A collaborative control method for improving the quality of fresh aquatic product supply chain

Abstract

The present invention discloses a collaborative control method for improving the quality of the fresh aquatic product supply chain, which belongs to the field of food preservation technology. The present invention uses electric field and magnetic field to assist mixed antifreeze protein treatment, and electromagnetic field to assist transportation and sales in a complete process. Due to the addition of a constant magnetic field and a pulsed electric field in the pretreatment process, the freezing point temperature of the fresh aquatic product is significantly reduced. The fresh aquatic product does not freeze at a lower temperature, the occurrence of product corruption during processing is reduced, and fewer ice crystals are formed in the subsequent supply chain transportation and sales stages. During the subsequent shelf storage period, the addition of the electromagnetic field causes the freezing point of the sample during the storage process to remain at a low level, resulting in less damage to cells and less nutritional loss. During the supply chain process, the TBA value, TVB-N value, and K value in the supply chain link increase slowly, the freshness of the product remains intact, the growth of microorganisms is slow, and the subsequent thawing link is omitted, thereby extending the shelf life of the fresh aquatic product and extending the sales period to achieve the purpose of increasing revenue.

Description

Technical Field

[0001] The invention discloses a collaborative control method for improving the quality of a fresh aquatic product supply chain, belonging to the field of food preservation. Background Art

[0002] The temperature of refrigerated food is generally set at 0-10℃, but at this temperature, psychrophilic microorganisms still grow rapidly. Therefore, researchers use lower storage temperatures, that is, close to the freezing point of the product, so as to further extend the shelf life of aquatic products while ensuring the quality of meat. It is also of great significance for the regulation of the freezing point of the product. Cold chain transportation refers to the transportation of goods at a certain temperature throughout the entire transportation process, whether it is loading and unloading, changing the mode of transportation, changing packaging equipment, etc. The cold chain transportation method can be road transportation, water transportation, rail transportation, air transportation, or a combination of multiple transportation methods. Cold chain transportation is an important part of cold chain logistics. Cold chain transportation is costly and involves more complex mobile refrigeration technology and insulation box manufacturing technology. Cold chain transportation management involves more risks and uncertainties.

[0003] Traditional aquatic product storage methods, such as air freezing and plate contact freezing, are simple to operate but often negatively impact product quality, severely reducing the edible, processing, and nutritional qualities of aquatic products. This not only results in significant economic losses for producers but also poses health risks to consumers. Therefore, the aquatic product industry urgently needs to develop more effective aquatic product storage and transportation technologies to improve the quality of fresh aquatic products and promote industry upgrading.

[0004] Zhang Min et al. (2020) disclosed a method (ZL201611047343.9) for significantly extending the shelf life of kudzu rice by adjusting its freezing point. The method primarily includes the following steps: raw material sorting, preparation of a soaking solution, immersion, draining, ice-temperature preservation, and desalination. The method soaks kudzu rice in a mixed solution of salts and sugars, while simultaneously using ultrasound to promote its absorption of antifreeze, lowering its freezing point. This method can extend the shelf life of kudzu rice to over 60 days. This patent only addresses issues inherent in traditional storage processes and can extend the product's shelf life, but it does not address the regulation of the transportation process or subsequent sales considerations.

[0005] Yu Tianfang (2022) disclosed a cold chain logistics preservation device for meat products (CN 217295446U), comprising a mounting plate with cavities formed on both sides thereof, second telescopic rods fixedly connected to both sides of the top of the mounting plate, and support mechanisms fixedly connected to both sides of the top of the mounting plate. A moving mechanism is fixedly connected to both sides of the bottom of the box. In this cold chain logistics preservation device for meat products, a threaded rod drives a threaded cylinder downward, causing the roller to contact the ground. At this point, the box can be moved on the ground, eliminating the need for human transport, saving time and effort and facilitating user use. During transportation, the first spring and the second telescopic rod are in a state of continuous tension and compression, providing a good cushioning effect for the box, preventing it from shaking during transportation. By firmly securing the box, the device prevents the food inside from being damaged by bumps during transportation. This patent primarily focuses on improving the transportation device during cold chain transportation, but does not address the issue of improving product freshness and quality during supply chain logistics based on product characteristics.

