Method for extracting sturgeon oil with skin repair function

Abstract

The application discloses an extraction method of sturgeon oil with skin repair function, which comprises the following steps: S1, preparation of crude fish oil of fish fat; S2, preparation of crude fish oil of fish liver; S3, preparation of crude fish oil of fish skin; S4, degumming and deacidification; and S5, refining. The fish oil extracted from different parts of sturgeon is mixed according to a specific proportion, the fish fat fish oil, the fish liver oil and the fish skin oil are mixed, and three kinds of functional components are added in the extraction process respectively, i.e. dihydroquercetin (providing antioxidant protection), phosphatidylserine (enhancing cell membrane repair and nutrient absorption) and curcumin (bringing anti-inflammatory and whitening effects), so that a multiple synergistic formula system is formed, and the prepared sturgeon oil is significantly enhanced in the repair function on the skin, and the bioavailability and stability of the product are improved.

Description

Technical Field

[0001] This invention belongs to the field of aquatic product processing technology, specifically relating to a method for extracting sturgeon oil with skin repair function. Background Technology

[0002] Sturgeon, also known as sturgeon, is the largest and longest-lived freshwater fish, and one of the oldest and most primitive groups of fish on Earth. Every part of it is valuable, possessing high economic and research value. Sturgeon flesh is thick and boneless, with a texture superior to salmon, and high nutritional value. Its roe is particularly high in protein and low in sugar, making it highly edible. my country's sturgeon farming industry has achieved remarkable results in artificial breeding and cultivation techniques, with the scale and output of sturgeon farming increasing year by year.

[0003] Sturgeon's main components include essential amino acids, vitamins, minerals, phosphorus, and potassium, with a protein content as high as 18%, and sturgeon roe protein content reaching up to 29%. Sturgeon meat contains various unsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Fish rich in unsaturated fatty acids are crucial for human health; consuming sturgeon has a positive regulatory effect on human blood pressure, metabolic processes, and skin regeneration. The abdomen, nose, tendons, and bones of the sturgeon can be used to prepare distinctive Chinese dishes, and its cartilage is high in chondroitin sulfate; consuming its bone products has immune-boosting and anti-aging effects. Its skin can be made into glue and is also a high-grade leather raw material.

[0004] Fish oil is a highly valuable natural health food. Its polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have functions such as inhibiting platelet aggregation, preventing thrombosis, dilating blood vessels, regulating blood lipids, and improving the fluidity of biological membranes. It has shown good efficacy in treating and preventing cardiovascular diseases, diabetes, dermatitis, colonic ulcers, and inhibiting tumors. Recent studies have also found that fish oil can improve brain function, enhance retinal reflexes, and prevent Alzheimer's disease. With the widespread recognition of the health benefits of fish oil, it has been widely used in health care, medicine, food, chemical, and animal feed industries, and market demand is increasing daily.

[0005] Fish oil production methods mainly include pressing, alkaline hydrolysis, solvent extraction, aqueous extraction, and enzymatic hydrolysis. Among these, pressing is primarily used as a byproduct of fishmeal processing plants, generally resulting in low oil extraction rates and poor quality. Alkaline hydrolysis is difficult to control; too low an alkali concentration leads to incomplete hydrolysis, while too high a concentration causes saponification, both reducing the oil extraction rate. Furthermore, the wastewater generated during extraction has a high sodium content, making it unusable and creating new waste. Solvent extraction uses organic solvents to extract fat from the raw material, potentially leaving solvent residues in the extracted fish oil, limiting its application. Enzymatic extraction, on the other hand, offers mild conditions, minimal damage to the functional components of fish oil, and produces high-quality fish oil. It also fully utilizes the enzymatic hydrolysate generated by protease hydrolysis. Chinese patent application CN110317672A discloses a method for preparing fish oil from rainbow trout fat, including fish oil extraction and refining. Fish oil extraction includes obtaining fish fat, chopping, preheating, negative pressure heating, and centrifugation. Fish oil refining includes physical decolorization, molecular distillation, and nitrogen-filled packaging. The beneficial effects of this invention are: its raw materials have high oil content, are free of impurities, are abundant in source, and are low in cost; the processing technology is simple, easy to operate, and readily applicable to industrial production; the product has a high oil yield, light color, no fishy odor or trans fatty acids, and the finished oil has good nutritional value, containing various unsaturated fatty acids and fat-soluble vitamins. However, fish oil is easily oxidized. Therefore, how to reduce its oxidation rate during preparation to obtain fish oil with better skin-repairing functions is of great significance in this field. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for extracting sturgeon oil with skin repair function.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for extracting sturgeon oil with skin-repairing properties includes the following steps:

[0009] S1. Fresh, intact, and unrotten fish fat is separated from the internal organs of sturgeon. Blood and impurities are removed from the fish fat, and it is chopped into small pieces. Then, it is added to a high-speed blender and blended into fat paste. The fat paste is added to distilled water, followed by dihydroquercetin and neutral protease. Enzymatic hydrolysis is carried out under ultrasonic conditions. After the enzymatic hydrolysis is completed, the enzyme is inactivated and filtered. The filtrate is centrifuged, and the supernatant clear oil is collected to obtain crude fish oil.

