Sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent

Abstract

The application discloses a sodium alginate-oligopeptide composite non-phosphorus squid water-retaining agent and belongs to the technical field of aquatic product processing. The water-retaining agent is composed of the following components in mass percentage: 0.3%-0.8% of sodium alginate, 0.5%-1.2% of oligopeptide, 0.2%-0.6% of sodium citrate, 1.0%-2.0% of sorbitol, 2.0%-3.0% of sodium chloride, and the rest is deionized water. The application adopts a non-phosphorus formula, avoids the safety hazard of phosphate, effectively inhibits the frozen denaturation of squid myofibrillar protein through the synergistic effect of sodium alginate and oligopeptide, reduces the thawing liquid loss, simultaneously improves the elasticity and tenderness of squid meat, and prolongs the shelf life. The preparation process is simple, the cost is low, the application is convenient, the water-retaining agent is suitable for frozen squids and various squid processing products, and has a good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of aquatic product processing technology, specifically to a sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent. Background Technology

[0002] Squid is highly nutritious and abundant, and freezing is its primary preservation method. However, long-term freezing can lead to problems such as thawing dehydration and meat quality deterioration, affecting product quality. Currently, commonly used industrial phosphorus-containing water-retaining agents, while offering good water retention, pose food safety risks and are inconsistent with green processing trends. Existing phosphorus-free water-retaining agents are mostly used in poultry, with few specifically designed for squid. Furthermore, single-component phosphorus-free water-retaining agents have limited water retention effects, failing to meet the demands of squid freezing processing. Sodium alginate, a natural anionic polysaccharide, possesses excellent water absorption, water retention, and film-forming properties, forming a dense gel network to bind water molecules while protecting myofibril proteins. Oligopeptides, with their small molecular weight and high water solubility, can inhibit protein freezing denaturation and improve meat tenderness. However, when used alone, both have insufficient water retention and antifreeze effects, failing to adequately address the water loss problem during squid freezing. Therefore, developing a well-formulated, highly effective, safe, and environmentally friendly compound phosphorus-free squid water-retaining agent has significant practical implications and industrial application value. Summary of the Invention

[0003] In view of the problems existing in the above and / or existing sodium alginate-oligopeptide composite phosphate-free squid water-retaining agents, the present invention is proposed.

[0004] Therefore, the purpose of this invention is to provide a sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent, which achieves synergistic effect through component compounding. It can effectively reduce water loss during squid freezing and thawing, improve meat quality, avoid the harm of phosphate, and has a simple preparation process and low cost, making it suitable for industrial production.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent, which is composed of the following components by mass percentage: sodium alginate 0.3%-0.8%, oligopeptides 0.5%-1.2%, sodium citrate 0.2%-0.6%, sorbitol 1.0%-2.0%, sodium chloride 2.0%-3.0%, and the balance being deionized water.

[0007] As a preferred embodiment of the sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent of the present invention, the oligopeptide is one or a combination of two of fish skin oligopeptides and soybean oligopeptides, with a molecular weight of 1000-3000 Da.

[0008] As a preferred embodiment of the sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent of the present invention, the sodium alginate is food grade, with a viscosity of 100-300 mPa·s, and is prepared by extraction from brown algae.

[0009] As a preferred embodiment of the sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent of the present invention, the optimal component ratio by mass percentage is: sodium alginate 0.5%, oligopeptide 0.8%, sodium citrate 0.4%, sorbitol 1.5%, sodium chloride 2.5%, and the balance being deionized water.

[0010] A method for preparing a sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent includes the following steps:

[0011] S1: Weigh each component according to the proportion;

[0012] S2: Place deionized water in an environment of 4-8℃, add sodium chloride and sodium citrate, and stir until completely dissolved;

[0013] S3: Add sodium alginate, oligopeptide and sorbitol in sequence, stirring for 10-15 minutes after each addition until a uniform and transparent solution is formed;

[0014] S4: Let the solution stand for 20-30 minutes to defoam, and the composite phosphorus-free squid water-retaining agent is obtained.

[0015] A preferred embodiment of the preparation method of a sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent is provided, wherein the stirring speed in step S3 is 150-200 r / min, and the solution temperature is kept stable at 4-8℃ during the stirring process.

