A method for instant extraction of antarctic krill oil based on low temperature plasma technology

Abstract

The application belongs to the technical field of extraction of marine animal lipid components, and particularly relates to a method for instant extraction of Antarctic krill oil based on low-temperature plasma technology. The method implements efficient low-temperature krill oil extraction process on a fishing ship in situ, realizes instant processing of Antarctic krill and preparation of high-activity krill oil. The application improves the utilization efficiency of all components and promotes the development of the krill oil industry towards instant, high-activity and high-value.

Description

Technical Field

[0001] This invention belongs to the field of marine animal lipid extraction technology, specifically relating to a method for real-time extraction of Antarctic krill oil based on low-temperature plasma technology. Background Technology

[0002] Antarctic krill is one of the species with the largest biomass in the Antarctic Ocean, with a current resource estimated at 650 million to 1 billion tons, possessing extremely high development potential. Antarctic krill is rich in protein, lipids, and active ingredients. Antarctic krill oil, extracted from krill, is characterized by its main active components: ω-3 polyunsaturated fatty acids, phospholipids, and natural astaxanthin. Studies have shown that krill oil has a clear preventive effect on cardiovascular diseases, and its overall activity is significantly superior to fish oil, making it a more advantageous raw material for health foods.

[0003] Commercial extraction of Antarctic krill oil has formed a processing system mainly based on shipboard milling and shore-based processing. However, the core technology has inherent limitations, especially in the protection and preservation of heat-sensitive components such as astaxanthin and phospholipids, which urgently need breakthroughs. Currently, mainstream extraction processes can be divided into three categories: organic solvent extraction, which uses solvents such as ethanol and n-hexane to dissolve lipids for efficient extraction, but the solvent recovery and refining process requires repeated high-temperature heating, which not only poses a safety hazard of trace solvent residues in the oil or shrimp powder, but also leads to the oxidation and inactivation of astaxanthin, the destruction of some phospholipid structures, and the degradation of heat-sensitive active ingredients; boiling method, which uses 95℃ high-temperature cooking to destroy the krill cell structure and release oil, and then obtains the oil phase by three-phase centrifugation. Although this method avoids the use of organic solvents, high-temperature cooking is a "destructive source" for heat-sensitive components such as astaxanthin and unsaturated fatty acids; and enzymatic hydrolysis, which uses alkaline or neutral proteases to degrade the krill protein network under mild conditions, destroying the lipid-binding structure to achieve release. This method is relatively mild, but has the drawbacks of high enzyme preparation costs and the potential generation of bitter peptides during the enzymatic hydrolysis process, which affects the flavor of the oil.

[0004] The common bottleneck in existing Antarctic krill oil extraction processes lies in their reliance on the traditional "catch-shipboard milling-shore extraction and processing" model. After being caught, Antarctic krill must be dried at low temperatures or freeze-dried on board before being transported to land-based factories for processing. The interval between harvesting and processing can be several weeks to months. During this process, despite the low temperatures, the autolytic enzymes such as proteases and lipases within the krill still slowly degrade lipids and proteins, significantly reducing the freshness of the raw material and increasing initial oxidation levels. More importantly, all current mainstream processes involve unavoidable heat treatment: organic solvent methods require high-temperature evaporation to recover the solvent and refining / degumming / bleaching; boiling methods rely on 95°C high-temperature cooking; and enzymatic hydrolysis requires heating to inactivate enzymes. These heat treatment steps directly cause astaxanthin oxidation and inactivation, damage to phospholipid structures, and accelerated oil oxidation, severely restricting the improvement of Antarctic krill oil quality.

[0005] To address the challenges of transporting and preserving Antarctic krill, immediate in-situ processing after harvesting is crucial to minimizing the time between catch and processing. This maximizes the freshness and stability of active ingredients, fundamentally resolving issues such as lipid oxidation and quality deterioration caused by autolytic enzyme activity, prolonged transportation, and high-temperature processing. Therefore, a new method for the immediate extraction of Antarctic krill oil is urgently needed. Summary of the Invention

[0006] Given the shortcomings of existing technologies, such as difficulties in transporting and preserving Antarctic krill, reliance on shore-based processing, and a lack of onboard oil extraction technology, which leads to easy deterioration of active ingredients and limited quality of krill oil, the present invention aims to provide a novel method for on-site extraction of Antarctic krill oil. This method achieves on-site processing of Antarctic krill and high-activity preparation of krill oil by implementing an efficient, low-temperature krill oil extraction process in situ on fishing vessels, while maintaining high retention rates of active ingredients such as ω-3 polyunsaturated fatty acids and astaxanthin, and high-quality characteristics of the oil. This invention not only overcomes the technical limitations of traditional shore-based processing due to decreased raw material freshness and heat treatment leading to loss of active ingredients, but also significantly improves the overall utilization efficiency of Antarctic krill resources, promoting the development of the krill oil industry towards on-site, high-activity, and high-value production.

