intestine, and induce an increase in the intestinal peristalsis frequency. Vitamin C and flavonoids have antioxidant effects, can reduce the free radical level (such as the MDA value) in the shrimp body, and enhance the activity of superoxide dismutase (SOD), thereby enhancing the stress resistance ability. This treatment promotes the evacuation of the shrimp intestine, significantly reduces the autolysis of protease and the microbial load during the live preservation process. During the treatment, maintain the dissolved oxygen ≥5mg / L, and regulate the intestinal motility rhythm through the nerve signal cascade reaction to ensure the stability of the intestinal evacuation rate.

[0010] The research of the present invention finds that within the temperature range of 5-11°C, the survival rate of shrimps is the highest. The cooling rate does not need to be strictly controlled, but rapid cooling (directly putting into cold water) will reduce the survival rate, and generally not higher than 10°C / h is sufficient. Transferring from room temperature to the fresh-keeping area of the refrigerator at 5-11°C, the survival rate of shrimps is between 80-85%, indicating that shrimps can adapt to the low-temperature stress caused by the temperature change of the refrigerator. The operation is simple and is suitable for home shrimp preservation.

[0011] Optionally, the salinity of the breeding water is 27‰.

[0012] The research of the present invention finds that when the salinity is 25-30‰, the survival rate of shrimps is significantly improved, and the optimal salinity is 27‰. After comparing various salts, it is found that the types of salts have no significant difference in the survival rate of shrimps.

[0013] Optionally, the concentration of citric acid in the live preservation solution is 0.7-1g / L, and the pH value is 6.5-6.9.

[0014] Optionally, the operation of adding the shrimps into the said live preservation solution is to put the shrimps into a live preservation container, place them in a flat way, and add the said live preservation solution.

[0015] The research of the present invention finds that separating the shrimp bodies can reduce the physical damage between them, ensure that the shrimps have enough space, and at the same time, the non-sealed environment is conducive to gas exchange. Therefore, the shrimps need to be laid flat at the bottom of the live preservation container. The specification of the live preservation container for placing one catty of shrimps (about 30 white shrimps) is not less than 25cm×35cm, and avoid stacking between the shrimp bodies when placing.

[0016] Optionally, before adding the live preservation solution, the shrimp are placed for 20 - 30 minutes to relieve the stress response.

[0017] Optionally, the water level of the live preservation solution is higher than 1 / 3 of the shrimp body.

[0018] The research of the present invention finds that a water level slightly higher than the shrimp body helps to reduce the stress response, but too high a water level will slow down the cooling rate. Therefore, the water level adjustment range is from 1 / 3 of the shrimp body to full immersion of the shrimp body.

[0019] Optionally, the temperature of the preservation environment is 7°C.

[0020] Optionally, after preserving for 0.5 - 4 hours, the temperature is raised to 10°C.

[0021] The research of the present invention finds that in the initial cooling stage, the temperature is controlled within a range lower than the conventional live preservation temperature so that the live shrimp can quickly enter the dormant state. After cooling for 30 minutes, the temperature is then slowly raised back to the normal live preservation temperature of 10°C. This operation can effectively shorten the time for the shrimp to enter dormancy, maintain its low metabolic state, significantly improve the survival rate and live preservation time, and improve the overall appearance color after 12 hours of live preservation. The rewarming technique not only further optimizes the live preservation effect on the basis of low-temperature induced dormancy, quickly enters low-temperature dormancy and then slowly rewarms, which can maintain the good appearance and color of the shrimp, making it more suitable for long-term survival in the refrigerated environment.

[0022] Optionally, the preservation time is 0 - 12 hours.

[0023] The present invention also provides a live preservation container for shrimp in a refrigerator, including a lid (1), a partition (2), an anti-collision device (3) and a box (4);

[0024] The lid (1) is covered and connected to the box (4); the partition (2) is movably placed inside the box (4); the anti-collision device (3) is threadedly connected to the upper and lower layers of the partition (2);

[0025] The box (4) is provided with ventilation holes (5); the partition (2) is provided with pores; the height of the ventilation holes (5) is higher than the height of the partition (2) in the box (4).

