Extraction method of sturgeon oil with skin repairing function

Abstract

The invention discloses an extraction method of sturgeon oil with a skin repairing function. The extraction method comprises the following steps: S1, preparing crude fish oil of fish fat; s2, preparing fish liver crude fish oil; s3, preparing fish skin crude fish oil; s4, degumming and deacidifying; and S5, refining. Fish oil extracted from different parts of sturgeons is mixed according to a specific proportion, and the fish fat oil, the cod liver oil and the fish skin oil are mixed according to a specific proportion. Meanwhile, three functional components, namely dihydroquercetin (providing antioxidant protection), phosphatidylserine (enhancing cell membrane repair and nutrient absorption) and curcumin (bringing anti-inflammatory and whitening effects), are respectively added in the extraction process, so that a multi-synergistic formula system is formed; according to the prepared sturgeon oil, the skin repairing function is remarkably enhanced, and meanwhile the bioavailability and stability of the product are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic product processing, and in particular relates to a method for extracting sturgeon oil with skin repairing function. Background Art

[0002] Sturgeon, also known as sturgeon, is the largest and longest-lived freshwater fish. It is also one of the oldest and most primitive groups of fish on Earth. It is a treasure from head to toe and has high economic and research value. Sturgeon meat is thick and boneless, and its meat quality is better than salmon. It has high nutritional value. Its fish roe has a very high protein content and low sugar content, and has high edible value. my country's sturgeon farming industry has achieved remarkable results in artificial cultivation and breeding technology, and the scale and output of sturgeon farming have increased year by year.

[0003] The main components of sturgeon include essential amino acids, vitamins, minerals, phosphorus, potassium, etc., among which the protein content is as high as 18%, and the protein content of sturgeon roe can be as high as 29%. Sturgeon meat contains a variety of unsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Fish rich in unsaturated fatty acids are essential to human health. Eating sturgeon has a positive regulatory effect on human blood pressure, metabolic process, skin regeneration, etc. The abdomen, nose, tendons, bones, etc. of sturgeon can be used to cook distinctive Chinese delicacies. In addition, the content of chondroitin sulfate in its cartilage is high. Eating its bone products has the effects of enhancing immunity and anti-aging. Its fish skin can be made into glue, which is also a high-grade leather raw material.

[0004] Fish oil is a natural health food with high utilization value. The polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contained in it have the functions of inhibiting platelet aggregation, anti-thrombosis, vasodilation, regulating blood lipids and improving biomembrane fluidity. It has good curative effects in the treatment and prevention of cardiovascular diseases, diabetes, dermatitis, colorectal ulcers and tumor inhibition. In recent years, studies have also found that fish oil has the functions of improving brain function, enhancing retinal reflex ability and preventing Alzheimer's disease. With the widespread recognition of the health value of fish oil, fish oil has been widely used in health care, medicine, food, chemical industry, feed and other fields, and the market demand is increasing.

[0005] The production methods of fish oil mainly include pressing method, light alkali hydrolysis method, solvent method, water method, enzymolysis method, etc. Among them, the pressing method is mainly used for by-products of fish meal processing plants, and the fish oil extraction rate is generally low and the quality is poor; the alkali concentration of the light alkali hydrolysis method is not easy to control, too low will result in incomplete hydrolysis, too high will cause saponification of fish oil, both will reduce the extraction rate of oil, and the wastewater generated during the extraction process has a high sodium salt content and cannot be further utilized, forming new waste; the solvent method uses an organic solvent to extract the fat in the raw material, and there may be solvent residues in the extracted fish oil, so the application is limited; while the enzyme extraction conditions are mild, the damage to the functional components of fish oil is low, the quality of the fish oil produced is high, and the protease hydrolysis can be fully utilized to produce enzymolysis liquid. Chinese patent application CN110317672A discloses a method for preparing fish oil from rainbow trout fish fat, including fish oil extraction and fish oil refining; wherein, fish oil extraction includes obtaining fish fat-chopping-preheating-negative pressure heating-centrifugal separation; fish refining includes physical decolorization-molecular distillation-nitrogen filling packaging. The beneficial effects of the present invention are: the raw material has high oil content, no impurities, rich sources, and low cost; the processing technology is simple, the operation is convenient, and it is easy to industrialize production; the product has high oil yield, light color, no fishy smell and trans fatty acids, and the finished oil has good nutritional value and contains a variety of unsaturated fatty acids and fat-soluble vitamins and other nutrients. However, fish oil has the characteristic of being easily oxidized. How to reduce its oxidation rate during the preparation process so that the prepared fish oil has better skin repair function is of great significance to the art. Summary of the invention

