A method for preserving shrimp in a refrigerator based on the synergistic effect of multi-parameter regulation and promoting air release.

Abstract

This invention discloses a method for preserving shrimp in a refrigerator based on the synergistic effect of multi-parameter regulation and air release, belonging to the field of live shrimp preservation technology. The preservation method of this invention includes: (1) preparing aquaculture water with a salinity of 25-30‰, soaking lemon slices in the aquaculture water and then removing them to obtain a preservation solution; (2) adding shrimp to the preservation solution and transferring them to an environment of 5-11℃ for storage. This 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, thus ensuring the quality of fresh live shrimp and providing a new technical approach to improving the freshness and taste of food ingredients.

Description

Technical Field

[0001] This invention relates to the field of live shrimp preservation technology, and in particular to a method for keeping shrimp alive in a refrigerator based on the synergistic effect of multi-parameter regulation and air release. Background Technology

[0002] With the improvement of living standards in China, consumer demand for fresh, high-quality seafood, especially live shrimp, continues to grow. Shrimp is a widely consumed seafood, and with the recent popularity of fitness and light eating, shrimp meat, as a low-calorie, low-fat, and high-nutrient-density food, is becoming increasingly popular. However, shrimp is susceptible to microbial spoilage; after death, it is easily contaminated by its own microorganisms and external microorganisms, leading to spoilage. Today, consumers' increasing demand for high-quality, safe, and long-shelf-life products has prompted greater attention to effective and safe shrimp preservation technologies.

[0003] Research revealed that the difficulty in preserving live shrimp after purchase is a significant pain point for many consumers, especially given the short lifespan of live shrimp, which typically dies within 1-2 hours. In such cases, consumers often choose to immediately process and freeze them, or briefly store them in the refrigerator. However, frozen shrimp lose their freshness, resulting in a decline in taste and texture, making it difficult to maintain the quality they possessed upon purchase. Through fundamental research on shrimp preservation characteristics, and by systematically studying and optimizing multiple factors affecting survival rates, this research provides an innovative solution to improve shrimp survival rates. It also explores the mechanism of quality changes in shrimp products during ecological ice-temperature preservation. Through innovative technologies and methods, the goal of temporarily holding live shrimp in a refrigerator for 12 hours can be achieved, providing consumers with more convenient and high-quality fresh shrimp products. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preserving shrimp in a refrigerator based on multi-parameter regulation and the synergistic effect of promoting air release, thereby solving the problems existing in the prior art. This invention utilizes low-temperature induced dormancy and precise microenvironment regulation to reduce the shrimp's metabolism and oxygen demand, enabling live shrimp to survive for extended periods in an oxygen-free environment. This ensures the quality of fresh live shrimp and provides a new technical approach to improving the freshness and taste of food.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] This invention provides a method for preserving shrimp in a refrigerator based on the synergistic effect of multi-parameter regulation and promoting air release, comprising the following steps:

[0007] (1) Prepare aquaculture water with a salinity of 25-30‰. Soak lemon slices in the aquaculture water and then remove them to obtain a survival solution.

[0008] (2) Place the shrimp in the preservation solution and transfer them to a refrigerator at 5-11°C for storage.

[0009] This invention found that shrimp survival rates significantly improved at salinity levels of 25-30‰. Soaking two lemon slices in 1L of brine and then removing them revealed that the core components of the lemon slices, including citric acid, vitamin C, flavonoids, limonene, and citral, are insoluble in the brine. Citric acid can disrupt the cell membranes of pathogenic bacteria, inhibiting the proliferation of common aquatic pathogens such as Vibrio parahaemolyticus and Aeromonas hydrophila. It can also activate the TRPV1 ion channel-mediated neural reflex mechanism in the shrimp's intestine, inducing increased intestinal peristalsis frequency. Vitamin C and flavonoids have antioxidant effects, reducing free radical levels (such as MDA) in shrimp and increasing superoxide dismutase (SOD) activity, thereby enhancing stress resistance. This treatment promotes intestinal emptying in shrimp, significantly reducing protease autolysis and microbial load during survival. Maintaining dissolved oxygen ≥5mg / L during treatment regulates intestinal motility rhythm through a neural signal cascade reaction, ensuring a stable intestinal emptying rate.

