Fresh-keeping and color-retaining processing method for golden pomfret blocks

Abstract

The invention relates to the technical field of golden pomfret fresh-keeping processing, in particular to a golden pomfret block fresh-keeping and color-retaining processing method. Comprising the following steps: opening the back of the trachinotus ovatus from a position 1-2cm away from the tail of the trachinotus ovatus, peeling, removing bones and removing viscera; washing, and dividing back muscles of trachinotus ovatus into a plurality of fish blocks; deionized water is put into a brown bottle, a plasma radio frequency device is placed below the liquid level of the deionized water for activating treatment for 1-5 min, the treated plasma radio frequency device is refrigerated at the temperature of 0-4 DEG C, and a multifunctional soaking solution is prepared; soaking the golden pomfret blocks into the multifunctional soaking liquid for 10-15 minutes, and stirring the liquid level once every 3-5 minutes during the soaking process; after soaking, taking out the golden pomfret blocks, and draining water; putting the golden pomfret blocks into a composite phosphate water-retaining agent, and performing ultrasonic treatment for 8-15 minutes; draining the fish blocks, and performing vacuum packaging. The method has the advantages that the storage period of the trachinotus ovatus blocks is prolonged; the red degree value and the content of nitrosomyoglobin of the trachinotus ovatus blocks are remarkably increased, and the sensory characteristics of the trachinotus ovatus blocks are maintained.

Description

Technical Field

[0001] The invention relates to the technical field of golden pomfret fresh-keeping and processing, and in particular to a method for fresh-keeping and color-preserving processing of golden pomfret pieces. Background Art

[0002] Golden pomfret is rich in nutrients such as high-quality protein, essential amino acids, unsaturated fatty acids and minerals. It is easy to digest and good for health, and occupies a high proportion in daily dietary consumption. The "freshness" of aquatic products is the main factor that determines their product value and shelf life, and the "color of fish meat" is an important sensory factor that affects consumer purchasing behavior.

[0003] Due to its high water activity, neutral pH and rich nutrients, golden pomfret is very susceptible to spoilage by microorganisms and enzymes during processing and storage, and myoglobin degradation causes browning of the fish meat. Currently, natural compounds and antioxidants are introduced to delay the browning of fish caused by oxidation, but the introduction of these substances may mask the flavor of the fish itself and affect the sensory quality; the use of antioxidants will also cause consumers to consider its safety. The invention patent application with Chinese patent publication number CN117530322A, publication date February 9, 2024, and invention name "A preservation method for improving the color change of fresh fish meat irradiated by electron beam" discloses a method for improving color by irradiation treatment. Although the above method successfully maintains the redness value of fresh meat, there are several concerns that need to be considered when lactic acid and sorbic acid are used in food as food additives: first, there is a limited amount standard; second, plasma activation is a complex process, and whether substances harmful to the human body will be produced in the process of activating lactic acid and sorbic acid; third, whether the introduction of the two will produce unwanted flavors and colors, changing the original taste and flavor of fresh meat.

[0004] The multifunctional soaking liquid is made by low-temperature plasma treatment on the water surface or underwater. The active substances generated by high-voltage discharge are transferred to the water, and a series of physical and chemical reactions occur to reduce the pH value of the water body and induce the generation of a variety of active substances. The interaction between the acidic environment and a large number of short-lived and long-lived chemicals in the multifunctional soaking liquid enables it to reduce bacteria and protect color.

[0005] Given the high nutritional value and high perishability of golden pomfret, a green processing technology suitable for golden pomfret fillets is urgently needed, which can not only extend the shelf life of fillets but also better maintain their sensory properties. The use of multifunctional soaking liquid as a non-thermal preservation technology to treat golden pomfret fillets not only has a significant antibacterial effect but also significantly improves the color of fillets during refrigeration, greatly meeting the needs of consumers. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a method for preserving and coloring golden pomfret chunks.