[0006] In view of the shortcomings of the prior art, the object of the present invention is to provide a method for extracting sturgeon oil with skin repair function.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for extracting sturgeon oil with skin repair function comprises the following steps:

[0009] S1. Separate fresh, complete, non-rotten and impurity-free fish fat from the sturgeon viscera, remove blood stains and impurities from the fish fat, chop it into small pieces, then add it into a wall-breaking machine to make fat paste, add the fat paste into distilled water, then add dihydroquercetin and neutral protease, perform enzymolysis under ultrasonic conditions, inactivate the enzyme after enzymolysis, filter, centrifuge the filtrate, collect the upper clear oil, and obtain fish fat crude fish oil;

[0010] S2, washing the sturgeon liver, crushing it with a pounder to obtain liver homogenate; adding the liver homogenate into distilled water, then adding phosphatidylserine and pepsin to perform enzymolysis, inactivating the enzyme after the enzymolysis, filtering, centrifuging the filtrate, collecting the supernatant oil, and obtaining cod liver crude fish oil;

[0011] S3, wash the sturgeon skin, chop it into small pieces, then add it into distilled water, stir it with a homogenizer, then add curcumin and papain, and perform enzymolysis under ultrasonic conditions. After the enzymolysis is completed, kill the enzyme, filter it, centrifuge the filtrate, collect the upper clear oil, and obtain fish skin crude fish oil;

[0012] S4, mixing the crude fish oil from fish fat in step S1, the crude fish oil from cod liver in step S2, and the crude fish oil from fish skin in step S3 uniformly to obtain mixed fish oil, and then degumming and deacidifying to obtain deacidified sturgeon fish oil;

[0013] S5, refining the deacidified sturgeon oil in step S4 to obtain the sturgeon oil with skin repairing function.

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

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

[0016] In the present invention, fish oil in sturgeon abdominal fat is prepared by mechanical separation and ultrasound-assisted enzymatic hydrolysis, which not only ensures the purity of the fish oil but also maintains its active ingredients; at the same time, the added dihydroquercetin can effectively prevent the fish oil from being oxidized during the extraction and storage process, thereby improving the stability of the fish oil.

[0017] Preferably, in step S2, the mass ratio of the 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 temperature of the enzymatic hydrolysis in step S2 is 35-45° C. and the time is 5-6 h.

[0019] In the present invention, a combined process of mechanical crushing and enzymatic hydrolysis is adopted to extract fish oil from sturgeon liver. At the same time, phosphatidylserine is added during the extraction process. As an emulsifier, phosphatidylserine can improve the stability of the oil-water interface, help to improve the enzymatic hydrolysis efficiency and the oil extraction rate; not only the product quality is improved by improving the process, but also the product efficacy is enhanced through its own biological activity.

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

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

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

[0023] Preferably, the mass ratio of the crude fish oil of fish fat, the crude fish oil of fish liver and the crude fish oil of fish skin in step S4 is 50-60:30-40:20-30; the specific steps of the degumming and deacidification are as follows: heating the mixed fish oil to 80-85° C., then adding a phosphoric acid solution with a mass concentration of 60%, stirring and centrifuging to remove the colloid precipitate, and taking the supernatant to obtain the degummed sturgeon oil; heating the degummed sturgeon oil in a water bath to 60-70° C., adding a 4 mol / L sodium hydroxide solution, and keeping the temperature for 30 minutes, then taking the upper oil sample and centrifuging it, and then washing the residual soap stock with hot deionized water, repeating twice to obtain the deacidified sturgeon oil.

[0024] Preferably, the specific steps in step S5 are as follows: the deacidified sturgeon oil in step S4 is refined by molecular distillation equipment, with a feed preheating temperature of 80-90° C., a rotation speed of 200-240 r / min, a distillation pressure of 5-10 Pa, a distillation temperature of 100-110° C., and a feed rate of 3-5 mL / min, to obtain the sturgeon oil.

