Bird's nest peptide with high antioxidant activity and preparation method of tablets of bird's nest peptide

Abstract

The invention relates to the technical field of protein and peptide, in particular to cubilose peptide with high antioxidant activity and a preparation method of tablets of the cubilose peptide. Comprising the following steps: preparing modified cubilose zymolyte; performing multiple enzymolysis on the modified cubilose zymolyte; the antioxidant stability of the cubilose peptide is enhanced. The resveratrol is grafted on the surface of cubilose protein through free radical reaction of the resveratrol, so that not only can the antioxidant capacity of the cubilose be enhanced, but also the water solubility of the cubilose can be improved, the subsequent enzyme can be better contacted with the cubilose, the enzymolysis efficiency is improved, and the enzymolysis effect is improved. According to the preparation method, cubilose peptide is added into cubilose, reduction of antioxidant activity of the cubilose peptide due to external oxidation factors and too long enzymolysis time is avoided, then the cubilose is subjected to glycosylation modification through chitosan, the dispersion and emulsification stability of the modified cubilose zymolyte can be improved, and the contact area of subsequent enzymes and the modified cubilose zymolyte is increased; the oxidation resistance and the subsequent enzymolysis efficiency are further enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of proteins and peptides, and in particular to a method for preparing a bird's nest peptide with high antioxidant activity and a tablet thereof. Background Art

[0002] Bird's nest has been praised as a nourishing and health-preserving treasure since ancient times. It is rich in nutrients, especially proteins, polysaccharides, amino acids, etc., which have certain health benefits. In recent years, with the deepening of research, the active ingredients of bird's nests, such as bird's nest peptides, have gradually become a research hotspot in the field of biomedicine and functional foods because of their multiple biological activities such as antioxidant, anti-aging, and immune regulation.

[0003] The active ingredients in bird's nests are mainly composed of proteins and carbohydrates. Due to the complex structure and poor solubility of the raw protein, it is difficult to directly utilize its biologically active ingredients. To this end, scientists use enzymatic hydrolysis technology to convert macromolecules in bird's nests into small molecule peptides, thereby improving their bioavailability. However, the existing technology often has the problem of insufficient enzymatic hydrolysis during the enzymatic hydrolysis of bird's nests, which leads to people often adding chemical reagents such as surfactants during the enzymatic hydrolysis process, or using physical means such as ultrasound assistance and microwave assistance to improve the enzymatic hydrolysis efficiency of bird's nests. However, whether adding chemical reagents or using physical means to assist, it will affect the activity of bird's nest peptides after enzymatic hydrolysis of the bird's nest, resulting in low product quality. Summary of the invention

[0004] In order to solve the above technical defects, the present invention has developed a method for preparing a bird's nest peptide with high antioxidant activity, which can effectively improve the enzymatic hydrolysis efficiency of bird's nests, ensure the stability of the enzymatic hydrolysis system, and is not easily disturbed by external oxidative factors. The prepared bird's nest peptide has high antioxidant activity and yield.

[0005] Furthermore, the present application provides a method for preparing a bird's nest peptide with high antioxidant activity, comprising the following steps: S1: Preparation of modified bird's nest hydrolysate The bird's nest is placed in clean water for soaking, filtered, and then placed in a colloid mill for shearing to obtain a bird's nest slurry, ascorbic acid, deionized water, and hydrogen peroxide solution are stirred and evenly mixed, and then added to the bird's nest slurry, and resveratrol is added after sufficient oscillation and stirring, and then dialyzed at low temperature to obtain a resveratrol-grafted bird's nest slurry, chitosan and resveratrol-grafted bird's nest slurry are placed in a PBS solution and mixed evenly, and then freeze-dried and added to a saturated KCl solution for sealing, and then filtered after standing to obtain a modified bird's nest enzymatic hydrolysate; S2: Multiple enzymatic hydrolysis of modified bird's nest hydrolysate The modified bird's nest hydrolysate and purified water are mixed and stirred, and the pH is adjusted, the temperature is raised and chitosanase is added for hydrolysis, and then the temperature is raised again and papain is added for hydrolysis to obtain a preliminary hydrolyzed bird's nest solution, the preliminary hydrolyzed bird's nest solution is hydrolyzed with flavor protease under high hydrostatic pressure, and filtered and centrifuged to obtain a bird's nest peptide solution; S3: Enhancement of the antioxidant stability of bird's nest peptide The bird's nest peptide solution, yeast extract and trehalose are mixed and then subjected to ultrasonic water bath treatment to obtain a bird's nest peptide antioxidant solution. The bird's nest peptide antioxidant solution and β-cyclodextrin are mixed and homogenized, then freeze-dried, and ground into powder to obtain a bird's nest peptide with high antioxidant activity.

