CN115161372A - Method and application of ultrasonic-assisted compound enzymatic hydrolysis to extract soybean peptides with hypoglycemic activity - Google Patents

Abstract

The invention discloses a method and application of ultrasonic-assisted compound enzymatic hydrolysis to extract soybean peptides with hypoglycemic activity, and relates to the technical field of soybean meal extraction, comprising the following steps: S1. obtaining soybean meal powder; S2. dispersing the soybean meal powder in water, and performing Ultra-high pressure homogenization treatment to obtain a homogenized soybean meal solution; S3. Under ultrasonic conditions, the homogenized soybean meal solution is enzymatically hydrolyzed by the first compound enzyme, and then centrifuged to obtain a residue and a first supernatant; S4. Disperse the residue in water, add the second compound enzyme to carry out enzymolysis, and then add the third compound enzyme to carry out enzymolysis to obtain an enzymolysis solution, and centrifuge the enzymolysis solution to obtain a second supernatant; S5. The supernatant liquid and the second supernatant liquid are mixed, concentrated and dried to obtain the soybean peptide; the soybean peptide extracted by this method has a high yield, and the obtained soybean peptide has a good hypoglycemic effect.

Description

Method for extracting soybean peptides with hypoglycemic activity by ultrasonic-assisted compound enzymolysis law and application

technical field

The invention relates to the technical field of soybean meal extraction, in particular to a method and application for the extraction of soybean peptides with hypoglycemic activity assisted by ultrasonic-assisted compound enzymolysis.

Background technique

Soybean peptide is the abbreviation of "peptidyl soybean protein hydrolyzate". It is a product obtained by special treatment of soybean protein after protease hydrolysis or fermentation. Its essential amino acid composition is exactly the same as that of soybean protein, and it also includes some free amino acids, a small amount of carbohydrates, moisture and ash. Compared with soybean protein, soybean polypeptide not only has the same essential amino acids as soybean protein, but also absorbs faster than soybean protein. It does not need to undergo enzymatic hydrolysis by pepsin, and digestion and absorption starts directly from the small intestine. It can quickly provide energy and has the function of accelerating muscle fatigue recovery. At the same time, it has excellent physical properties such as high concentration, high solubility, low viscosity, high fluidity and thermal stability. At the same time, soybean peptide powder contains a variety of bioactive peptides, which have a variety of physiological functions, including anti-oxidation, lowering blood pressure, lowering cholesterol, lowering blood lipids, anti-fatigue, and enhancing immunity. Soybean peptide has a slow inhibitory effect on α-glucosidase. α-glucosidase is distributed on the intestinal microvilli. Its function is to rapidly decompose sugar for glucose in the body. Therefore, soybean peptide is mixed with other carbohydrates and sugars. It is not affected by the amount of insulin secretion, and can play a good role in inhibiting the rise of blood sugar, and soybean active peptide is rich in leucine, which can stimulate insulin secretion, so that the body can effectively use its own insulin to control blood sugar concentration.

There are three main raw materials for preparing soybean peptides: soybean meal, soybean protein isolate and soybean meal. Using soybean flour to extract soybean peptides, because soybeans contain more oil, the preparation of soybean peptides from soybean flour must first undergo degreasing treatment, and then undergo enzymatic hydrolysis treatment to obtain the final product. The preparation process is complicated and the yield is not high; using Soybean protein isolate to extract soybean peptide is to directly subject soybean protein isolate to enzymatic hydrolysis to obtain soybean peptide finished product. This method is relatively simple to prepare soybean peptide, but the cost of soybean protein isolate is relatively high, and the raw material for producing soybean protein isolate is generally soybean meal, that is, soybean meal. After alkali-soluble acid precipitation treatment, the protein is denatured and precipitated, the yield of the obtained soybean protein isolate is low, and more acid and alkali are used, which brings environmental pollution; while soybean peptide is extracted from soybean oil after low temperature or flash evaporation The protein obtained after the desolvation treatment has a small degree of protein denaturation and a high water-soluble protein content. In the related art, such as the Chinese patent soybean peptide, preparation method and application with the publication number of CN1274361C, it is disclosed that the soybean meal can be used to directly remove the soybean peptide. After enzymatic hydrolysis, soybean peptide products can be obtained, and soybean peptides can be directly produced by using soybean meal, which saves the link of producing soybean protein isolate, and is simple and environmentally friendly.