[0010] S2. Wash the sturgeon liver, crush it with a homogenizer to obtain liver homogenate; add the liver homogenate to distilled water, then add phosphatidylserine and pepsin for enzymatic hydrolysis. After enzymatic hydrolysis, inactivate the enzyme, filter, centrifuge the filtrate, and collect the clear oil from the upper layer to obtain crude fish liver oil.

[0011] S3. Wash the sturgeon skin, cut it into small pieces, add it to distilled water, stir it with a homogenizer, then add curcumin and papain, and perform enzymatic hydrolysis under ultrasonic conditions. After the enzymatic hydrolysis is completed, inactivate the enzyme, filter, centrifuge the filtrate, collect the clear oil in the upper layer, and obtain crude fish oil from the fish skin.

[0012] S4. Mix the fish fat crude fish oil from step S1, the fish liver crude fish oil from step S2, and the fish skin crude fish oil from step S3 evenly to obtain mixed fish oil, and then degumming and deacidification to obtain deacidified sturgeon fish oil.

[0013] S5. The deacidified sturgeon oil from step S4 is refined to obtain the sturgeon oil with skin repair function.

[0014] Preferably, in step S1, the mass ratio of chyme to distilled water is 1:7-10, the amount of dihydroquercetin added is 0.3-0.5% of the mass of chyme, and the amount of neutral protease added is 2-3% of the mass of chyme.

[0015] Preferably, the frequency of the ultrasound in step S1 is 700-900 kHz, the temperature of the enzymatic hydrolysis is 40-50℃, and the time is 2-3 hours.

[0016] In this invention, fish oil from sturgeon abdominal fat is prepared by mechanical separation and ultrasound-assisted enzymatic hydrolysis, which ensures the purity of the fish oil and preserves its active ingredients. At the same time, the addition of dihydroquercetin can effectively prevent the fish oil from oxidizing during extraction and storage, thereby improving the stability of the fish oil.

[0017] Preferably, in step S2, the mass ratio of liver homogenate to distilled water is 1:6-8, the amount of phosphatidylserine added is 0.5-0.8%, and the amount of pepsin added is 3-4%.

[0018] Preferably, the enzymatic hydrolysis in step S2 is carried out at a temperature of 35-45°C for 5-6 hours.

[0019] In this invention, a combination of mechanical crushing and enzymatic hydrolysis is used to extract fish oil from sturgeon liver. Phosphatidylserine is added during the extraction process. As an emulsifier, phosphatidylserine can improve the stability of the oil-water interface, which helps to improve the enzymatic hydrolysis efficiency and oil extraction rate. This not only improves the product quality by improving the process, but also enhances the product efficacy through its own biological activity.

[0020] Preferably, in step S3, the mass ratio of sturgeon skin to distilled water is 1:1-3, the amount of curcumin added is 0.6-1% of the mass of sturgeon skin, and the amount of papain added is 2-3% of the mass of sturgeon skin.

[0021] Preferably, the frequency of ultrasound in step S3 is 600-700 kHz, the temperature of enzymatic hydrolysis is 55-60℃, and the time is 3-4 h.

[0022] In this invention, sturgeon skin oil is prepared by mechanical separation and ultrasound-assisted enzymatic hydrolysis. The curcumin added during the extraction process can not only prevent the oil from oxidizing during the extraction process, but also assist the release of the oil through its lipophilic characteristics, thereby improving the oil extraction rate.

[0023] Preferably, the mass ratio of crude fish fat oil, crude fish liver oil, and crude fish skin oil in step S4 is 50-60:30-40:20-30; the specific steps of degumming and deacidification are as follows: heat the mixed fish oil to 80-85℃, then add a 60% phosphoric acid solution, stir, and centrifuge to remove the precipitate of the gelatinous substance. Take the supernatant, which is the degummed sturgeon fish oil; heat the degummed sturgeon fish oil in a water bath to 60-70℃, add a 4mol / L sodium hydroxide solution, keep warm for 30min, then take the upper oil sample, centrifuge, and wash away the residual soap residue with hot deionized water. Repeat twice to obtain deacidified sturgeon fish oil.