[0006] Yang Zhao et al. (2021) disclosed a new type of pulsed magnetic field-assisted freezing and preservation refrigerator (publication number: CN113758104A), which includes a refrigerator body, a refrigeration system, and a pulsed magnetic field generating system. The pulsed magnetic field generating system includes at least one group of magnetic field generating units, each group of magnetic field generating units includes a number of magnetic field generating coils 3 distributed around the refrigerator body. The magnetic field generating coils 3 of each group of magnetic field generating units are connected to a pulse power supply and generate a pulsed magnetic field in the refrigerator cavity. This invention changes the metabolism of food cells, thereby effectively inhibiting cell apoptosis and extending the shelf life of food. At the same time, the pulsed magnetic field has the effect of increasing the crystallization rate, reducing the size of ice crystals, and making the distribution of ice crystals more uniform, which is beneficial for maintaining the freshness and flavor of meat during freezing. However, it does not involve the regulation of the transportation process and the consideration of the subsequent sales links.

[0007] Su Laijin et al. (2021) disclosed a method for rapid freezing of aquatic products using an electric field (CN112400973A). This method utilizes low-voltage ice temperature treatment and high-voltage freezing treatment, along with the addition of a preservative. This method results in smaller ice crystals and fewer in number than in conventional freezing methods. However, this method is primarily applicable to aquatic products, limiting its use to ice-layer heat transfer freezing, and cannot be applied to other meat freezing methods. Furthermore, this method fails to reduce the energy consumption required for freezing while maintaining meat quality. Yang Zhao et al. (2022) disclosed a method for storing meat using a variable intermittent ratio magnetic field (CN113995004A), which uses different magnetic fields to control ice crystal size. This invention discloses a method for storing meat using a variable intermittent ratio magnetic field. The method involves placing meat in a refrigerated environment with an intermittent magnetic field, maintaining the temperature within the range of -18°C to -25°C, freezing the meat, periodically monitoring the ice crystal size, and adjusting the magnetic field on-off time ratio based on the ice crystal size. The present invention introduces the non-thermal effect of magnetic field on food, and selects the most suitable magnetic field application process for the corresponding meat through experimental determination, which can significantly improve the quality of meat after long-term frozen storage, reduce juice loss caused by freezing, and extend the storage time of meat. This patent still focuses on the freezing process and does not consider how to lower the freezing point and eliminate the subsequent thawing process.

[0008] Fang Bin et al. (2022) disclosed a high-quality quick-freezing device and method (CN114543409A). This invention utilizes an oscillating magnetic field and an oscillating electric field to reduce the size and increase the number of ice crystals in quick-frozen foods, achieving a more uniform quick-freezing temperature. This suppresses the phenomenon of excessive ice crystal growth that damages cells, contributing to improved quality and extended frozen food preservation. However, this patent still applies to the freezing process and does not change the freezing temperature.

[0009] Liu Yangxiong (2022) disclosed a vegetable logistics and fresh-keeping distribution device (CN 217075611U), which includes a box body, a carrying plate and an air duct. A protective door is installed on one side of the box body, and the carrying plate is installed on the bottom of the box body. Ventilation slots are evenly distributed on the carrying plate. An air blower is installed in the ventilation slot. Protective nets are installed on both sides of the air blower. An insulation layer is installed on the surrounding walls of the box body. By providing the air blower and the protective net, the protective net can prevent impurities from entering the air blower. Then, during the flow of cold air in the ventilation slot, the air blower accelerates the flow rate of the cold air and improves the temperature adjustment speed in the box body. By providing an electrostatic generator and an electrostatic adsorption plate, the static electricity generated by the electrostatic generator can be applied to the electrostatic adsorption plate, and then the electrostatic adsorption plate adsorbs dust in the cold air to prevent it from adhering to the vegetables, thereby improving the quality of the vegetables. This patent focuses on improving the equipment issues in the transportation process and does not make corresponding adjustments to the product itself.