[0006] Furthermore, step S1 of preparing the modified bird's nest enzymatic hydrolysate comprises the following steps: S1.1: 2-3 parts by weight of bird's nest is placed in a container, 80-100 parts by weight of clean water is added, and the mixture is soaked in an environment of 12-15°C for 3-5 hours, and then filtered using a filter sieve with an aperture of 0.2-0.5 mm to obtain a foamed bird's nest, and the foamed bird's nest is placed in a colloid mill, the gap between the grinding teeth of the colloid mill is adjusted to 150-200 μm, and sheared for 30-35 minutes to obtain a bird's nest slurry; S1.2: 0.2-0.3 parts by weight of ascorbic acid and 60-80 parts by weight of deionized water are placed in a container, stirred at a stirring speed of 150-200 rpm for 8-10 minutes, and then 0.8-1 parts by weight of hydrogen peroxide solution are added. Stirring is continued at the same stirring speed for 8-10 minutes, and then 10-12 parts by weight of bird's nest slurry are added. After sufficient shaking and stirring, a bird's nest slurry pretreatment liquid is obtained. Resveratrol obtained by grape extraction is added to the bird's nest slurry pretreatment liquid to allow resveratrol to be added to the bird's nest slurry pretreatment liquid. The final concentration of the bird's nest slurry pretreatment liquid is 0.4-0.5mmol / L, and then the bird's nest slurry pretreatment liquid added with resveratrol is placed in an environment of 3-4°C and stirred at a stirring speed of 80-120rpm for 20-24 hours, and then placed in a dialysis bag with a molecular weight cutoff of 1000-1500Da for water dialysis for 25-30 hours to obtain resveratrol-grafted bird's nest slurry, and the resveratrol-grafted bird's nest slurry is stored in an anaerobic environment at 2-4°C for standby use; S1.3: Place chitosan and resveratrol grafted bird's nest slurry in a container at a mass ratio of 1: (1.5-2), add 100-120 times the volume of PBS solution and stir evenly, then place in a freeze dryer for freeze drying to obtain a modified bird's nest freeze-dried material, soak the modified bird's nest freeze-dried material in a saturated KCl solution for sealed storage, then stand at 50-55°C for 20-24 hours, and filter to obtain the modified bird's nest enzymatic hydrolysate.

[0007] Furthermore, step S2 of modifying the multiple enzymatic hydrolysis of the bird's nest hydrolysate comprises the following steps: S2.1: 1-2 parts by weight of the modified bird's nest hydrolysate and 60-80 parts by weight of purified water are mixed in a container, 0.1-0.2 mol / L acetic acid aqueous solution is added while stirring to adjust the pH to 5.5-6, the temperature is raised to 42-45°C, chitosanase is added at an enzyme-substrate ratio of 2000-2500 U / mg, the temperature is maintained for 3-4 minutes with magnetic stirring, the temperature is then raised to 55-60°C, papain is added at an enzyme-substrate ratio of 4000-4500 U / mg, the temperature is maintained for 6-8 minutes with magnetic stirring, the temperature is then raised to 95-100°C and kept for 10-15 minutes to inactivate the enzyme, and a preliminary enzymatic bird's nest solution is obtained; S2.2: Add the preliminary enzymatic bird's nest solution to the PBS solution at a volume ratio of 1: (1-2), the concentration of the PBS solution is 40-50mmol / L, the pH is 7.4, and then add the flavor protease at an enzyme-substrate ratio of 6000-7500U / mg. After mixing evenly, vacuum pack it in a polyethylene bag and place it in a high hydrostatic pressure treatment equipment. Adjust the temperature to 50-55℃ and the hydrostatic pressure to 100-150Mpa. Treat for 3-5 hours to obtain an enzymatic bird's nest solution. Treat the enzymatic bird's nest solution at 95-100℃ for 15-20 minutes, cool it to 25-30℃, filter it with a 1-2mm filter membrane, and then centrifuge it at 10000-12000rpm for 15-20 minutes. Retain the supernatant to obtain a bird's nest peptide solution.

[0008] Furthermore, step S3 of strengthening the antioxidant stability of bird's nest peptide comprises the following steps: S3.1: 10-15 parts by weight of bird's nest peptide solution, 0.4-0.6 parts by weight of yeast extract and 0.3-0.4 parts by weight of trehalose are mixed and placed in a sealed container, and then placed in an ultrasonic water bath, the power of the ultrasonic water bath is adjusted to 350-400W, the temperature is 50-52°C, and the ultrasonic treatment is stopped after 6-8 minutes, and the temperature is maintained for 20-25 minutes in a water bath to obtain a bird's nest peptide antioxidant solution; S3.2: Mix the bird's nest peptide antioxidant solution and β-cyclodextrin in a mass ratio of 1: (3-4) and place them in a homogenizer. Adjust the homogenization power to 6-7.5kw and homogenize for 10-20 minutes. Then place them in a vacuum dryer and freeze-dry them at -70℃--40℃. Then grind them into powder to obtain bird's nest peptide with high antioxidant activity.

[0009] Furthermore, in step S1.2, the concentration of the ascorbic acid and hydrogen peroxide solution in deionized water is 4-4.5 mol / L.

[0010] Furthermore, the PBS solution in step S1.3 is prepared by mixing KH2PO4, Na2HPO4 and NaCl with deionized water in a mass ratio of 1:6:33, with a concentration of 20-25 mmol / L and a pH of 7.2-7.4.

[0011] Furthermore, the enzyme-substrate ratio in step S2 refers to the ratio of enzyme activity to the dry weight of the modified bird's nest enzymatic hydrolysate.

[0012] Furthermore, the glutathione content of the yeast extract in step S3.1 is 30%.

[0013] Furthermore, the present application provides a bird's nest peptide with high antioxidant activity, which is prepared by the above-mentioned method for preparing a bird's nest peptide with high antioxidant activity.

[0014] Furthermore, the present application provides a method for preparing a bird's nest peptide tablet with high antioxidant activity, comprising the following steps: the bird's nest peptide with high antioxidant activity prepared by the above-mentioned method for preparing a bird's nest peptide with high antioxidant activity, starch and microcrystalline cellulose are stirred and mixed evenly in a mass ratio of 1: (1-1.5): (0.5-1), and then 25-30wt% of ethanol is added and continued to stir to obtain a soft material, and soft material particles are obtained after passing through a 20-25 mesh sieve, and the soft material particles, carboxymethyl starch and magnesium stearate are mixed evenly in a mass ratio of 1: (0.2-0.25): (0.015-0.02) and placed in a tablet press for tableting to obtain a bird's nest peptide tablet with high antioxidant activity.