[0024] Preferably, the specific steps in step S5 are as follows: The deacidified sturgeon oil from step S4 is refined using a molecular distillation apparatus. The feed preheating temperature is 80-90℃, the rotation speed is 200-240r / min, the distillation pressure is 5-10Pa, the distillation temperature is 100-110℃, and the feed rate is 3-5mL / min, thereby obtaining the sturgeon oil.

[0025] This invention also protects a sturgeon oil with skin repair function prepared by the method described above.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The method for extracting sturgeon oil with skin repair function provided by the present invention extracts fish oil from the abdominal fat of sturgeon by ultrasound-assisted enzymatic method. The dihydroquercetin added during the extraction process has significant anti-inflammatory and collagen synthesis-promoting effects. At the same time, it can work synergistically with omega-3 fatty acids such as EPA and DHA in fish oil to enhance the bioavailability of fish oil, improve its permeability, and thus promote the skin repair function of fish oil.

[0028] (2) The method for extracting sturgeon oil with skin repair function provided by the present invention extracts fish oil from sturgeon liver by enzymatic extraction. The added phosphatidylserine not only improves the extraction rate of fish oil, but also, as a phospholipid, phosphatidylserine has the function of maintaining cell membrane integrity, promoting cell renewal and repair. It can synergistically enhance the transdermal absorption capacity of nutrients with fat-soluble nutrients such as vitamins A and D in fish liver oil, and improve the dispersibility and bioavailability of sturgeon oil. Sturgeon skin fish oil is prepared by mechanical separation and ultrasonic-assisted enzymatic hydrolysis. The curcumin added during the extraction process can not only prevent the oil from oxidizing during the extraction process, but also assist the release of oil through its lipophilic characteristics, thereby improving the extraction rate of fish oil. At the same time, curcumin has significant anti-inflammatory and antioxidant effects, can inhibit the formation of melanin, has a whitening effect, promotes collagen synthesis, improves skin elasticity, and enhances the skin repair efficacy of sturgeon oil.

[0029] (3) The method for extracting sturgeon oil with skin repair function provided by the present invention mixes fish oil extracted from different parts of sturgeon in a specific ratio. The fish fat oil is rich in EPA and DHA, the fish liver oil contains vitamins A and D, and the fish skin oil contains collagen components. At the same time, three active ingredients are added during the extraction process: dihydroquercetin (providing antioxidant protection), phosphatidylserine (enhancing cell membrane repair and nutrient absorption), and curcumin (bringing anti-inflammatory and whitening effects), forming a multi-synergistic formulation system. The synergistic effect of multiple active ingredients in the prepared sturgeon oil significantly enhances the skin repair function, including strengthening the epidermal barrier, anti-oxidation and anti-aging, improving elasticity and moisturizing ability, whitening and anti-inflammatory effects, etc., while improving the bioavailability and stability of the product. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] In this invention, the neutral protease was purchased from Hebei Jiuyu Biotechnology Co., Ltd., with an enzyme activity of 100,000 U / g; the papain was purchased from Guangzhou Huayu Biotechnology Co., Ltd., with an enzyme activity of 100,000 U / g; and the pepsin was purchased from Guangzhou Huayu Biotechnology Co., Ltd., with an enzyme activity of 50,000 U / g.

[0032] Example 1

[0033] A method for extracting sturgeon oil with skin-repairing properties includes the following steps:

[0034] S1. Preparation of crude fish oil from fish fat: Fresh, intact fish fat free from decay and impurities was separated from the internal organs of sturgeon. Blood and impurities were removed from the fish fat, and it was chopped into small pieces. Then, it was added to a blender and blended into fat paste. 100g of fat paste was added to 900g of distilled water, followed by 0.4g of dihydroquercetin and 2.5g of neutral protease. The mixture was enzymatically hydrolyzed at an ultrasonic frequency of 800kHz and a temperature of 45℃ for 2.5h. After the enzymatic hydrolysis was completed, the enzyme was inactivated by boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish oil.

[0035] S2. Preparation of crude fish liver oil: Sturgeon liver was washed, crushed in a homogenizer, and a liver homogenate was obtained. 100g of liver homogenate was added to 700g of distilled water, followed by 0.7g of phosphatidylserine and 3.5g of pepsin. The mixture was enzymatically hydrolyzed at 40℃ for 5.5h. After the enzymatic hydrolysis was completed, the enzyme was inactivated in boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish liver oil.