[0025] The present invention also protects a sturgeon oil with skin repairing function prepared by the method as 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 is to extract fish oil from sturgeon abdominal fat by ultrasound-assisted enzyme method. Dihydroquercetin added during the extraction process has significant anti-inflammatory and collagen synthesis promoting effects. At the same time, it can cooperate with omega-3 fatty acids such as EPA and DHA in fish oil to enhance the bioavailability of fish oil and improve its permeability, thereby promoting the skin repair function of fish oil.

[0028] (2) The method for extracting sturgeon oil with skin repair function provided by the present invention comprises the following steps: extracting fish oil from sturgeon liver by enzymatic method; the added phosphatidylserine can not only improve the extraction rate of fish oil, but also, as a phospholipid substance, has the function of maintaining the integrity of cell membranes, can promote cell renewal and repair, and can synergize with fat-soluble nutrients such as vitamin A and D in cod liver oil to enhance the transdermal absorption capacity of nutrients, thereby improving the dispersibility and bioavailability of sturgeon oil; preparing sturgeon skin fish oil by mechanical separation and ultrasound-assisted enzymatic hydrolysis; the added curcumin during the extraction process can not only prevent the oxidation of oil during the extraction process, but also assist the release of oil through its lipophilic characteristics, thereby improving the extraction rate of fish oil; and 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 effect of sturgeon oil.

[0029] (3) The method for extracting sturgeon oil with skin repair function provided by the present invention comprises mixing fish oil extracted from different parts of sturgeon in a specific ratio, wherein the fish fat oil is rich in EPA and DHA, the cod liver oil contains vitamins A and D, and the fish skin oil contains collagen components. Meanwhile, three functional ingredients are added during the extraction process: dihydroquercetin (provides antioxidant protection), phosphatidylserine (enhances cell membrane repair and nutrient absorption), and curcumin (brings anti-inflammatory and whitening effects), thereby forming a multiple synergistic formula 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, and the like, while improving the bioavailability and stability of the product. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the present 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; 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 repair function comprises the following steps:

[0034] S1. Preparation of crude fish oil from fish fat: fresh, complete, non-rotten and impurity-free fish fat is separated from the viscera of sturgeon, blood stains and impurities are removed from the fish fat, chopped into small pieces, and then added into a wall-breaking machine to make fat paste, 100g of fat paste is added into 900g of distilled water, followed by adding 0.4g of dihydroquercetin and 2.5g of neutral protease, and enzymolysis is performed at an ultrasonic frequency of 800kHz and a temperature of 45°C for 2.5h. After the enzymolysis is completed, the enzyme is inactivated in boiling water for 15min, filtered, and the filtrate is centrifuged at 5000r / min for 15min, and the supernatant oil is collected to obtain crude fish oil from fish fat;

[0035] S2. Preparation of crude fish oil from cod liver: Wash sturgeon liver, crush it with a pounder to obtain liver homogenate; add 100 g of liver homogenate to 700 g of distilled water, then add 0.7 g of phosphatidylserine and 3.5 g of pepsin, perform enzymolysis at 40° C. for 5.5 h, inactivate the enzyme in boiling water for 15 min after the enzymolysis is completed, filter, centrifuge the filtrate at 5000 r / min for 15 min, collect the supernatant oil, and obtain crude fish oil from cod liver;

[0036] S3, preparation of fish skin crude fish oil: 100g sturgeon skin was washed, chopped into 5mm×5mm small pieces, then added into 200g distilled water, stirred with a homogenizer, then added 0.8g curcumin, 2.5g papain, and enzymolysis was performed at an ultrasonic frequency of 650kHz and a temperature of 55°C for 3.5h. After the enzymolysis was completed, the enzyme was deactivated in boiling water for 15min, filtered, and the filtrate was centrifuged at 5000r / min for 15min, and the upper clear grease was collected to obtain fish skin crude fish oil;

[0037] S4, degumming and deacidification: 55g of crude fish oil from fish fat in step S1, 35g of crude fish oil from cod liver in step S2, and 25g of crude fish oil from fish skin in step S3 are mixed evenly to obtain mixed fish oil, and then the mixed fish oil is heated to 80°C, followed by adding a phosphoric acid solution having a mass concentration of 60% (the mass ratio of the mixed fish oil to the phosphoric acid solution is 1:100), stirring and centrifuging to remove the colloid precipitate, and taking the supernatant to obtain the degummed sturgeon oil; the degummed sturgeon oil is heated to 65°C in a water bath, 4mol / L of sodium hydroxide solution is added (the mass ratio of the degummed sturgeon oil to the sodium hydroxide solution is 2:100), and the mixture is kept warm for 30min, and then the upper oil sample is centrifuged, and the residual soap stock is washed off with hot deionized water, and the mixture is repeated twice to obtain the deacidified sturgeon oil;

[0038] S5, refining: the deacidified sturgeon oil in step S4 is refined by molecular distillation equipment, with feed preheating temperature of 85°C, rotation speed of 220r / min, distillation pressure of 5Pa, distillation temperature of 105°C, and feed rate of 4mL / min, to obtain the sturgeon oil.