[0016] An application of a sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent is disclosed. The agent is used for squid preservation and processing. The specific method is as follows: the pretreated squid is placed in the water-retaining agent, the mass ratio of squid to water-retaining agent is 1:3-5, and soaked at 4-8℃ for 2-4 hours. After draining, the squid is frozen for preservation.

[0017] As a preferred embodiment of the application of the sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent described in this invention, the squid pretreatment steps are as follows: thaw the frozen squid, gut and remove the head, skin, internal organs and spine, clean it, take the back muscle and cut it into 20-30g pieces, drain the surface water and set aside.

[0018] As a preferred embodiment of the application of the sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent described in this invention, the mixture is stirred once every 30 minutes during the soaking process, with a stirring speed of 50-80 r / min and the stirring direction remaining consistent.

[0019] As a preferred embodiment of the application of the sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent described in this invention, the freezing and storage conditions are -18~-20℃, and the storage period can reach 6-8 months.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. This invention uses a phosphate-free formula that contains no phosphate components, thereby effectively avoiding food safety hazards caused by excessive use of phosphates. It conforms to the trend of green and healthy food processing and is suitable for various squid processed products.

[0022] 2. To achieve synergistic effects of components, the combination of the gel-forming properties of sodium alginate and the protein protection effect of oligopeptides can effectively inhibit the freeze denaturation of squid myofibrillar proteins, reduce freeze-drying loss and thawing juice loss.

[0023] 3. The addition of sodium citrate and sorbitol to the formula not only helps to improve water retention, but also improves the elasticity and tenderness of squid meat, inhibits fat oxidation, and extends the frozen storage period of squid to 6-8 months, effectively improving product quality and commercial value.

[0024] 4. The preparation process is simple, requires no complex equipment, is easy to operate, and all components are food-grade raw materials with wide availability and low cost, making it easy to achieve large-scale industrial production and with broad application prospects. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific embodiments, but these descriptions do not limit the scope of protection of the present invention.

[0026] Example 1

[0027] A sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent, comprising the following components by mass percentage: sodium alginate 0.3%, fish skin oligopeptides 0.5%, sodium citrate 0.2%, sorbitol 1.0%, sodium chloride 2.0%, with the remainder being deionized water.

[0028] Preparation method:

[0029] 1. Weigh out 0.3 kg of sodium alginate, 0.5 kg of fish skin oligopeptides, 0.2 kg of sodium citrate, 1.0 kg of sorbitol, 2.0 kg of sodium chloride, and 96.0 kg of deionized water according to the above proportions;

[0030] 2. Place deionized water in an environment of 4℃ and use a constant temperature water bath to control the temperature, ensuring that the temperature fluctuation of the solution does not exceed ±0.5℃. Add sodium chloride and sodium citrate, and stir at 150r / min for 10min until the two are completely dissolved.

[0031] 3. Add sodium alginate, fish skin oligopeptide and sorbitol in sequence. After each component is added, continue stirring at 150 r / min for 10 min. During the stirring process, maintain a constant temperature water bath at 4℃. After stirring, use a laser particle size analyzer to check the uniformity of the solution to ensure that the particle size is ≤50μm and a uniform and transparent solution is formed.

[0032] 4. Place the above solution in a vacuum degassing machine and let it stand for 20 minutes under a vacuum of 0.08-0.10 MPa to remove air bubbles from the solution. After degassing, use a viscometer to test the viscosity of the solution to ensure that the viscosity is within the range of 150-250 mPa·s. The water-retaining agent is obtained after degassing.

[0033] Application method:

[0034] 1. Squid pretreatment: Place frozen squid in a refrigerated environment at 0-4℃ and thaw slowly for 8-10 hours until the core temperature of the squid reaches 0-2℃. After gutting, remove the head, skin, internal organs and backbone. Wash repeatedly with clean water 3-4 times to remove surface impurities and dirt. Take the squid back muscle and cut it into 20-30g pieces with a thickness of 1-1.5cm. Use filter paper to absorb the surface moisture.

[0035] 2. Mix the pretreated squid with the above water-retaining agent at a mass ratio of 1:3, place it in a 4℃ environment and use a constant temperature water bath to control the temperature, soak for 2 hours, and stir once every 30 minutes at a speed of 50r / min, keeping the stirring direction consistent, and stirring for 30 seconds each time;

[0036] 3. After soaking, drain the surface moisture of the squid with filter paper, vacuum pack it, and then freeze it at -18℃. The freezing rate should be controlled at 5-8℃ / h until the core temperature of the squid reaches below -18℃.

