Application of hydrolyzed krill oil extract in brain strengthening

Abstract

The invention discloses application of a hydrolyzed krill oil extract in the aspect of brain strengthening, and particularly relates to the technical field of health care products. The hydrolyzed krill oil extract with high content of LPC and sn-1-LPC-DHA is prepared by the preparation method disclosed by the invention, sn-1-LPC-DHA and EPA take effect synergistically in a certain proportion, the cognitive function of a mouse is improved, the memory and attention of the mouse are further improved, the intelligence of the mouse is enhanced, the brain development of the mouse is promoted, and the brain strengthening effect is achieved.

Description

[0001] This application claims the priority of Chinese Application No. 2024110629564, titled "A Krill Oil Extract and Its Preparation Method and Application", filed on August 5, 2024, the content of which is incorporated herein by reference in its entirety. Technical Field

[0002] The present invention relates to the technical field of health products, and specifically relates to the use of a hydrolyzed krill oil extract in enhancing brain function. Background Art

[0003] Docosahexaenoic acid (DHA) is an essential fatty acid crucial to the human body and plays a vital role in maintaining the normal functions of the brain, retina, heart, liver, and other important tissues. DHA is an important component of brain cell membranes and can promote the growth and development of nerve cells; it is rich in the retina, and appropriate intake of DHA helps protect eyesight and prevent eye diseases. In addition, DHA also has the effects of reducing blood viscosity and inhibiting platelet aggregation, which is also beneficial for reducing the risk of cardiovascular and cerebrovascular diseases; DHA also has certain anti-inflammatory and immunomodulatory effects, which helps maintain the normal function of the human immune system.

[0004] Eicosapentaenoic acid (EPA) is a type of Omega-3 fatty acid and an essential nutrient for the human body. EPA helps reduce the levels of cholesterol and triglycerides, promotes the metabolism of saturated fatty acids in the body, thereby reducing blood viscosity, enhancing blood circulation, and improving tissue oxygen supply to eliminate fatigue. And it can prevent the deposition of fat on the blood vessel wall, prevent the formation and development of atherosclerosis, and prevent cardiovascular diseases such as cerebral thrombosis, cerebral hemorrhage, and hypertension.

[0005] Krill oil is rich in natural EPA and DHA, and its unique molecular structure and lipid composition show potential advantages compared with fish oil and algal extracts. Research has found that EPA and DHA in krill oil exist in the form of phospholipids, and this natural binding form is highly similar to the phospholipid bilayer structure of human cell membranes, making it have higher bioavailability, capable of more efficiently crossing the blood-brain barrier and precisely delivering nutrients to brain nerve cells, providing strong support for improving brain function. Summary of the Invention

[0006] The purpose of the present invention is to provide the use of a hydrolyzed krill oil extract containing sn-1-LPC-DHA and EPA that can enter the brain in enhancing brain function.

[0007] In the first aspect, the present invention provides the use of a hydrolyzed krill oil extract in the preparation of foods, health products, and dietary supplements for enhancing brain function.

[0008] In some embodiments, the hydrolyzed krill oil extract is used to improve memory and concentration, enhance cognitive ability, and boost intelligence.

[0009] In some embodiments, the content of LPC in the hydrolyzed krill oil extract is ≥ 10%.

[0010] In some embodiments, the content of LPC in the hydrolyzed krill oil extract is ≥ 20%.

[0011] In some embodiments, the content of LPC in the hydrolyzed krill oil extract is 20 - 90%.

[0012] In some embodiments, the content of LPC in the hydrolyzed krill oil extract is 20 - 70%.

[0013] In some embodiments, the content of LPC in the hydrolyzed krill oil extract is 30 - 50%.

[0014] In some embodiments, the content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is ≤ 90%.

[0015] In some embodiments, the content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is ≤ 70%.

[0016] In some embodiments, the content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is 0 - 50%.

[0017] In some embodiments, the content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is 0 - 30%.

[0018] In some embodiments, the content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is 0 - 20%.

[0019] In some embodiments, the content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is 0 - 15%.

[0020] In some embodiments, the content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is ≤ 90%.

[0021] In some embodiments, the content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is ≤ 70%.

[0022] In some embodiments, the content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is 0 - 50%.

[0023] In some embodiments, the content of sn-2-LPC-DHA in the hydrolyzed krill oil extract is 0 - 30%.

[0024] In some embodiments, the content of sn-2-LPC-DHA in the hydrolyzed krill oil extract is 0-20%.

[0025] In some embodiments, the content of sn-2-LPC-DHA in the hydrolyzed krill oil extract is 0-15%.

[0026] In some embodiments, in the hydrolyzed krill oil extract, the content of sn-1-LPC-DHA in LPC-DHA is ≥50%.

[0027] In some embodiments, in the hydrolyzed krill oil extract, the content of sn-1-LPC-DHA in LPC-DHA is ≥70%, further ≥80%, ≥90%, ≥95%, ≥99%.

[0028] In some embodiments, in the hydrolyzed krill oil extract, the content of sn-2-LPC-DHA in LPC-DHA is ≤50%.

[0029] In some embodiments, in the hydrolyzed krill oil extract, the content of sn-2-LPC-DHA in LPC-DHA is ≥30%, further ≤20%, ≤10%, ≤5%, ≤1%.

[0030] In some embodiments, in the hydrolyzed krill oil extract, the total content of EPA and DHA is ≥10%.

[0031] In some embodiments, in the hydrolyzed krill oil extract, the total content of EPA and DHA is 10%-90%.

[0032] In some embodiments, in the hydrolyzed krill oil extract, the total content of EPA and DHA is 20%-70%.

[0033] In some embodiments, in the hydrolyzed krill oil extract, the total content of EPA and DHA is 20%-50%.

[0034] In some embodiments, in the hydrolyzed krill oil extract, the total content of EPA and DHA is 30-40%.

[0035] In some embodiments, in the hydrolyzed krill oil extract, the mass ratio of EPA to DHA is greater than 2:1.

[0036] In some embodiments, in the hydrolyzed krill oil extract, the mass ratio of EPA to DHA is 2-100:1.

[0037] In some embodiments, in the hydrolyzed krill oil extract, the mass ratio of EPA to DHA is 2-50:1.

[0038] In some embodiments, in the hydrolyzed krill oil extract, the mass ratio of EPA to DHA is 2-30:1.

[0039] In some embodiments, in the hydrolyzed krill oil extract, the mass ratio of EPA to DHA is 2-10:1, specifically 2-9:1, 2-8:1, 2-8:1, 2-7:1, 2-6:1, 2-5:1, 2-4:1, 2-3:1.

[0040] In some embodiments, the natural sources of the above LPC, DHA, LPC-DHA, sn-1-LPC-DHA, sn-2-LPC-DHA, and EPA include but are not limited to one or a combination of several of fish oil, krill oil, eggs, soybeans, and marine microalgae.