[0026] The present invention discloses the following technical effects:

[0027] The present invention provides a method for keeping shrimp alive in a refrigerator based on the synergistic effect of multi-parameter regulation and promoting evacuation, which can keep shrimp alive in the refrigerator for more than 12 hours. When users cook for dinner or even the next day, they can enjoy a taste almost equal to that of live shrimp. This experience can significantly improve the freshness preservation effect of ingredients, enhance the flexible usability of ingredients, enable users to easily enjoy a high-quality food experience, and solve the pain point problem of difficult freshness preservation of live aquatic products. In addition, through this method, consumers can store fresh shrimp at home in a household refrigerator in a short time, enrich the functions of refrigerator products, and improve the market competitiveness of refrigerator products. The present invention has broad application prospects and commercial value. The innovation of this technology lies in combining the characteristics of shrimp live preservation and refrigerator manufacturing technology, providing a brand-new storage solution for shrimp products for consumers.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. High survival rate: Through innovative interfacial effect, low-temperature induced dormancy and microenvironment regulation technologies, shrimp can survive for more than 12 hours in the refrigerator without special oxygen supply conditions, significantly improving the effect of traditional storage methods.

[0030] 2. Stable and reliable: Through systematic research and optimization of multiple parameters, the optimal combination of live preservation parameters is determined, making the live preservation effect stable and reliable. The extended survival time keeps the shrimp still alive before cooking, providing a taste and flavor close to that of fresh ones, and greatly improving the quality of ingredients and user experience.

[0031] 3. Simple operation: The operation steps and parameters involved in the present invention are easy to control and implement, without the need for complex equipment and oxygen supply support, which is convenient for household users to apply in daily life. It not only meets the needs of consumers for fresh ingredients but also helps supermarkets improve the quality of live fresh products, having broad application prospects.

[0032] 4. Intestinal purification advantage: Through the neuroendocrine regulation mechanism mediated by organic acids, the autonomous intestinal evacuation of shrimp before live preservation is realized, reducing the sediment content in the cooked product by 82% and slowing down the accumulation rate of total volatile basic nitrogen (TVB-N) by 57%, significantly improving the food safety and sensory quality. Moreover, fresh lemons are easily available in ordinary families. The organic acids are introduced into the live preservation water body and release volatile components, which have a dual effect of inhibiting the generation of odor substances and enhancing the flavor during the live preservation process of aquatic products. Description of the Drawings

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 It is the overall structure diagram of the live preservation container of the present invention; among them, the description of the reference numerals: 1. Lid; 2. Partition board; 3. Anti-collision device; 4. Box; 5. Ventilation holes;

[0035] Figure 2 It is the placement situation of the prawns in the live preservation container in Example 1 in the refrigerator;

[0036] Figure 3 It is the statistical result of the survival rate of prawns under different salinities;

[0037] Figure 4 It is the statistical result of the survival rate of prawns under different temperature conditions;

[0038] Figure 5 It is the stacking situation of the prawns in Example 4; among them, A is the stacking degree of 150%; B is the stacking degree of 95%;

[0039] Figure 6 It is the state of the prawns under different rewarming operations; among them, A is the non-rewarming group; B is the rewarming group;

[0040] Figure 7 It is the prawn shrimp lines after the treatment of adding lemon slices or not; among them, A is the group with lemon slices added; B is the group without addition;

[0041] Figure 8 It is the live preservation solution after the treatment of adding lemon slices or not; among them, A is tap water; B is the group without addition; C is the group with lemon slices added;

[0042] Figure 9 It is the detection result of the muscle quality of the prawns under different live preservation times; among them, A is muscle hardness; B is muscle elasticity; C is muscle cohesiveness; D is muscle resilience; E is muscle adhesiveness; F is muscle chewiness;

[0043] Figure 10 It is the detection result of the antioxidant stress index of the prawns under different live preservation times;

[0044] Figure 11Detection results of free amino acid contents in prawns under different holding times; among them, A-K are aspartic acid (asp), glutamic acid (glu), histidine (his), alanine (ala), tyrosine (tyr), valine (val), norvaline (nva), phenylalanine (phe), lysine (lys), leucine (leu), γ-aminobutyric acid (gaba) in sequence;