[0039] Example 2

[0040] A method for extracting sturgeon oil with skin repair function comprises the following steps:

[0041] S1. Preparation of crude fish oil from fish fat: fresh, complete, non-rotten and impurity-free fish fat is separated from the viscera of sturgeon, blood stains and impurities are removed from the fish fat, chopped into small pieces, and then added into a wall-breaking machine to make fat paste, 100g of fat paste is added into 700g of distilled water, followed by adding 0.3g of dihydroquercetin and 2g of neutral protease, and enzymolysis is performed at an ultrasonic frequency of 700kHz and a temperature of 40°C for 3h. After the enzymolysis is completed, the enzyme is inactivated in boiling water for 15min, filtered, and the filtrate is centrifuged at 5000r / min for 15min, and the upper clear oil is collected to obtain crude fish oil from fish fat;

[0042] S2. Preparation of crude fish oil from cod liver: wash the sturgeon liver, crush it with a pounder to obtain liver homogenate; add 100 g of liver homogenate to 600 g of distilled water, then add 0.5 g of phosphatidylserine and 3 g of pepsin, perform enzymolysis at 35° C. for 6 h, inactivate the enzyme in boiling water for 15 min after the enzymolysis is completed, filter, centrifuge the filtrate at 5000 r / min for 15 min, collect the supernatant oil, and obtain crude fish oil from cod liver;

[0043] S3, preparation of fish skin crude fish oil: 100g sturgeon skin was washed and chopped into 5mm×5mm small pieces, then added into 100g distilled water, stirred with a homogenizer, then added with 0.6g curcumin and 2g papain, and enzymolyzed for 4h at an ultrasonic frequency of 600kHz and a temperature of 55°C. After the enzymolysis was completed, the enzyme was deactivated in boiling water for 15min, filtered, and the filtrate was centrifuged at 5000r / min for 15min, and the upper clear oil was collected to obtain fish skin crude fish oil;

[0044] S4, degumming and deacidification: 50g of crude fish oil from fish fat in step S1, 30g of crude fish oil from cod liver in step S2, and 20g of crude fish oil from fish skin in step S3 are mixed evenly to obtain mixed fish oil, and then the mixed fish oil is heated to 80°C, followed by adding a phosphoric acid solution having a mass concentration of 60% (the mass ratio of the mixed fish oil to the phosphoric acid solution is 1:100), stirring and centrifuging to remove the colloid precipitate, and taking the supernatant to obtain the degummed sturgeon oil; the degummed sturgeon oil is heated to 60°C in a water bath, 4mol / L of sodium hydroxide solution is added (the mass ratio of the degummed sturgeon oil to the sodium hydroxide solution is 2:100), and the mixture is kept warm for 30min, and then the upper oil sample is centrifuged, and the residual soap stock is washed off with hot deionized water, and the mixture is repeated twice to obtain the deacidified sturgeon oil;

[0045] S5, refining: the deacidified sturgeon oil in step S4 is refined by molecular distillation equipment, with feed preheating temperature of 80°C, rotation speed of 200r / min, distillation pressure of 5Pa, distillation temperature of 100-110°C, and feed rate of 3mL / min, to obtain the sturgeon oil.