[0015] The beneficial effects are as follows: 1. The bird's nest slurry is prepared by foaming the bird's nest and then placing it in a colloid mill to shear it into nanoparticles. The bird's nest slurry is placed in a mixed solution of ascorbic acid, deionized water and hydrogen peroxide solution, and then resveratrol is added for continuous stirring. In this process, ascorbic acid promotes hydrogen peroxide to generate highly active hydroxyl free radicals through its reducing properties. These highly active hydroxyl free radicals act on the protein in the bird's nest to induce a free radical reaction. At this time, resveratrol also participates in the free radical reaction through phenolic hydroxyl groups, thereby being grafted on the protein surface, which can not only enhance the antioxidant capacity of the bird's nest It can also improve the water solubility of the bird's nest, help the subsequent enzyme to better contact with the bird's nest, improve the enzymatic hydrolysis efficiency, avoid external oxidative factors and long enzymatic hydrolysis time leading to a decrease in the antioxidant activity of the bird's nest peptide, and then use chitosan to glycosylate the bird's nest, which can not only improve the dispersion and emulsification stability of the modified bird's nest hydrolysate, enhance the contact area between the subsequent enzyme and the modified bird's nest hydrolysate, improve the enzymatic hydrolysis efficiency, but also further enhance the antioxidant capacity. In summary, the enzymatic hydrolysis efficiency and antioxidant capacity of the bird's nest are improved, thereby ensuring the high antioxidant activity of the enzymatic hydrolysis process and the bird's nest peptide obtained after enzymatic hydrolysis.

[0016] The invention uniformly disperses the modified bird's nest enzymolyzate in purified water, and then adjusts the pH and temperature to first enzymolyze chitosan, so that part of the glycosylated chitosan can be enzymolyzed into smaller monosaccharides, reducing the shielding of chitosan on bird's nest protein, making it easier for subsequent proteases to combine with proteins and catalyze hydrolysis, while controlling the enzymolysis time, maintaining an appropriate glycosylation state, stabilizing the solution system, promoting subsequent pre-enzymolysis of papain and complete enzymolysis of flavor protease, and improving the activity, nutritional value and flavor taste of the bird's nest peptide product.

[0017] The present invention obtains a bird's nest peptide antioxidant solution by mixing a bird's nest peptide solution, a yeast extract and trehalose in an ultrasonic water bath, and then freeze-drying the bird's nest peptide antioxidant solution and β-cyclodextrin after homogenization. The bird's nest peptide, the yeast extract and the trehalose are coated together by β-cyclodextrin, which can not only further enhance the antioxidant capacity of the bird's nest peptide, but also avoid the influence of the external environment and the activity of the bird's nest peptide during tableting. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a flow chart of the preparation method of the bird's nest peptide with high antioxidant activity used in the embodiments of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0020] Example 1: A method for preparing a bird's nest peptide with high antioxidant activity, such as Figure 1 As shown, the following steps are included: S1: Preparation of modified bird's nest hydrolysate S1.1: 2 parts by weight of bird's nests are placed in a container, 80 parts by weight of clean water are added, and the mixture is soaked in an environment of 12° C. for 3 hours, and then filtered using a filter sieve with a pore size of 0.2 mm to obtain a foamed bird's nest, and the foamed bird's nests are placed in a colloid mill, the gap between the grinding teeth of the colloid mill is adjusted to 150 μm, and sheared for 30 minutes to obtain a bird's nest slurry; S1.2: 0.2 parts by weight of ascorbic acid and 60 parts by weight of deionized water are placed in a container, stirred at a stirring speed of 150 rpm for 8 minutes, then 0.8 parts by weight of a hydrogen peroxide solution with a concentration of 4 mol / L is added, stirring is continued at the same stirring speed for 8 minutes, then 10 parts by weight of bird's nest slurry is added, and bird's nest slurry pretreatment liquid is obtained after sufficient oscillation and stirring, and resveratrol obtained by grape extraction is added to the bird's nest slurry pretreatment liquid to make the final concentration of resveratrol in the bird's nest slurry pretreatment liquid be 0.4 mmol / L, and then the bird's nest slurry pretreatment liquid with resveratrol is placed in an environment of 3°C and stirred at a stirring speed of 80 rpm for 20 hours, and then placed in a dialysis bag with a molecular weight cutoff of 1000 Da for water dialysis for 25 hours to obtain resveratrol-grafted bird's nest slurry, and the resveratrol-grafted bird's nest slurry is stored in an anaerobic environment at 2°C for standby use; S1.3: Place chitosan and resveratrol grafted bird's nest slurry in a mass ratio of 1:1.5 in a container, add 100 times the volume of PBS solution and stir evenly. The PBS solution is prepared by KH2PO4, Na2HPO4 and NaCl in a mass ratio of 1:6:33 with deionized water, and its concentration is 20mmol / L and pH is 7.2. Then place it in a freeze dryer for freeze-drying to obtain a modified bird's nest freeze-dried material. Soak the modified bird's nest freeze-dried material in a saturated KCl solution for sealed storage, and then let it stand at 50°C for 20 hours and filter to obtain a modified bird's nest enzymatic hydrolysate.