[0007] The present invention aims to provide a method for preserving and coloring golden pomfret chunks, which specifically comprises the following steps: S1. Fish meat pre-processing: Open the back of the golden pomfret 1-2 cm from the tail, remove the skin, bones and internal organs; rinse, take the back muscles of the golden pomfret and divide them into several pieces; S2. Preparation of multifunctional soaking solution: deionized water is placed in a brown bottle, and a plasma radio frequency device is placed below the liquid surface of the deionized water for activation treatment for 1 to 5 minutes. After treatment, the device is refrigerated at 0 to 4°C for 30 to 60 minutes to prepare a multifunctional soaking solution; S3. Sample processing: immerse the golden pomfret pieces in a multifunctional soaking solution for 10 to 15 minutes, stirring the liquid surface every 3 to 5 minutes; after soaking, remove the golden pomfret pieces and drain the water; S4. Soaking fish pieces in phosphate water retaining agent: Place golden pomfret pieces in composite phosphate water retaining agent and perform ultrasonic treatment for 8-15 minutes; S5. Vacuum packaging: Drain the moisture from the fish pieces and vacuum pack the fish pieces without moisture on the surface.

[0008] Preferably, in step S4, the composite phosphate water-retaining agent accounts for 0.3-0.5% of the mass of the golden pomfret chunks; the composite phosphate water-retaining agent includes sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate.

[0009] Preferably, the weight ratio of sodium tripolyphosphate, the sodium pyrophosphate and the sodium hexametaphosphate is 1-2:1-2:1.

[0010] Preferably, the weight ratio of sodium tripolyphosphate, the sodium pyrophosphate and the sodium hexametaphosphate is 2:2:1.

[0011] Preferably, in step S2, the output power of the plasma jet device is 650-800 W, and the gas flow rate is 0.5-1 L / min.

[0012] Preferably, the gas component of the plasma jet device is air.

[0013] Preferably, in step S3, the mass volume ratio of the golden pomfret chunks to the multifunctional soaking liquid is 1 g: 2-4 mL.

[0014] Preferably, the power of the ultrasonic treatment in step S4 is 150-300W.

[0015] Preferably, the vacuum packaging method in step S5 is to put the golden pomfret pieces into a vacuum packaging bag and vacuum-seal the bag using a vacuum packaging machine; the vacuum degree of the vacuum packaging machine is -0.1 MPa.

[0016] Preferably, sterile water is used to rinse the golden pomfret in step S1.

[0017] Compared with the prior art, the present invention can achieve the following beneficial effects: The preparation method of the present invention can extend the storage period of golden pomfret pieces by 3 to 5 days. Although the brightness of the red meat part is slightly reduced, the redness value and the content of nitrosylmyoglobin can be significantly increased, and the yellowness value of the fish pieces can be reduced, and a good coloring effect can be achieved; in addition, the heme iron content is maintained, the increase of the metmyoglobin content and the non-heme iron content is reduced, and the juice loss rate during cold storage is reduced, thereby effectively maintaining the sensory characteristics and storage stability of the golden pomfret pieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention is a flowchart of a method for preserving and coloring golden pomfret chunks provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0021] The present invention provides a method for preserving and coloring golden pomfret chunks, which specifically comprises the following steps: S1. Fish meat pre-processing: Open the back of the golden pomfret 1-2 cm from the tail, remove the skin, bones and internal organs; rinse, take the back muscles of the golden pomfret and cut them into several pieces of the same size; S2. Preparation of multifunctional soaking solution: deionized water is placed in a brown bottle, and a plasma radio frequency device is placed below the liquid surface of the deionized water for activation treatment for 1 to 5 minutes. After treatment, the device is refrigerated at 0 to 4°C for 30 to 60 minutes to prepare a multifunctional soaking solution; S3. Sample processing: immerse the golden pomfret pieces in a multifunctional soaking solution for 10 to 15 minutes, stirring the liquid surface every 3 to 5 minutes; after soaking, remove the golden pomfret pieces and drain the water; S4. Soaking fish pieces in phosphate water retaining agent: Place golden pomfret pieces in composite phosphate water retaining agent and perform ultrasonic treatment for 8-15 minutes; S5. Vacuum packaging: Drain the moisture from the fish pieces and vacuum pack the fish pieces without moisture on the surface.

[0022] Specifically, in step S1, sterile water is used to rinse the golden pomfret.

[0023] Specifically, in step S2, the output power of the plasma jet device is 650-800 W, and the gas flow rate is 0.5-1 L / min; The plasma jet device uses a 220V, 50Hz power supply, and the gas component is air.

[0024] Specifically, in step S2, the plasma jet device is placed 15-25 mm below the deionized water surface.