[0041] In some embodiments, the present invention also provides a method for preparing a hydrolyzed krill oil extract, comprising the following steps:

[0042] 1) Enzymatic hydrolysis: Mix krill oil and water, add lipase and stir. After stirring, raise the temperature to inactivate the enzyme to obtain a mixed solution;

[0043] 2) Dehydration: Add an organic solvent to the mixed solution in step 1) for demulsification, and after demulsification, concentrate and dehydrate to obtain a dehydrated product;

[0044] 3) Purification: Add acetone to the dehydrated product in step 2), stir and let stand to remove the supernatant; add acetone again, stir and let stand to remove the supernatant, and vacuum concentrate to obtain a crude product;

[0045] 4) Removal of free fatty acids: Dissolve the crude product in step 3) in an organic solvent, adjust the pH to 8 and react. After the reaction, adjust the pH of the solution to 8 again. After the reaction, filter to obtain a filtrate;

[0046] 5) Concentration and drying: Concentrate and dry the filtrate to obtain a brownish-red paste product.

[0047] In some embodiments, in step 1), the mass ratio of the krill oil to water is 1:1-45, preferably 1:1-30, and more preferably 1:1-15; the preheating temperature is 24-180 °C, preferably 32-120 °C, and more preferably 40-60 °C; the mass of the added lipase accounts for 1.8-27% of the mass of the krill oil, preferably 2.4-18%, and more preferably 3-9%.

[0048] In some embodiments, in step 2), the organic solvent includes but is not limited to one or a combination of several of methanol, ethanol, acetone, or ethyl acetate, preferably methanol, ethanol, or acetone, and more preferably ethanol; the volume of the added organic solvent is 0.6-18 times the mass of the water in step (1), preferably 0.8-6 times, and more preferably 1-2 times.

[0049] In some embodiments, in step 3), the mass of acetone added to the dehydrated product is 3 - 30 times that of krill oil, preferably 4 - 20 times, and more preferably 5 - 10 times; the mass of acetone added again is 1.2 - 45 times that of krill oil, preferably 1.6 - 15 times, and more preferably 2 - 5 times.

[0050] In some embodiments, in step 4), the organic solvent includes but is not limited to one or a combination of several of methanol, ethanol, acetone, or ethyl acetate, preferably methanol, ethanol, or acetone, and more preferably ethanol; the mass of the organic solvent is 0.6 - 3 times the mass of the crude product, preferably 0.8 - 2 times, and more preferably 1 time; the mass fraction of sodium hydroxide in the sodium hydroxide ethanol solution is 0 - 6%, preferably 0 - 4%, and more preferably 0 - 2%.

[0051] In some embodiments, the food, health product, and dietary supplement further include food - acceptable additives.

[0052] In some embodiments, the food, health product, and dietary supplement can be made into tablets, capsules, soft capsules, gel candies, oral liquids, or gummies.

[0053] Beneficial effects: In the hydrolyzed krill oil extract prepared by the present invention, high - content sn - 1 - LPC - DHA and EPA act synergistically in a certain proportion, improving the cognitive function of mice, further enhancing the memory and attention of mice, enhancing the intelligence of mice, promoting the brain development of mice, and having a brain - strengthening effect. Description of the Drawings

[0054] Figure 1 It is the detection result of the attention behavior.

[0055] Figure 2 It is the detection result of the Y - maze behavior.

[0056] Figure 3 It is the detection result of each index of the water maze.

[0057] Figure 4 It is the detection result of the DHA, EPA, and omega - 3 contents in the brain.

[0058] Figure 5 It is the result of the DHA, EPA, and omega - 3 contents in the eyeballs.

[0059] Figure 6 It is the result of the DHA, EPA, and omega - 3 contents in the serum.

[0060] Figure 7 It is the result of the BDNF contents in the serum and the brain. Detailed Embodiments

[0061] For the convenience of those skilled in the art, the present invention will be further described below in conjunction with embodiments. The content mentioned in the embodiments does not limit the present invention.

[0062] Example 1

[0063] (1) Mix 100 g of krill oil with 100 g of water, stir until it becomes a homogeneous emulsion state, preheat to 50 °C, then add lipase accounting for 3% of the mass of krill oil, react for 60 min, after the reaction ends, raise the temperature to 90 °C to inactivate the enzyme, and obtain a mixed solution;

[0064] (2) Add 95% ethanol with a volume 1 - 2 times that of the water in step (1) to the mixed solution in step (1) for demulsification. After demulsification, vacuum concentrate to an anhydrous state to obtain a dehydrated product;

[0065] (3) Add acetone with a mass 5 times that of krill oil to the dehydrated product in step (2), stir for 60 min, then cool to below 0 °C, stand for 8 h, and remove the supernatant. Then add acetone with a mass 3 times that of krill oil, stir for 60 min, cool to below 0 °C, stand for 3 h, remove the supernatant, and vacuum concentrate to remove the remaining acetone to obtain a crude product;

[0066] (4) Dissolve the crude product obtained in step (3) in 95% ethanol with a mass 1 time that of it, dropwise add a 1% sodium hydroxide ethanol solution until the pH of the solution reaches 6, then react for 60 min. After the reaction ends, dropwise add a 1% sodium hydroxide ethanol solution until the pH of the solution is 8. After the reaction ends, filter to remove the precipitated fatty acid salts to obtain a filtered solution;

[0067] (5) Vacuum concentrate the filtered solution in step (4) to remove ethanol, control the moisture content of the material below 2%, and the residual amounts of acetone and ethanol below 5000 ppm. Finally, obtain 40 g of a brownish - red paste - like product, with a yield of 40%. The content of sn - 1 - LPC - DHA detected in the product is 6%, and the content of LPC is 35.8%.

[0068] Example 2

[0069] (1) Mix 100 g of krill oil with 500 g of water, stir until it becomes a homogeneous emulsion state, preheat to 50 °C, then add lipase accounting for 3% of the mass of krill oil, react for 60 min, after the reaction ends, raise the temperature to 90 °C to inactivate the enzyme, and obtain a mixed solution;

[0070] (2) Add 95% ethanol with a volume 1 - 2 times that of the water in step (1) to the mixed solution in step (1) for demulsification. After demulsification, vacuum concentrate to an anhydrous state to obtain a dehydrated product;

[0071] (3) Add acetone five times the mass of the krill oil to the product dehydrated in step (2), stir for 60 min, then cool to below 0 °C, let stand for 8 h, and remove the supernatant. Then add acetone three times the mass of the krill oil, stir for 60 min, cool to below 0 °C, let stand for 4 h, remove the supernatant, and concentrate under vacuum to remove the remaining acetone to obtain the crude product;

[0072] (4) Dissolve the crude product obtained in step (3) in 95% ethanol with a mass equal to its own, add a 1% sodium hydroxide ethanol solution dropwise until the pH of the solution reaches 6, react for 60 min, and after the reaction, add a 1% sodium hydroxide ethanol solution dropwise until the pH of the solution is 8. After the reaction, filter to remove the precipitated fatty acid salts to obtain the filtered solution;

[0073] (5) Concentrate the filtered solution obtained in step (4) under vacuum to remove ethanol, control the moisture content of the material below 2%, and the residual amounts of acetone and ethanol below 5000 ppm. Finally, 40 g of a brownish-red paste product is obtained, with a yield of 40%. The content of sn-1-LPC-DHA in the product is detected to be 10.3%, and the LPC content is 48.4%.