[0010] This invention found that shrimp have the highest survival rate within a temperature range of 5-11℃. The cooling rate does not need to be strictly controlled, but rapid cooling (direct immersion in cold water) will reduce the survival rate; generally, a rate not exceeding 10℃ / h is sufficient. When transferred from room temperature to the 5-11℃ preservation zone of a refrigerator, the shrimp survival rate is between 80-85%, indicating that shrimp can adapt to the low-temperature stress caused by refrigerator temperature fluctuations. This method is simple to operate and suitable for home shrimp preservation.

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

[0012] This invention found that shrimp survival rates significantly improved at salinity levels of 25-30‰, with the optimal salinity being 27‰. Comparison with various types of salt revealed no significant difference in shrimp survival rates between different salt types.

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

[0014] Optionally, the operation of adding shrimp to the preservation solution involves placing the shrimp in a preservation container, laying them flat, and then adding the preservation solution.

[0015] This invention has found that separating shrimp reduces physical damage to each other, ensures sufficient space for the shrimp, and facilitates gas exchange in a non-sealed environment. Therefore, the shrimp should be laid flat at the bottom of the storage container. The storage container for one pound of shrimp (approximately 30 whiteleg shrimp) should be no smaller than 25cm × 35cm, and stacking of the shrimp should be avoided.

[0016] Optionally, shrimp can be left to stand for 20-30 minutes before adding the survival solution to alleviate stress.

[0017] Optionally, the water level of the survival solution is higher than 1 / 3 of the shrimp's body.

[0018] The present invention has found that a water level slightly higher than the shrimp's body helps reduce 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's body to the shrimp being fully submerged.

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

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

[0021] This invention reveals that during the initial cooling phase, controlling the temperature below the conventional survival temperature allows live shrimp to quickly enter a dormant state. After 30 minutes of cooling, the temperature is slowly raised back to the normal survival temperature of 10°C. This operation effectively shortens the time it takes for shrimp to enter dormancy, maintains their low metabolic state, significantly improves survival rate and survival time, and enhances their overall appearance and color after 12 hours of survival. The warming technology further optimizes the survival effect based on low-temperature induced dormancy; the rapid entry into low-temperature dormancy followed by slow warming maintains the shrimp's good appearance and color, making them more suitable for long-term survival in refrigerated environments.

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

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

[0024] The lid (1) covers and 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);

[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] This invention provides a method for preserving shrimp in refrigerators based on multi-parameter regulation and the synergistic effect of promoting air release. This method allows shrimp to survive in the refrigerator for more than 12 hours, enabling users to enjoy shrimp with almost the same quality and taste as live shrimp when cooking for dinner or even the next day. This significantly improves the preservation effect of food and enhances its versatility, allowing users to easily enjoy a high-quality culinary experience and solving the pain point of difficulty in preserving live aquatic products. Furthermore, this method allows consumers to store live shrimp in their home refrigerators within a short time after purchase, enriching the functionality of refrigerator products and enhancing their market competitiveness. This invention has broad application prospects and commercial value. The innovation of this technology lies in combining the shrimp preservation characteristics with refrigerator manufacturing technology to provide consumers with a completely new shrimp storage solution.

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

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

[0030] 2. Stable and reliable: Through systematic research and optimization of multiple parameters, the optimal combination of survival parameters has been determined, which makes the survival effect stable and reliable. The extended survival time allows the shrimp to remain active before cooking, providing a near-fresh taste and flavor, and greatly improving the quality of ingredients and user experience.