[0046] Example 3

[0047] A method for extracting sturgeon oil with skin repair function comprises the following steps:

[0048] S1. Preparation of crude fish oil from fish fat: fresh, complete, non-rotten and impurity-free fish fat is separated from the viscera of sturgeon, blood stains and impurities are removed from the fish fat, minced into small pieces, and then added into a wall-breaking machine to make fat paste, 100g of fat paste is added into 1000g of distilled water, followed by adding 0.5g of dihydroquercetin and 3g of neutral protease, and enzymolysis is performed at an ultrasonic frequency of 900kHz and a temperature of 50°C for 2h. After the enzymolysis is completed, the enzyme is inactivated in boiling water for 15min, filtered, and the filtrate is centrifuged at 5000r / min for 15min, and the supernatant oil is collected to obtain crude fish oil from fish fat;

[0049] S2. Preparation of crude fish oil from cod liver: Wash sturgeon liver, crush it with a pounder to obtain liver homogenate; add 100 g of liver homogenate to 800 g of distilled water, then add 0.8 g of phosphatidylserine and 4 g of pepsin, perform enzymolysis at 45° C. for 5 h, inactivate the enzyme in boiling water for 15 min after the enzymolysis is completed, filter, centrifuge the filtrate at 5000 r / min for 15 min, collect the supernatant oil, and obtain crude fish oil from cod liver;

[0050] S3, preparation of crude fish oil from fish skin: 100g of sturgeon skin was washed and chopped into 5mm×5mm small pieces, then added into 300g of distilled water, stirred with a homogenizer, then 1g of curcumin and 3g of papain were added, and the ultrasonic frequency was 700kHz and the temperature was 60°C for enzymolysis for 3h. After the enzymolysis was completed, the enzyme was deactivated in boiling water for 15min, filtered, and the filtrate was centrifuged at 5000r / min for 15min, and the upper clear oil was collected to obtain crude fish oil from fish skin;

[0051] S4, degumming and deacidification: 60g crude fish oil from fish fat in step S1, 40g crude fish oil from cod liver in step S2, and 30g crude fish oil from fish skin in step S3 are mixed evenly to obtain mixed fish oil, and then the mixed fish oil is heated to 85°C, followed by adding a phosphoric acid solution having a mass concentration of 60% (the mass ratio of the mixed fish oil to the phosphoric acid solution is 1:100), stirring and centrifuging to remove the colloid precipitate, and taking the supernatant to obtain the degummed sturgeon oil; the degummed sturgeon oil is heated to 70°C in a water bath, 4mol / L sodium hydroxide solution is added (the mass ratio of the degummed sturgeon oil to the sodium hydroxide solution is 2:100), and the mixture is kept warm for 30min, and then the upper oil sample is centrifuged, and the residual soap stock is washed off with hot deionized water, and the mixture is repeated twice to obtain the deacidified sturgeon oil;

[0052] S5, refining: the deacidified sturgeon oil in step S4 is refined by molecular distillation equipment, with feed preheating temperature of 90° C., rotation speed of 240 r / min, distillation pressure of 10 Pa, distillation temperature of 110° C., and feed rate of 5 mL / min, to obtain the sturgeon oil.

[0053] Comparative Example 1

[0054] A method for extracting sturgeon oil with skin repair function comprises the following steps:

[0055] S1. Preparation of crude fish oil from fish fat: fresh, complete, non-rotten and impurity-free fish fat is separated from the viscera of sturgeon, blood stains and impurities are removed from the fish fat, chopped into small pieces, and then added into a wall-breaking machine to make fat paste, 100g of fat paste is added into 900g of distilled water, followed by adding 2.5g of neutral protease, and enzymolysis is performed at an ultrasonic frequency of 800kHz and a temperature of 45°C for 2.5h. After the enzymolysis is completed, the enzyme is inactivated in boiling water for 15min, filtered, and the filtrate is centrifuged at 5000r / min for 15min, and the supernatant oil is collected to obtain crude fish oil from fish fat;

[0056] S2. Preparation of crude fish oil from cod liver: Wash sturgeon liver, crush it with a pounder to obtain liver homogenate; add 100 g of liver homogenate to 700 g of distilled water, then add 0.7 g of phosphatidylserine and 3.5 g of pepsin, perform enzymolysis at 40° C. for 5.5 h, inactivate the enzyme in boiling water for 15 min after the enzymolysis is completed, filter, centrifuge the filtrate at 5000 r / min for 15 min, collect the supernatant oil, and obtain crude fish oil from cod liver;

[0057] S3, preparation of fish skin crude fish oil: 100g sturgeon skin was washed, chopped into 5mm×5mm small pieces, then added into 200g distilled water, stirred with a homogenizer, then added 0.8g curcumin, 2.5g papain, and enzymolysis was performed at an ultrasonic frequency of 650kHz and a temperature of 55°C for 3.5h. After the enzymolysis was completed, the enzyme was deactivated in boiling water for 15min, filtered, and the filtrate was centrifuged at 5000r / min for 15min, and the upper clear grease was collected to obtain fish skin crude fish oil;