[0021] S2: Multiple enzymatic hydrolysis of modified bird's nest hydrolysate S2.1: 1 part by weight of the modified bird's nest hydrolysate and 60 parts by weight of purified water were mixed in a container, 0.1 mol / L acetic acid aqueous solution was added while stirring to adjust the pH to 5.5, the temperature was raised to 42°C, chitosanase was added at an enzyme-substrate ratio of 2000U / mg, the temperature was maintained for 3 minutes with magnetic stirring, then the temperature was raised to 55°C, papain was added at an enzyme-substrate ratio of 4000U / mg, the temperature was maintained for 6 minutes with magnetic stirring, then the temperature was raised to 95°C and kept warm for 10 minutes to inactivate the enzyme, and a preliminary enzymatic bird's nest solution was obtained; S2.2: Add the preliminary enzymatic bird's nest solution into the PBS solution at a volume ratio of 1:1. The concentration of the PBS solution is 40mmol / L and the pH is 7.4. Then, add the flavor protease at an enzyme-substrate ratio of 6000U / mg. After mixing evenly, vacuum pack it in a polyethylene bag and put it into a high hydrostatic pressure treatment equipment. Adjust the temperature to 50°C and the hydrostatic pressure to 100Mpa. Treat for 3 hours to obtain an enzymatic bird's nest solution. Treat the enzymatic bird's nest solution at 95°C for 15 minutes. After cooling to 25°C, filter it with a 1mm filter membrane and centrifuge it at 10,000rpm for 15 minutes. Retain the supernatant to obtain a bird's nest peptide solution.

[0022] S3: Enhancement of the antioxidant stability of bird's nest peptide S3.1: 10 parts by weight of bird's nest peptide solution, 0.4 parts by weight of yeast extract with a glutathione content of 30% and 0.3 parts by weight of trehalose are mixed and placed in a sealed container, and then placed in an ultrasonic water bath, the power of the ultrasonic water bath is adjusted to 350W, the temperature is adjusted to 50°C, and the ultrasonic treatment is stopped after 6 minutes, and the temperature is maintained for 20 minutes in a water bath to obtain a bird's nest peptide antioxidant solution; S3.2: Mix the bird's nest peptide antioxidant solution and β-cyclodextrin in a mass ratio of 1:3 and place in a homogenizer. Adjust the homogenization power to 6 kW and homogenize for 10 minutes. Then place in a vacuum dryer and freeze-dry at -70°C. Then grind into powder to obtain a bird's nest peptide with high antioxidant activity.

[0023] A method for preparing a bird's nest peptide tablet with high antioxidant activity comprises the following steps: uniformly stirring a bird's nest peptide with high antioxidant activity prepared by the above-mentioned method for preparing a bird's nest peptide with high antioxidant activity, starch and microcrystalline cellulose at a mass ratio of 1:1:0.5, then adding 25wt% of ethanol and continuing stirring to obtain a soft material, passing through a 20-mesh sieve to obtain soft material particles, uniformly mixing the soft material particles, carboxymethyl starch and magnesium stearate at a mass ratio of 1:0.2:0.015, and then placing in a tablet press for tableting to obtain a bird's nest peptide tablet with high antioxidant activity.

[0024] Example 2: A method for preparing a bird's nest peptide with high antioxidant activity, such as Figure 1 As shown, the following steps are included: S1: Preparation of modified bird's nest hydrolysate S1.1: 3 parts by weight of bird's nests are placed in a container, 100 parts by weight of clean water is added, and the mixture is soaked in an environment of 12° C. for 3 hours, and then filtered using a filter sieve with a pore size of 0.2 mm to obtain a foamed bird's nest, and the foamed bird's nest is placed in a colloid mill, the gap between the grinding teeth of the colloid mill is adjusted to 150 μm, and sheared for 30 minutes to obtain a bird's nest slurry; S1.2: 0.3 parts by weight of ascorbic acid and 80 parts by weight of deionized water are placed in a container, stirred at a stirring speed of 150 rpm for 8 minutes, then 1 part by weight of a hydrogen peroxide solution with a concentration of 4 mol / L is added, stirring is continued at the same stirring speed for 8 minutes, then 12 parts by weight of bird's nest slurry is added, and bird's nest slurry pretreatment liquid is obtained after sufficient oscillation and stirring, and resveratrol obtained by grape extraction is added to the bird's nest slurry pretreatment liquid to make the final concentration of resveratrol in the bird's nest slurry pretreatment liquid be 0.4 mmol / L, and then the bird's nest slurry pretreatment liquid with resveratrol is placed in an environment of 3°C and stirred at a stirring speed of 80 rpm for 20 hours, and then placed in a dialysis bag with a molecular weight cutoff of 1000 Da for water dialysis for 25 hours to obtain resveratrol-grafted bird's nest slurry, and the resveratrol-grafted bird's nest slurry is stored in an anaerobic environment at 2°C for standby use; S1.3: Place chitosan and resveratrol grafted bird's nest slurry in a mass ratio of 1:2 in a container, add 100 times the volume of PBS solution and stir evenly. The PBS solution is prepared by KH2PO4, Na2HPO4 and NaCl in a mass ratio of 1:6:33 with deionized water, and its concentration is 20mmol / L and pH is 7.2. Then place it in a freeze dryer for freeze-drying to obtain a modified bird's nest freeze-dried material. Soak the modified bird's nest freeze-dried material in a saturated KCl solution for sealed storage, and then let it stand at 50°C for 20 hours and filter to obtain a modified bird's nest enzymatic hydrolysate.

[0025] S2: Multiple enzymatic hydrolysis of modified bird's nest hydrolysate S2.1: 2 parts by weight of the modified bird's nest hydrolysate and 80 parts by weight of purified water were mixed in a container, 0.1 mol / L acetic acid aqueous solution was added while stirring to adjust the pH to 5.5, the temperature was raised to 42°C, chitosanase was added at an enzyme-substrate ratio of 2000U / mg, the temperature was maintained for 4 minutes with magnetic stirring, then the temperature was raised to 55°C, papain was added at an enzyme-substrate ratio of 4000U / mg, the temperature was maintained for 6 minutes with magnetic stirring, then the temperature was raised to 95°C and kept for 10 minutes to inactivate the enzyme, and a preliminary enzymatic bird's nest solution was obtained; S2.2: Add the preliminary enzymatic bird's nest solution into the PBS solution at a volume ratio of 1:2. The concentration of the PBS solution is 40mmol / L and the pH is 7.4. Then, add the flavor protease at an enzyme-substrate ratio of 6000U / mg. After mixing evenly, vacuum pack it in a polyethylene bag and put it into a high hydrostatic pressure treatment equipment. Adjust the temperature to 50°C and the hydrostatic pressure to 100Mpa. Treat for 8 hours to obtain the enzymatic bird's nest solution. Treat the enzymatic bird's nest solution at 95°C for 15 minutes. After cooling to 25°C, filter it with a 1mm filter membrane and centrifuge it at 10,000rpm for 15 minutes. Retain the supernatant to obtain the bird's nest peptide solution.