[0045] Figure 12 Detection results of free amino acid contents in prawns under different holding times; A-D are serine (ser), glycine (gly), citrulline (cit), cysteine (cys) in sequence;

[0046] Figure 13 Detection results of free amino acid contents in prawns under different holding times; A-J are asparagine (asn), glutamine (gln), threonine (thr), arginine (arg), methionine (met), tryptophan (trp), isoleucine (ile), hydroxyproline (hyp), sarcosine (sar), proline (pro) in sequence;

[0047] Figure 14 Detection results of volatile components in prawns under different holding times;

[0048] Figure 15 Statistical results of volatile components in prawns under different holding times. Detailed implementation manners

[0049] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be regarded as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and implementation schemes of the present invention.

[0050] It should be understood that the terms described in the present invention are only used to describe specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0051] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0052] Without departing from the scope or spirit of the present invention, various improvements and variations can be made to the specific embodiments of the description of the present invention, which will be obvious to those skilled in the art. Other embodiments obtained from the description of the present invention will be obvious to those skilled in the art. The description and examples of the present invention are merely exemplary.

[0053] Regarding the use of "comprising", "including", "having", "containing", etc. in this article, they are all open-ended terms, meaning including but not limited to.

[0054] The technical solution of the present invention is as follows:

[0055] A method for keeping live shrimp in a refrigerator based on the synergistic effect of multi-parameter regulation and promoting evacuation:

[0056] Put one catty of penaeid shrimp into a live-keeping container with a specification of not less than 25cm×35cm×15cm. The penaeid shrimp are placed in a flat way to avoid stacking. Put the penaeid shrimp into a clean live-keeping container and keep them in captivity for 20-30 minutes to relieve the stress response. Adjust the salinity of 1L of water to 27‰, add two lemon slices and soak for about 20 minutes, then take them out, so that the citric acid concentration in the salt water is in the range of 0.7-1g / L and the pH value is in the range of 6.5-6.9 to prepare a live-keeping solution. Pour the live-keeping solution into the container, and the water level should be higher than 1 / 3 of the shrimp body. Place the container in the fresh-keeping area of the refrigerator, and set the temperature of the fresh-keeping area of the refrigerator to 5-11°C. It can be directly put into the refrigerator from room temperature without controlling the cooling rate, but avoid rapid cooling. After cooling for 0.5-4 hours, raise the temperature of the fresh-keeping area of the refrigerator to 10°C, which can optimize the live-keeping effect.

[0057] The overall structure of the above-mentioned live-keeping container is as Figure 1 shown. Among them, 1. Lid; 2. Partition board; 3. Anti-collision device; 4. Box; 5. Ventilation holes.

[0058] Among them, the pore size of the partition board is 1×1cm, which can separate the shrimp from the excrement during the live-keeping process. The excrement precipitates, and the shrimp are always in relatively clean water on the upper layer of the partition board. The anti-collision device consists of a detachable knob, which is installed on the partition board in a spiral manner. The detachable knob placed on the lower layer can adjust the height of the partition board by disassembling, and placed on the upper layer can reduce the damage caused by collisions between shrimp bodies. The number and position of the detachable knobs are not limited and can be adjusted according to the number of shrimp and to make the partition board placed horizontally. The box is overall transparent, which is convenient for observing the water level and the survival status of the shrimp. The specification of the box is not limited and can be adjusted according to the number of shrimp. There are 4 ventilation holes with a diameter of 1cm on each of the left and right sides of the box to ensure air circulation inside the box. The hole positions are set at the upper part of the box, which can avoid the escape of shrimp and effectively prevent the water splashed by the shrimp's activities; the four sides of the box are chamfered to reduce the damage caused by the right-angled sides during the shrimp's activities.

[0059] The applicable scope of this container includes but is not limited to shrimps. Other crustaceans such as crabs and shellfish are also applicable.