[0074] Example 3

[0075] (1) Mix 100 g of krill oil with 1000 g of water, stir until a homogeneous emulsion state is achieved, preheat to 50 °C, then add a lipase at 3% of the mass of the krill oil, react for 60 min, and after the reaction, raise the temperature to 90 °C to inactivate the enzyme to obtain a mixed solution;

[0076] (2) Add 95% ethanol with a volume 1 - 2 times that of the water in step (1) to the mixed solution in step (1) for demulsification, and after demulsification, concentrate under vacuum to an anhydrous state to obtain the dehydrated product;

[0077] (3) Add acetone ten times the mass of the krill oil to the product dehydrated in step (2), stir for 60 min, then cool to below 0 °C, let stand for 16 h, and remove the supernatant. Then add acetone five times the mass of the krill oil, stir for 60 min, cool to below 0 °C, let stand for 8 h, remove the supernatant, and concentrate under vacuum to remove the remaining acetone to obtain the crude product;

[0078] (4) Dissolve the crude product obtained in step (3) in ethanol with a mass equal to its own, add a 1% sodium hydroxide ethanol solution dropwise until the pH of the solution reaches 6 and react for 60 min, and after the reaction, add a 1% sodium hydroxide ethanol solution dropwise until the pH of the solution is 8. After the reaction, filter to remove the precipitated fatty acid salts to obtain the filtered solution;

[0079] (5) Concentrate the filtered solution in step (4) under vacuum to remove ethanol, control the moisture content of the material below 2%, and the residual amounts of acetone and ethanol below 5000 ppm. Finally, 50 g of a brownish-red paste product is obtained, with a yield of 50%. The content of sn-1-LPC-DHA in the product is detected to be 8.5%, and the LPC content is 45.3%.

[0080] Example 4

[0081] (1) Mix 100 g of krill oil with 1500 g of water, stir until a homogeneous emulsion state is achieved, preheat to 50 °C, then add lipase at 3% of the mass of the krill oil, react for 60 min, and after the reaction is completed, raise the temperature to 90 °C to inactivate the enzyme; a mixed solution is obtained.

[0082] (2) Add 95% ethanol with a volume 1 - 2 times that of the water in step (1) to the mixed solution in step (1) for demulsification, and after demulsification, concentrate to anhydrous state under vacuum to obtain a dehydrated product.

[0083] (3) Add acetone 10 times the mass of the krill oil to the dehydrated product in step (2), stir for 60 min, then cool to below 0 °C, stand for 16 h, and remove the supernatant. Then add acetone 5 times the mass of the krill oil, stir for 60 min, cool to below 0 °C, stand for 8 h, remove the supernatant, and concentrate under vacuum to remove the remaining acetone to obtain a crude product.

[0084] (4) Dissolve the crude product obtained in step (3) in ethanol with a mass 1 time that of it, dropwise add a 1% sodium hydroxide ethanol solution until the pH of the solution reaches 6, then react for 60 min. After the reaction is completed, dropwise add a 1% sodium hydroxide ethanol solution until the pH of the solution is 8. After the reaction is completed, filter to remove the precipitated fatty acid salts to obtain a filtered solution.

[0085] (5) Concentrate the filtered solution in step (4) under vacuum to remove ethanol, control the moisture content of the material below 2%, and the residual amounts of acetone and ethanol below 5000 ppm. Finally, 50 g of a brownish-red paste product is obtained, with a yield of 50%. The content of sn-1-LPC-DHA in the product is detected to be 8.7%, and the LPC content is 44.6%.

[0086] Example 5

[0087] (1) Mix 100 g of krill oil with 500 g of water, stir until a homogeneous emulsion state is achieved, preheat to 50 °C, then add lipase at 6% of the mass of the krill oil, react for 60 min, and after the reaction is completed, raise the temperature to 90 °C to inactivate the enzyme to obtain a mixed solution.

[0088] (2) Add 95% ethanol with a volume 1 - 2 times that of the water in step (1) to the mixed solution in step (1) for demulsification. After demulsification, concentrate it under vacuum to an anhydrous state to obtain the dehydrated product;

[0089] (3) Add acetone with a mass 5 times that of the krill oil to the dehydrated product in step (2), stir for 60 min, then cool to below 0 °C, let it stand for 8 h, and remove the supernatant. Then add acetone with a mass 2 times that of the krill oil, stir for 60 min, cool to below 0 °C, let it stand for 4 h, remove the supernatant, and concentrate under vacuum to remove the remaining acetone to obtain the crude product;

[0090] (4) Dissolve the crude product obtained in step (3) in ethanol with a mass 1 time that of it, add a 1% sodium hydroxide ethanol solution dropwise until the pH of the solution reaches 6, then react for 60 min. After the reaction ends, add a 1% sodium hydroxide ethanol solution dropwise until the pH of the solution is 8. After the reaction ends, filter to remove the precipitated fatty acid salts to obtain the filtered solution;

[0091] (5) Concentrate the filtered solution in step (4) under vacuum to remove ethanol, control the moisture content of the material to be below 2%, and the residual amounts of acetone and ethanol to be below 5000 ppm. Finally, 46 g of a brown - red paste - like product is obtained, with a yield of 46%. The content of sn - 1 - LPC - DHA in the product is detected to be 7.6%, and the LPC content is 42.8%.