[0010] Therefore, the fresh food supply chain industry urgently needs a method that can significantly reduce the freezing point of products and preserve samples in an unfrozen state for a long time, thereby eliminating the subsequent thawing process. Summary of the Invention

[0011] This invention aims to improve the quality of fresh aquatic products by lowering their freezing point through a combination of antifreeze and pulsed electromagnetic fields (PEFs). Using common fresh aquatic products as the primary raw material, and following a process of raw material preparation, simulated transportation, and storage in a supermarket environment, this method significantly lowers the freezing point of fresh aquatic products (from -1.7°C to -2.2°C to -4°C to -6°C) through the use of a mixed antifreeze solution and PEF-assisted freezing. This method also minimizes quality loss during PEF-assisted supply chain transportation and storage. The use of PEF-assisted and PEF-assisted supply chain transportation and storage significantly improves the subsequent quality of fresh aquatic products, such as TVB-N, TBA, and K values, preserves nutrients, and enhances sensory quality. This extends the shelf life of fresh aquatic products, extending their sales period and ultimately increasing revenue.

[0012] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0013] A collaborative control method for improving the quality of a fresh aquatic product supply chain comprises the following steps:

[0014] (1) Sample pre-cooling treatment: Fresh aquatic products are whole or cut into blocks of uniform size and placed in a magnetic field freezer to pre-cool the mixed liquid to obtain pre-cooled products;

[0015] (2) Cooperative treatment to maintain a low freezing point temperature in a supply chain logistics environment: the treated product obtained in step (1) is placed in a logistics transport device, and a mixed liquid is stored and transported over long distances using a combination of a phased pulsed magnetic field and a pulsed electric field;

[0016] (3) Cooperative processing to maintain low freezing point temperature in the supply chain supermarket environment: the products in the transportation process are stored and sold in the supermarket environment using pulsed magnetic field combined with pulsed electric field;

[0017] In one embodiment of the present invention, step (1) is specifically as follows: cutting the fresh aquatic product to be processed into blocks with a volume of 150-250cm 3 , or uniform blocks with a block thickness of 3-5 cm or a mass of 150-250 g; and placed in a magnetic field freezer to pre-cool the mixed liquid.

[0018] In one embodiment of the present invention, the mass fraction of the mixed solution in step (1) is: hemoglobin 20-40%, herring antifreeze protein (hAFP) 0.5-0.8%, DCR39 0.1-0.3%, magnetic nano zinc oxide 0.02-0.04 g / kg, and the solvent is water.

[0019] In one embodiment of the present invention, the mixed solution in step (1) is composed of four substances. Hemoglobin is extracted from pig blood and is used to maintain product color and lower the freezing point of fresh aquatic products. Herring antifreeze protein (hAFP) is extracted from deep-sea herring. DCR39 is a 39-amino acid peptide produced in the larvae of the red-winged beetle. Magnetic nano-zinc oxide is used to inhibit bacteria and conduct electromagnetic energy, further lowering the freezing point.

[0020] In one embodiment of the present invention, the four substances in the mixture in step (1) are synthesized by solid phase peptide synthesis (SPPS) protocol according to standard chemical methods, purified to a homogeneity of >99% by reversed-phase high performance liquid chromatography, and confirmed by high-resolution mass spectrometry.

[0021] In one embodiment of the present invention, the nano zinc oxide in step (1) is magnetic, and its electromagnetic conductivity is improved by more than 85% compared with ordinary nano zinc oxide.

[0022] In one embodiment of the present invention, the collaborative treatment of maintaining a low freezing point temperature in step (2) is divided into two stages: the first stage is a physical field treatment stage, in which a pulsed magnetic field and a pulsed electric field are added to freeze the sample to -4 to -6°C; the second stage is a transportation stage, in which the sample is kept at a temperature fluctuation within 0.5°C to simulate transportation for 10 to 18 hours.

[0023] In one embodiment of the present invention, the pre-cooling treatment temperature in step (1) is 0°C, the magnetic field strength is 6-10mT, the pulse period is 60s, wherein the action is 40s and the rest is 20s, the voltage is 220V, and the frequency range of the pulsed magnetic field generated by the magnetic field generating unit is 0-100 kHz.

[0024] In one embodiment of the present invention, the precooling time in step (1) is 2 to 6 hours.

[0025] In one embodiment of the present invention, the parameters of the pulsed magnetic field and pulsed electric field for the coordinated treatment of maintaining a subfreezing temperature in the supply chain logistics environment in step (2) are as follows: an electric field strength of 30-50 kV / m, a pulse period of 60 seconds, an electric field operating for 35 seconds and an off time of 15 seconds, a constant magnetic field with a magnetic field strength of 10-30 mT, a voltage of 220 V, a frequency range of 0-100 kHz for the pulsed magnetic field generated by the magnetic field generating unit, and a treatment temperature of -10°C. The temperature fluctuation is maintained within 0.5°C during transportation for 10-18 hours.