[0007] The technical solution of this invention is: a method for real-time extraction of Antarctic krill oil based on low-temperature plasma technology, comprising the following steps: Step 1: Low-temperature plasma targeted enzyme inactivation: After draining the caught Antarctic krill, add buffer solution to homogenize and obtain a homogenate. Use low-temperature plasma jet (FE-DBD) to rapidly inactivate enzymes in the homogenate to obtain a krill pretreated slurry. Step 2: Infrared-assisted exogenous immobilized enzymatic hydrolysis: After soaking and removing impurities from the inorganic carrier, it is dispersed in a buffer solution, and a mixed enzyme solution containing trypsin and papain is added. After stirring at room temperature, the immobilized enzyme is filtered and vacuum dried to obtain inorganic carrier immobilized enzyme; take the krill pretreatment slurry obtained in Step 1, add the prepared immobilized enzyme, and use infrared-assisted enzymatic hydrolysis to obtain krill enzymatic hydrolysate; Step 3: Extraction of krill oil: Take the krill enzymatic hydrolysate obtained in Step 2, add an organic solvent, mix and stir thoroughly, let stand for layering, take the solvent phase, evaporate the solvent to obtain crude krill oil. Step 4: Refining krill oil: The crude krill oil obtained in step 3 is dissolved in anhydrous ethanol, filtered through a hollow fiber ultrafiltration membrane, and the krill oil is obtained by desolvation.

[0008] Preferably, in the method, the pH of the buffer solution in step 1 is 6.0~7.0; more preferably, the buffer solution is a 0.05~0.1M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution or a Tris-HCl buffer solution.

[0009] Preferably, in the method, the weight ratio of Antarctic krill to the volume ratio of buffer solution in step 1 is 2~5:1, where the weight is in kg and the volume is in L.

[0010] Preferably, in the method, the enzyme inactivation time in step 1 is 2-5 min, the gas used is He + 0.5% O2, the power is 10-12 kV, the distance is 3-8 mm, and the temperature is maintained at 30-40℃; Preferably, in the method, the inorganic carrier in step 2 is mesoporous silica gel or titanium dioxide.

[0011] Preferably, in the summary of the method, the ratio of the weight of inorganic material to the protein content of the mixed enzyme in step 2 is 1:70~100, wherein the weight of inorganic material is in kg and the protein content is in g.

[0012] Preferably, in the method, the protein ratio of trypsin to papain in step 2 is 1:2~3.5.

[0013] In a preferred embodiment of the present invention, the trypsin activity is 9.0 × 10⁻⁶. 5 The enzyme activity of papain is 8.6 × 10 U / g. 5 U / g.

[0014] Preferably, in the method, in step 2, the infrared-assisted enzymatic hydrolysis time is 25~55 min, the infrared radiation physical field parameters are set to a long-wave infrared wavelength range of 3~9 μm, and the heating temperature is set to 40~55℃.

[0015] Preferably, in the method, in step 3, the organic solvent is one or more of anhydrous ethanol, isopropanol, acetone, ethyl acetate, isohexane, hexane, and petroleum ether.

[0016] More preferably, in the method, in step 3, the organic solvent is any two of ethanol, isopropanol, acetone or ethyl acetate.

[0017] Preferably, in the method, the ratio of krill enzymatic hydrolysate to organic solvent in step 3 is 1:1~5.

[0018] Preferably, in the method, in step 4, the hollow fiber ultrafiltration membrane is made of polyvinylidene fluoride with a pore size of 5000~10000 Daltons.

[0019] Preferably, in the method, in step 4, anhydrous ethanol is added to make the weight-to-volume ratio of crude krill oil to ethanol 1:2~3, wherein the weight of crude krill oil is in kg and the volume of anhydrous ethanol is in L.