[0092] Example 6

[0093] (1) Mix 100 g of krill oil with 500 g of water, stir until it becomes a uniform emulsion state, preheat to 50 °C, then add a lipase with a mass 9% of the krill oil, react for 60 min, and after the reaction ends, raise the temperature to 90 °C to inactivate the enzyme to obtain a mixed solution;

[0094] (2) Add 95% ethanol with a volume 1 - 2 times that of the water in step (1) to the mixed solution in step (1) for demulsification. After demulsification, concentrate it under vacuum to an anhydrous state to obtain the dehydrated product;

[0095] (3) Add acetone with a mass 10 times that of the krill oil to the dehydrated product in step (2), stir for 60 min, then cool to below 0 °C, let it stand for 8 h, and remove the supernatant. Then add acetone with a mass 5 times that of the krill oil, stir for 60 min, cool to below 0 °C, let it stand for 4 h, remove the supernatant, and concentrate under vacuum to remove the remaining acetone to obtain the crude product;

[0096] (4) The crude product obtained in step (3) is dissolved in 95% ethanol with a mass equal to its own mass. A 1% sodium hydroxide ethanol solution is added dropwise until the pH of the solution reaches 6, and then the reaction proceeds for 60 min. After the reaction ends, a 1% sodium hydroxide ethanol solution is added dropwise again until the pH of the solution reaches 8. After the reaction ends, the precipitated fatty acid salt is filtered off to obtain a filtered solution;

[0097] (5) The filtered solution in step (4) is concentrated under vacuum to remove ethanol, and the moisture content of the material is controlled below 2%, and the residual amounts of acetone and ethanol are below 5000 ppm. Finally, 43.7 g of a dark red paste-like product is obtained, with a yield of 43.7%. The content of sn-1-LPC-DHA in the product is detected to be 9%, and the content of LPC is 43.2%.

[0098] Example 7

[0099] (1) 100 g of krill oil is mixed with 500 g of water and stirred until a homogeneous emulsion state is obtained. After preheating to 50 °C, lipase accounting for 9% of the mass of the krill oil is added, and the reaction proceeds for 30 min. After the reaction ends, the temperature is raised to 90 °C to inactivate the enzyme, obtaining a mixed solution;

[0100] (2) 95% ethanol with a volume 1 - 2 times that of the water in step (1) is added to the mixed solution in step (1) for demulsification. After demulsification, it is concentrated under vacuum to an anhydrous state to obtain a dehydrated product;

[0101] (3) Acetone with a mass 10 times that of the krill oil is added to the dehydrated product in step (2), stirred for 60 min, then cooled to below 0 °C, and left standing for 8 h. The supernatant is removed. Then, acetone with a mass 5 times that of the krill oil is added, stirred for 60 min, cooled to below 0 °C, and left standing for 4 h. The supernatant is removed, and the remaining acetone is removed by vacuum concentration to obtain a crude product;

[0102] (4) The crude product obtained in step (3) is dissolved in ethanol with a mass equal to its own mass. A 1% sodium hydroxide ethanol solution is added dropwise until the pH of the solution reaches 6, and then the reaction proceeds for 60 min. After the reaction ends, a 1% sodium hydroxide ethanol solution is added dropwise again until the pH of the solution reaches 8. After the reaction ends, the precipitated fatty acid salt is filtered off to obtain a filtered solution;

[0103] (5) The filtered solution in step (4) is concentrated under vacuum to remove ethanol, and the moisture content of the material is controlled below 2%, and the residual amounts of acetone and ethanol are below 5000 ppm. Finally, 46 g of a dark red paste-like product is obtained, with a yield of 46%. The content of sn-1-LPC-DHA in the product is detected to be 7.6%, and the content of LPC is 42.3%.

[0104] Example 8

[0105] (1) Mix 100 g of krill oil with 500 g of water, stir until it becomes a homogeneous emulsion state, preheat to 50 °C, then add lipase accounting for 9% of the mass of krill oil, react for 120 min, after the reaction, raise the temperature to 90 °C to inactivate the enzyme, and obtain a mixed solution;

[0106] (2) Add 95% ethanol with a volume 1 - 2 times that of the water in step (1) to the mixed solution in step (1) for demulsification. After demulsification, vacuum concentrate to an anhydrous state to obtain a dehydrated product;

[0107] (3) Add acetone with a mass 10 times that of krill oil to the dehydrated product in step (2), stir for 60 min, then cool to below 0 °C, let it stand for 8 h, and remove the supernatant. Then add acetone with a mass 5 times that of krill oil, stir for 60 min, cool to below 0 °C, let it stand for 4 h, remove the supernatant, and vacuum concentrate to remove the remaining acetone to obtain a crude product;

[0108] (4) Dissolve the crude product obtained in step (3) in 95% ethanol with a mass 1 times that of it, dropwise add a 1% sodium hydroxide ethanol solution until the pH of the solution reaches 6, then react for 60 min. After the reaction, dropwise add a 1% sodium hydroxide ethanol solution until the pH of the solution is 8. After the reaction, filter to remove the precipitated fatty acid salts to obtain a filtered solution;

[0109] (5) Vacuum concentrate the filtered solution in step (4) to remove ethanol, control the moisture content of the material below 2%, and the residual amounts of acetone and ethanol below 5000 ppm. Finally, obtain 46 g of a brown - red paste - like product, with a yield of 46%. The content of sn - 1 - LPC - DHA detected in the product is 6.8%, and the content of LPC is 37.6%.

[0110] Example 9

[0111] (1) Mix 100 g of krill oil with 500 g of water, stir until it becomes a homogeneous emulsion state, preheat to 40 °C, then add lipase accounting for 9% of the mass of krill oil, react for 120 min, after the reaction, raise the temperature to 90 °C to inactivate the enzyme, and obtain a mixed solution;

[0112] (2) Add 95% ethanol with a volume 1 - 2 times that of the water in step (1) to the mixed solution in step (1) for demulsification. After demulsification, vacuum concentrate to an anhydrous state to obtain a dehydrated product;

[0113] (3) Add acetone with a mass 10 times that of krill oil to the dehydrated product in step (2), stir for 60 min, then cool to below 0 °C, let it stand for 8 h, and remove the supernatant. Then add acetone with a mass 5 times that of krill oil, stir for 60 min, cool to below 0 °C, let it stand for 4 h, remove the supernatant, and vacuum concentrate to remove the remaining acetone to obtain a crude product;

[0114] (4) The crude product obtained in step (3) is dissolved in 95% ethanol with a mass equal to its own, and a 1% sodium hydroxide ethanol solution is added dropwise until the pH of the solution reaches 6, followed by reacting for 60 min. After the reaction, a 1% sodium hydroxide ethanol solution is added dropwise again until the pH of the solution reaches 8. After the reaction, the precipitated fatty acid salt is filtered off to obtain the filtered solution;

[0115] (5) The filtered solution in step (4) is concentrated under vacuum to remove ethanol, and the moisture content of the material is controlled below 2%, and the residual amounts of acetone and ethanol are below 5000 ppm. Finally, 46 g of a brownish-red paste product is obtained, with a yield of 46%. The content of sn-1-LPC-DHA detected in the product is 6.5%, and the LPC content is 37.8%.