[0026] In one embodiment of the present invention, the temperature of the product of step (3) during storage is -5 to -7°C.

[0027] In one embodiment of the present invention, in step (3), the pulsed magnetic field and the pulsed electric field act simultaneously, and the pulse period during the process is 3 hours, with the electric and magnetic fields operating for 1 hour and resting for 2 hours. The magnetic field strength is 6-10 mT, and the electric field strength is 50-100 kV / m.

[0028] In one embodiment of the present invention, during the supermarket environment storage of the sample in step (3), the storage temperature variation range is less than 0.5°C.

[0029] Beneficial effects of the present invention:

[0030] The present invention uses a mixed antifreeze solution for treatment before transportation and sale, and adds a constant magnetic field and a pulsed electric field during the supply chain transportation process, which significantly reduces the freezing point temperature of fresh aquatic products (from -1.7℃~-2.2℃ to -4℃~-6℃). Fresh aquatic products do not freeze at lower temperatures, reducing the damage caused by the freezing process, resulting in less quality changes and high freshness levels in the subsequent supply chain transportation stage. During the subsequent shelf sales period, the addition of the electromagnetic field causes the freezing point of the product to remain at a lower temperature, effectively inhibiting the growth and reproduction of microorganisms, further extending the shelf life of the product in the sales stage, causing less damage to cells and less nutrient loss in cells, so it is more convenient to sell on the shelf for a long time. Through cold chain transportation and shelf sales, the increase of TBA value, TVB-N value and K value in the supply chain link is slowed down, the growth of microorganisms is slow, the color difference value has no significant change compared with fresh samples, the protein and amino acid content is well preserved, and the retention rate of minerals such as iron, zinc, and potassium is greater than 95%. The product hardness is 10%-15% higher than that of ordinary transportation and sales, which is closer to the hardness of fresh products. The content of vitamins such as vitamin A is greater than 95% of the fresh sample. It is a method for improving the quality of fresh aquatic products in the supply chain with slow spoilage, low microbial level, good color and aroma retention, perfect quality protection, 1.5~4 times longer shelf life, simple process flow, and suitable for industrial production. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to specific examples.

[0032] Example 1: Collaborative Control Method for Lowering the Freezing Point of Fresh Hairtail and Improving Supply Chain Quality

[0033] (1) Fresh hairtail was cut into evenly sized pieces and randomly divided into four groups. The samples were pre-cooled in a 10 mT magnetic field for 4 hours with a mixture of hemoglobin 33%, herring antifreeze protein (hAFP) 0.5%, DCR39 0.1%, and magnetic nano-zinc oxide 0.03 g / kg until the core temperature reached 4°C. The pre-cooled samples were obtained.

[0034] (2) Place the pre-cooled sample in the pulsed electric field magnetic field equipment for supply chain transportation, turn on the pulsed electric field strength of 70 kV / m, keep the magnetic field constant, the magnetic field strength is 30 mT, the ambient temperature is -10 °C, and when the center temperature reaches -5.2 °C, keep the temperature fluctuation within 0.5 °C for 16 hours;

[0035] (3) After transportation, the electric and magnetic fields are turned off. During the subsequent storage period, the magnetic field strength is 6mT, the electric field strength is 70kV / m, and the supermarket environment is stored for 20 days (the supply chain supermarket environment storage temperature is -6℃).

[0036] After the storage time in the supply chain supermarket environment was over, the samples were removed from the refrigerator and directly exposed to the air. When the center temperature of the sample reached 4°C, it was considered the end point. The total colony count, TBA value, TVB-N value, K value, color, iron and zinc content, texture, cooking loss, low-field nuclear magnetic resonance and other physical and chemical properties of hairtail were measured and compared with fresh samples and the control group (no pretreatment, ordinary transportation and storage) to explore the influence of the combined method.

[0037] The results showed that the freezing point temperature of fresh hairtail was significantly reduced (from -1.9℃ to -5.2℃) during long-term storage and transportation compared with ordinary transportation and storage. The TVB-N, TBA, and K values ​​of the treated group were significantly lower than those of the untreated group. The total colony count after treatment was reduced by 25% compared with ordinary transportation. The content of minerals such as iron and zinc was retained at a rate greater than 96% compared with fresh products. The protein content was retained at a rate greater than 95% compared with fresh samples. The vitamin A content was retained at a rate greater than 94% compared with fresh products. The hardness was increased by 11% compared with ordinary treatment, which was closer to the hardness of fresh samples.