[0058] S4, degumming and deacidification: 55g of crude fish oil from fish fat in step S1, 35g of crude fish oil from cod liver in step S2, and 25g of crude fish oil from fish skin in step S3 are mixed evenly to obtain mixed fish oil, and then the mixed fish oil is heated to 80°C, followed by adding a phosphoric acid solution having a mass concentration of 60% (the mass ratio of the mixed fish oil to the phosphoric acid solution is 1:100), stirring and centrifuging to remove the colloid precipitate, and taking the supernatant to obtain the degummed sturgeon oil; the degummed sturgeon oil is heated to 65°C in a water bath, 4mol / L of sodium hydroxide solution is added (the mass ratio of the degummed sturgeon oil to the sodium hydroxide solution is 2:100), and the mixture is kept warm for 30min, and then the upper oil sample is centrifuged, and the residual soap stock is washed off with hot deionized water, and the mixture is repeated twice to obtain the deacidified sturgeon oil;

[0059] S5, refining: the deacidified sturgeon oil in step S4 is refined by molecular distillation equipment, with feed preheating temperature of 85°C, rotation speed of 220r / min, distillation pressure of 5Pa, distillation temperature of 105°C, and feed rate of 4mL / min, to obtain the sturgeon oil.

[0060] Compared with Example 1, in this comparative example, dihydroquercetin was not added when preparing the crude fish oil from fish fat.

[0061] Comparative Example 2

[0062] A method for extracting sturgeon oil with skin repair function comprises the following steps:

[0063] S1. Preparation of crude fish oil from fish fat: fresh, complete, non-rotten and impurity-free fish fat is separated from the viscera of sturgeon, blood stains and impurities are removed from the fish fat, chopped into small pieces, and then added into a wall-breaking machine to make fat paste, 100g of fat paste is added into 900g of distilled water, followed by adding 0.4g of dihydroquercetin and 2.5g of neutral protease, and enzymolysis is performed at an ultrasonic frequency of 800kHz and a temperature of 45°C for 2.5h. After the enzymolysis is completed, the enzyme is inactivated in boiling water for 15min, filtered, and the filtrate is centrifuged at 5000r / min for 15min, and the supernatant oil is collected to obtain crude fish oil from fish fat;

[0064] S2. Preparation of crude fish oil from cod liver: Wash sturgeon liver, crush it with a pounder to obtain liver homogenate; add 100 g of liver homogenate to 700 g of distilled water, then add 3.5 g of pepsin, and perform enzymolysis at 40° C. for 5.5 h. After the enzymolysis is completed, inactivate the enzyme in boiling water for 15 min, filter, centrifuge the filtrate at 5000 r / min for 15 min, collect the supernatant oil, and obtain crude fish oil from cod liver;

[0065] S3, preparation of fish skin crude fish oil: 100g sturgeon skin was washed, chopped into 5mm×5mm small pieces, then added into 200g distilled water, stirred with a homogenizer, then added 0.8g curcumin, 2.5g papain, and enzymolysis was performed at an ultrasonic frequency of 650kHz and a temperature of 55°C for 3.5h. After the enzymolysis was completed, the enzyme was deactivated in boiling water for 15min, filtered, and the filtrate was centrifuged at 5000r / min for 15min, and the upper clear grease was collected to obtain fish skin crude fish oil;

[0066] S4, degumming and deacidification: 55g of crude fish oil from fish fat in step S1, 35g of crude fish oil from cod liver in step S2, and 25g of crude fish oil from fish skin in step S3 are mixed evenly to obtain mixed fish oil, and then the mixed fish oil is heated to 80°C, followed by adding a phosphoric acid solution having a mass concentration of 60% (the mass ratio of the mixed fish oil to the phosphoric acid solution is 1:100), stirring and centrifuging to remove the colloid precipitate, and taking the supernatant to obtain the degummed sturgeon oil; the degummed sturgeon oil is heated to 65°C in a water bath, 4mol / L of sodium hydroxide solution is added (the mass ratio of the degummed sturgeon oil to the sodium hydroxide solution is 2:100), and the mixture is kept warm for 30min, and then the upper oil sample is centrifuged, and the residual soap stock is washed off with hot deionized water, and the mixture is repeated twice to obtain the deacidified sturgeon oil;

[0067] S5, refining: the deacidified sturgeon oil in step S4 is refined by molecular distillation equipment, with feed preheating temperature of 85°C, rotation speed of 220r / min, distillation pressure of 5Pa, distillation temperature of 105°C, and feed rate of 4mL / min, to obtain the sturgeon oil.