[0060] Example 1

[0061] This example verified the influence of different salinities on the survival rate of shrimps. The verification process is as follows:

[0062] Put one catty of prawns into a live-holding container with the specification of 25cm×35cm×15cm. The prawns are placed in a flat way to avoid stacking. Keep them in temporary cultivation for 30 minutes to relieve the stress response. Adjust the salinity of 1L water to 0, 5‰, 10‰, 15‰, 20‰, 25‰, 30‰, 35‰ respectively with sea salt, add two lemon slices, soak for 20min and then take them out, so that the final concentration of citric acid is in the range of 0.7 - 1g / L and the pH value is in the range of 6.5 - 6.9 to prepare the live-holding solution. Pour the live-holding solution into the container until the water level completely covers the shrimp body. Transfer the container from room temperature to the fresh-keeping area of the refrigerator at 7℃ ( Figure 2 ). Detect the survival rate after 12h.

[0063] The method for detecting the survival rate is as follows: Adopt the stepwise temperature-raising method. Take the shrimps out of the container box and put them into the buffer transition pools (salinity 20‰) at 15℃, 20℃, 26℃ in turn, maintain for 5 minutes at each stage, observe the activities of the shrimp body throughout the process, and any one of the following situations is regarded as survival:

[0064] (1) The abdominal feet show intermittent rowing movements; (2) The gill cover structure actively pumps water to promote the water flow exchange in the gills; (3) The eyestalk has a reaction after being stimulated; (4) There is resistance when pinching the tail with fingers; (5) The chelipeds and walking legs are active.

[0065] The survival rate of prawns under different salinities is as Figure 3 shown. It can be seen that the survival rate is better when the salinity is 25 - 30‰. Considering the actual operation, 27‰ is taken as the salt concentration standard.

[0066] Example 2

[0067] This example verified the influence of different temperature conditions on the survival rate of shrimps. The verification process is as follows:

[0068] Put one catty of prawns into a live-holding container with specifications of 25 cm × 35 cm × 15 cm. The prawns are placed in a flat-laying manner to avoid stacking. Keep them in temporary culture for 30 minutes to relieve the stress response. Adjust the salinity of 1 L of water to 27‰ with sea salt, add two lemon slices, soak for 20 min and then take them out, so that the final concentration of citric acid is in the range of 0.7 - 1 g / L and the pH value is in the range of 6.5 - 6.9 to prepare the live-holding solution. Pour the live-holding solution into the container so that the water level completely covers the prawn bodies. Transfer the container from room temperature to the fresh-keeping area of the refrigerator at 3℃, 5℃, 7℃, 9℃, 11℃, 13℃, and 15℃ respectively. Detect the survival rate after 12 h. The survival rate detection method is the same as that in Example 1.

[0069] The survival rates of prawns under different temperature conditions are as Figure 4 shown. It can be seen that the survival rates of prawns are better at 7 - 9℃. By observing the prawn bodies, it is found that when the temperature is lower than 5℃, the prawn bodies turn white, indicating that the prawn bodies are damaged; when the temperature is higher than 11℃, the prawns do not enter dormancy. Combining the experimental phenomena and the survival rate, 7℃ is selected as the live-holding temperature.

[0070] Example 3

[0071] This example verifies the influence of different types of salts on the survival rate of prawns. The verification process is as follows:

[0072] Put one catty of prawns into a live-holding container with specifications of 25 cm × 35 cm × 15 cm. The prawns are placed in a flat-laying manner to avoid stacking. Keep them in temporary culture for 30 minutes to relieve the stress response. Adjust the salinity of 1 L of water to 27‰ with natural edible salt, snow crystal salt, natural sea salt, and sea crystal respectively. Add two lemon slices, soak for 20 min and then take them out, so that the final concentration of citric acid is in the range of 0.7 - 1 g / L and the pH value is in the range of 6.5 - 6.9 to prepare the live-holding solution. Pour the live-holding solution into the container so that the water level completely covers the prawn bodies. Transfer the container from room temperature to the fresh-keeping area of the refrigerator at 7℃. Detect the survival rate after 12 h. The survival rate detection method is the same as that in Example 1.

[0073] The component information of the above various types of salts is shown in Table 1. The survival rates of prawns under different types of salts are shown in Table 2. It can be seen from Table 2 that there is no significant difference in the survival rates of the four types of salts.