However, the hypoglycemic effect of soybean peptides extracted from soybean meal in the related art is not good.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method and application for extracting soybean peptides with hypoglycemic activity by ultrasonic-assisted compound enzymolysis, and the obtained soybean peptides have good hypoglycemic effect.

In order to achieve the above-mentioned technical purpose, the application adopts the following technical solutions:

In the first aspect, the present application improves a method for extracting soybean peptides with hypoglycemic activity by ultrasonic-assisted compound enzymolysis, comprising the following steps:

S1. Obtain soybean meal powder;

S2. Disperse the soybean meal powder in water, and carry out homogenization treatment to obtain a homogenized soybean meal liquid;

S3. Preheat the soybean meal liquid;

S4. Under ultrasonic conditions, the homogenized and preheated soybean meal liquid is enzymolyzed by the first compound enzyme, and then centrifuged to obtain supernatant 1, and the second compound enzyme is added to the supernatant 1 for enzymolysis to obtain enzymolysis liquid, the enzymatic hydrolyzate was centrifuged to obtain supernatant 2;

S5. Concentrate and dry the supernatant 2 to obtain soybean peptide;

Wherein, the first composite enzyme is a mixture comprising serine protease, bromelain and papain, the second composite enzyme is a mixture comprising trypsin, fungal protease, and flavor protease, and the pressure of the homogeneous treatment is 200Mpa-300Mpa, and the homogeneous The times are 1-2 times, the homogenization temperature is 50-70°C, more preferably, the pressure of the homogenization treatment is 250Mpa-280Mpa, the homogenization times are 2 times, and the homogenization temperature is 60-65°C.

In this application, the pressure of the homogenization treatment is "200Mpa-300Mpa", hereinafter collectively referred to as "ultra-high pressure homogenization treatment", as known to those skilled in the art, "ultra-high pressure homogenization treatment" refers to the Under the action of ultra-high pressure, the machine flows through a cavity with a special internal structure at a high speed, and the molecules in the material, such as protein and starch, undergo physical and chemical changes through extrusion, shearing, impact and other forces. , structural properties and a series of changes, and finally achieve a homogeneous effect.

Since 80% of soybean meal is soluble protein, after protein denaturation, the enzymatic hydrolysis site of protein can be exposed by ultrasonic process, which can better promote the enzymatic hydrolysis reaction, improve the extraction yield of soybean peptide, and maximize the protein in soybean meal powder. Selective hydrolysis, based on the above ideas, the mechanism of extracting soybean peptides in this scheme is: firstly use ultra-high pressure homogenization treatment to destroy the microstructure of the protein, reduce the size of the protein particles, and reduce the difficulty for the subsequent enzymolysis of the protein and the dissolution of the protein , Under the condition of ultrasonic, the cytoplasm can flow and the cells vibrate, thereby thinning or breaking the cell wall, which is conducive to the release and extraction of intracellular active components, and also reduces the dissolution resistance of intracellular active components and proteins. , This scheme selectively hydrolyzes the dissolved protein into soybean peptides to the greatest extent through a segmented compound enzymatic hydrolysis method.

In terms of component selection of composite enzymes, through the continuous efforts of the inventor, different types of enzymes have been screened, such as trypsin, papain, flavor protease, alkaline protease, pepsin, etc. It was unexpectedly discovered that the first composite enzyme The mixture of serine protease, bromelain and papain was selected, and the second compound enzyme was selected as a mixture of trypsin, fungal protease and flavor protease. When used together, the effect was the best, the extraction rate was the highest, and there was synergy among the three groups of enzymes. effect.

It is worth mentioning that the ultra-high pressure homogenization treatment in this scheme also has the effect of providing a more suitable substrate for the first composite enzyme to enhance the affinity between the first composite enzyme and the substrate, thereby improving the enzyme of the first composite enzyme. On the other hand, because the secondary structure of the protein can be destroyed by the ultra-high pressure homogenization treatment, the affinity between the second complex enzyme and the substrate is increased, and the more smoothly specific enzymatically degraded protein is soybean peptide.