[0026] S3: Enhancement of the antioxidant stability of bird's nest peptide S3.1: 15 parts by weight of bird's nest peptide solution, 0.6 parts by weight of yeast extract with a glutathione content of 30% and 0.4 parts by weight of trehalose are mixed and placed in a sealed container, and then placed in an ultrasonic water bath, the power of the ultrasonic water bath is adjusted to 350W, the temperature is adjusted to 50°C, and the ultrasonic treatment is stopped after 6 minutes, and the temperature is maintained for 20 minutes in a water bath to obtain a bird's nest peptide antioxidant solution; S3.2: Mix the bird's nest peptide antioxidant solution and β-cyclodextrin in a mass ratio of 1:4 and place them in a homogenizer. Adjust the homogenization power to 6 kW and homogenize for 10 minutes. Then place them in a vacuum dryer and freeze-dry them at -70°C. Then grind them into powder to obtain bird's nest peptide with high antioxidant activity.

[0027] A method for preparing a bird's nest peptide tablet with high antioxidant activity comprises the following steps: uniformly stirring a bird's nest peptide with high antioxidant activity prepared by the above method for preparing a bird's nest peptide with high antioxidant activity, starch and microcrystalline cellulose at a mass ratio of 1:1.5:1, then adding 30wt% of ethanol and continuing stirring to obtain a soft material, passing through a 20-mesh sieve to obtain soft material particles, uniformly mixing the soft material particles, carboxymethyl starch and magnesium stearate at a mass ratio of 1:0.25:0.02, and then placing in a tablet press for tableting to obtain a bird's nest peptide tablet with high antioxidant activity.

[0028] Example 3: A method for preparing a bird's nest peptide with high antioxidant activity, such as Figure 1 As shown, the following steps are included: S1: Preparation of modified bird's nest hydrolysate S1.1: 2 parts by weight of bird's nests are placed in a container, 80 parts by weight of clean water are added, and the mixture is soaked in an environment of 15°C for 5 hours, and then filtered using a filter sieve with a pore size of 0.5 mm to obtain a foamed bird's nest, and the foamed bird's nests are placed in a colloid mill, the gap between the grinding teeth of the colloid mill is adjusted to 200 μm, and sheared for 35 minutes to obtain a bird's nest slurry; S1.2: 0.2 parts by weight of ascorbic acid and 60 parts by weight of deionized water are placed in a container, stirred at a stirring speed of 200 rpm for 10 minutes, then 0.8 parts by weight of a hydrogen peroxide solution with a concentration of 4.5 mol / L is added, stirring is continued at the same stirring speed for 10 minutes, then 10 parts by weight of bird's nest slurry is added, and bird's nest slurry pretreatment liquid is obtained after sufficient oscillation and stirring, and resveratrol obtained by grape extraction is added to the bird's nest slurry pretreatment liquid to make the final concentration of resveratrol in the bird's nest slurry pretreatment liquid be 0.5 mmol / L, and then the bird's nest slurry pretreatment liquid with resveratrol is placed in an environment of 4°C and stirred at a stirring speed of 120 rpm for 24 hours, and then placed in a dialysis bag with a molecular weight cutoff of 1500 Da for water dialysis for 30 hours to obtain resveratrol-grafted bird's nest slurry, and the resveratrol-grafted bird's nest slurry is stored in an anaerobic environment at 4°C for standby use; S1.3: Place chitosan and resveratrol grafted bird's nest slurry in a mass ratio of 1:2 in a container, add 120 times the volume of PBS solution and stir evenly. The PBS solution is prepared by KH2PO4, Na2HPO4 and NaCl in a mass ratio of 1:6:33 with deionized water, and its concentration is 25mmol / L and pH is 7.4. Then place it in a freeze dryer for freeze-drying to obtain a modified bird's nest freeze-dried material. Soak the modified bird's nest freeze-dried material in a saturated KCl solution for sealed storage, and then let it stand at 55°C for 24 hours and filter to obtain a modified bird's nest enzymatic hydrolysate.

[0029] S2: Multiple enzymatic hydrolysis of modified bird's nest hydrolysate S2.1: 1 part by weight of the modified bird's nest hydrolysate and 60 parts by weight of purified water were mixed in a container, 0.2 mol / L acetic acid aqueous solution was added while stirring to adjust the pH to 6, the temperature was raised to 45°C, chitosanase was added at an enzyme-substrate ratio of 2500U / mg, the temperature was maintained for 4 minutes with magnetic stirring, the temperature was then raised to 60°C, papain was added at an enzyme-substrate ratio of 4500U / mg, the temperature was maintained for 8 minutes with magnetic stirring, the temperature was then raised to 100°C and kept for 15 minutes to inactivate the enzyme, and a preliminary enzymatic bird's nest solution was obtained; S2.2: Add the preliminary enzymatic bird's nest solution into the PBS solution at a volume ratio of 1:2. The concentration of the PBS solution is 50mmol / L and the pH is 7.4. Then, add the flavor protease at an enzyme-substrate ratio of 7500U / mg. After mixing evenly, vacuum pack it in a polyethylene bag and put it into a high hydrostatic pressure treatment equipment. Adjust the temperature to 55°C and the hydrostatic pressure to 150Mpa. Treat for 5 hours to obtain the enzymatic bird's nest solution. Treat the enzymatic bird's nest solution at 100°C for 20 minutes. After cooling to 30°C, filter it with a 2mm filter membrane and centrifuge it at 12000rpm for 20 minutes. Keep the supernatant to obtain the bird's nest peptide solution.