[0020] Compared with the prior art, the present invention has the following outstanding advantages: 1. The preparation method of the present invention involves directly subjecting the fish to low-temperature plasma targeted enzyme inactivation treatment after capture, thus avoiding the degradation of enzyme activity during long-term storage and transportation; the oxidation degree of the treated product is significantly reduced, allowing it to directly enter the subsequent processing stage, or it can be refrigerated and then treated. 2. The preparation method of this invention uses immobilized enzymes, which improves enzyme utilization and allows the prepared immobilized enzymes to be recycled more than 15 times; infrared-assisted enzymatic hydrolysis, while enhancing aroma, significantly improves the retention rate of key active substances such as astaxanthin and phospholipid-type Omega-3 in the obtained product, thereby improving the nutritional value and functionality of the product; hollow fiber ultrafiltration membrane filtration can effectively remove bitter peptides, etc. 3. The product obtained by this invention has a bright color and excellent flavor: due to the low degree of oxidation and the complete preservation of astaxanthin, the product presents a brighter orange-red color and has no fishy or rancid taste. 4. The preparation method of the present invention has low energy consumption and is environmentally friendly. It enables on-the-spot processing on board, eliminating the need for large-scale transportation and additional energy consumption to bring raw materials back to shore, significantly reducing production costs and meeting the requirements of green and sustainable development. Detailed Implementation

[0021] The following specific embodiments further illustrate the present invention, but do not limit the scope of the present invention in any way. Those skilled in the art can make various modifications or improvements based on the basic idea of ​​the present invention, but as long as they do not depart from the basic idea of ​​the present invention, they are all within the scope of the present invention.

[0022] Example 1 Step 1: Low-temperature plasma targeted enzyme inactivation: After draining the caught Antarctic krill, weigh 10 kg of it as raw material to be treated, add 5 L of 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution with pH 6.0, homogenize to obtain a homogenate, and use low-temperature plasma jet (FE-DBD) to rapidly inactivate enzymes in the homogenate for 5 min, using He + 0.5% O2 gas, power of 10 kV, distance of 3 mm, and temperature maintained at 30~40℃ to obtain krill pretreated slurry; Step 2: Infrared-assisted exogenous immobilization and enzymatic hydrolysis: Take 1.0 kg of mesoporous silica gel, soak it in 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution for 15 min to remove surface impurities, filter, disperse in 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution, add a mixed enzyme solution containing 23.3 g of trypsin and 46.7 g of papain protein, the trypsin activity is 9.0 × 10⁻⁶. 5 The enzyme activity of papain is 8.6 × 10 U / g. 5U / g. After stirring at room temperature, the immobilized enzyme was filtered and vacuum dried to obtain mesoporous silica immobilized enzyme; take the krill pretreatment slurry obtained in step 1, add the prepared immobilized enzyme, and use infrared-assisted enzymatic hydrolysis. The infrared radiation time was 25 min, the infrared radiation physical field parameters were set to a long-wave infrared wavelength range of 9 μm, and the heating temperature was set to 40~55℃. After the enzymatic hydrolysis was completed, the mixture was filtered to obtain krill enzymatic hydrolysate. Step 3: Extraction of krill oil: Take the krill enzymatic hydrolysate obtained in Step 2, add 40L of anhydrous ethanol and acetone (volume ratio of 1:1), mix and stir thoroughly, let stand for separation, take the solvent phase, evaporate the solvent to obtain crude krill oil. Step 4: Refining of krill oil: Take 0.5 kg of crude krill oil obtained in Step 3, add 1 L of anhydrous ethanol to dissolve it, and then filter it through a hollow fiber ultrafiltration membrane with a pore size of 10,000 Daltons. After evaporation and desolventization of the ultrafiltrate, secondary desolventized krill oil is obtained. This step is repeated twice to obtain refined krill oil.