[0031] 3. Easy to operate: The operation steps and parameters involved in this invention are easy to control and implement, without the need for complicated equipment and oxygen supply support. It is convenient for home users to use in daily life, which not only meets consumers' demand for fresh food, but also helps supermarkets improve the quality of live seafood products, and has broad application prospects.

[0032] 4. Advantages of intestinal purification: Through the neuroendocrine regulation mechanism mediated by organic acids, the shrimp achieve autonomous intestinal emptying before preservation, reducing the mud and sand content of the cooked product by 82% and slowing the accumulation rate of volatile basic nitrogen (TVB-N) by 57%, significantly improving food safety and sensory quality. Fresh lemons are readily available in ordinary households, and the introduction of organic acids and release of volatile components into the preservation water has a dual effect of inhibiting the generation of off-flavor substances and enhancing flavor during the preservation of aquatic products. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is an overall structural diagram of the container for preserving life according to the present invention; wherein, the reference numerals are explained as follows: 1. lid; 2. partition; 3. anti-collision device; 4. box; 5. vent hole;

[0035] Figure 2 This describes the placement of shrimp in the preservation container in the refrigerator, as shown in Example 1.

[0036] Figure 3 Statistical results of shrimp survival rates under different salinities;

[0037] Figure 4 The results show the statistical results of shrimp survival rates under different temperature conditions;

[0038] Figure 5 The image shows the stacking arrangement of shrimp in Example 4; where A represents a stacking degree of 150% and B represents a stacking degree of 95%.

[0039] Figure 6 The shrimp states under different warming conditions are shown; where A is the group without warming and B is the group with warming.

[0040] Figure 7 Shrimp veins were observed with and without lemon slices added; Group A represents the group with lemon slices added, and Group B represents the group without lemon slices added.

[0041] Figure 8 The preservation solutions were prepared with and without lemon slices; where A is tap water; B is the group without lemon slices; and C is the group with lemon slices.

[0042] Figure 9 The results show the muscle quality of shrimp under different holding times; where A represents muscle firmness; B represents muscle elasticity; C represents muscle cohesion; D represents muscle elasticity; E represents muscle adhesion; and F represents muscle chewiness.

[0043] Figure 10 The results of detecting antioxidant stress indicators in shrimp under different survival times;

[0044] Figure 11The results show the content of free amino acids in shrimp under different holding times; among them, AK are aspartic acid (ASP), glutamic acid (GL), histidine (His), alanine (ALA), tyrosine (TYR), valine (VA), n-valine (NVA), phenylalanine (PHE), lysine (LYS), leucine (LEU), and γ-aminobutyric acid (GABA).

[0045] Figure 12 The results of free amino acid content detection in shrimp under different holding times; AD, in order, are serine (ser), glycine (gly), citrulline (cit), and cysteine ​​(cys).

[0046] Figure 13 The results of free amino acid content detection in shrimp under different holding times; AJ are asparagine (asn), glutamine (gln), threonine (thr), arginine (arg), methionine (met), tryptophan (trp), isoleucine (ile), hydroxyproline (hyp), sarcosine (sar), and proline (pro).

[0047] Figure 14 Results of volatile component detection in shrimp at different holding times;

[0048] Figure 15 The statistical results of volatile components in shrimp under different holding times are presented. Detailed Implementation

[0049] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0050] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0051] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0052] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0053] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

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

[0055] A method for preserving shrimp in a refrigerator based on the synergistic effect of multi-parameter regulation and promoting air release:

[0056] Place one pound of shrimp in a container at least 25cm × 35cm × 15cm, laying the shrimp flat to avoid stacking. Keep the shrimp in the clean container for 20-30 minutes to alleviate stress. Adjust the salinity of 1L of water to 27‰, add two lemon slices and soak for about 20 minutes, then remove them. This will ensure the citric acid concentration in the brine is between 0.7-1g / L and the pH is between 6.5-6.9, preparing a preservation solution. Pour the preservation solution into the container, ensuring the water level is above one-third of the shrimp's body. Place the container in the refrigerator's crisper drawer, set the temperature to 5-11℃. The shrimp can be placed directly from room temperature without controlling the cooling rate, but rapid cooling should be avoided. After cooling for 0.5-4 hours, raise the crisper drawer temperature to 10℃ to optimize preservation.