[0116] Example 10

[0117] (1) 100 g of krill oil is mixed with 500 g of water and stirred until a homogeneous emulsion state is reached. After preheating to 60 °C, lipase accounting for 9% of the mass of the krill oil is added, and the reaction is carried out for 120 min. After the reaction, the temperature is raised to 90 °C to inactivate the enzyme, obtaining a mixed solution;

[0118] (2) 95% ethanol with a volume 1 - 2 times that of the water in step (1) is added to the mixed solution in step (1) for demulsification. After demulsification, it is concentrated under vacuum to an anhydrous state to obtain the dehydrated product;

[0119] (3) Acetone with a mass 10 times that of the krill oil is added to the dehydrated product in step (2), stirred for 60 min, then cooled to below 0 °C, and left standing for 8 h to remove the supernatant. Then, acetone with a mass 5 times that of the krill oil is added, stirred for 60 min, cooled to below 0 °C, and left standing for 4 h to remove the supernatant. The remaining acetone is removed by vacuum concentration to obtain the crude product;

[0120] (4) The crude product obtained in step (3) is dissolved in 95% ethanol with a mass equal to its own, and a 1% sodium hydroxide ethanol solution is added dropwise until the pH of the solution reaches 6, followed by reacting for 60 min. After the reaction, a 1% sodium hydroxide ethanol solution is added dropwise again until the pH of the solution reaches 8. After the reaction, the precipitated fatty acid salt is filtered off to obtain the filtered solution;

[0121] (5) The filtered solution in step (4) is concentrated under vacuum to remove ethanol, and the moisture content of the material is controlled below 2%, and the residual amounts of acetone and ethanol are below 5000 ppm. Finally, 46 g of a brownish-red paste product is obtained, with a yield of 46%. The content of sn-1-LPC-DHA detected in the product is 7.1%, and the LPC content is 40.1%.

[0122] Comparative Example 1

[0123] (1) Mix 100 g of krill oil with 500 g of 80% ethanol solution, stir until it is in a dissolved state, preheat to 50 °C, then add lipase at 3% of the mass of the krill oil, react for 60 min, and after the reaction, raise the temperature to 90 °C to inactivate the enzyme to obtain a mixed solution;

[0124] (2) Vacuum concentrate the mixed solution in step (1) at 60 °C until it is anhydrous to obtain a dehydrated product;

[0125] (3) Add acetone 10 times the mass of the krill oil to the dehydrated product in step (2), stir for 60 min, then cool to below 0 °C, let stand for 8 h, and remove the supernatant. Then add acetone 5 times the mass of the krill oil, stir for 60 min, cool to below 0 °C, let stand for 4 h, remove the supernatant, and vacuum concentrate to remove the remaining acetone to obtain a crude product;

[0126] (4) Dissolve the crude product obtained in step (3) in ethanol of 1 times its mass, add a 1% sodium hydroxide ethanol solution dropwise until the pH of the solution reaches 6, then react for 60 min. After the reaction, add a 1% sodium hydroxide ethanol solution dropwise until the pH of the solution is 8. After the reaction, filter to remove the precipitated fatty acid salts to obtain a filtered solution;

[0127] (5) Vacuum concentrate the filtered solution in step (4) to remove ethanol, control the moisture content of the material below 2%, and the residual amounts of acetone and ethanol below 5000 ppm. Finally, 52 g of a brownish-red paste product is obtained, with a yield of 52%. The content of sn-1-LPC-DHA in the product is detected to be 0.023%, and the LPC content is 5.8%.

[0128] Comparative Example 2

[0129] (1) Mix 100 g of krill oil with 500 g of 60% ethanol solution, stir until it is in a dissolved state, preheat to 50 °C, then add lipase at 3% of the mass of the krill oil, react for 60 min, and after the reaction, raise the temperature to 90 °C to inactivate the enzyme to obtain a mixed solution;

[0130] (2) Vacuum concentrate the mixed solution in step (1) at 60 °C until it is anhydrous to obtain a dehydrated product;

[0131] (3) Add acetone 10 times the mass of the krill oil to the dehydrated product in step (2), stir for 60 min, then cool to below 0 °C, let stand for 8 h, and remove the supernatant. Then add acetone 5 times the mass of the krill oil, stir for 60 min, cool to below 0 °C, let stand for 4 h, remove the supernatant, and vacuum concentrate to remove the remaining acetone to obtain a crude product;

[0132] (4) The crude product obtained in step (3) is dissolved in ethanol with a mass 1 time that of the crude product, and a 1% sodium hydroxide ethanol solution is added dropwise until the pH of the solution reaches 6, followed by reacting for 60 min. After the reaction ends, a 1% sodium hydroxide ethanol solution is added dropwise again until the pH of the solution reaches 8. After the reaction ends, the precipitated fatty acid salt is filtered off to obtain the filtered solution;

[0133] (5) The filtered solution in step (4) is concentrated under vacuum to remove ethanol, the moisture content of the material is controlled below 2%, and the residual amounts of acetone and ethanol are below 5000 ppm. Finally, 52 g of a brownish-red paste product is obtained, with a yield of 52%. The content of sn-1-LPC-DHA detected in the product is 1.02%, and the content of LPC is 9.18%.

[0134] Comparative Example 3

[0135] (1) 100 g of krill oil is mixed with 500 g of water, stirred until a homogeneous emulsion state is achieved, the pH is adjusted to 9.5, and after preheating to 60 °C, a lipase accounting for 3% of the mass of the krill oil is added, followed by reacting for 120 min. After the reaction ends, the temperature is raised to 90 °C to inactivate the enzyme, obtaining a mixed solution;

[0136] (2) 95% ethanol with a volume 1 - 2 times that of the water in step (1) is added to the mixed solution in step (1) for demulsification. After demulsification, it is concentrated under vacuum to an anhydrous state to obtain the dehydrated product;

[0137] (3) Acetone with a mass 10 times that of the krill oil is added to the dehydrated product in step (2), stirred for 60 min, then cooled to below 0 °C, and left standing for 8 h. The supernatant is removed. Then, acetone with a mass 5 times that of the krill oil is added, stirred for 60 min, cooled to below 0 °C, and left standing for 4 h. The supernatant is removed, and the remaining acetone is removed by vacuum concentration to obtain the crude product;

[0138] (4) The crude product obtained in step (3) is dissolved in 95% ethanol with a mass 1 time that of the crude product, and a 1% sodium hydroxide ethanol solution is added dropwise until the pH of the solution reaches 6, followed by reacting for 60 min. After the reaction ends, a 1% sodium hydroxide ethanol solution is added dropwise again until the pH of the solution reaches 8. After the reaction ends, the precipitated fatty acid salt is filtered off to obtain the filtered solution;

[0139] (5) The filtered solution in step (4) is concentrated under vacuum to remove ethanol, the moisture content of the material is controlled below 2%, and the residual amounts of acetone and ethanol are below 5000 ppm. Finally, 51 g of a brownish-red paste product is obtained, with a yield of 51%. The content of sn-1-LPC-DHA detected in the product is 2.18%, and the content of LPC is 12.16%.