[0030] S3: Enhancement of the antioxidant stability of bird's nest peptide S3.1: 10 parts by weight of bird's nest peptide solution, 0.4 parts by weight of yeast extract with a glutathione content of 30% and 0.3 parts by weight of trehalose are mixed and placed in a sealed container, and then placed in an ultrasonic water bath, the power of the ultrasonic water bath is adjusted to 400W, the temperature is adjusted to 52°C, and the ultrasonic treatment is stopped after 8 minutes, and the temperature is maintained for 25 minutes in a water bath to obtain a bird's nest peptide antioxidant solution; S3.2: Mix the bird's nest peptide antioxidant solution and β-cyclodextrin in a mass ratio of 1:3 and place them in a homogenizer. Adjust the homogenization power to 7.5kw and homogenize for 20 minutes. Then place them in a vacuum dryer and freeze-dry them at -40°C. Then grind them into powder to obtain bird's nest peptide with high antioxidant activity.

[0031] A method for preparing a bird's nest peptide tablet with high antioxidant activity comprises the following steps: uniformly stirring a bird's nest peptide with high antioxidant activity prepared by the above method for preparing a bird's nest peptide with high antioxidant activity, starch and microcrystalline cellulose at a mass ratio of 1:1:0.5, then adding 25wt% of ethanol and continuing stirring to obtain a soft material, passing through a 25-mesh sieve to obtain soft material particles, uniformly mixing the soft material particles, carboxymethyl starch and magnesium stearate at a mass ratio of 1:0.2:0.015, and then placing in a tablet press for tableting to obtain a bird's nest peptide tablet with high antioxidant activity.

[0032] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 removes step S1.2, and replaces the resveratrol-grafted bird's nest pulp in step S1.3 with a bird's nest pulp of equal mass. The remaining steps are the same as Example 1 to obtain a bird's nest peptide solution, which is recorded as Comparative Example 1.

[0033] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, chitosan is not added in step S1.3 to obtain a modified bird's nest enzymatic hydrolysate, and the remaining steps are the same as in Example 1 to obtain a bird's nest peptide solution, which is recorded as Comparative Example 2.

[0034] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that, in Comparative Example 3, chitosanase is not added for enzymatic hydrolysis in step S2.1. After adjusting the pH, the temperature is directly raised to 55°C, papain is added at an enzyme-substrate ratio of 4000U / mg, the temperature is maintained for 6 minutes of magnetic stirring, and then the temperature is raised to 95°C and kept warm for 10 minutes to inactivate the enzyme to obtain a preliminary enzymatic hydrolysis bird's nest solution. The remaining steps are the same as in Example 1 to obtain a bird's nest peptide solution, which is recorded as Comparative Example 3.

[0035] Comparative Example 4: The difference between Comparative Example 4 and Example 1 is that Comparative Example 4 removes step S3.1, replaces the bird's nest peptide antioxidant solution in step S3.2 with a bird's nest peptide solution of equal mass to obtain bird's nest peptide, replaces the subsequent bird's nest peptide with high antioxidant activity with bird's nest peptide, and adds 0.4 parts by weight of yeast extract and 0.3 parts by weight of trehalose during the tableting process of high antioxidant activity bird's nest peptide tablets. The remaining steps are the same as in Example 1 to obtain high antioxidant activity bird's nest peptide tablets, which are recorded as Comparative Example 4.

[0036] Experiment 1: Take the bird's nest peptide solution prepared in Example 1 and Comparative Examples 1-3, and measure the A516nm absorbance in a microplate reader according to the operating steps of the instruction manual of the DPPH free radical scavenging ability kit, and record it as the bird's nest peptide absorbance. Use 80% methanol as a blank control to measure the A516nm absorbance, and record it as the blank absorbance. Calculate the DPPH free radical scavenging rate, DPPH free radical scavenging rate = 1-bird's nest peptide absorbance / blank absorbance × 100%, record it as the experimental group, repeat the parallel experiment once, record it as the parallel group, record the data and make a table, as shown in Table 1.

[0037] Table 1: DPPH free radical scavenging rate of bird's nest peptides

[0038] Experiment 2: Take the bird's nest peptide solution prepared in Example 1 and Comparative Examples 1-3, use a UV-visible spectrophotometer to measure the bird's nest peptide content in the bird's nest peptide solution, and calculate the bird's nest peptide yield. Bird's nest peptide yield = (bird's nest peptide mass / bird's nest mass) × 100%, and record the data as shown in Table 2.

[0039] Table 2: Yield of bird's nest peptides

[0040] It can be seen from the data of the examples and comparative example 1 in Tables 1 and 2 that the DPPH radical scavenging rate of the prepared bird's nest peptides decreased when the bird's nest pulp was not treated with resveratrol, and the yield of bird's nest peptides also decreased. This proves that treating the bird's nest pulp with resveratrol can not only enhance the antioxidant capacity of the bird's nest, but also improve the enzymatic hydrolysis efficiency.

[0041] It can be seen from the data of the embodiment and comparative example 2 in Table 1 and Table 2 that the DPPH radical scavenging rate of the obtained bird's nest peptide is reduced, and the yield of the bird's nest peptide is also reduced when the resveratrol grafted bird's nest pulp is not glycosylated by chitosan. It can be proved that the glycosylation modification of the bird's nest by chitosan can not only improve the dispersion and emulsification stability of the modified bird's nest hydrolysate, enhance the contact area between the subsequent enzyme and the modified bird's nest hydrolysate, improve the enzymatic hydrolysis efficiency, but also further enhance the antioxidant capacity.