[0036] S3. Preparation of crude fish oil from fish skin: Wash 100g of sturgeon skin, cut it into small pieces of 5mm×5mm, add it to 200g of distilled water, stir it with a homogenizer, then add 0.8g of curcumin and 2.5g of papain, and enzymatically hydrolyze it at an ultrasonic frequency of 650kHz and a temperature of 55℃ for 3.5h. After the enzymatic hydrolysis is completed, inactivate the enzyme in boiling water for 15min, filter it, centrifuge the filtrate at 5000r / min for 15min, collect the clear oil from the upper layer, and obtain crude fish oil from fish skin.

[0037] S4. Degumming and Deacidification: Mix 55g of crude fish fat oil from step S1, 35g of crude fish liver oil from step S2, and 25g of crude fish skin oil from step S3 evenly to obtain mixed fish oil. Then heat the mixed fish oil to 80℃, and add a 60% phosphoric acid solution (the mass ratio of mixed fish oil to phosphoric acid solution is 1:100). After stirring, centrifuge to remove the gelatinous precipitate, and take the supernatant, which is the degummed sturgeon fish oil. Heat the degummed sturgeon fish oil in a water bath to 65℃, add a 4mol / L sodium hydroxide solution (the mass ratio of degummed sturgeon fish oil to sodium hydroxide solution is 2:100), keep warm for 30min, then take the upper oil sample, centrifuge, and wash away the residual soap with hot deionized water. Repeat twice to obtain deacidified sturgeon fish oil.

[0038] S5. Refining: The deacidified sturgeon oil from step S4 is refined using a molecular distillation apparatus. The feed preheating temperature is 85℃, the rotation speed is 220r / min, the distillation pressure is 5Pa, the distillation temperature is 105℃, and the feed rate is 4mL / min to obtain the sturgeon oil.

[0039] Example 2

[0040] A method for extracting sturgeon oil with skin-repairing properties includes the following steps:

[0041] S1. Preparation of crude fish oil from fish fat: Fresh, intact fish fat free from decay and impurities was separated from the internal organs of sturgeon. Blood and impurities were removed from the fish fat, and it was chopped into small pieces. Then, it was added to a blender and blended into fat paste. 100g of fat paste was added to 700g of distilled water, followed by 0.3g of dihydroquercetin and 2g of neutral protease. The mixture was enzymatically hydrolyzed at an ultrasonic frequency of 700kHz and a temperature of 40℃ for 3h. After the enzymatic hydrolysis was completed, the enzyme was inactivated by boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish oil.

[0042] S2. Preparation of crude fish liver oil: Sturgeon liver was washed, crushed in a homogenizer, and a liver homogenate was obtained. 100g of liver homogenate was added to 600g of distilled water, followed by 0.5g of phosphatidylserine and 3g of pepsin. The mixture was enzymatically hydrolyzed at 35℃ for 6h. After the enzymatic hydrolysis was completed, the enzyme was inactivated in boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish liver oil.

[0043] S3. Preparation of crude fish oil from fish skin: Wash 100g of sturgeon skin, cut it into small pieces of 5mm×5mm, add it to 100g of distilled water, stir it with a homogenizer, then add 0.6g of curcumin and 2g of papain, and enzymatically hydrolyze it at an ultrasonic frequency of 600kHz and a temperature of 55℃ for 4h. After the enzymatic hydrolysis is completed, inactivate the enzyme in boiling water for 15min, filter it, centrifuge the filtrate at 5000r / min for 15min, collect the clear oil from the upper layer, and obtain crude fish oil from fish skin.

[0044] S4. Degumming and Deacidification: Mix 50g of crude fish fat oil from step S1, 30g of crude fish liver oil from step S2, and 20g of crude fish skin oil from step S3 evenly to obtain mixed fish oil. Then heat the mixed fish oil to 80℃, and add a 60% phosphoric acid solution (the mass ratio of mixed fish oil to phosphoric acid solution is 1:100). After stirring, centrifuge to remove the gelatinous precipitate, and take the supernatant, which is the degummed sturgeon fish oil. Heat the degummed sturgeon fish oil in a water bath to 60℃, add a 4mol / L sodium hydroxide solution (the mass ratio of degummed sturgeon fish oil to sodium hydroxide solution is 2:100), keep warm for 30min, then take the upper oil sample, centrifuge, and wash away the residual soap with hot deionized water. Repeat twice to obtain deacidified sturgeon fish oil.

[0045] S5. Refining: The deacidified sturgeon oil from step S4 is refined using a molecular distillation apparatus. The feed preheating temperature is 80℃, the rotation speed is 200r / min, the distillation pressure is 5Pa, the distillation temperature is 100-110℃, and the feed rate is 3mL / min to obtain the sturgeon oil.