Preferably, the ultrasonic power is 300-600W, and the ultrasonic time is 1-3h. More preferably, the ultrasonic power is 400-500W, and the ultrasonic time is 2-3h.

Preferably, in step S4, the pH of the enzymatic hydrolysis of the first compound enzyme is 4-6, the enzymatic hydrolysis temperature is 50-60° C., and the enzymatic hydrolysis time is 2-4 h.

Preferably, in step S4, the pH of the enzymatic hydrolysis of the second compound enzyme is 7.5-8.5, the temperature of the enzymatic hydrolysis is 50-60°C, and the time of the enzymatic hydrolysis is 2-6 h.

Preferably, in the first composite enzyme, the mass ratio of serine protease, bromelain and papain is (2-3):(0.5-1):(2-2.5), more preferably, serine protease, bromelain and papain The mass ratio of papain was 2:1:2.

Preferably, in the second composite enzyme, the mass ratio of trypsin, fungal protease and flavor protease is (1.5-2):(2-2.5):(0.1-0.2), more preferably, trypsin, fungal protease, The mass ratio of flavor protease was 2:2:0.2.

Preferably, in step S4, the rotational speed of centrifugation is 20000-30000r/min, the centrifugation temperature is 25±5°C, and the centrifugation time is 10-20min.

Preferably, in step S5, the method of concentration is membrane filtration, the pore size of the membrane in the membrane filtration is 500-3000D, and the temperature of the membrane filtration is 20-30°C; more preferably, the pore size of the membrane used in the membrane filtration is 500-1000D .

Preferably, the mass ratio of the first composite enzyme to the soybean meal powder is 0.5-3:100, and the mass ratio of the third composite enzyme to the residue is 0.5-3:100.

According to the second aspect of the present invention, an application of soybean peptide in hypoglycemic drugs is provided.

Soybean peptide has inhibitory effect on α-glucosidase on the human small intestine wall, can play a certain role in lowering blood sugar, and can be used as the main component of hypoglycemic drugs.

The beneficial effects of the invention are as follows: in this scheme, under the synergistic action of ultra-high pressure homogenization and ultrasound, the soybean meal is subjected to synergistic segmented compound enzymolysis, the reaction conditions are mild, the enzymolysis efficiency is high, and the dissolved protein can be dissolved to the greatest extent. Selectively hydrolyzed into soybean peptides, and the extraction yield is high; the mixture of the first supernatant and the second supernatant is concentrated by membrane filtration to remove the residual enzymes, macromolecular polysaccharides, small molecular inorganic salts, water in the solution. and other impurities, retain soybean peptides to the greatest extent, realize decolorization and impurity removal of soybean peptides, improve the edibility of soybean peptides, and have a good hypoglycemic effect.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The embodiments of the present application provide a method for extracting soybean peptides with hypoglycemic activity by ultrasonic-assisted compound enzymolysis, comprising the following steps:

S1. Pulverize the soybean meal flakes and pass through a 60-80 mesh sieve to obtain soybean meal powder;

S2. Disperse the soybean meal powder in 15-20 times the mass of water, and perform ultra-high pressure homogenization treatment. The pressure of ultra-high pressure homogenization is 200Mpa-300Mpa, the homogenization times are 1-2 times, and the homogenization temperature is 50-70 ℃, to obtain homogenized soybean meal liquid;

S3. Preheat the homogenized soybean meal solution at 80-100°C for 30min-1h;

S4. Under the condition that the ultrasonic power is 300-600W and the ultrasonic time is 1-3h, the homogenized soybean meal liquid is enzymatically hydrolyzed by the first compound enzyme, the pH is 4-6, and the enzymatic hydrolysis is 2- 4h, then centrifuge the enzymatic hydrolysis solution at 20000-30000r/min for 10-20min at 25±5℃ to separate the supernatant 1, adjust the pH of the supernatant 1 to 7.5-8.5, add the second compound at 50-60℃ The enzyme is hydrolyzed for 2-6 hours to obtain an enzymatic hydrolysis solution, and the enzymatic hydrolysis solution is centrifuged at 20000-30000 r/min for 10-20 min at 25±5°C to separate, and supernatant 2 is obtained;

S5. Concentrate and dry the supernatant 2 to obtain soybean peptide;

Wherein, the first complex enzyme is a mixture of serine protease, bromelain and papain, and the second complex enzyme is a mixture including trypsin, fungal protease, and flavor protease.