[0074] Table 1 Component information of various types of salts

[0075] Salt name Salt type Iodine content Potassium content Sodium content Natural edible salt Sea salt 2250.0 μg / 100g Not added 37370 mg / 100g Snow crystal salt Lake salt Not added Not added 38553 mg / 100g Seawater natural salt Lake salt 2250.0 μg / 100g Not added 38553 mg / 100g Seawater crystal / Not added 400 mg / L 10000 mg / L

[0076] Table 2 Survival rates of prawns under different types of salts

[0077] Salt name Natural edible salt Snow crystal salt Seawater natural salt Seawater crystal Survival rate (%) 84.5 83.6 83.5 88.6

[0078] Example 4

[0079] This example verified the effect of different stacking methods on the survival rate of shrimps, and the verification process is as follows:

[0080] Put one catty of shrimps into a preservation container with the specification of 25cm×35cm×15cm, and adopt different stacking methods. Keep them in captivity for 30 minutes to relieve the stress response. Adjust the salinity of 1L water to 27‰ with natural edible salt, add two lemon slices, soak for 20 minutes and then take them out, so that the final concentration of citric acid is in the range of 0.7-1g / L and the pH value is in the range of 6.5-6.9 to prepare a preservation solution. Pour the preservation solution into the container, and the water level completely covers the shrimp bodies. Transfer the container from room temperature to the fresh-keeping area of a 7°C refrigerator. Detect the survival rate after 12 hours. The survival rate detection method is the same as that in Example 1.

[0081] The stacking arrangements of 150% and 95% of the shrimps are as Figure 5 shown. The survival rates of shrimps under different stacking methods are shown in Table 3. It can be seen that if the shrimps are placed too densely, they will cause damage to other shrimps (stab wounds by the frontal sword) due to stress, resulting in a decrease in the survival rate. According to the results, at least a gap of 1 / 2 shrimp body width should be reserved between two shrimps when placing them.

[0082] Table 3 Survival rates of shrimps under different stacking methods

[0083] Stacking degree Loose (50%) Relatively compact (80%) Shoulder to shoulder (95%) Piled up (150%) Survival rate (%) 88.5 87.6 78.5 59.3

[0084] Note: The stacking degree is the percentage of the flat-laying area of the shrimps in the area of the box.

[0085] Example 5

[0086] This example verified the effect of different water levels on the survival rate of shrimps, and the verification process is as follows:

[0087] Put one catty of shrimps into a preservation container with the specification of 25cm×35cm×15cm, and place the shrimps in a flat-laying manner to avoid stacking. Keep them in captivity for 30 minutes to relieve the stress response. Adjust the salinity of 1L water to 27‰ with natural edible salt, add two lemon slices, soak for 20 minutes and then take them out, so that the final concentration of citric acid is in the range of 0.7-1g / L and the pH value is in the range of 6.5-6.9 to prepare a preservation solution. Pour the preservation solution into the container, and the water levels are set at 1 / 3, 1 / 2, and full coverage (soaking) of the shrimp bodies respectively. Transfer the container from room temperature to the fresh-keeping area of a 7°C refrigerator. Detect the survival rate after 12 hours. The survival rate detection method is the same as that in Example 1.

[0088] The survival rates of shrimps under different water levels are shown in Table 4. It can be seen that there is no obvious difference in the survival rates of the three groups because the interfacial effect forms a water film on the surface of the shrimp bodies, keeping the shrimp bodies moist. Therefore, it is required that the water level is at least 1 / 3 of the flat-laying height of the shrimp bodies.

[0089] Table 4 Survival rate of shrimps under different water levels

[0090] Water level 1 / 3 1 / 2 Full coverage Survival rate (%) 85.3 82.2 86.2

[0091] Example 6

[0092] This example verified the effect of the rewarming operation on the survival rate of shrimps. The verification process is as follows:

[0093] Put one catty of shrimps into a live-holding container with specifications of 25 cm × 35 cm × 15 cm. The shrimps are placed in a flat manner to avoid stacking. Keep them in temporary culture for 30 minutes to relieve the stress response. Adjust the salinity of 1 L of water to 27‰ with natural edible salt, add two lemon slices, soak for 20 min and then take them out, so that the final concentration of citric acid is in the range of 0.7 - 1 g / L and the pH value is in the range of 6.5 - 6.9 to prepare a live-holding solution. Pour the live-holding solution into the container, and the water level is at half of the shrimp body. One group transfers the container from room temperature to the fresh-keeping area of a 7°C refrigerator (non-rewarming group); another group transfers the container from room temperature to the fresh-keeping area of a 7°C refrigerator and places it for 4 h, then raises the refrigerator temperature to 10°C (rewarming group). Detect the survival rate after 12 h. The survival rate detection method is the same as that in Example 1.