[0057] The overall structure of the above-mentioned preservation container is as follows: Figure 1 As shown. Among them, 1. lid; 2. partition; 3. anti-collision device; 4. box; 5. ventilation hole.

[0058] The partition has 1×1cm pores, separating shrimp from their excrement during the survival process. Excrement settles, and the shrimp remain in relatively clean water on the upper layer of the partition. The anti-collision device consists of detachable knobs, screwed onto the partition. These knobs, when placed on the lower layer, allow for height adjustment of the partition; when placed on the upper layer, they reduce damage from collisions between shrimp. The number and position of the detachable knobs are not limited and can be adjusted according to the number of shrimp and to allow for horizontal placement of the partition. The box is entirely transparent, facilitating observation of the water level and shrimp survival status. The box's dimensions are not limited and can be adjusted according to the number of shrimp. Four 1cm diameter ventilation holes are located on each side of the box to ensure air circulation. These holes are positioned at the top of the box to prevent shrimp escape and effectively stop water splashing out during shrimp activity. The four edges of the box are chamfered to reduce damage to shrimp from sharp corners.

[0059] This container is applicable to shrimp, and is also suitable for other crustaceans such as crabs and shellfish.

[0060] Example 1

[0061] This embodiment verifies the effect of different salinities on shrimp survival rate. The verification process is as follows:

[0062] Place one pound of prawns in a 25cm×35cm×15cm container, laying them flat to avoid stacking. Temporarily hold them for 30 minutes to alleviate stress. Adjust the salinity of 1L of water to 0, 5‰, 10‰, 15‰, 20‰, 25‰, 30‰, and 35‰ using sea salt. Add two lemon slices and soak for 20 minutes, then remove the lemon slices. This will ensure a final citric acid concentration of 0.7-1g / L and a pH of 6.5-6.9, preparing a preservation solution. Pour the preservation solution into the container, ensuring the water level completely covers the prawns. Transfer the container from room temperature to the 7°C refrigerator's crisper drawer. Figure 2 Survival rate was tested after 12 hours.

[0063] The survival rate detection method is as follows: Using a segmented heating method, shrimp are removed from the container and sequentially placed in buffer transition tanks (salinity 20‰) at 15℃, 20℃, and 26℃, maintaining each stage for 5 minutes. Shrimp activity is observed throughout the process. Survival is considered achieved if any of the following conditions are met:

[0064] (1) Intermittent paddling motions are observed in the ventral foot; (2) The gill cover structure actively pumps water to promote water exchange in the gills; (3) The eyestalk reacts to stimulation; (4) There is resistance when the tail is pinched with fingers; (5) Chelicerae and walking legs are active.

[0065] Shrimp survival rates at different salinities, such as Figure 3 As shown, the survival rate is better at a salinity of 25-30‰. Considering practical operation, 27‰ is used as the standard salt concentration.

[0066] Example 2

[0067] This embodiment verifies the effect of different temperature conditions on shrimp survival rate. The verification process is as follows:

[0068] One pound of shrimp was placed in a 25cm×35cm×15cm container, laid flat to avoid stacking. The shrimp were temporarily kept for 30 minutes to alleviate stress. The salinity of 1L of water was adjusted to 27‰ with sea salt. Two lemon slices were added and soaked for 20 minutes, then removed, to achieve a final citric acid concentration of 0.7-1g / L and a pH of 6.5-6.9, thus preparing a survival solution. The survival solution was poured into the container, ensuring the water completely covered the shrimp. The container was then transferred from room temperature to the refrigerator's crisper drawer at 3℃, 5℃, 7℃, 9℃, 11℃, 13℃, and 15℃. Survival rates were measured after 12 hours. The survival rate testing method was the same as in Example 1.