[0023] Example 2 Step 1: Low-temperature plasma targeted enzyme inactivation: After draining the caught Antarctic krill, weigh 10 kg of it as raw material to be treated, add 2 L of 0.1 M Tris-HCl buffer solution with pH 7.0, homogenize to obtain a homogenate, use FE-DBD to rapidly inactivate enzymes in the homogenate for 2 min, use He + 0.5% O2 gas, power of 10 kV, distance of 8 mm, and maintain the temperature at 30~40℃ to obtain krill pretreated slurry; Step 2: Infrared-assisted exogenous immobilized enzymatic hydrolysis: Take 1.0 kg of titanium dioxide, soak it in 0.1 M Tris-HCl buffer solution for 15 min to remove surface impurities, filter, disperse it in 0.1 M Tris-HCl buffer solution, and add a mixed enzyme solution containing 22.2 g of trypsin and 77.8 g of papain. The trypsin activity is 9.0 × 10⁻⁶. 5 The enzyme activity of papain is 8.6 × 10 U / g. 5 U / g. After stirring at room temperature for 30 min, the immobilized enzyme was obtained by filtration and vacuum drying for 1 h to obtain titanium dioxide immobilized enzyme; take the krill pretreatment slurry obtained in step 1, add the prepared immobilized enzyme, and use infrared-assisted enzymatic hydrolysis. The infrared radiation time was 55 min, the infrared radiation physical field parameters were set to a long-wave infrared wavelength range of 3 μm, and the heating temperature was set to 40~55℃. After the enzymatic hydrolysis was completed, the mixture was filtered to obtain krill enzymatic hydrolysate. Step 3: Extraction of krill oil: Take the krill enzymatic hydrolysate obtained in Step 2, add 40L of isopropanol and ethyl acetate (volume ratio of 1:1), mix and stir thoroughly, let stand for separation, take the solvent phase, evaporate the solvent to obtain crude krill oil. Step 4: Refining of krill oil: Take 0.5 kg of crude krill oil obtained in Step 3, add 1.5 L of anhydrous ethanol, and filter through a hollow fiber ultrafiltration membrane with a pore size of 5000 Daltons. After evaporation and desolventization of the ultrafiltrate, obtain secondary desolventized krill oil. Repeat this step twice more to obtain refined krill oil.

[0024] Comparative Example 1 Step 1: Pretreatment: After draining the caught Antarctic krill, weigh 10 kg of it as raw material to be treated, add 5 L of 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution at pH 6.0, and homogenize to obtain a homogenate. Step 2: Infrared-assisted exogenous immobilization and enzymatic hydrolysis: Take 1.0 kg of mesoporous silica gel, soak it in 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution for 15 min to remove surface impurities, filter, disperse in 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution, add a mixed enzyme solution containing 23.3 g of trypsin and 46.7 g of papain protein, the trypsin activity is 9.0 × 10⁻⁶. 5 The enzyme activity of papain is 8.6 × 10 U / g. 5 U / g. After stirring at room temperature, the immobilized enzyme was filtered and vacuum dried to obtain mesoporous silica gel immobilized enzyme; the homogenate obtained in step 1 was taken, and the prepared immobilized enzyme was added. Infrared-assisted enzymatic hydrolysis was performed. The infrared radiation time was 25 min, the infrared radiation physical field parameters were set to a long-wave infrared wavelength range of 9 μm, and the heating temperature was set to 40~55℃. After the enzymatic hydrolysis was completed, the mixture was filtered to obtain krill enzymatic hydrolysate. Step 3: Extraction of krill oil: Take the krill enzymatic hydrolysate obtained in Step 2, add 40L of anhydrous ethanol and acetone (volume ratio of 1:1), mix and stir thoroughly, let stand for separation, take the solvent phase, evaporate the solvent to obtain crude krill oil. Step 4: Refining of krill oil: Take 0.5 kg of crude krill oil obtained in Step 3, add 1 L of anhydrous ethanol, and filter through a hollow fiber ultrafiltration membrane with a pore size of 10,000 Daltons. After evaporation and desolventization of the ultrafiltrate, obtain secondary desolventized krill oil. Repeat this step twice more to obtain refined krill oil.