[0038] Table 1 Total colony counts and physical and chemical indicators of hairtails treated with different methods

[0039]

[0040] Table 2 Freezing point of hairtail fish with different treatments

[0041]

[0042] Example 2: Collaborative Control Method for Lowering the Freezing Point of Fresh Grass Carp and Improving Supply Chain Quality

[0043] (1) Fresh grass carp was cut into evenly sized pieces. The sample was pre-cooled in a mixture (hemoglobin 33%, herring antifreeze protein (hAFP) 0.5%, DCR39 0.1%, magnetic nano-zinc oxide 0.04 g / kg) in an 8 mT magnetic field for 3 hours until the center temperature reached 4°C, and the pre-cooled sample was obtained.

[0044] (2) Place the pre-cooled sample into a pulsed electric field magnetic field device that simulates supply chain transportation. Turn on the pulsed electric field strength of 50 kV / m, keep the magnetic field constant, the magnetic field strength of 20 mT, and the processing temperature of -10°C. When the center temperature reaches -4.9°C, keep the temperature fluctuation within 0.5°C and transport for 14 hours.

[0045] (3) After transportation, the electric and magnetic fields were turned off. During the subsequent storage period, the magnetic field strength was 8 mT, the electric field strength was 50 kV / m, and the frozen storage was 15 days (the ambient storage temperature in the supply chain supermarket was -6°C).

[0046] After the storage time in the supply chain supermarket environment was over, the samples were removed from the refrigerator and directly exposed to the air. When the center temperature of the sample reached 4°C, it was considered the end point. The total colony count, TBA value, TVB-N value, K value, color, iron and zinc content, texture, cooking loss, low-field nuclear magnetic resonance and other physical and chemical properties of grass carp were measured and compared with fresh samples and the control group (no pretreatment, ordinary transportation and storage) to explore the influence of the combined method.

[0047] The results showed that the freezing point temperature of fresh grass carp was significantly reduced (from -2.1℃ to -4.9℃) during long-term storage and transportation compared with ordinary transportation and storage. The TVB-N, TBA, and K values ​​of the treated group were significantly lower than those of the untreated group. The total colony count after treatment was reduced by 30% compared with ordinary transportation, the protein content was retained at a rate of greater than 96% compared with fresh products, the hardness was increased by 12% compared with ordinary treatment, closer to the hardness of fresh samples, and the vitamin A content was retained at a rate of greater than 95% compared with fresh products.

[0048] Table 3 Total colony counts and physical and chemical indicators of grass carp under different treatments

[0049]

[0050] Table 4 Freezing point of grass carp under different treatments

[0051]

[0052] Example 3: Collaborative Control Method for Lowering the Freezing Point of Razor Clams and Improving Supply Chain Quality

[0053] (1) Fresh razor clams were divided into uniform portions according to their shapes. The products were pre-cooled in a mixture (hemoglobin 33%, herring antifreeze protein (hAFP) 0.5%, DCR39 0.1%, and magnetic nano-zinc oxide 0.03 g / kg) in a 10 mT magnetic field for 4 hours until the center temperature reached 4°C, and the pre-cooled samples were obtained.

[0054] (2) Place the pre-cooled sample in a pulsed electric field magnetic field device simulating supply chain transportation, turn on the pulsed electric field strength of 70 kV / m, keep the magnetic field constant, the magnetic field strength is 30 mT, the ambient temperature is -10°C, and when the center temperature reaches -5.2°C, keep the temperature fluctuation within 0.5°C to simulate transportation for 16 hours;

[0055] (3) After transportation, the electric and magnetic fields are turned off. During the subsequent storage period, the magnetic field strength is 6mT, the electric field strength is 70kV / m, and the supermarket environment is stored for 20 days (the supply chain supermarket environment storage temperature is -6℃).