[0140] Comparative Example 4

[0141] Mix 100 g of krill oil with 500 g of water, stir until a homogeneous emulsion state is achieved, preheat to 50 °C, then add lipase accounting for 3% of the mass of krill oil, react for 60 min, after the reaction, raise the temperature to 90 °C to inactivate the enzyme, and obtain a mixed solution;

[0142] (2) Add 95% ethanol with a volume 1 - 2 times that of the water in step (1) to the mixed solution in step (1) for demulsification. After demulsification, vacuum concentrate to an anhydrous state to obtain a dehydrated product;

[0143] (3) Add acetone with a mass 5 times that of the krill oil to the dehydrated product in step (2), stir for 60 min, then cool to below 0 °C, let stand for 8 h, and remove the supernatant. Then add acetone with a mass 3 times that of the krill oil, stir for 60 min, cool to below 0 °C, let stand for 4 h, remove the supernatant, and vacuum concentrate to remove the remaining acetone to obtain a crude product;

[0144] (4) Dissolve the crude product obtained in step (3) in 95% ethanol with a mass 1 time that of it, dropwise add 2% sodium hydroxide aqueous solution until the pH of the solution reaches 6, then react for 60 min. After the reaction, dropwise add 2% sodium hydroxide aqueous solution until the pH of the solution is 7. After the reaction, filter to remove the precipitated fatty acid salts to obtain a filtered solution; no salts precipitate under this condition.

[0145] Comparative Example 5

[0146] (1) Mix 100 g of krill oil with 500 g of 2.6% sodium hydroxide aqueous solution, stir until a homogeneous emulsion state is achieved, preheat to 65 °C, then react for 60 min, and rotary evaporate to remove ethanol to obtain a mixed solution;

[0147] (2) Add 1000 mL of water to the mixed solution in step (1), stir evenly, adjust the pH to 3 with hydrochloric acid, separate and collect the upper oil phase, and rotary evaporate and dry to obtain a crude product;

[0148] (3) Add acetone with a mass 5 times that of the krill oil to the dehydrated crude product in step (2), stir for 60 min, then cool to below 0 °C, let stand for 8 h, and remove the supernatant. Then add acetone with a mass 3 times that of the krill oil, stir for 60 min, cool to below 0 °C, let stand for 4 h, remove the supernatant, and vacuum concentrate to remove the remaining acetone to obtain a crude product;

[0149] (4) Dissolve the crude product obtained in step (3) in 95% ethanol with a mass 1 time that of it, dropwise add 1% sodium hydroxide ethanol solution until the pH of the solution reaches 6, then react for 60 min. After the reaction, dropwise add 1% sodium hydroxide ethanol solution until the pH of the solution is 8. After the reaction, filter to remove the precipitated fatty acid salts to obtain a filtered solution;

[0150] (5) Vacuum concentrate the filtered solution in step (4) to remove ethanol, control the moisture content of the material below 2%, and the residual amounts of acetone and ethanol below 5000 ppm. Finally, 55 g of a brownish-red paste product is obtained, with a yield of 55%. The content of sn-1-LPC-DHA in the product is below the detection limit, and the LPC content is below the detection limit.

[0151] Comparative Example 6

[0152] (1) Mix 100 g of krill oil with 500 g of 1.6% sodium hydroxide aqueous solution, stir until a homogeneous emulsion state is obtained, preheat to 65 °C, react for 60 min, and then rotary evaporate to remove ethanol to obtain a mixed solution.

[0153] (2) Add 1000 mL of water to the mixed solution in step (1), stir evenly, adjust the pH to 3 with hydrochloric acid, separate and collect the upper oil phase, and rotary evaporate and dry to obtain a crude product.

[0154] (3) Add acetone 5 times the mass of krill oil to the dehydrated crude product in step (2), stir for 60 min, cool to below 0 °C, stand for 8 h, and remove the supernatant. Then add acetone 3 times the mass of krill oil, stir for 60 min, cool to below 0 °C, stand for 4 h, remove the supernatant, and vacuum concentrate to remove the remaining acetone to obtain a crude product.

[0155] (4) Dissolve the crude product obtained in step (3) in 95% ethanol with a mass 1 time that of itself, dropwise add 1% sodium hydroxide ethanol solution until the solution pH reaches 6, react for 60 min, and then dropwise add 1% sodium hydroxide ethanol solution until the solution pH is 8. After the reaction is completed, filter to remove the precipitated fatty acid salts to obtain a filtered solution.

[0156] (5) Vacuum concentrate the filtered solution in step (4) to remove ethanol, control the moisture content of the material below 2%, and the residual amounts of acetone and ethanol below 5000 ppm. Finally, 55 g of a brownish-red paste product is obtained, with a yield of 55%. The content of sn-1-LPC-DHA in the product is below the detection limit, and the LPC content is below the detection limit.

[0157] Among them, in the above examples, the moisture content of the material refers to the determination method of moisture in foods in GB 5009.3-2016; the residual amounts of acetone and ethanol refer to the second method in General Rules 0861, Volume IV of the Chinese Pharmacopoeia 2020 Edition;

[0158] The contents of sn-1-LPC-DHA and LPC in the brownish-red paste product are determined by HPLC. For the efficacy evaluation experiment on improving attention and memory of the hydrolyzed krill oil extract in Example 11 1 Experimental materials

[0159] 1.1 Sample preparation

[0160] Sample: Hydrolyzed krill oil (further purified from the product prepared in Example 2). The content of LPC-DHA (sn-1-LPC-DHA) in the sample is 19.1%, the DHA content is 9.53%, and the EPA content is 25%. The sample is formulated with deionized water to a specified concentration and then gavaged, freshly prepared and used every day.

[0161] 1.2 Experimental animals

[0162] Experimental animals for attention: SPF grade, 4 weeks old, male, 25 C57 mice. Purchased from Changzhou Cavens Experimental Animal Co., Ltd., experimental animal license number: SCXK (Su) 2021-0013. All experimental animals were adaptively fed for one week before the formal experiment began.

[0163] Experimental animals for memory: SPF grade, 4 weeks old, male, 30 C57 mice. Purchased from Changzhou Cavens Experimental Animal Co., Ltd., experimental animal license number: SCXK (Su) 2021-0013. All experimental animals were adaptively fed for one week before the formal experiment began.

[0164] 1.3 Instruments, consumables and reagents

[0165] Five-hole attention test system (Shanghai Xinruan Information Technology Co., Ltd., XR-XS128); water maze test system (Shanghai Xinruan Information Technology Co., Ltd., XR-XM101); Y maze test system (Shanghai Xinruan Information Technology Co., Ltd., XR-XY1032); electronic balance (Mettler-Toledo, ME204TE); multi-functional vortex mixer (JOANLAB, VM-500pro); -20°C refrigerator (Qingdao Haier Group, DW-25L262); magnetic stirrer (Dalong, MS-H-ProA).