[0069] Shrimp survival rates under different temperature conditions, such as Figure 4 As shown, the shrimp survival rate is better at 7-9℃. Observation of the shrimp revealed that when the temperature is below 5℃, the shrimp bodies turn white, indicating damage; when the temperature is above 11℃, the shrimp do not enter dormancy. Based on the experimental results and survival rate, 7℃ was selected as the survival temperature.

[0070] Example 3

[0071] This embodiment verifies the effect of different salt types on shrimp survival rate. The verification process is as follows:

[0072] One pound of prawns was placed in a 25cm×35cm×15cm container, laid flat to avoid stacking. They were temporarily kept for 30 minutes to alleviate stress. The salinity of 1L of water was adjusted to 27‰ using natural table salt, snow crystal salt, natural sea salt, and sea salt. Two lemon slices were added and soaked for 20 minutes, then removed, to achieve a final citric acid concentration of 0.7-1g / L and a pH of 6.5-6.9, thus preparing a survival solution. The survival solution was poured into the container, completely covering the prawns. The container was then transferred from room temperature to a 7°C refrigerator. The survival rate was measured after 12 hours. The survival rate testing method was the same as in Example 1.

[0073] The composition information of each salt type is shown in Table 1. The shrimp survival rates under different salt types are shown in Table 2. As can be seen from Table 2, there is no significant difference in survival rates among the four salt types.

[0074] Table 1. Composition information of each type of salt

[0075] Salt Name Salt type Iodine content Potassium content Sodium content Natural edible salt sea ​​salt 2250.0μg / 100g No additions 37370mg / 100g Snow Crystal Salt Lake salt No additions No additions 38553mg / 100g Seawater natural salt Lake salt 2250.0μg / 100g No additions 38553mg / 100g Sea Crystal / No additions 400mg / L 10000mg / L

[0076] Table 2. Shrimp survival rate under different salinity conditions

[0077] Salt Name Natural edible salt Snow Crystal Salt Seawater natural salt Sea Crystal Survival rate (%) 84.5 83.6 83.5 88.6

[0078] Example 4

[0079] This embodiment verifies the impact of different stacking methods on shrimp survival rate. The verification process is as follows:

[0080] One pound of shrimp was placed in a 25cm×35cm×15cm container using various stacking methods. They were temporarily held for 30 minutes to alleviate stress. The salinity of 1L of water was adjusted to 27‰ using natural table salt. Two lemon slices were added and soaked for 20 minutes, then removed, to achieve a final citric acid concentration of 0.7-1g / L and a pH of 6.5-6.9, thus preparing a survival solution. The survival solution was poured into the container, completely covering the shrimp. The container was then transferred from room temperature to a 7°C refrigerator. Survival rate was measured after 12 hours. The survival rate testing method was the same as in Example 1.

[0081] The stacking arrangements of 150% and 95% shrimp are as follows: Figure 5 As shown in Table 3, the survival rates of shrimp under different stacking methods are as follows. It can be seen that if the shrimp are placed too densely, they will cause stress to other shrimp (frontal stab wounds), thus leading to a decrease in survival rate. Based on the results, it is necessary to maintain a gap of at least 1 / 2 the width of the shrimp body between two shrimp.

[0082] Table 3 Shrimp survival rate under different stacking methods

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

[0084] Note: The degree of stacking is the percentage of the box area occupied by the shrimp when laid flat.

[0085] Example 5

[0086] This embodiment verifies the effect of different water levels on shrimp survival rates. The verification process is as follows:

[0087] One pound of prawns was placed in a 25cm×35cm×15cm container, laid flat to avoid stacking. They were temporarily kept for 30 minutes to alleviate stress. The salinity of 1L of water was adjusted to 27‰ using natural table salt. Two lemon slices were added and soaked for 20 minutes, then removed, to achieve a final citric acid concentration of 0.7-1g / L and a pH of 6.5-6.9, thus preparing a survival solution. The survival solution was poured into the container, with the water level set to 1 / 3, 1 / 2, and fully covered (immersed) of the prawns. The container was then transferred from room temperature to a 7°C refrigerator. The survival rate was measured after 12 hours. The survival rate testing method was the same as in Example 1.