[0056] After the storage time in the supply chain supermarket environment was over, the samples were removed from the refrigerator and directly exposed to the air. When the center temperature of the sample reached 4°C, it was considered the end point. The total colony count, TBA value, TVB-N value, K value, color, iron and zinc content, texture, cooking loss, low-field nuclear magnetic resonance and other physical and chemical properties of the razor clam were measured and compared with the fresh samples and the control group (no pretreatment, ordinary transportation and storage) to explore the influence of the combined method.

[0057] The results showed that the freezing point temperature of fresh razor clams was significantly reduced (from -1.5℃ to -4.2℃). During long-term storage and transportation, the TVB-N, TBA, and K values ​​of the treated group were significantly lower than those of the untreated group. The total colony count after treatment was reduced by 35% compared with ordinary transportation. The retention rate of minerals such as iron and zinc was greater than 96% compared with fresh products, the retention rate of protein content was greater than 95% compared with fresh samples, and the retention rate of vitamin A content was greater than 94% compared with fresh products. The hardness was increased by 11% compared with ordinary treatment, which was closer to the hardness of fresh samples.

[0058] Table 5 Total colony counts and physical and chemical indicators of razor clams treated with different methods

[0059]

[0060] Table 6 Freezing point of razor clams treated with different methods

[0061]

[0062] Example 4: Collaborative Control Method for Lowering the Freezing Point of Shrimp and Improving Supply Chain Quality

[0063] (1) The shrimp were divided into parts with uniform mass. The products were pre-cooled in a mixture (hemoglobin 33%, herring antifreeze protein (hAFP) 0.5%, DCR39 0.1%, magnetic nano zinc oxide 0.04 g / kg) in a 7 mT magnetic field for 2 hours until the center temperature reached 4°C, and the pre-cooled samples were obtained.

[0064] (2) The pre-cooled samples were transported in a pulsed electric field magnetic field device to simulate the supply chain. During the micro-freezing process, the pulsed electric field strength was turned on at 90 kV / m, the magnetic field was constant, the magnetic field strength was 40 mT, the freezing temperature was -10°C, and when the center temperature reached -5.8°C, the temperature fluctuation was kept within 0.5°C to simulate transportation for 18 hours;

[0065] (3) After transportation, the electric field was turned off. During the subsequent storage period, the magnetic field strength was 8 mT, the electric field strength was 80 kV / m, and the product was stored in a supermarket environment for 25 days (the supermarket environment storage temperature was -7°C).

[0066] After the storage time in the supply chain supermarket environment was over, the samples were removed from the refrigerator and exposed to direct air. When the center temperature of the sample reached 4°C, it was considered the end point. The total colony count, TBA value, TVB-N value, K value, color, iron and zinc content, texture, cooking loss, low-field nuclear magnetic resonance and other physical and chemical properties of the shrimp were measured and compared with the fresh samples and the control group (no pretreatment, ordinary transportation and storage) to explore the influence of the combined method.

[0067] The results showed that the freezing point temperature of fresh shrimp was significantly reduced (from -1.5℃ to -5.8℃). During long-term storage and transportation, the TVB-N, TBA, and K values ​​of the treated group were significantly lower than those of the untreated group. The total colony count after treatment was reduced by 40% compared with ordinary transportation. The content of minerals such as iron and zinc was retained at a rate of greater than 96% compared with fresh products. The protein content was retained at a rate of greater than 95% compared with fresh samples. The vitamin A content was retained at a rate of greater than 94% compared with fresh products. The hardness was increased by 11% compared with ordinary treatment, which was closer to the hardness of fresh samples.

[0068] Magnetic fields are a common physical field. Research has shown that, due to the magnetic effect of living organisms, magnetic field assistance can significantly impact the frozen storage process of foods. Appropriate magnetic field strength can alter the physical and chemical properties of biomacromolecules and cell membranes, effectively scavenging free radicals, improving food freshness and extending shelf life. Magnetic fields can also influence the freezing process of water, reducing the size of ice crystals formed during freezing, effectively minimizing freezing losses and improving the quality of frozen foods. Pulsed magnetic fields can alter the cell membrane structure of meat products, altering cell metabolism, thereby effectively inhibiting cell apoptosis and extending food shelf life. Furthermore, pulsed magnetic fields can significantly lower the freezing point of fresh aquatic products, reduce ice crystal size, and achieve more uniform ice crystal distribution, beneficially maintaining freshness and flavor during low-temperature storage. Therefore, developing magnetic and electric field-assisted methods for lowering the freezing point holds great research potential. Applying a magnetic field during the phase transition phase may disrupt the hydrogen bonds between free water molecules. Consequently, large water molecules are broken down into smaller clusters, or even single molecules, lowering the freezing point of the product. Antifreeze protein, as a natural freezing point regulator, can adjust the freezing point well, but the change is not enough. Therefore, physical field-assisted means are used to significantly lower the freezing point, so that the product does not freeze at low temperatures, thereby eliminating the subsequent long thawing process, making the product closer to a fresh sample, and maximizing the freshness of the product during the supply chain process.