[0025] Comparative Example 2 Step 1: Low-temperature plasma targeted enzyme inactivation: After draining the caught Antarctic krill, weigh 10 kg of it as raw material to be treated, add 5 L of 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution with pH 6.0, homogenize to obtain a homogenate, use FE-DBD to rapidly inactivate enzymes in the homogenate, the inactivation time is 5 min, the gas is He + 0.5% O2, the power is 10 kV, the distance is 3 mm, and the temperature is maintained at 30~40℃ to obtain krill pretreated slurry; Step 2: Exogenous Immobilization and Enzymatic Digestion: Take 1.0 kg of mesoporous silica gel, soak it in 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution for 15 min to remove surface impurities, filter, disperse in 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution, add a mixed enzyme solution containing 23.3 g of trypsin and 46.7 g of papain protein, the trypsin activity is 9.0 × 10⁻⁶. 5 The enzyme activity of papain is 8.6 × 10 U / g. 5 U / g. After stirring at room temperature, the immobilized enzyme was filtered and vacuum dried to obtain mesoporous silica gel immobilized enzyme; the krill pretreatment slurry obtained in step 1 was taken, and the prepared immobilized enzyme was added. After enzymatic hydrolysis for 25 min, the mixture was filtered to obtain krill enzymatic hydrolysate; Step 3: Extraction of krill oil: Take the krill enzymatic hydrolysate obtained in Step 2, add 40L of anhydrous ethanol and acetone (volume ratio of 1:1), mix and stir thoroughly, let stand for separation, take the solvent phase, evaporate the solvent to obtain crude krill oil. Step 4: Refining of krill oil: Take 0.5 kg of crude krill oil obtained in Step 3, add 1 L of anhydrous ethanol, and filter through a hollow fiber ultrafiltration membrane with a pore size of 10,000 Daltons. After evaporation and desolventization of the ultrafiltrate, obtain secondary desolventized krill oil. Repeat this step twice more to obtain refined krill oil.

[0026] Comparative Example 3 Step 1: Low-temperature plasma targeted enzyme inactivation: After draining the caught Antarctic krill, weigh 10 kg of it as raw material to be treated, add 5 L of 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution with pH 6.0, homogenize to obtain a homogenate, use FE-DBD to rapidly inactivate enzymes in the homogenate, the inactivation time is 5 min, the gas is He + 0.5% O2, the power is 10 kV, the distance is 3 mm, and the temperature is maintained at 30~40℃ to obtain krill pretreated slurry; Step 2: Infrared-assisted exogenous immobilization and enzymatic hydrolysis: Take 1.0 kg of mesoporous silica gel, soak it in 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution for 15 min to remove surface impurities, filter, disperse in 0.05 M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution, add a mixed enzyme solution containing 23.3 g of trypsin and 46.7 g of papain protein, the trypsin activity is 9.0 × 10⁻⁶. 5 The enzyme activity of papain is 8.6 × 10 U / g. 5U / g. After stirring at room temperature, the immobilized enzyme was filtered and vacuum dried to obtain mesoporous silica immobilized enzyme; take the krill pretreatment slurry obtained in step 1, add the prepared immobilized enzyme, and use infrared-assisted enzymatic hydrolysis. The infrared radiation time was 25 min, the infrared radiation physical field parameters were set to a long-wave infrared wavelength range of 9 μm, and the heating temperature was set to 40~55℃. After the enzymatic hydrolysis was completed, the mixture was filtered to obtain krill enzymatic hydrolysate. Step 3: Extraction of krill oil: Take the krill enzymatic hydrolysate obtained in Step 2, add 40L of anhydrous ethanol and acetone (volume ratio of 1:1), mix and stir thoroughly, let stand for separation, take the solvent phase, evaporate the solvent to obtain crude krill oil. Step 4: Refining of krill oil: Take 0.5 kg of crude krill oil obtained in step 3, add 1 L of anhydrous ethanol to dissolve it, filter it three times with 60-mesh silk cloth, and then desolvent to obtain krill oil.

[0027] Verification Implementation Examples Performance testing of krill oil The krill oil obtained from the examples and comparative examples was tested according to the following methods, and the results are shown in Table 1.

[0028] (1) Aroma evaluation: Ten people who are sensitive to the flavor of krill oil were randomly selected. A 10 mL oil sample was taken and the oil was stirred and smelled. The overall flavor of the oil sample was evaluated. The flavor sensory score was: 1-weak; 2-obvious; 3-medium; 4-strong; 5-strong. The evaluation result was the average score of the 10 volunteers.

[0029] (2) Determination of each component: The content of EPA and DHA in shrimp oil was determined according to GB 5009.168-2016 Determination of total fat, saturated fat (acid) and unsaturated fat (acid) in food. The hydrolysis extraction-gas chromatography method was used to determine the content of EPA and DHA in shrimp oil.

[0030] (3) The method for determining oxidative stability is as follows: The Schaal oven accelerated method was used. Under light-protected conditions, an iodine flask containing 100g of Antarctic krill oil was placed in a constant temperature drying oven at (62±1)℃. Samples were taken every 2 days to determine the peroxide value (POV) to evaluate the oxidative stability of Antarctic krill oil. The determination of POV value was carried out in accordance with the national standard GB / T5009.227.