[0088] The survival rates of shrimp at different water levels are shown in Table 4. It can be seen that there is no significant difference in the survival rates among the three groups. This is because the interface effect forms a water film on the surface of the shrimp, keeping the shrimp moist. Therefore, the water level should be at least 1 / 3 of the height of the shrimp when laid flat.

[0089] Table 4. Shrimp survival rate at 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 embodiment verifies the impact of rewarming operations on shrimp survival rates. The verification process is as follows:

[0093] One pound of shrimp was placed in a 25cm×35cm×15cm container, laid flat to avoid stacking. The shrimp were temporarily kept for 30 minutes to alleviate stress. The salinity of 1L of water was adjusted to 27‰ using natural table salt. Two lemon slices were added and soaked for 20 minutes, then removed, to achieve a final citric acid concentration of 0.7-1g / L and a pH of 6.5-6.9, thus preparing a survival solution. The survival solution was poured into the container until the water level reached halfway up the shrimp. One group had their containers moved from room temperature to a 7°C refrigerator (non-warming group); the other group had their containers moved from room temperature to a 7°C refrigerator (warming group) and then the refrigerator temperature was raised to 10°C after 4 hours. Survival rates were measured after 12 hours. The survival rate testing method was the same as in Example 1.

[0094] Table 5 shows the shrimp survival rates under different warming conditions, and the shrimp conditions are as follows: Figure 6 As shown in the figure, there was no significant difference in survival rate between the two groups, but the shrimp in the warmed-up group had better color than those in the non-warmed-up group, and the shrimp in the warmed-up group were more likely to recover when placed in room temperature water after 12 hours.

[0095] Table 5. Shrimp survival rate under different rewarming conditions

[0096] warm-up operation Not warmed up warming up Survival rate (%) 85 88.3

[0097] Example 7

[0098] This embodiment verifies the effect of adding lemon slices on the survival rate of shrimp. The verification process is as follows:

[0099] One pound of shrimp was placed in a 25cm×35cm×15cm container, laid flat to avoid stacking. They were temporarily kept for 30 minutes to alleviate stress. One group (with lemon slices) had its salinity adjusted to 27‰ in 1L of water using natural salt, then two lemon slices were added and soaked for 20 minutes. The citric acid concentration was adjusted to 0.7-1g / L, and the pH to 6.5-6.9, to prepare the preservation solution. The other group (without lemon slices) had its salinity adjusted to 27‰ using only natural salt, also to prepare the preservation solution. The preservation solution was poured into the container until the water level reached halfway up the shrimp. The container was then transferred from room temperature to a 7°C refrigerator. After 12 hours, the survival rate and the clarity of the preservation solution were tested. The survival rate testing method was the same as in Example 1.

[0100] The shrimp survival rate is shown in Table 6. The shrimp veins of the two treatment groups are shown in Table 6. Figure 7 As shown, the clarity of the survival solution is as follows: Figure 8 As shown in the figure, there was no significant difference in survival rate between the two groups. However, the shrimp in the lemon slice group were more transparent, and their intestinal emptying was better than that of the control group. The shrimp vein changed from brown to light gray, indicating that they could empty their intestines better. The survival solution in the lemon slice group was more turbid, which also indicates that the shrimp could empty their intestines better in the survival solution with lemon slices.

[0101] Table 6. Shrimp survival rates with and without lemon slices.