[0046] Example 3

[0047] A method for extracting sturgeon oil with skin-repairing properties includes the following steps:

[0048] S1. Preparation of crude fish oil from fish fat: Fresh, intact fish fat free from decay and impurities was separated from the internal organs of sturgeon. Blood and impurities were removed from the fish fat, and it was chopped into small pieces. Then, it was added to a blender and blended into fat paste. 100g of fat paste was added to 1000g of distilled water, followed by 0.5g of dihydroquercetin and 3g of neutral protease. The mixture was enzymatically hydrolyzed at an ultrasonic frequency of 900kHz and a temperature of 50℃ for 2 hours. After the enzymatic hydrolysis was completed, the enzyme was inactivated by boiling water for 15 minutes. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15 minutes. The clear oil in the supernatant was collected to obtain crude fish oil.

[0049] S2. Preparation of crude fish liver oil: Sturgeon liver was washed, crushed in a homogenizer, and a liver homogenate was obtained. 100g of liver homogenate was added to 800g of distilled water, followed by 0.8g of phosphatidylserine and 4g of pepsin. The mixture was enzymatically hydrolyzed at 45℃ for 5h. After the enzymatic hydrolysis was completed, the enzyme was inactivated in boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish liver oil.

[0050] S3. Preparation of crude fish oil from fish skin: Wash 100g of sturgeon skin, cut it into small pieces of 5mm×5mm, add it to 300g of distilled water, stir it with a homogenizer, then add 1g of curcumin and 3g of papain, and enzymatically hydrolyze it at an ultrasonic frequency of 700kHz and a temperature of 60℃ for 3h. After the enzymatic hydrolysis is completed, inactivate the enzyme in boiling water for 15min, filter it, centrifuge the filtrate at 5000r / min for 15min, collect the clear oil from the upper layer, and obtain crude fish oil from fish skin.

[0051] S4. Degumming and Deacidification: Mix 60g of crude fish fat oil from step S1, 40g of crude fish liver oil from step S2, and 30g of crude fish skin oil from step S3 evenly to obtain mixed fish oil. Then heat the mixed fish oil to 85°C, and add a 60% phosphoric acid solution (the mass ratio of mixed fish oil to phosphoric acid solution is 1:100). After stirring, centrifuge to remove the gelatinous precipitate, and take the supernatant, which is the degummed sturgeon fish oil. Heat the degummed sturgeon fish oil in a water bath to 70°C, add a 4mol / L sodium hydroxide solution (the mass ratio of degummed sturgeon fish oil to sodium hydroxide solution is 2:100), keep warm for 30 minutes, then take the upper oil sample, centrifuge, and wash away the residual soap residue with hot deionized water. Repeat twice to obtain deacidified sturgeon fish oil.

[0052] S5. Refining: The deacidified sturgeon oil from step S4 is refined using a molecular distillation apparatus. The feed preheating temperature is 90℃, the rotation speed is 240r / min, the distillation pressure is 10Pa, the distillation temperature is 110℃, and the feed rate is 5mL / min to obtain the sturgeon oil.

[0053] Comparative Example 1

[0054] A method for extracting sturgeon oil with skin-repairing properties includes the following steps:

[0055] S1. Preparation of crude fish oil from fish fat: Fresh, intact fish fat free from decay and impurities was separated from the internal organs of sturgeon. Blood and impurities were removed from the fish fat, and it was chopped into small pieces. Then, it was added to a blender and blended into fat paste. 100g of fat paste was added to 900g of distilled water, followed by 2.5g of neutral protease. The mixture was enzymatically hydrolyzed at an ultrasonic frequency of 800kHz and a temperature of 45℃ for 2.5h. After the enzymatic hydrolysis was completed, the enzyme was inactivated by boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The clear oil in the supernatant was collected to obtain crude fish oil.

[0056] S2. Preparation of crude fish liver oil: Sturgeon liver was washed, crushed in a homogenizer, and a liver homogenate was obtained. 100g of liver homogenate was added to 700g of distilled water, followed by 0.7g of phosphatidylserine and 3.5g of pepsin. The mixture was enzymatically hydrolyzed at 40℃ for 5.5h. After the enzymatic hydrolysis was completed, the enzyme was inactivated in boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish liver oil.

[0057] S3. Preparation of crude fish oil from fish skin: Wash 100g of sturgeon skin, cut it into small pieces of 5mm×5mm, add it to 200g of distilled water, stir it with a homogenizer, then add 0.8g of curcumin and 2.5g of papain, and enzymatically hydrolyze it at an ultrasonic frequency of 650kHz and a temperature of 55℃ for 3.5h. After the enzymatic hydrolysis is completed, inactivate the enzyme in boiling water for 15min, filter it, centrifuge the filtrate at 5000r / min for 15min, collect the clear oil from the upper layer, and obtain crude fish oil from fish skin.