[0094] The survival rate of shrimps under different rewarming operations is shown in Table 5, and the state of the shrimps is as Figure 6 shown. It can be seen that there is no obvious difference in the survival rate between the two groups, but the color of the shrimps in the rewarming group is better than that in the non-rewarming group, and the shrimps in the rewarming group are more likely to recover when placed in normal temperature water after 12 h.

[0095] Table 5 Survival rate of shrimps under different rewarming operations

[0096] Rewarming operation Not rewarmed Rewarmed Survival rate (%) 85 88.3

[0097] Example 7

[0098] This example verified the effect of adding lemon slices or not on the survival rate of shrimps. The verification process is as follows:

[0099] Put one catty of shrimps into a live-holding container with specifications of 25 cm × 35 cm × 15 cm. The shrimps are placed in a flat manner to avoid stacking. Keep them in temporary culture for 30 minutes to relieve the stress response. One group (the group with lemon slices added) adjusts the salinity of 1 L of water to 27‰ with natural edible salt, then adds two lemon slices, soaks for 20 min and then takes them out, so that the final concentration of citric acid is in the range of 0.7 - 1 g / L and the pH value is in the range of 6.5 - 6.9 to prepare a live-holding solution; another group (the non-added group) only adds natural edible salt to adjust the salinity to 27‰ to prepare a live-holding solution. Pour the live-holding solution into the container, and the water level is at half of the shrimp body. Transfer the container from room temperature to the fresh-keeping area of a 7°C refrigerator and place it. Detect the survival rate and the clarity of the live-holding solution after 12 h. The survival rate detection method is the same as that in Example 1.

[0100] The survival rate of prawns is shown in Table 6. The prawn intestinal tracts of the two groups after treatment are as Figure 7 shown, and the clarity of the live preservation solution is as Figure 8 shown. It can be seen that there is no significant difference in the survival rates of the two groups. However, the prawn bodies in the group with lemon slices added are more transparent, and the intestinal evacuation effect is better than that of the control group. The prawn intestinal tracts change from the original brown to light gray, indicating that the intestinal tracts can be evacuated better; the live preservation solution in the group with lemon slices added is more turbid, which also indicates that prawns can evacuate their intestinal tracts better in the live preservation solution with lemon slices added.

[0101] Table 6 Survival rates of prawns with or without lemon slices added

[0102] Survival solution Group with lemon slices added Group without addition Survival rate (%) 88.3 86

[0103] Example 8

[0104] This example verified the influence of the live preservation environment on the survival rate of prawns. The verification process is as follows:

[0105] Put one catty of prawns into a live preservation container with specifications of 25 cm × 35 cm × 15 cm. The prawns are placed in a flat-laying manner to avoid stacking. Keep them in temporary cultivation for 30 minutes to relieve the stress response. After adjusting the salinity of 1 L of water to 27‰ with natural edible salt, add two lemon slices, soak for 20 min and then take them out, so that the final concentration of citric acid is in the range of 0.7 - 1 g / L and the pH value is in the range of 6.5 - 6.9 to prepare the live preservation solution. Pour the live preservation solution into the container, and the water level is at half of the prawn bodies. For one group, transfer the container from room temperature to the fresh-keeping area of a refrigerator at 7°C; for the other group, transfer the container from room temperature to a laboratory chiller with a cooling rate of 4°C / h (this rate is the same as the refrigerator cooling rate) and place it there. Detect the survival rate after 12 h. The method for detecting the survival rate is the same as that in Example 1.

[0106] The survival rates of prawns under different live preservation environments are shown in Table 7. It can be seen that there is no significant difference in the survival rates of the two groups. Therefore, the live preservation method of the present invention is applicable to the live preservation treatment of prawns at home, and the refrigerator can also avoid the influence of external sounds and light on prawns.