[0166] Mouse BDNF content ELISA detection kit (Enzyme-linked Biology, ml002219-1).

[0167] 2 Attention evaluation method

[0168] 2.1 Experimental grouping and treatment

[0169] After 3 weeks of adaptation training and preparatory training for 25 mice, 13 mice were selected. The 13 mice were divided into a control group and a sample group, with 6 in the control group and 7 in the sample group, and the following treatments were carried out:

[0170] (1) Control group (n = 6): 6 mice were gavaged with deionized water after 3 months of formal training, and continuous training was carried out during the period of gavage with deionized water, continuously gavaged for 4 weeks, once a day;

[0171] (2) Hydrolyzed krill oil group (n = 7): After 3 months of formal training, 7 mice were intragastrically administered hydrolyzed krill oil (3148 mg / kg). Continuous training was carried out during the intragastric administration of hydrolyzed krill oil for 4 consecutive weeks, once a day.

[0172] The intragastric administration doses of the active ingredients of the samples in each group are shown in Table 1 specifically.

[0173] Table 1. Grouping design and doses of animal experiments

[0174]

[0175]

[0176] 2.2 Monitoring of animal physiological indexes

[0177] During the experiment, the activity status, mental state, and food intake of the mice were observed, etc. The body weight data of the mice were recorded twice a week after intragastric administration of the samples, and the body weights of the mice in each group were weighed again before the final test.

[0178] 2.3 Five-hole attention experimental method

[0179] Each group of mice was intragastrically administered according to the training plan after completing attention training and detection every morning. The control group of mice was intragastrically administered the same volume of deionized water, and the sample group of mice was intragastrically administered hydrolyzed krill oil (DHA intake was 300 mg / kg). In the last 3 days of intragastric administration, the correct rate of the mice was detected according to the formal five-hole attention detection method, and the correct response times, correct rate, omission response times, and omission rate were analyzed on the day with the most correct results.

[0180] 2.4 Data processing and statistical methods

[0181] The data obtained from the experiment were expressed as mean ± standard error (Mean ± SEM), and all data were processed and statistically analyzed using GraphPad Prism 8.0. The comparison between the means of two groups of samples was performed using a t-test, and the comparison between the means of multiple groups of samples was performed using an ANOVA test. p < 0.05 indicated that the difference was statistically significant.

[0182] 3 Memory evaluation method

[0183] 3.1 Experimental grouping and treatment

[0184] (1) Control group (n = 10): After the adaptive feeding was completed, the mice were intragastrically administered the same volume of deionized water for 30 consecutive days, once a day. After 30 days, a 7-day water maze experiment was carried out. After the water maze experiment, a 1-day Y maze experiment was carried out. During the water maze and Y maze experiments, normal intragastric administration was carried out, and the samples were taken after the Y maze experiment;

[0185] (2) Low-dose hydrolyzed krill oil group (n = 10): After the adaptive feeding period, mice were intragastrically administered with low-dose hydrolyzed krill oil (525 mg / kg) once a day for 30 consecutive days. After 30 days, a 7-day Morris water maze test was conducted, followed by a 1-day Y maze test. During the water maze and Y maze tests, mice were intragastrically administered as normal, and samples were taken after the Y maze test.

[0186] (3) High-dose hydrolyzed krill oil group (n = 10): After the adaptive feeding period, mice were intragastrically administered with high-dose hydrolyzed krill oil (3148 mg / kg) once a day for 30 consecutive days. After 30 days, a 7-day Morris water maze test was conducted, followed by a 1-day Y maze test. During the water maze and Y maze tests, mice were intragastrically administered as normal, and samples were taken after the Y maze test.

[0187] The intragastric administration doses of the active ingredients in each group of samples are shown in Table 2 specifically.

[0188] Table 2 Grouping design and doses of animal experiments

[0189]

[0190] 3.2 Monitoring of animal physiological indices

[0191] During the experiment, the activity status, mental state, and food intake of mice were observed. After intragastric administration of the samples, the body weight data of mice were recorded twice a week, and the body weights of mice in each group were measured again before terminal sampling.

[0192] 3.3 Y maze test method

[0193] Principle of Y maze test: Taking advantage of the natural tendency of mice to explore new environments, mice will enter each arm of the Y maze to explore and make correct choices based on memory, which can effectively evaluate their spatial working memory ability.

[0194] The specific experimental method is as follows: Starting from the starting arm, the arms are marked as A, B, and C in the counterclockwise direction. Mice are placed at the end of the starting arm (arm A), and the total number of times and the order of mice entering each arm within 5 minutes are recorded. When the adjacent three arm entry orders are not repeated (ABC, ACB, BAC, BCA, CAB, CBA), it is considered to complete a correct alternation response.

[0195] The number of correct alternation responses is statistically analyzed, and the spontaneous alternation rate is calculated. Spontaneous alternation rate (%) = [Number of correct alternation responses / (N - 2)] × 100%, where N = the total number of arm entry times.

[0196] 3.4 Morris water maze test method

[0197] Principle of Morris water maze test: By taking advantage of the instinct of mice to find a resting place in water, the learning and memory ability of mice to sense spatial position and direction (spatial orientation) is tested through two parts: the place navigation test and the spatial probe test.

[0198] 3.4.1 Place navigation

[0199] The experimental platform is placed in a certain quadrant. The visible platform experiment is tested for 5 days, with one training session per day. The mice enter the water facing the pool wall from the quadrant opposite to the quadrant where the platform is located, and the time it takes for the mice to find the platform (escape latency) is recorded. After the mice find the experimental platform, they are allowed to stay on the platform for 10 seconds. The maximum escape latency determined in this experiment is set at 60 seconds, that is, the maximum time limit allowed for the experimental animals to find the platform in the visible platform experiment is 60 seconds. If the mice cannot find the platform within 60 seconds, they are guided onto the platform and recorded as 60 seconds in the experimental record form.

[0200] 3.4.2 Spontaneous spatial exploration experiment

[0201] The experiment is tested for one day. On the second day after the mice perform the place navigation experiment, the platform is removed, and the mice enter the water facing the pool wall from the quadrant far away from the platform. The number of times the mice cross the platform and the time they stay in each quadrant within 1 minute are recorded. The detection indicators are the number of times crossing the platform and the time staying in the target quadrant.

[0202] 3.5 Determination of DHA, EPA and BDNF contents

[0203] After the memory behavioral test, the mice are sacrificed by taking blood from the eye socket, and the serum is collected for the determination of DHA, EPA contents and BDNF content; the eyes of the mice are removed to detect the DHA and EPA contents in the eyes; at the same time, the mouse skull is cut open with surgical scissors to remove the whole brain for the determination of DHA, EPA contents and BDNF content.