[0102] Keep alive solution Add lemon slices No group added Survival rate (%) 88.3 86

[0103] Example 8

[0104] This embodiment verifies the impact of the survival environment on the survival rate of shrimp. The verification process is as follows:

[0105] One pound of shrimp was placed in a 25cm×35cm×15cm container, laid flat to avoid stacking. The shrimp were temporarily kept for 30 minutes to alleviate stress. The salinity of 1L of water was adjusted to 27‰ using natural table salt. Two lemon slices were added and soaked for 20 minutes, then removed, ensuring a final citric acid concentration of 0.7-1g / L and a pH of 6.5-6.9 to prepare the preservation solution. The preservation solution was poured into the container until the water level reached halfway up the shrimp. One group of containers was transferred from room temperature to a 7°C refrigerator's crisper compartment; the other group was transferred from room temperature to a laboratory chiller with a cooling rate of 4°C / h (the same rate as the refrigerator). Survival rates were measured after 12 hours. The survival rate testing method was the same as in Example 1.

[0106] Table 7 shows the shrimp survival rates under different preservation environments. It can be seen that there is no significant difference in survival rates between the two groups. Therefore, the preservation method of this invention is suitable for home shrimp preservation, and the refrigerator can also prevent the shrimp from being affected by external noise and light.

[0107] Table 7. Shrimp survival rates under different preservation environments.

[0108] Environment preservation Refrigerator Freshness Section Laboratory chiller temperature control Survival rate (%) 85 87.5

[0109] Example 9

[0110] This embodiment tested the survival and quality of shrimp under different preservation times. The testing process is as follows:

[0111] One pound of prawns was placed in a 25cm×35cm×15cm container, laid flat to avoid stacking. They were then temporarily held for 30 minutes to alleviate stress. A preservative solution was prepared by adjusting the salinity of 1L of water to 27‰ with natural salt, adding two lemon slices, and soaking for 20 minutes. The solution was then poured into the container until the water level reached halfway up the prawns. The container was then transferred from room temperature to a 7°C refrigerator's crisper drawer. Samples were taken at 0, 3, 6, 9, and 12 hours to assess prawn quality. Quality indicators included muscle quality, antioxidant stress levels, and changes in nutritional components.

[0112] 1. Muscle quality

[0113] Test results as follows Figure 9 As shown, compared with 0h, the firmness, elasticity, and cohesiveness of the shrimp tail meat remained basically unchanged after 12h of preservation; elasticity, adhesiveness, and chewiness were improved; water retention and pH showed no significant changes before and after preservation.

[0114] 2. Antioxidant stress indicators

[0115] Test results as follows Figure 10 As shown, MDA (malondialdehyde) first decreased and then increased with prolonged storage time, indicating a transition from antioxidant stress to enhanced oxidative stress during the storage process. Specifically, after shrimp are placed in the refrigerator, their antioxidant defense mechanisms are activated, leading to a temporary decrease in MDA. As the temperature continues to drop, these defense mechanisms are depleted, causing MDA to rise, reflecting increased peroxidation. CAT (catalase) first decreased and then increased, indicating that after low-temperature stress, shrimp recover and adapt to environmental changes through the expression and activity of antioxidant enzymes, reflecting their adaptability. POD (peroxidase) first increased and then decreased before gradually stabilizing. After shrimp enter a low-temperature environment, POD, as part of the antioxidant system, may consume a large amount of antioxidants to cope with low-temperature stress, causing its activity to initially decrease. As shrimp enter a dormant / low-temperature adaptation state, POD activity gradually recovers and increases to maintain normal physiological functions. GSH-Px (glutathione peroxidase) initially decreased and then increased. GSH-Px is also a component of the antioxidant defense system. In the initial stages of cooling, the shrimp's oxidative load was excessive, leading to a decrease in activity. As the organism adapts, its activity gradually increases to cope with the continuous oxidative stress. T-AOC (total antioxidant capacity) gradually increased. In the early stages, to cope with the oxidative stress brought by low temperatures, the shrimp's antioxidant system was activated, leading to increased activity. Afterward, it gradually adapted to this low temperature, reaching a new equilibrium. T-SOD (superoxide dismutase) gradually decreased. The decrease in T-SOD activity is related to its process of scavenging superoxide free radicals in the body to protect the organism from damage. Under low-temperature stress, a large number of free radicals are produced in the shrimp's body, which attack SOD, causing its activity to decrease.