[0107] Table 7 Survival rates of prawns under different live preservation environments

[0108] Survival environment Refrigerator fresh-keeping area Laboratory chiller temperature control Survival rate (%) 85 87.5

[0109] Example 9

[0110] This example detected the survival situation and quality of prawns under different live preservation times. The detection process is as follows:

[0111] Put one catty of prawns into a live-holding container with specifications of 25 cm × 35 cm × 15 cm. The prawns are placed in a flat-laying manner to avoid stacking. Keep them in temporary cultivation for 30 minutes to relieve the stress response. After adjusting the salinity of 1 L of water to 27‰ with natural edible salt, add two lemon slices, soak for 20 minutes, and then take them out to prepare the live-holding solution. Pour the live-holding solution into the container, and the water level is at 1 / 2 of the shrimp body. Transfer the container from room temperature to the fresh-keeping area of a 7°C refrigerator. Take samples at 0, 3, 6, 9, and 12 h respectively to detect the quality of the shrimps. The shrimp quality indicators include muscle quality, antioxidant stress indicators, and changes in nutritional components.

[0112] 1. Muscle quality

[0113] The detection results are as Figure 9 shown. It can be seen that compared with 0 h, after 12 h of live-holding, the hardness, elasticity, and cohesiveness of the tail meat of the shrimp basically remain unchanged; the resilience, gumminess, and chewiness are improved; there is no obvious change in the water-holding capacity and pH before and after live-holding.

[0114] 2. Antioxidant stress indicators

[0115] The detection results are as Figure 10 shown. It can be seen that with the extension of the live-holding time, MDA (malondialdehyde) first decreases and then increases, indicating that during the live-holding process, there is a transition from antioxidant stress to enhanced oxidative stress. That is: after the shrimps are put into the refrigerator, the antioxidant defense mechanism in their bodies is activated, resulting in a brief decrease in MDA. As the cooling continues, the defense mechanism is exhausted, leading to an increase in MDA, reflecting an increase in peroxidation. CAT (catalase) first decreases and then increases, indicating that after low-temperature stress, the shrimp body restores and adapts to environmental changes through the expression and activity of antioxidant enzymes, reflecting the adaptability of the shrimp body. POD (peroxidase) first increases, then decreases, and gradually stabilizes. After the shrimp enters the low-temperature environment, as part of the antioxidant system, POD may consume a large amount of antioxidant substances in response to low-temperature stress, and its activity may first decrease. As the shrimp enters the dormant / adapted low-temperature state, the activity of POD gradually recovers and increases to maintain normal physiological functions. GSH-Px (glutathione peroxidase) first decreases and then increases. GSH-Px is also a component of the antioxidant defense system. In the initial stage of cooling, the oxidative load of the shrimp body is too heavy, resulting in a decrease in activity. As the organism adapts, the activity gradually increases to cope with the continuous oxidative stress. T-AOC (total antioxidant capacity) gradually increases. In the early stage, the shrimp activates its antioxidant system in response to the oxidative stress brought by low temperature, resulting in an increase in activity. Then it gradually adapts to this low temperature and reaches a new equilibrium state. T-SOD (superoxide dismutase) gradually decreases. The decrease in T-SOD activity is related to its process of scavenging superoxide radicals in the body to protect the live-holding organism from damage. Under low-temperature stress, a large number of free radicals are generated in the shrimp body, and the free radicals will attack SOD, leading to a decrease in its activity.

[0116] From the changes in 6 antioxidant indexes over 12 hours, it can be seen that the oxidative stress of shrimp is relatively active at 3 - 6 hours, but it does not cause irreversible damage to the shrimp body.

[0117] 3. Changes in nutritional components

[0118] 25 free amino acids: The test results are as Figures 11 - 13 shown. It can be seen that the overall content of amino acids decreases from 0 to 6 hours and then increases after 6 - 12 hours. Among them, 11 free amino acids are increased compared with before live preservation (glutamic acid +16%, asparagine +17%, histidine +15%, alanine +16%, tyrosine +7%, valine +9%, norvaline +15%, phenylalanine +6%, lysine +4%, leucine +10%, γ-aminobutyric acid +39%), the contents of 4 amino acids decrease (serine -15%, glycine -18%, citrulline -27%, cysteine -5%), and the rest have no obvious changes.