[0058] S4. Degumming and Deacidification: Mix 55g of crude fish fat oil from step S1, 35g of crude fish liver oil from step S2, and 25g of crude fish skin oil from step S3 evenly to obtain mixed fish oil. Then heat the mixed fish oil to 80℃, and add a 60% phosphoric acid solution (the mass ratio of mixed fish oil to phosphoric acid solution is 1:100). After stirring, centrifuge to remove the gelatinous precipitate, and take the supernatant, which is the degummed sturgeon fish oil. Heat the degummed sturgeon fish oil in a water bath to 65℃, add a 4mol / L sodium hydroxide solution (the mass ratio of degummed sturgeon fish oil to sodium hydroxide solution is 2:100), keep warm for 30min, then take the upper oil sample, centrifuge, and wash away the residual soap with hot deionized water. Repeat twice to obtain deacidified sturgeon fish oil.

[0059] S5. Refining: The deacidified sturgeon oil from step S4 is refined using a molecular distillation apparatus. The feed preheating temperature is 85℃, the rotation speed is 220r / min, the distillation pressure is 5Pa, the distillation temperature is 105℃, and the feed rate is 4mL / min to obtain the sturgeon oil.

[0060] Compared with Example 1, this comparative example did not add dihydroquercetin when preparing crude fish oil.

[0061] Comparative Example 2

[0062] A method for extracting sturgeon oil with skin-repairing properties includes the following steps:

[0063] S1. Preparation of crude fish oil from fish fat: Fresh, intact fish fat free from decay and impurities was separated from the internal organs of sturgeon. Blood and impurities were removed from the fish fat, and it was chopped into small pieces. Then, it was added to a blender and blended into fat paste. 100g of fat paste was added to 900g of distilled water, followed by 0.4g of dihydroquercetin and 2.5g of neutral protease. The mixture was enzymatically hydrolyzed at an ultrasonic frequency of 800kHz and a temperature of 45℃ for 2.5h. After the enzymatic hydrolysis was completed, the enzyme was inactivated by boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish oil.

[0064] S2. Preparation of crude fish liver oil: Sturgeon liver was washed, crushed in a crusher, and homogenized to obtain liver homogenate; 100g of liver homogenate was added to 700g of distilled water, followed by 3.5g of pepsin, and enzymatically hydrolyzed at 40℃ for 5.5h. After enzymatic hydrolysis, the enzyme was inactivated in boiling water for 15min, filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish liver oil.

[0065] S3. Preparation of crude fish oil from fish skin: Wash 100g of sturgeon skin, cut it into small pieces of 5mm×5mm, add it to 200g of distilled water, stir it with a homogenizer, then add 0.8g of curcumin and 2.5g of papain, and enzymatically hydrolyze it at an ultrasonic frequency of 650kHz and a temperature of 55℃ for 3.5h. After the enzymatic hydrolysis is completed, inactivate the enzyme in boiling water for 15min, filter it, centrifuge the filtrate at 5000r / min for 15min, collect the clear oil from the upper layer, and obtain crude fish oil from fish skin.

[0066] S4. Degumming and Deacidification: Mix 55g of crude fish fat oil from step S1, 35g of crude fish liver oil from step S2, and 25g of crude fish skin oil from step S3 evenly to obtain mixed fish oil. Then heat the mixed fish oil to 80℃, and add a 60% phosphoric acid solution (the mass ratio of mixed fish oil to phosphoric acid solution is 1:100). After stirring, centrifuge to remove the gelatinous precipitate, and take the supernatant, which is the degummed sturgeon fish oil. Heat the degummed sturgeon fish oil in a water bath to 65℃, add a 4mol / L sodium hydroxide solution (the mass ratio of degummed sturgeon fish oil to sodium hydroxide solution is 2:100), keep warm for 30min, then take the upper oil sample, centrifuge, and wash away the residual soap with hot deionized water. Repeat twice to obtain deacidified sturgeon fish oil.

[0067] S5. Refining: The deacidified sturgeon oil from step S4 is refined using a molecular distillation apparatus. The feed preheating temperature is 85℃, the rotation speed is 220r / min, the distillation pressure is 5Pa, the distillation temperature is 105℃, and the feed rate is 4mL / min to obtain the sturgeon oil.

[0068] Compared with Example 1, this comparative example did not add phosphatidylserine when preparing crude fish liver oil.