[0037] Tests showed that the squid treated in this embodiment had a soaking weight gain of 15.2%, a thawing loss of 8.3%, and after being stored for 6 months, the meat still maintained good elasticity and tenderness, with no obvious off-odor.

[0038] Example 2

[0039] A sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent, comprising the following components by mass percentage: sodium alginate 0.8%, soybean oligopeptides 1.2%, sodium citrate 0.6%, sorbitol 2.0%, sodium chloride 3.0%, with the remainder being deionized water.

[0040] Preparation method:

[0041] 1. Weigh out 0.8 kg of sodium alginate, 1.2 kg of soybean oligopeptides, 0.6 kg of sodium citrate, 2.0 kg of sorbitol, 3.0 kg of sodium chloride, and 92.4 kg of deionized water according to the above proportions;

[0042] 2. Place deionized water in an 8°C environment and use a constant temperature water bath to control the temperature, ensuring that the solution temperature fluctuation does not exceed ±0.5°C. Add sodium chloride and sodium citrate, and stir at 200 r / min for 15 min until both are completely dissolved.

[0043] 3. Add sodium alginate, soybean oligopeptides and sorbitol in sequence. After each component is added, continue stirring at 200 r / min for 15 min. During the stirring process, maintain a constant temperature water bath at 8℃. After stirring, use a laser particle size analyzer to check the uniformity of the solution to ensure that the particle size uniformity is ≤50μm and a uniform and transparent solution is formed.

[0044] 4. Place the above solution in a vacuum degassing machine and let it stand for 30 minutes under a vacuum of 0.08-0.10 MPa to remove air bubbles from the solution. After degassing, use a viscometer to test the viscosity of the solution to ensure that the viscosity is within the range of 150-250 mPa·s. The water-retaining agent is obtained after degassing.

[0045] Application method:

[0046] 1. Squid pretreatment: Place frozen squid in a refrigerated environment at 0-4℃ and thaw slowly for 8-10 hours until the core temperature of the squid reaches 0-2℃. After gutting, remove the head, skin, internal organs and backbone. Wash repeatedly with clean water 3-4 times to remove surface impurities and dirt. Take the squid back muscle and cut it into 20-30g pieces with a thickness of 1-1.5cm. Use filter paper to absorb the surface moisture.

[0047] 2. Mix the pretreated squid with the above water-retaining agent at a mass ratio of 1:5, place it in an 8℃ environment and use a constant temperature water bath to control the temperature, soak for 4 hours, and stir once every 30 minutes at a speed of 80r / min, keeping the stirring direction consistent, and stirring for 30 seconds each time;

[0048] 3. After soaking, drain the surface moisture of the squid with filter paper, vacuum pack it, and then freeze it at -20℃. The freezing rate should be controlled at 5-8℃ / h until the core temperature of the squid reaches below -18℃.

[0049] According to the test results, the squid treated in this example had a soaking weight gain rate of 18.7%, a thawing loss rate of 7.8%, and after being stored for 8 months, the meat had good elasticity and no obvious nutrient loss or off-flavor.

[0050] Example 3

[0051] A sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent, comprising the following components by mass percentage: sodium alginate 0.5%, fish skin oligopeptides 0.8%, sodium citrate 0.4%, sorbitol 1.5%, sodium chloride 2.5%, with the remainder being deionized water.

[0052] Preparation method:

[0053] 1. Weigh out 0.5 kg of sodium alginate, 0.8 kg of fish skin oligopeptides, 0.4 kg of sodium citrate, 1.5 kg of sorbitol, 2.5 kg of sodium chloride, and 94.3 kg of deionized water according to the above proportions;

[0054] 2. Place deionized water in a 6℃ environment and use a constant temperature water bath to control the temperature, ensuring that the solution temperature fluctuation does not exceed ±0.5℃. Add sodium chloride and sodium citrate, and stir at 180r / min for 12min until both are completely dissolved.

[0055] 3. Add sodium alginate, fish skin oligopeptide and sorbitol in sequence. After each component is added, continue stirring at 180 r / min for 12 min. During the stirring process, maintain a constant temperature water bath at 6℃. After stirring, use a laser particle size analyzer to check the uniformity of the solution to ensure that the particle size is ≤50μm and a uniform and transparent solution is formed.