[0025] Specifically, in step S3, the mass volume ratio of the golden pomfret chunks to the multifunctional soaking liquid is 1 g: 2-4 mL.

[0026] Specifically, in step S4, the composite phosphate water retaining agent accounts for 0.3-0.5% of the mass of the golden pomfret block; The composite phosphate water retaining agent includes sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate, and the weight ratio of sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate is 1~2:1~2:1.

[0027] Specifically, the ultrasonic treatment in step S4 uses a 220V, 50KHz power supply with a power of 150-300W.

[0028] Specifically, the vacuum packaging method in step S5 is to put the golden pomfret pieces into a vacuum packaging bag and use a vacuum packaging machine to vacuum seal; the vacuum degree of the vacuum packaging machine is -0.1 MPa.

[0029] Example 1 This embodiment provides a method for preserving and coloring golden pomfret chunks, which specifically comprises the following steps: S1. Fish meat pre-processing: Open the back of the golden pomfret 1-2 cm from the tail, remove the skin, bones and internal organs; rinse the fish fillet with sterile water, remove the abdominal fat, and take the back muscle of the fish fillet and divide it into several fish pieces of the same size (30±0.5g); S2. Preparation of multifunctional soaking solution: Deionized water was placed in a brown bottle, and the plasma radio frequency device was placed 20 mm below the liquid surface of the deionized water for activation treatment for 3 minutes. After treatment, it was refrigerated at 0-4°C for 60 minutes to prepare a multifunctional soaking solution; the output power of the plasma jet device was 750 W, and the air flow rate was 0.6 L / min; S3. Sample processing: Soak the golden pomfret pieces in the multifunctional soaking solution for 10-15 minutes, stirring the liquid surface every 3-5 minutes; after soaking, take out the golden pomfret pieces and place them on clean gauze to drain the water; the mass volume ratio of the golden pomfret pieces to the multifunctional soaking solution is 1g:3mL; S4. Soaking fish pieces in a phosphate water retaining agent: Place the golden pomfret pieces in a composite phosphate water retaining agent and soak for 10 minutes under ultrasonic treatment; the ultrasonic power is 200W; The composite phosphate water retaining agent accounts for 0.3% of the mass of the golden pomfret block; the composite phosphate water retaining agent includes sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate, and the weight ratio of sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate is 2:2:1; S5. Vacuum packaging: drain the water from the fish pieces, put the golden pomfret pieces with no moisture on the surface into vacuum packaging bags, and vacuum seal them using a vacuum packaging machine; the vacuum degree of the vacuum packaging machine is -0.1MPa; after packaging, refrigerate at 0~4℃.

[0030] Example 2 The present embodiment provides a method for preserving and coloring golden pomfret chunks, wherein: the composite phosphate water retaining agent comprises sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate, and the weight ratio of sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate is 1:1:1; The remaining steps are the same as in Example 1.

[0031] Example 3 This embodiment provides a method for preserving and coloring golden pomfret chunks, wherein: in step S2, the output power of the plasma jet device is 650W, and the air flow rate is 1L / min; In step S4, the composite phosphate water retaining agent accounts for 0.5% of the mass of the golden pomfret block; The remaining steps are the same as in Example 1.

[0032] Example 4 This embodiment provides a method for preserving and coloring golden pomfret fillets, wherein: in step S2, the plasma jet device is placed 25 mm below the level of deionized water; In step S4, the ultrasonic treatment power is set to 250W; The remaining steps are the same as in Example 1.

[0033] Comparative Example 1 This comparative example provides a method for processing golden pomfret chunks, which specifically comprises the following steps: S1. Fish meat pre-processing: Open the back of the golden pomfret 1-2 cm from the tail, remove the skin, bones and internal organs; rinse the fish fillet with sterile water, remove the abdominal fat, and take the back muscle of the fish fillet and divide it into several fish pieces of the same size (30±0.5g); S2. Prepare pre-cooled deionized water: Refrigerate an equal amount of deionized water to the multifunctional soaking solution at 4°C for 30 to 60 minutes in advance.