[0069] Comparative Example 3

[0070] A method for extracting sturgeon oil with skin-repairing properties includes the following steps:

[0071] S1. Preparation of crude fish oil from fish fat: Fresh, intact fish fat free from decay and impurities was separated from the internal organs of sturgeon. Blood and impurities were removed from the fish fat, and it was chopped into small pieces. Then, it was added to a blender and blended into fat paste. 100g of fat paste was added to 900g of distilled water, followed by 0.4g of dihydroquercetin and 2.5g of neutral protease. The mixture was enzymatically hydrolyzed at an ultrasonic frequency of 800kHz and a temperature of 45℃ for 2.5h. After the enzymatic hydrolysis was completed, the enzyme was inactivated by boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish oil.

[0072] S2. Preparation of crude fish liver oil: Sturgeon liver was washed, crushed in a homogenizer, and a liver homogenate was obtained. 100g of liver homogenate was added to 700g of distilled water, followed by 0.7g of phosphatidylserine and 3.5g of pepsin. The mixture was enzymatically hydrolyzed at 40℃ for 5.5h. After the enzymatic hydrolysis was completed, the enzyme was inactivated in boiling water for 15min. The mixture was filtered, and the filtrate was centrifuged at 5000r / min for 15min. The supernatant clear oil was collected to obtain crude fish liver oil.

[0073] S3. Preparation of crude fish oil from fish skin: Wash 100g of sturgeon skin, cut it into small pieces of 5mm×5mm, add it to 200g of distilled water, stir it with a homogenizer, then add 2.5g of papain, and enzymatically hydrolyze it at an ultrasonic frequency of 650kHz and a temperature of 55℃ for 3.5h. After the enzymatic hydrolysis is completed, inactivate the enzyme in boiling water for 15min, filter it, centrifuge the filtrate at 5000r / min for 15min, collect the clear oil from the upper layer, and obtain crude fish oil from fish skin.

[0074] S4. Degumming and Deacidification: Mix 55g of crude fish fat oil from step S1, 35g of crude fish liver oil from step S2, and 25g of crude fish skin oil from step S3 evenly to obtain mixed fish oil. Then heat the mixed fish oil to 80℃, and add a 60% phosphoric acid solution (the mass ratio of mixed fish oil to phosphoric acid solution is 1:100). After stirring, centrifuge to remove the gelatinous precipitate, and take the supernatant, which is the degummed sturgeon fish oil. Heat the degummed sturgeon fish oil in a water bath to 65℃, add a 4mol / L sodium hydroxide solution (the mass ratio of degummed sturgeon fish oil to sodium hydroxide solution is 2:100), keep warm for 30min, then take the upper oil sample, centrifuge, and wash away the residual soap with hot deionized water. Repeat twice to obtain deacidified sturgeon fish oil.

[0075] S5. Refining: The deacidified sturgeon oil from step S4 is refined using a molecular distillation apparatus. The feed preheating temperature is 85℃, the rotation speed is 220r / min, the distillation pressure is 5Pa, the distillation temperature is 105℃, and the feed rate is 4mL / min to obtain the sturgeon oil.

[0076] Compared with Example 1, this comparative example did not add curcumin when preparing crude fish oil from fish skin.

[0077] The extraction rates of crude fish oil in Examples 1-3 and Comparative Examples 1-3 were calculated. Crude fish oil extraction rate = crude fish oil content / mass of crude fat in raw material × 100%. The contents of EPA and DHA in the prepared sturgeon oil were also measured. The results are shown in Table 1 below:

[0078] Table 1

[0079]

[0080] As can be seen from Table 1, the method for extracting sturgeon oil with skin repair function provided by the present invention improves the extraction rate of sturgeon oil and increases the content of EPA and DHA in sturgeon oil.

[0081] The sturgeon oil prepared in Example 1 and Comparative Examples 1-3 was used to conduct a skin repair efficacy experiment, as follows: SPF-grade male Kunming mice were randomly divided into a model group and the Example 1 and Comparative Examples 1-3 groups, with 10 mice in each group. After one week of acclimatization under suitable conditions, the mice were subjected to model treatment. They were anesthetized by intraperitoneal injection of 10% chloral hydrate (0.003 mL / g), and their hair was removed with sodium sulfide. After hair removal, the skin was wiped with 75% ethanol, and sterile surgical scissors were used to make incisions of similar size on the back of the mice. 0.5 mL of the corresponding sturgeon oil was evenly applied to the wounds. The model group was left untreated and allowed to heal naturally. The medication was administered once daily for 7 days. On the 8th day after surgery, photographs were taken, the wound area was measured, and the healing rate was calculated. The results are shown in Table 2:

[0082] Table 2

[0083] Healing rate (%) Model group 52.6％ Example 1 94.2％ Comparative Example 1 87.3％ Comparative Example 2 88.5％ Comparative Example 3 84.9％

[0084] As can be seen from Table 3, the sturgeon oil prepared by this invention has a good effect on promoting skin repair and has good application prospects.