[0068] Compared with Example 1, in this comparative example, no phosphatidylserine was added when preparing the cod liver crude fish oil.

[0069] Comparative Example 3

[0070] A method for extracting sturgeon oil with skin repair function comprises the following steps:

[0071] S1. Preparation of crude fish oil from fish fat: fresh, complete, non-rotten and impurity-free fish fat is separated from the viscera of sturgeon, blood stains and impurities are removed from the fish fat, chopped into small pieces, and then added into a wall-breaking machine to make fat paste, 100g of fat paste is added into 900g of distilled water, followed by adding 0.4g of dihydroquercetin and 2.5g of neutral protease, and enzymolysis is performed at an ultrasonic frequency of 800kHz and a temperature of 45°C for 2.5h. After the enzymolysis is completed, the enzyme is inactivated in boiling water for 15min, filtered, and the filtrate is centrifuged at 5000r / min for 15min, and the supernatant oil is collected to obtain crude fish oil from fish fat;

[0072] S2. Preparation of crude fish oil from cod liver: Wash sturgeon liver, crush it with a pounder to obtain liver homogenate; add 100 g of liver homogenate to 700 g of distilled water, then add 0.7 g of phosphatidylserine and 3.5 g of pepsin, perform enzymolysis at 40° C. for 5.5 h, inactivate the enzyme in boiling water for 15 min after the enzymolysis is completed, filter, centrifuge the filtrate at 5000 r / min for 15 min, collect the supernatant oil, and obtain crude fish oil from cod liver;

[0073] S3, preparation of crude fish oil from fish skin: 100g sturgeon skin was washed, chopped into 5mm×5mm small pieces, then added into 200g distilled water, stirred with a homogenizer, then 2.5g papain was added, and the ultrasonic frequency was 650kHz and the temperature was 55°C for enzymolysis for 3.5h. After the enzymolysis was completed, the enzyme was deactivated in boiling water for 15min, filtered, and the filtrate was centrifuged at 5000r / min for 15min, and the upper clear grease was collected to obtain crude fish oil from fish skin;

[0074] S4, degumming and deacidification: 55g of crude fish oil from fish fat in step S1, 35g of crude fish oil from cod liver in step S2, and 25g of crude fish oil from fish skin in step S3 are mixed evenly to obtain mixed fish oil, and then the mixed fish oil is heated to 80°C, followed by adding a phosphoric acid solution having a mass concentration of 60% (the mass ratio of the mixed fish oil to the phosphoric acid solution is 1:100), stirring and centrifuging to remove the colloid precipitate, and taking the supernatant to obtain the degummed sturgeon oil; the degummed sturgeon oil is heated to 65°C in a water bath, 4mol / L of sodium hydroxide solution is added (the mass ratio of the degummed sturgeon oil to the sodium hydroxide solution is 2:100), and the mixture is kept warm for 30min, and then the upper oil sample is centrifuged, and the residual soap stock is washed off with hot deionized water, and the mixture is repeated twice to obtain the deacidified sturgeon oil;

[0075] S5, refining: the deacidified sturgeon oil in step S4 is refined by molecular distillation equipment, with feed preheating temperature of 85°C, rotation speed of 220r / min, distillation pressure of 5Pa, distillation temperature of 105°C, and feed rate of 4mL / min, to obtain the sturgeon oil.

[0076] Compared with Example 1, curcumin was not added when preparing the fish skin crude fish oil in this comparative example.