[0119] Nucleotides: After 12 hours of live preservation, AMP (adenylic acid) and HXR (inosine) in nucleotides are significantly increased, ADP (adenosine diphosphate) has a small increase, and ATP decreases by 23%. The rest of the nucleotides have no obvious changes.

[0120] Volatile components: The test results are as Figure 14 shown. It can be seen that 51, 54, and 49 volatile flavor components are identified in the samples at 0, 6, and 12 hours respectively. The proportion of aldehyde components in the three groups of samples is relatively large, reaching 72.87%, 58.89%, and 48.40% respectively. Among them, isovaleraldehyde has a relatively high proportion. Compared with before and after live preservation, the types of volatile flavor components contained after 12 hours of live preservation are basically unchanged, the proportion of aldehydes decreases, and the proportion of ketones, aldehydes, and hydrocarbons increases (increasing the aroma of shrimp meat). As Figure 15 shown, the vast majority of volatile components are isovaleraldehyde (accounting for 61.9%, 50.9%, and 41.7% respectively), and the bitter substances decrease.

[0121] The above results show that when one catty of shrimp is placed in a live preservation container with specifications of 25 cm × 35 cm × 15 cm, it is placed in a flat manner to avoid stacking. It is temporarily raised for 30 minutes to relieve the stress response. After adjusting the salinity of 1 L of water to 27‰ with natural edible salt, two lemon slices are added and the shrimp are soaked for 20 minutes and then fished out to prepare the live preservation solution. The live preservation solution is poured into the container, and the water level is 1 / 3 higher than the shrimp body. The container is transferred from room temperature to the fresh-keeping area of a 7°C refrigerator and placed, which can effectively preserve the shrimp within 12 hours and keep the quality of the shrimp unchanged significantly.

[0122] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the spirit of the present invention's design, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for keeping shrimp alive in a refrigerator based on the synergistic effect of multi-parameter regulation and emptying promotion, characterized in that: The steps include: (1) preparing aquaculture water with a salinity of 25-30‰, soaking lemon slices in the aquaculture water, and then taking them out to obtain a preservative solution; (2) Place the shrimps in the preservative solution and store in a refrigerator at 5-11°C.

2. The method for keeping shrimp alive in a refrigerator according to claim 1, characterized in that: The salinity of the aquaculture water is 27‰.

3. The method for keeping shrimp alive in a refrigerator according to claim 1, characterized in that: The concentration of citric acid in the preservative solution is 0.7-1 g / L, and the pH value is 6.5-6.

9.

4. The method for keeping shrimp alive in a refrigerator according to claim 1, characterized in that: The operation of adding the shrimps into the survival solution is to put the shrimps into the survival container, lay them out in a flat manner, and add the survival solution.

5. The method for keeping shrimp alive in a refrigerator according to claim 1, characterized in that: Before adding the keep-alive solution, the shrimps are placed for 20-30 minutes to relieve stress response.

6. The method for keeping shrimp alive in a refrigerator according to claim 1, characterized in that: The water level of the keep-alive solution is higher than 1 / 3 of the shrimp body.

7. The method for keeping shrimp alive in a refrigerator according to claim 1, characterized in that: The storage temperature is 7°C.

8. The method for keeping shrimp alive in a refrigerator according to claim 1, characterized in that: After the storage for 0.5-4 hours, the temperature is raised to 10°C.

9. The method for keeping shrimp alive in a refrigerator according to claim 1, characterized in that: The storage time is 0-12h.

10. A shrimp refrigerator keep-alive container, characterized in that: It comprises a cover (1), a partition (2), an anti-collision device (3) and a box (4); The cover (1) is connected to the box (4); the partition (2) is movably placed inside the box (4); the anti-collision device (3) is threadedly connected to the upper and lower layers of the partition (2); The box (4) is provided with ventilation holes (5); the partition (2) is provided with pores; the height of the ventilation holes (5) is higher than the height of the partition (2) in the box (4).

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