[0085] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for extracting sturgeon oil with skin-repairing functions, characterized in that, Includes the following steps: S1. Fresh, intact, and unrotten fish fat is separated from the internal organs of sturgeon. Blood and impurities are removed from the fish fat, and it is chopped into small pieces. Then, it is added to a high-speed blender and blended into fat paste. The fat paste is added to distilled water, followed by dihydroquercetin and neutral protease. Enzymatic hydrolysis is carried out under ultrasonic conditions. After the enzymatic hydrolysis is completed, the enzyme is inactivated and filtered. The filtrate is centrifuged, and the supernatant clear oil is collected to obtain crude fish oil. S2. Wash the sturgeon liver, crush it with a homogenizer to obtain liver homogenate; add the liver homogenate to distilled water, then add phosphatidylserine and pepsin for enzymatic hydrolysis. After enzymatic hydrolysis, inactivate the enzyme, filter, centrifuge the filtrate, and collect the clear oil from the upper layer to obtain crude fish liver oil. S3. Wash the sturgeon skin, cut it into small pieces, add it to distilled water, stir it with a homogenizer, then add curcumin and papain, and perform enzymatic hydrolysis under ultrasonic conditions. After the enzymatic hydrolysis is completed, inactivate the enzyme, filter it, centrifuge the filtrate, collect the clear oil in the upper layer, and obtain crude fish oil from the fish skin. S4. Mix the fish fat crude fish oil from step S1, the fish liver crude fish oil from step S2, and the fish skin crude fish oil from step S3 evenly to obtain mixed fish oil, and then degumming and deacidification to obtain deacidified sturgeon fish oil. S5. The deacidified sturgeon oil in step S4 is refined to obtain the sturgeon oil with skin repair function. In step S1, the mass ratio of chyme fat to distilled water is 1:7-10, the amount of dihydroquercetin added is 0.3-0.5% of the mass of chyme fat, and the amount of neutral protease added is 2-3% of the mass of chyme fat. In step S2, the mass ratio of liver homogenate to distilled water is 1:6-8, the amount of phosphatidylserine added is 0.5-0.8%, and the amount of pepsin added is 3-4%. In step S3, the mass ratio of sturgeon skin to distilled water is 1:1-3, the amount of curcumin added is 0.6-1% of the mass of sturgeon skin, and the amount of papain added is 2-3% of the mass of sturgeon skin.

2. The extraction method according to claim 1, characterized in that, The frequency of ultrasound in step S1 is 700-900kHz, the temperature of enzymatic hydrolysis is 40-50℃, and the time is 2-3h.

3. The extraction method according to claim 1, characterized in that, The enzymatic hydrolysis in step S2 is carried out at a temperature of 35-45℃ for 5-6 hours.

4. The extraction method according to claim 1, characterized in that, The frequency of ultrasound in step S3 is 600-700 kHz, the temperature of enzymatic hydrolysis is 55-60℃, and the time is 3-4 h.

5. The extraction method according to claim 1, characterized in that, The mass ratio of crude fish fat oil, crude fish liver oil, and crude fish skin oil in step S4 is 50-60:30-40:20-30. The specific steps of degumming and deacidification are as follows: Heat the mixed fish oil to 80-85℃, then add a 60% phosphoric acid solution, stir, and centrifuge to remove the precipitate of the gelatinous substance. Take the supernatant, which is the degummed sturgeon fish oil. Heat the degummed sturgeon fish oil in a water bath to 60-70℃, add a 4mol / L sodium hydroxide solution, keep warm for 30 minutes, then take the upper oil sample, centrifuge, and wash away the residual soap residue with hot deionized water. Repeat twice to obtain deacidified sturgeon fish oil.

6. The extraction method according to claim 1, characterized in that, The specific steps in step S5 are as follows: The deacidified sturgeon oil from step S4 is refined using a molecular distillation apparatus. The feed preheating temperature is 80-90℃, the rotation speed is 200-240r / min, the distillation pressure is 5-10Pa, the distillation temperature is 100-110℃, and the feed rate is 3-5mL / min, thus obtaining the sturgeon oil.

7. A sturgeon oil with skin repair function prepared by the method according to any one of claims 1-6.

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