[0031] (4) The extraction rate is determined by the percentage of the extracted oil by mass of Antarctic krill.

[0032] The results are shown in the table below. The extraction rate is expressed as %, POV is expressed as g / 100g, phospholipids, DHA, and EPA are expressed as g / 100g shrimp oil, and total astaxanthin is expressed as mg / kg.

[0033] Table 1 Evaluation Results of Antarctic Krill Oil Indicators Experimental results show that the present invention, through direct immediate processing of the raw materials after harvesting and the use of infrared-assisted enzymatic hydrolysis combined with hollow fiber ultrafiltration membrane filtration, effectively avoids the problems of enzyme activity degradation and lipid oxidation and quality deterioration caused by traditional long-term storage and transportation. The resulting krill oil exhibits significantly reduced oxidation and improved stability, with a marked increase in key functional components compared to the comparative example. Comparative Example 1, lacking enzyme inactivation treatment, resulted in poor oxidative stability due to residual enzyme activity and a high POV value. Comparative Example 2, without infrared-assisted enzymatic hydrolysis, produced an off-odor. Comparative Example 3, using silk cloth filtration instead of hollow fiber ultrafiltration membrane filtration, resulted in a yellowish final product with trace precipitation and a bitter taste.

Claims

1. A method for real-time extraction of Antarctic krill oil based on low-temperature plasma technology, characterized in that, The method includes the following steps: Step 1: Low-temperature plasma targeted enzyme inactivation: After draining the caught Antarctic krill, add buffer solution to homogenize and obtain a homogenate. Use low-temperature plasma jet to rapidly inactivate enzymes in the homogenate to obtain krill pretreated slurry. Step 2: Infrared-assisted exogenous immobilized enzymatic hydrolysis: After soaking and removing impurities from the inorganic carrier, it is dispersed in a buffer solution, and a mixed enzyme solution containing trypsin and papain is added. After stirring at room temperature, the immobilized enzyme is filtered and vacuum dried to obtain inorganic carrier immobilized enzyme; take the krill pretreatment slurry obtained in Step 1, add the prepared immobilized enzyme, and use infrared-assisted enzymatic hydrolysis to obtain krill enzymatic hydrolysate; Step 3: Extraction of krill oil: Take the krill enzymatic hydrolysate obtained in Step 2, add an organic solvent, mix and stir thoroughly, let stand for layering, take the solvent phase, evaporate the solvent to obtain crude krill oil. Step 4: Refining of krill oil: The crude krill oil obtained in step 3 is dissolved in anhydrous ethanol, filtered through a hollow fiber ultrafiltration membrane, and the filtrate is desolventized to obtain krill oil. In the method described above, in step 1, the weight ratio of Antarctic krill to the volume ratio of the buffer solution is 2-5:1, where the weight is expressed in kg and the volume in L. In step 1, the buffer solution is a 0.05-0.1M potassium dihydrogen phosphate / disodium hydrogen phosphate buffer solution or a Tris-HCl buffer solution. In step 1, the enzyme inactivation time is 2-5 min, the gas used is He + 0.5% O2, the power is 10-12 kV, the distance is 3-8 mm, and the temperature is maintained at 30-40℃. In step 2, the inorganic carrier is mesoporous silica gel or titanium dioxide. In step 2, the infrared-assisted enzymatic hydrolysis time is 25-55 min, the infrared radiation physical field parameters are set to a long-wave infrared wavelength range of 3-9 μm, and the heating temperature is set to 40-55℃.

2. The method as described in claim 1, characterized in that, In the method, the ratio of the weight of the inorganic material to the protein content of the mixed enzyme in step 2 is 1:70~100, wherein the weight of the inorganic material is in kg and the protein content is in g.

3. The method as described in claim 1, characterized in that, In the method, the protein ratio of trypsin to papain in step 2 is 1:2~3.

5.

4. The method as described in claim 1, characterized in that, In the method, in step 3, the organic solvent is one or more of anhydrous ethanol, isopropanol, acetone, ethyl acetate, isohexane, hexane, and petroleum ether.

5. The method as described in claim 1, characterized in that, In the method, the ratio of krill enzymatic hydrolysate to organic solvent in step 3 is 1:1~5.

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