[0042] It can be seen from the data of the examples and comparative example 3 in Tables 1 and 2 that the DPPH radical scavenging rate of the obtained bird's nest peptide decreased, and the yield of the bird's nest peptide also decreased when the modified bird's nest hydrolysate was not hydrolyzed by chitosanase. This proves that chitosanase can increase the activity of the bird's nest peptide product and increase the yield of the bird's nest peptide.

[0043] Experiment 3: Take the high antioxidant activity bird's nest peptide tablets prepared in Example 4 and Comparative Example 4, respectively, and mix them evenly with the DPPH standard solution at a mass ratio of 1:3 at room temperature, let it stand for 35 minutes, read the absorbance at 516nm of the ultraviolet spectrophotometer, and record it as the absorbance of the experimental group. Mix deionized water and the DPPH standard solution at a mass ratio of 1:3, let it stand for 35 minutes, read the absorbance at 516nm of the ultraviolet spectrophotometer, and record it as the absorbance of the blank group. Calculate the DPPH free radical scavenging rate, DPPH free radical scavenging rate = 1-absorbance of the experimental group / absorbance of the blank group × 100%, repeat three parallel experiments and take the average value, record the data and make a table, as shown in Table 3.

[0044] Table 3: DPPH free radical scavenging rate of bird's nest peptide tablets with high antioxidant activity

[0045] It can be seen from the data of the examples and comparative example 4 in Table 3 that when the bird's nest peptide, yeast extract and trehalose are not coated with β-cyclodextrin, the antioxidant performance of the obtained bird's nest peptide tablets with high antioxidant activity is reduced, and it can be seen from the DPPH free radical scavenging rate of the examples in Table 1 that the antioxidant capacity of the bird's nest peptide tablets with high antioxidant activity is greater than the antioxidant capacity of the bird's nest peptide. It can be proved that the bird's nest peptide, yeast extract and trehalose are coated together by β-cyclodextrin, which can not only further enhance the antioxidant capacity of the bird's nest peptide, but also avoid the influence of the external environment and the activity of the bird's nest peptide during tableting.

[0046] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for preparing a bird's nest peptide with high antioxidant activity and a tablet thereof, characterized in that: The following steps are involved: S1: Preparation of modified bird's nest hydrolysate The bird's nest is placed in clean water for soaking, filtered, and then placed in a colloid mill for shearing to obtain a bird's nest slurry, ascorbic acid, deionized water, and hydrogen peroxide solution are stirred and evenly mixed, and then added to the bird's nest slurry, and resveratrol is added after sufficient oscillation and stirring, and then dialyzed at low temperature to obtain a resveratrol-grafted bird's nest slurry, chitosan and resveratrol-grafted bird's nest slurry are placed in a PBS solution and mixed evenly, and then freeze-dried and added to a saturated KCl solution for sealing, and then filtered after standing to obtain a modified bird's nest enzymatic hydrolysate; S2: Multiple enzymatic hydrolysis of modified bird's nest hydrolysate The modified bird's nest hydrolysate and purified water are mixed and stirred, and the pH is adjusted, the temperature is raised and chitosanase is added for hydrolysis, and then the temperature is raised again and papain is added for hydrolysis to obtain a preliminary hydrolyzed bird's nest solution, the preliminary hydrolyzed bird's nest solution is hydrolyzed with flavor protease under high hydrostatic pressure, and filtered and centrifuged to obtain a bird's nest peptide solution; S3: Enhancement of the antioxidant stability of bird's nest peptide The bird's nest peptide solution, yeast extract and trehalose are mixed and then subjected to ultrasonic water bath treatment to obtain a bird's nest peptide antioxidant solution. The bird's nest peptide antioxidant solution and β-cyclodextrin are mixed and homogenized, then freeze-dried, and ground into powder to obtain a bird's nest peptide with high antioxidant activity.

2. The method for preparing a bird's nest peptide with high antioxidant activity and a tablet thereof according to claim 1, characterized in that: Step S1: preparing a modified bird's nest enzymatic hydrolysate, comprising the following steps: S1.1: 2-3 parts by weight of bird's nest is placed in a container, 80-100 parts by weight of clean water is added, and the mixture is soaked in an environment of 12-15°C for 3-5 hours, and then filtered using a filter sieve with an aperture of 0.2-0.5 mm to obtain a foamed bird's nest, and the foamed bird's nest is placed in a colloid mill, the gap between the grinding teeth of the colloid mill is adjusted to 150-200 μm, and sheared for 30-35 minutes to obtain a bird's nest slurry; S1.2: 0.2-0.3 parts by weight of ascorbic acid and 60-80 parts by weight of deionized water are placed in a container, stirred at a stirring speed of 150-200 rpm for 8-10 minutes, and then 0.8-1 parts by weight of hydrogen peroxide solution are added. Stirring is continued at the same stirring speed for 8-10 minutes, and then 10-12 parts by weight of bird's nest slurry are added. After sufficient shaking and stirring, a bird's nest slurry pretreatment liquid is obtained. Resveratrol obtained by grape extraction is added to the bird's nest slurry pretreatment liquid to allow resveratrol to be added to the bird's nest slurry pretreatment liquid. The final concentration of the bird's nest slurry pretreatment liquid is 0.4-0.5mmol / L, and then the bird's nest slurry pretreatment liquid added with resveratrol is placed in an environment of 3-4°C and stirred at a stirring speed of 80-120rpm for 20-24 hours, and then placed in a dialysis bag with a molecular weight cutoff of 1000-1500Da for water dialysis for 25-30 hours to obtain resveratrol-grafted bird's nest slurry, and the resveratrol-grafted bird's nest slurry is stored in an anaerobic environment at 2-4°C for standby use; S1.3: Place chitosan and resveratrol grafted bird's nest slurry in a container at a mass ratio of 1: (1.5-2), add 100-120 times the volume of PBS solution and stir evenly, then place in a freeze dryer for freeze drying to obtain a modified bird's nest freeze-dried material, soak the modified bird's nest freeze-dried material in a saturated KCl solution for sealed storage, then stand at 50-55°C for 20-24 hours, and filter to obtain the modified bird's nest enzymatic hydrolysate.