[0034] S3. Sample processing: Soak the golden pomfret pieces in deionized water for 10-15 minutes, stirring the liquid surface every 3-5 minutes; after soaking, take out the golden pomfret pieces and place them on clean gauze to drain the water; the mass volume ratio of the golden pomfret pieces to the multifunctional soaking solution is 1g:3mL; S4. Soaking fish pieces in phosphate water retaining agent: Place the golden pomfret pieces in the composite phosphate water retaining agent and soak them in ultrasound for 10 min; The composite phosphate water retaining agent accounts for 0.3% of the mass of the golden pomfret block; the composite phosphate water retaining agent includes sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate, and the weight ratio of sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate is sodium tripolyphosphate: sodium pyrophosphate: sodium hexametaphosphate = 2:2:1; S5. Vacuum packaging: drain the water from the fish pieces, put the golden pomfret pieces with no moisture on the surface into vacuum packaging bags, and vacuum seal them using a vacuum packaging machine; the vacuum degree of the vacuum packaging machine is -0.1MPa; after packaging, refrigerate at 0~4℃.

[0035] Comparative Example 2 This comparative example provides a method for processing golden pomfret chunks, wherein the vacuum packaging in step S5 is replaced with ordinary plastic bag packaging; The remaining steps are the same as in Example 4.

[0036] Comparative Example 3 This comparative example provides a method for processing golden pomfret fillets, wherein: the vacuum packaging in step S5 is replaced by ordinary plastic bag packaging; and the remaining processing steps are the same as those in comparative example 1.

[0037] Comparative Example 4 This comparative example provides a method for processing golden pomfret chunks, wherein: in step S4, no ultrasonic treatment is performed when the composite phosphate water retaining agent is soaked; In step S5, the vacuum packaging is replaced by ordinary plastic bag packaging; the remaining processing steps are the same as those in comparative example 1.

[0038] Comparative Example 5 This comparative example provides a method for processing golden pomfret chunks, wherein: the composite phosphate water retaining agent in step S4 is replaced by sodium tripolyphosphate; and the remaining steps are the same as those in Example 1.

[0039] Comparative Example 6 This comparative example provides a method for processing golden pomfret chunks, wherein: the composite phosphate water retaining agent in step S4 is replaced by sodium pyrophosphate; and the remaining steps are the same as those in Example 1.

[0040] Comparative Example 7 This comparative example provides a method for processing golden pomfret chunks, wherein: the composite phosphate water-retaining agent in step S4 is replaced by sodium hexametaphosphate; and the remaining steps are the same as those in Example 1.

[0041] Comparative Example 8 This comparative example provides a method for processing golden pomfret chunks, wherein: in step S4, the composite phosphate water-retaining agent is replaced with a phosphate-free water-retaining agent; and the remaining steps are the same as in Example 1.

[0042] The golden pomfret pieces obtained by processing in Examples 1 to 4 and Comparative Examples 1 to 8 were tested for total colony count, juice loss rate, L* (brightness value), a* (redness value), b* (yellowness value), nitrosylmyoglobin, metmyoglobin content, heme iron and non-heme iron content, and the results are shown in Tables 1 and 2; Table 1 Quality changes of golden pomfret chunks at different storage times

[0043]

[0044]

[0045] Table 2 Determination results of nitrosylmyoglobin, metmyoglobin, heme iron and non-heme iron contents in fish fillets at different storage times

[0046]

[0047]

[0048] As can be seen from the table, compared with the comparative example, the total number of colonies in the embodiment decreased significantly, indicating that the method has a significant inhibitory effect on the total number of colonies and can extend the shelf life of fish blocks by 3 to 5 days. The bacteriostatic effect of the multifunctional soaking solution is attributed to the interaction between the acidic environment and a large number of short-lived and long-lived chemicals, which can produce strong oxidative stress (oxidative DNA damage, protein and lipid peroxidation) on the cell membrane and internal structure of microorganisms.

[0049] Compared with Comparative Example 2, the total number of colonies in Example 1 using vacuum packaging was reduced because vacuum packaging inhibited bacterial growth and reduced oxidation reactions by excluding air and reducing oxygen content, thereby maintaining the quality of the fish pieces.