[0069] Table 7 Total colony counts and physical and chemical indicators of shrimps treated with different methods

[0070]

[0071] Table 8 Freezing point of shrimps with different treatments

[0072]

[0073] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A collaborative control method for improving the quality of fresh aquatic product supply chain, characterized in that: The following steps are involved: (1) Sample pre-cooling treatment: Fresh aquatic products are whole or cut into even-sized blocks and placed in a magnetic field freezer to pre-cool the phosphorus-free mixed solution for 2–6 h to obtain pre-cooled products; The mass fractions of the components of the phosphorus-free mixed solution are: 20-40% hemoglobin, 0.5-0.8% herring antifreeze protein, 0.1-0.3% DCR39, 0.002-0.004% magnetic nano-zinc oxide, and the balance is water; hemoglobin is extracted from pig blood, herring antifreeze protein is extracted from deep-sea herring, and DCR39 is a 39-amino acid peptide produced in the larvae of the red wing beetle; the three protein substances in the phosphorus-free mixed solution are all synthesized by solid-phase peptide synthesis (SPPS) protocol according to standard chemical methods, purified to a homogeneity of >99% by reversed-phase high-performance liquid chromatography, and confirmed by high-resolution mass spectrometry; the magnetic nano-zinc oxide has an electromagnetic conductivity improved by more than 85% compared to ordinary nano-zinc oxide; The pre-cooling treatment temperature is 0°C, the magnetic field intensity is 6-10 mT, the pulse period is 60 seconds, including 40 seconds of action and 20 seconds of rest, the voltage is 220V, and the frequency range of the pulsed magnetic field generated by the magnetic field generating unit is 0-100 kHz; (2) Co-processing to maintain a low freezing point temperature in a supply chain logistics environment: the treated product obtained in step (1) is placed in a logistics transport device, and stored in a phosphorus-free mixed liquid using a phased pulsed magnetic field and a pulsed electric field combined with the mixed liquid for long-distance transportation; The collaborative treatment to maintain the subfreezing point temperature is divided into two stages: the first stage is the physical field treatment stage, in which pulsed magnetic fields and pulsed electric fields are added to pre-cool the sample to -4 to -6°C; the second stage is the transportation stage, in which the sample is transported over long distances for 10 to 18 hours while maintaining a temperature fluctuation within 0.5°C. The electric field strength is 30-50 kV / m, the pulse period is 60 seconds, the electric field is on for 35 seconds and off for 15 seconds, the magnetic field is constant, the magnetic field strength is 10-30 mT, the voltage is 220V, the frequency range of the pulsed magnetic field generated by the magnetic field generating unit is 0-100 kHz, and the processing temperature is -10°C; the temperature fluctuation is kept within 0.5°C during long-distance transportation for 10-18 hours; (3) Cooperative processing to maintain low freezing point temperature in the supply chain supermarket environment: the products in the transportation process are stored and sold in the supermarket environment using pulsed magnetic field combined with pulsed electric field; Among them, the pulsed magnetic field and pulsed electric field act simultaneously, and the pulse period during the process is 3 hours, the electric field and magnetic field work for 1 hour and stop for 2 hours; the magnetic field intensity is 6~10 mT, and the electric field intensity is 50~100 kV / m; the temperature of the product during the storage process is -5~-7℃, and during storage in the supermarket environment, the storage temperature change range is less than 0.5℃.

2. The method according to claim 1, characterized in that Step (1) specifically comprises: packaging the fresh aquatic product to be processed into portions with a mass of 100 to 250 g each, and then placing the portions in a magnetic field freezer to pre-cool the phosphorus-free mixed solution.

3. The method according to claim 1, characterized in that The fresh aquatic product is selected from one of hairtail, grass carp, razor clam and shrimp.

Images