[0077] The extraction rate of each crude fish oil in Examples 1-3 and Comparative Examples 1-3 was calculated, crude fish oil extraction rate = crude fish oil content / mass of crude fat in raw material × 100%, and the content of EPA and DHA in the prepared sturgeon oil was detected at the same time. 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 repairing 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 subjected to a skin repair efficacy experiment, as follows: SPF-grade Kunming male mice were randomly divided into a model group and Example 1, Comparative Examples 1-3 groups, with 10 mice in each group. After the mice were adaptively fed under appropriate conditions for 1 week, the modeling and medication treatment began, and 10% chloral hydrate (0.003 mL / g) was injected intraperitoneally for anesthesia. The hair was removed with sodium sulfide. After depilation, the skin was wiped with 75% ethanol, and a wound of similar size was cut on the back of the mouse with sterilized surgical scissors. 0.5 mL of the correspondingly prepared sturgeon oil was evenly applied to the wound. The model group was not treated and allowed to heal naturally. The drug was administered once a day for 7 days. Photos were taken on the 8th day after surgery, 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] It can be seen from Table 3 that the sturgeon oil prepared by the present invention has good effect of promoting skin repair and has good application prospects.

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

Claims

1. A method for extracting sturgeon oil with skin repair function, characterized in that: The following steps are involved: S1. Separate fresh, complete, non-rotten and impurity-free fish fat from the sturgeon viscera, remove blood stains and impurities from the fish fat, chop it into small pieces, then add it into a wall-breaking machine to make fat paste, add the fat paste into distilled water, then add dihydroquercetin and neutral protease, perform enzymolysis under ultrasonic conditions, inactivate the enzyme after enzymolysis, filter, centrifuge the filtrate, collect the upper clear oil, and obtain fish fat crude fish oil; S2, washing the sturgeon liver, crushing it with a pounder to obtain liver homogenate; adding the liver homogenate into distilled water, then adding phosphatidylserine and pepsin to perform enzymolysis, inactivating the enzyme after the enzymolysis, filtering, centrifuging the filtrate, collecting the supernatant oil, and obtaining cod liver crude fish oil; S3, wash the sturgeon skin, chop it into small pieces, then add it into distilled water, stir it with a homogenizer, then add curcumin and papain, and perform enzymolysis under ultrasonic conditions. After the enzymolysis is completed, kill the enzyme, filter it, centrifuge the filtrate, collect the upper clear oil, and obtain fish skin crude fish oil; S4, mixing the crude fish oil from fish fat in step S1, the crude fish oil from cod liver in step S2, and the crude fish oil from fish skin in step S3 uniformly to obtain mixed fish oil, and then degumming and deacidifying to obtain deacidified sturgeon fish oil; S5, refining the deacidified sturgeon oil in step S4 to obtain the sturgeon oil with skin repairing function.

2. The extraction method according to claim 1, characterized in that In step S1, the mass ratio of the shredded fat to the distilled water is 1:7-10, the amount of the dihydroquercetin added is 0.3-0.5% of the mass of the shredded fat, and the amount of the neutral protease added is 2-3% of the mass of the shredded fat.

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

4. The extraction method according to claim 1, characterized in that In step S2, the mass ratio of the 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%.

5. The extraction method according to claim 1, characterized in that The enzymatic hydrolysis temperature in step S2 is 35-45° C. and the time is 5-6 h.

6. The extraction method according to claim 1, characterized in that In step S3, the mass ratio of the sturgeon skin to the distilled water is 1:1-3, the added amount of the curcumin is 0.6-1% of the mass of the sturgeon skin, and the added amount of the papain is 2-3% of the mass of the sturgeon skin.

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

8. The extraction method according to claim 1, characterized in that The mass ratio of the crude fish oil of fish fat, the crude fish oil of fish liver and the crude fish oil of fish skin in step S4 is 50-60:30-40:20-30; the specific steps of the degumming and deacidification are as follows: heating the mixed fish oil to 80-85° C., then adding a phosphoric acid solution with a mass concentration of 60%, stirring and centrifuging to remove the colloid precipitate, and taking the supernatant to obtain the degummed sturgeon oil; heating the degummed sturgeon oil to 60-70° C. in a water bath, adding a 4 mol / L sodium hydroxide solution, and keeping the temperature for 30 minutes, then taking the upper oil sample and centrifuging it, and then washing the residual soap stock with hot deionized water, and repeating twice to obtain the deacidified sturgeon oil.

9. The extraction method according to claim 1, characterized in that The specific steps in step S5 are as follows: the deacidified sturgeon oil in step S4 is refined by molecular distillation equipment, with a feed preheating temperature of 80-90° C., a rotation speed of 200-240 r / min, a distillation pressure of 5-10 Pa, a distillation temperature of 100-110° C., and a feed rate of 3-5 mL / min, to obtain the sturgeon oil.

10. Sturgeon oil with skin repairing function prepared by the method according to any one of claims 1 to 9.

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