[0116] The changes in six antioxidant indicators over 12 hours show that shrimp exhibited relatively active oxidative stress between 3 and 6 hours, but this did not cause irreversible damage to the shrimp.

[0117] 3. Changes in nutritional composition

[0118] 25 free amino acids: Detection results are as follows Figures 11-13 As shown, the overall amino acid content decreased from 0 to 6 hours and then increased from 6 to 12 hours. Among them, the content of 11 free amino acids increased compared to before preservation (glutamic acid +16%, asparagine +17%, histidine +15%, alanine +16%, tyrosine +7%, valine +9%, valine +15%, phenylalanine +6%, lysine +4%, leucine +10%, γ-aminobutyric acid +39%), the content of 4 amino acids decreased (serine -15%, glycine -18%, citrulline -27%, cysteine ​​-5%), and the rest showed no significant changes.

[0119] Nucleotides: After 12 hours of inactivation, AMP (adenosine) and HXR (inosine) in nucleotides were significantly increased, ADP (adenosine diphosphate) was slightly increased, ATP decreased by 23%, and the remaining nucleotides showed no significant changes.

[0120] Volatile components: Detection results are as follows Figure 14 As shown, 51, 54, and 49 volatile flavor components were identified in the 0, 6, and 12-hour samples, respectively. Aldehydes accounted for a relatively large proportion in all three groups, reaching 72.87%, 58.89%, and 48.40%, respectively. Isovaleraldehyde was particularly prominent. Comparing the samples before and after preservation, the number of volatile flavor components remained largely unchanged after 12 hours of preservation, with a decrease in the proportion of aldehydes and an increase in ketones, aldehydes, and hydrocarbons (enhancing shrimp aroma). Figure 15 As shown, the vast majority of the volatile components are isovaleraldehyde (accounting for 61.9%, 50.9%, and 41.7% respectively), while the amount of bitter substances is reduced.

[0121] The above results indicate that placing one pound of shrimp in a 25cm×35cm×15cm container, laid flat to avoid stacking, and temporarily holding them for 30 minutes to alleviate stress, provides a preservation solution. Adjusting the salinity of 1L of water to 27‰ with natural table salt, adding two lemon slices, and soaking for 20 minutes before removing the shrimp, yields a preservation solution. Pour the solution into the container, ensuring the water level is one-third above the shrimp. Transferring the container from room temperature to a 7℃ refrigerator's crisper drawer effectively preserves the shrimp for up to 12 hours, maintaining their quality without significant changes.

[0122] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preserving shrimp in a refrigerator based on the synergistic effect of multi-parameter regulation and promoting air release, characterized in that, Includes the following steps: (1) Prepare aquaculture water with a salinity of 25-30‰. Soak lemon slices in the aquaculture water and then remove them to obtain a survival solution. (2) Place the shrimp in the preservation solution and store them in a refrigerator at 7-9°C; After storing for 0.5-4 hours, the temperature is raised to 10°C. The concentration of citric acid in the survival solution is 0.7-1 g / L, and the pH value is 6.5-6.9; The water level of the survival solution is higher than 1 / 3 of the shrimp's body.

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

3. The method for preserving shrimp in a refrigerator according to claim 1, characterized in that, The operation of adding shrimp to the preservation solution involves placing the shrimp in a preservation container, laying them flat, and then adding the preservation solution.

4. The method for preserving shrimp in a refrigerator according to claim 1, characterized in that, Before adding the survival solution, let the shrimp sit for 20-30 minutes to alleviate the stress response.

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

6. The method for preserving shrimp in a refrigerator according to claim 1, characterized in that, The storage time is 0-12 hours.

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