[0056] 4. Place the above solution in a vacuum degassing machine and let it stand for 25 minutes under a vacuum of 0.08-0.10 MPa to remove air bubbles from the solution. After degassing, use a viscometer to test the viscosity of the solution to ensure that the viscosity is within the range of 150-250 mPa·s. The water-retaining agent is obtained after degassing.

[0057] Application method:

[0058] 1. Squid pretreatment: Place frozen squid in a refrigerated environment at 0-4℃ and thaw slowly for 8-10 hours until the core temperature of the squid reaches 0-2℃. After gutting, remove the head, skin, internal organs and backbone. Wash repeatedly with clean water 3-4 times to remove surface impurities and dirt. Take the squid back muscle and cut it into 20-30g pieces with a thickness of 1-1.5cm. Use filter paper to absorb the surface moisture.

[0059] 2. Mix the pretreated squid with the above water-retaining agent at a mass ratio of 1:4, place it in a 6℃ environment and use a constant temperature water bath to control the temperature, soak for 3 hours, and stir once every 30 minutes at a speed of 60r / min, keeping the stirring direction consistent, and stirring for 30 seconds each time;

[0060] 3. After soaking, drain the surface moisture of the squid with filter paper, vacuum pack it, and then freeze it at -19℃. The freezing rate should be controlled at 5-8℃ / h until the core temperature of the squid reaches below -18℃.

[0061] Tests showed that the squid treated in this embodiment had a soaking weight gain of 20.3%, a thawing loss of 6.5%, and after 7 months of storage, the meat was tender, elastic, and retained its nutrients completely, exhibiting the best overall quality.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent, characterized in that, By mass percentage, it consists of the following components: sodium alginate 0.3%-0.8%, oligopeptides 0.5%-1.2%, sodium citrate 0.2%-0.6%, sorbitol 1.0%-2.0%, sodium chloride 2.0%-3.0%, with the balance being deionized water.

2. The sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent according to claim 1, characterized in that, The oligopeptide is one or a combination of two of fish skin oligopeptides and soybean oligopeptides, with a molecular weight of 1000-3000 Da.

3. The sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent according to claim 2, characterized in that, The sodium alginate is food grade, with a viscosity of 100-300 mPa·s, and is prepared by extraction from brown algae.

4. The sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent according to claim 3, characterized in that, The optimal composition by mass percentage is: sodium alginate 0.5%, oligopeptides 0.8%, sodium citrate 0.4%, sorbitol 1.5%, sodium chloride 2.5%, with the remainder being deionized water.

5. A method for preparing a sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent as described in any one of claims 1-4, characterized in that, Includes the following steps: S1: Weigh each component according to the proportion; S2: Place deionized water in an environment of 4-8℃, add sodium chloride and sodium citrate, and stir until completely dissolved; S3: Add sodium alginate, oligopeptide and sorbitol in sequence, stirring for 10-15 minutes after each addition until a uniform and transparent solution is formed; S4: Let the solution stand for 20-30 minutes to defoam, and the composite phosphorus-free squid water-retaining agent is obtained.

6. The preparation method of the sodium alginate-oligopeptide composite phosphorus-free squid water-retaining agent according to claim 5, characterized in that, In step S3, the stirring speed is 150-200 r / min, and the solution temperature is kept stable at 4-8℃ during the stirring process.

7. The application of a sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent as described in any one of claims 1-4, characterized in that, The method for preserving squid is as follows: the pretreated squid is placed in the water-retaining agent with a mass ratio of squid to water-retaining agent of 1:3-5, soaked at 4-8℃ for 2-4 hours, drained and then frozen for preservation.

8. The application of the sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent according to claim 7, characterized in that, The pretreatment steps for squid are as follows: thaw frozen squid, gut and remove head, skin, internal organs and spine, clean thoroughly, take back muscle and cut into 20-30g pieces, drain surface water and set aside.

9. The application of the sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent according to claim 7, characterized in that, Stir every 30 minutes during the soaking process, at a speed of 50-80 r / min, and keep the stirring direction consistent.

10. The application of the sodium alginate-oligopeptide composite phosphate-free squid water-retaining agent according to claim 7, characterized in that, The freezing and storage conditions are -18 to -20°C, and the storage period can reach 6-8 months.