[0204] 3.6 Data processing and statistical methods

[0205] The data obtained from the experiment are expressed as mean ± standard error (Mean ± SEM). All data are processed and statistically analyzed using GraphPad Prism 8.0. The comparison between the means of two groups of samples is performed using the t-test, and the comparison between the means of multiple groups of samples is performed using the ANOVA test. p < 0.05 indicates that the difference is statistically significant.

[0206] 4 Results of attention evaluation

[0207] 4.1 Clinical observation results

[0208] Throughout the entire experimental process, the activity levels and food intakes of the mice in the control group and the sample group are normal, their hair is normal, and their mental states are all good. There are no significant differences among the groups.

[0209] 4.2 Body weight monitoring results

[0210] According to the experimental design, the diet of animals needs to be controlled during the attention experiment. Usually, the diet is restricted the night before the experiment to increase the motivation of animals for rewards. After the training of mice is completed, sample gavage is carried out. The body weight of mice is relatively stable during the training period, which conforms to the experimental design, and there is no statistical difference in the body weight of mice in each group.

[0211] 4.3 Results of attention behavior detection

[0212] The experimental results are as Figure 1 shown. Compared with the control group, the number of correct responses and the correct rate in the hydrolyzed krill oil group are significantly increased, and the number of omission responses and the omission rate are decreased.

[0213] 5 Memory evaluation results

[0214] 5.1 Clinical observation results

[0215] During the whole experimental process, the activity level and food intake of mice in the control group and each sample group are normal, the hair is normal, and the mental state is good. There is no significant difference among the groups.

[0216] 5.2 Body weight monitoring results

[0217] During the whole experimental process, the body weight of mice in each group is relatively stable, and there is no statistical difference among the groups.

[0218] 5.3 Results of Y-maze behavior detection

[0219] The experimental results are as Figure 2 shown. Compared with the control group, the number of alternations, the alternation rate and the number of arm entries in the low- and high-dose sample groups are increased.

[0220] 5.4 Results of water maze behavior detection

[0221] The experimental results are as Figure 3 shown. In the place navigation experiment for 5 consecutive days, on the fifth day of place cruise, compared with the control group, the time to find the platform in the low- and high-dose sample groups is significantly reduced, and the number of times of crossing the platform and the residence time in the target quadrant are both increased. Based on the above results, it is shown that hydrolyzed krill oil can improve the learning and memory ability of mice.

[0222] 5.5 Results of DHA, EPA and omega-3 contents in the brain, eyeballs and serum

[0223] The detection results are as Figures 4-6As shown, compared with the control group, after mice were gavaged with high-dose hydrolyzed krill oil, the contents of DHA, EPA, and Omega-3 in the brains and eyes of the mice increased significantly. After gavaging with low-dose hydrolyzed krill oil, only the content of EPA in the brains and eyes of the mice increased significantly, and the contents of DHA and Omega-3 increased to some extent, but there was no significant difference compared with the control group. The experimental results show that gavaging mice with hydrolyzed krill oil can increase the contents of DHA, EPA, and Omega-3 in the brain.

[0224] Compared with the control group, after gavaging with high-dose hydrolyzed krill oil, the contents of DHA, EPA, and Omega-3 in the serum of the mice increased significantly, indicating that the contents of DHA, EPA, and Omega-3 in the serum can be increased after mice are gavaged with high-dose hydrolyzed krill oil.

[0225] 5.6 Results of BDNF Content in Brain and Serum

[0226] Brain-Derived Neurotrophic Factor (BDNF) is a protein widely expressed in the central nervous system and peripheral nervous system and belongs to the neurotrophic factor family. BDNF plays an important role in the survival, growth, differentiation, and functional maintenance of neurons, especially in the processes of learning, memory, and cognition.

[0227] The test results are as Figure 7 shown. Compared with the control group, there was no significant difference in the BDNF content in the brains of the mice in the low- and high-dose hydrolyzed krill oil groups, while the BDNF content in the serum increased significantly. This indicates that gavaging mice with low- and high-dose hydrolyzed krill oil can promote the synthesis of BDNF in the serum.

[0228] It should be understood that the detailed description of the technical solutions of the present invention with the help of the preferred embodiments is illustrative rather than restrictive. Those of ordinary skill in the art can modify the technical solutions recorded in each embodiment or perform equivalent substitution on some of the technical features based on reading the specification of the present invention; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

1. Use of a hydrolyzed krill oil extract in the preparation of foods, health products, and dietary supplements for brain health.

2. The use according to claim 1, wherein The hydrolyzed krill oil extract is used to improve memory and attention, enhance cognitive ability, boost intelligence, and promote brain health.

3. The use according to claim 2, characterized in that, The content of LPC in the hydrolyzed krill oil extract is ≥ 10%.

4. The use according to claim 3, characterized in that, The content of sn-1-LPC-DHA in the hydrolyzed krill oil extract is ≤ 90%.

5. The use according to claim 3, characterized in that, The content of sn-2-LPC-DHA in the hydrolyzed krill oil extract is ≤ 90%.

6. The use according to claim 3, characterized in that, In the hydrolyzed krill oil extract, the content of sn-1-LPC-DHA in LPC-DHA is ≥ 50%.

7. The use according to claim 3, characterized in that, In the hydrolyzed krill oil extract, the content of sn-2-LPC-DHA in LPC-DHA is ≤ 50%.

8. The use according to claim 3, characterized in that, In the hydrolyzed krill oil extract, the total content of EPA and DHA is ≥ 10%.

9. The use according to claim 8, wherein In the hydrolyzed krill oil extract, the mass ratio of EPA to DHA is greater than 2:

1.

10. The use according to any one of claims 1-9, characterized in that, The hydrolyzed krill oil extract is prepared by a preparation method including the following steps: 1) Enzymatic hydrolysis: Mix krill oil and water, add lipase and stir. After stirring, raise the temperature to inactivate the enzyme to obtain a mixed solution. 2) Dehydration: Add an organic solvent to the mixed solution in step 1) for demulsification. After demulsification, concentrate and dehydrate to obtain a dehydrated product. 3) Purification: Add acetone to the dehydrated product in step 2), stir and let stand to remove the supernatant; add acetone again, stir and let stand to remove the supernatant, and concentrate under vacuum to obtain a crude product. 4) Removal of free fatty acids: Dissolve the crude product in step 3) in an organic solvent, adjust the pH to 8 and react. After the reaction, adjust the pH of the solution to 8 again. After the reaction, filter to obtain a filtrate. 5) Concentration and drying: Concentrate and dry the filtrate to obtain a brownish-red paste product.

11. The use according to any one of claims 1 to 10, characterized in that, The foods, health products, and dietary supplements further include food-acceptable additives.

12. The use according to claim 11, wherein The foods, health products, and dietary supplements can be made into tablets, capsules, soft capsules, gel candies, oral liquids, or gummies.

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