[0050] Compared with Comparative Example 3, it is found that Example 1 significantly reduces the total number of colonies and prolongs the shelf life of food by combining the multifunctional soaking liquid with vacuum packaging. This is because although vacuum packaging reduces the oxygen content and inhibits the growth of aerobic microorganisms, the growth and reproduction of anaerobic microorganisms continue during cold storage, and the multifunctional soaking liquid has a broad-spectrum bactericidal effect on microorganisms, which plays a synergistic role and inhibits the growth of microorganisms to a greater extent.

[0051] Compared with Examples 1-3, it is found that the sound waves generated by ultrasound accelerate the depolymerization of microorganisms due to cavitation, and increase the penetration of the composite phosphate water retaining agent into the fish meat, thereby improving the water holding capacity of the fish meat during cold storage, significantly reducing the juice loss rate, and playing a role in water retention and tenderization. Therefore, this highlights the importance of using a multifunctional soaking liquid combined with ultrasound and vacuum packaging to synergistically treat fish blocks in inhibiting microorganisms.

[0052] Compared with the comparative example, the juice loss rate of the golden pomfret pieces in the embodiment during cold storage is significantly reduced, indicating that the method of the present invention can increase the penetration of the water retaining agent and has a more obvious water-retaining and tenderizing effect during cold storage. Among them, the comparison between Example 1 and Comparative Example 8 found that the composite phosphate water retaining agent is better than the phosphorus-free water retaining agent in reducing the juice loss rate. The phosphorus-free water retaining agent is more suitable for conditioning products and has a relatively fluffy taste, while the composite phosphate is more suitable for the processing of firm fish products; phosphates chelate with metal ions such as calcium and magnesium in the muscle, destroying the protein theme network structure, thereby improving the protein's ability to bind water and reducing juice loss during cold storage. The comparison between Example 1 and Comparative Examples 5-7 found that compared with a single water retaining agent, the composite water retaining agent has better processing and storage effects and less juice loss rate after appropriate proportioning. Juice loss not only affects the appearance, flavor and texture, but also leads to the loss of water-soluble nutritional compounds such as minerals, while providing nutrients for microorganisms. In the embodiment, ultrasonic treatment is combined with the composite phosphate water retaining agent during the soaking process to improve the permeability of the water retaining agent, more efficiently play the role of water retention and tenderization, and reduce the loss of juice during the cold storage of fish meat. In addition, compared with the comparative example, the embodiment using multifunctional soaking can better retain most of the water in the myofibril and reduce water loss.

[0053] It can be seen from the table that, compared with the comparative example, the L* and b* of the golden pomfret pieces in the embodiment are significantly reduced, indicating that the method of the present invention has a significant coloring effect and can comprehensively improve its sensory quality. In the comparative example, due to the degradation of myoglobin during cold storage, iron ions are released from heme, which has a significant promoting effect on lipid oxidation. The free radicals and other intermediates produced by lipid oxidation will destroy the pigments in the meat and cause it to brown, resulting in an increase in the content of metmyoglobin and an increase in the yellowness value in the control example. The active nitrogen (NO 3- 、NO 2- ) has a certain effect of reducing bacteria and protecting color, and delays the increase of yellowness value, which shows that the multifunctional soaking liquid can protect the good color of golden pomfret pieces to a certain extent.

[0054] Compared with Comparative Examples 1, 3, and 4, the content of a* and nitrosylmyoglobin in the golden pomfret pieces of the embodiment significantly increased, and the content of metmyoglobin significantly decreased. In Comparative Examples 1, 3, and 4, deionized water was used for soaking. Due to the degradation of myoglobin, the oxymyoglobin in the meat combined with oxygen to transform into metmyoglobin, thereby reducing the a* of the meat. Nitrosylmyoglobin is a stable pink substance. There is a large amount of active nitrogen (NO 3- and NO 2- ), these substances can be converted into NO under the action of reducing substances (H2O2) in the soaking liquid. NO can combine with myoglobin to form nitrosomyoglobin, which makes the meat appear bright red and increases the a* value, which explains the increase in nitrosomyoglobin content and a* in the fish pieces after being treated with the multifunctional soaking liquid in the experimental example. The multifunctional soaking liquid treatment improves the coloring effect of the fish pieces.