3. The method for preparing a bird's nest peptide with high antioxidant activity and a tablet thereof according to claim 2, characterized in that: Step S2: multiple enzymatic hydrolysis of modified bird's nest enzymatic hydrolysate, comprising the following steps: S2.1: 1-2 parts by weight of the modified bird's nest hydrolysate and 60-80 parts by weight of purified water are mixed in a container, 0.1-0.2 mol / L acetic acid aqueous solution is added while stirring to adjust the pH to 5.5-6, the temperature is raised to 42-45°C, chitosanase is added at an enzyme-substrate ratio of 2000-2500 U / mg, the temperature is maintained for 3-4 minutes with magnetic stirring, the temperature is then raised to 55-60°C, papain is added at an enzyme-substrate ratio of 4000-4500 U / mg, the temperature is maintained for 6-8 minutes with magnetic stirring, the temperature is then raised to 95-100°C and kept for 10-15 minutes to inactivate the enzyme, and a preliminary enzymatic bird's nest solution is obtained; S2.2: Add the preliminary enzymatic bird's nest solution to the PBS solution at a volume ratio of 1: (1-2), the concentration of the PBS solution is 40-50mmol / L, the pH is 7.4, and then add the flavor protease at an enzyme-substrate ratio of 6000-7500U / mg. After mixing evenly, vacuum pack it in a polyethylene bag and place it in a high hydrostatic pressure treatment equipment. Adjust the temperature to 50-55℃ and the hydrostatic pressure to 100-150Mpa. Treat for 3-5 hours to obtain an enzymatic bird's nest solution. Treat the enzymatic bird's nest solution at 95-100℃ for 15-20 minutes, cool it to 25-30℃, filter it with a 1-2mm filter membrane, and then centrifuge it at 10000-12000rpm for 15-20 minutes. Retain the supernatant to obtain a bird's nest peptide solution.

4. The method for preparing a bird's nest peptide with high antioxidant activity and a tablet thereof according to claim 3, characterized in that: Step S3: Strengthening the antioxidant stability of bird's nest peptide, comprising the following steps: S3.1: 10-15 parts by weight of bird's nest peptide solution, 0.4-0.6 parts by weight of yeast extract and 0.3-0.4 parts by weight of trehalose are mixed and placed in a sealed container, and then placed in an ultrasonic water bath, the power of the ultrasonic water bath is adjusted to 350-400W, the temperature is 50-52°C, and the ultrasonic treatment is stopped after 6-8 minutes, and the temperature is maintained for 20-25 minutes in a water bath to obtain a bird's nest peptide antioxidant solution; S3.2: Mix the bird's nest peptide antioxidant solution and β-cyclodextrin in a mass ratio of 1: (3-4) and place them in a homogenizer. Adjust the homogenization power to 6-7.5kw and homogenize for 10-20 minutes. Then place them in a vacuum dryer and freeze-dry them at -70℃--40℃. Then grind them into powder to obtain bird's nest peptide with high antioxidant activity.

5. The method for preparing a bird's nest peptide with high antioxidant activity and a tablet thereof according to claim 2, characterized in that: The concentration of the ascorbic acid added to the hydrogen peroxide solution in deionized water in step S1.2 is 4-4.5 mol / L.

6. The method for preparing a bird's nest peptide with high antioxidant activity and a tablet thereof according to claim 2, characterized in that: The PBS solution in step S1.3 is prepared by mixing KH2PO4, Na2HPO4 and NaCl with deionized water in a mass ratio of 1:6:33, with a concentration of 20-25 mmol / L and a pH of 7.2-7.

4.

7. The method for preparing a bird's nest peptide with high antioxidant activity and a tablet thereof according to claim 3, characterized in that: The enzyme-substrate ratio in step S2 refers to the ratio of enzyme activity to the dry weight of the modified bird's nest hydrolysate.

8. The method for preparing a bird's nest peptide with high antioxidant activity and a tablet thereof according to claim 4, characterized in that: The glutathione content of the yeast extract in step S3.1 is 30%.

9. A bird's nest peptide with high antioxidant activity, characterized in that: The bird's nest peptide with high antioxidant activity and its tablet preparation method are prepared by any one of claims 1 to 8.

10. A method for preparing a bird's nest peptide tablet with high antioxidant activity, characterized in that: The following steps are involved: The bird's nest peptide with high antioxidant activity prepared by the method for preparing a bird's nest peptide with high antioxidant activity and tablets thereof according to any one of claims 1 to 8, starch and microcrystalline cellulose are stirred and mixed uniformly in a mass ratio of 1: (1-1.5): (0.5-1), and then 25-30wt% of ethanol is added and stirred continuously to obtain a soft material, which is passed through a 20-25 mesh sieve to obtain soft material particles, and the soft material particles, carboxymethyl starch and magnesium stearate are mixed uniformly in a mass ratio of 1: (0.2-0.25): (0.015-0.02) and placed in a tablet press for tableting to obtain bird's nest peptide tablets with high antioxidant activity.

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