[0055] Compared with Comparative Examples 1, 3, and 4, the non-heme iron content of the golden pomfret chunks in the embodiment is significantly reduced, and the heme iron content is significantly increased. The heme iron and non-heme iron contents in fish muscle are negatively correlated. In the comparative example, during cold storage, myoglobin degrades, heme is destroyed, and free iron is released from heme, so the heme iron content is gradually decreasing; at the same time, the degradation of muscle protein and the destruction of the porphyrin ring lead to the release of free iron, which can act as a pro-oxidant in fish muscle and is related to the enhancement of lipid oxidation. The synergistic treatment of the multifunctional soaking liquid combined with ultrasound and vacuum packaging in the embodiment can maintain the storage stability of fish meat, reduce the destruction of muscle tissue, heme and porphyrin ring, thereby effectively maintaining the heme iron content and reducing the accumulation of non-heme iron, and reducing the occurrence of lipid oxidation.

[0056] Based on the above embodiments and comparative examples, the preparation method of the present invention can extend the storage period of golden pomfret fillets by 3 to 5 days. Although the brightness of the red meat portion is slightly reduced, the redness value and the content of nitrosylmyoglobin can be significantly increased, and the yellowness value of the fish fillets can be reduced, which has a good coloring effect; in addition, the heme iron content is maintained, the increase of metmyoglobin content and non-heme iron content is reduced, and the juice loss rate during refrigeration is reduced, thereby effectively maintaining the sensory characteristics and storage stability of the golden pomfret fillets.

[0057] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0058] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preserving and coloring golden pomfret chunks, characterized in that: The specific steps include: S1. Fish meat pre-processing: Open the back of the golden pomfret 1-2 cm from the tail, remove the skin, bones and internal organs; rinse, take the back muscles of the golden pomfret and divide them into several pieces; S2. Preparation of multifunctional soaking solution: deionized water is placed in a brown bottle, and a plasma radio frequency device is placed below the liquid surface of the deionized water for activation treatment for 1 to 5 minutes. After treatment, the device is refrigerated at 0 to 4°C for 30 to 60 minutes to prepare a multifunctional soaking solution; S3. Sample processing: immerse the golden pomfret pieces in a multifunctional soaking solution for 10 to 15 minutes, stirring the liquid surface every 3 to 5 minutes; after soaking, remove the golden pomfret pieces and drain the water; S4. Soaking fish pieces in phosphate water retaining agent: Place golden pomfret pieces in composite phosphate water retaining agent and perform ultrasonic treatment for 8-15 minutes; S5. Vacuum packaging: Drain the moisture from the fish pieces and vacuum pack the fish pieces without moisture on the surface.

2. The method for preserving and coloring golden pomfret chunks according to claim 1, characterized in that: In step S4, the composite phosphate water retaining agent accounts for 0.3-0.5% of the mass of the golden pomfret block; the composite phosphate water retaining agent includes sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate.

3. The method for preserving and coloring golden pomfret chunks according to claim 2, characterized in that: The weight ratio of the sodium tripolyphosphate, the sodium pyrophosphate and the sodium hexametaphosphate is 1-2:1-2:

1.

4. The method for preserving and coloring golden pomfret chunks according to claim 2, characterized in that: The weight ratio of the sodium tripolyphosphate, the sodium pyrophosphate and the sodium hexametaphosphate is 2:2:

1.

5. The method for preserving and coloring golden pomfret chunks according to claim 1, characterized in that: In step S2, the output power of the plasma jet device is 650-800 W, and the gas flow rate is 0.5-1 L / min.

6. The method for preserving and coloring golden pomfret chunks according to claim 5, characterized in that: The gas component of the plasma jet device is air.

7. The method for preserving and coloring golden pomfret chunks according to claim 1, characterized in that: In step S3, the mass volume ratio of the golden pomfret chunks to the multifunctional soaking liquid is 1 g: 2-4 mL.

8. The method for preserving and coloring golden pomfret chunks according to claim 1, characterized in that: The power of the ultrasonic treatment in step S4 is 150-300W.

9. The method for preserving and coloring golden pomfret chunks according to claim 1, characterized in that: The vacuum packaging method in step S5 is to put the golden pomfret pieces into a vacuum packaging bag and use a vacuum packaging machine to vacuum seal; the vacuum degree of the vacuum packaging machine is -0.1 MPa.

10. The method for preserving the freshness and color of golden pomfret chunks according to claim 1, characterized in that: In step S1, the golden pomfret is rinsed with sterile water.

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