In some embodiments, in the first complex enzyme, the mass ratio of serine protease, bromelain and papain is (2-3):(0.5-1):(2-2.5).

In some embodiments, in the second composite enzyme, the mass ratio of trypsin, fungal protease, and flavor protease is (1.5-2):(2-2.5):(0.1-0.2).

In some embodiments, the mass ratio of the first composite enzyme to soybean meal is 0.5-3:100, and the mass ratio of the second composite enzyme to soybean meal is 0.5-3:100.

In some embodiments, in step S5, the method of concentration is membrane filtration, the membrane pore size in membrane filtration is 150-300D, and the temperature of membrane filtration is 20-30°C.

In some embodiments, the method of drying is spray drying.

The embodiments of the present application also provide the application of soybean peptides in hypoglycemic agents.

Example 1

A method for ultrasonic-assisted compound enzymolysis to extract soybean peptides with hypoglycemic activity, comprising the following steps:

S1. 1kg soybean meal flakes are ground and pulverized and crossed through a 60 mesh sieve to obtain soybean meal powder;

S2. Disperse the soybean meal powder in 20 times the mass of water, and place the suspension in a 200Mpa ultra-high pressure homogenizer to homogenize twice at 70°C to obtain a homogenized soybean meal solution;

S3. The homogenized soybean meal liquid is heated to 100°C and maintained for 30min;

S4. While sonicating the homogenized soybean meal liquid at a power of 300W, add 0.5% soybean meal mass of the first compound enzyme to perform enzymatic hydrolysis on the homogenized soybean meal liquid. The pH of the enzymatic hydrolysis is 4 and the temperature is 50°C. 2h, during the enzymolysis process, the temperature of the feed solution was maintained at 50 °C, and the enzymatic hydrolysis solution was centrifuged at 30,000 r/min for 10 min at 25 °C to separate to obtain the first supernatant, and then the pH of the first supernatant was adjusted to 7.5, add the second compound enzyme of 0.5% soybean meal quality and continue enzymolysis for 2h. During the enzymolysis process, keep the temperature of the feed liquid at 50 °C to obtain the enzymatic hydrolysis solution. Separation to obtain a second supernatant, wherein the second composite enzyme is a mixture of serine protease, bromelain and papain with a mass ratio of 2:1:2, and the third composite enzyme is a mass ratio of 2:2:0.2 Mixture of trypsin, fungal protease, flavor protease;

S5. The second supernatant is concentrated by using a multifunctional organic membrane pilot-scale device with a model of BONA-GM-1818H, wherein the membrane pore size is 150D, and the temperature of membrane filtration is 30°C, and then sprayed by a spray dryer. After drying, soybean peptides are obtained.

Example 2

A method for ultrasonic-assisted compound enzymolysis to extract soybean peptides with hypoglycemic activity, comprising the following steps:

S1. 1kg soybean meal flakes are ground and pulverized and crossed through an 80 mesh sieve to obtain soybean meal powder;

S2. Disperse the soybean meal powder in 20 times the mass of water, and place the suspension in a 200Mpa ultra-high pressure homogenizer to homogenize twice at 70°C to obtain a homogenized soybean meal solution;

S3. The homogenized soybean meal liquid is heated to 90°C and maintained for 60min;

S4. While sonicating the homogenized soybean meal liquid at a power of 600W, add the first compound enzyme of 2% soybean meal quality to carry out enzymatic hydrolysis of the homogenized soybean meal liquid. The pH of the enzymatic hydrolysis is 5, the temperature is 60 °C, and the The time was 4 h, and then centrifuged at 20000 r/min for 20 min at 30 °C to separate, to obtain the residue and the first supernatant, wherein the first composite enzyme was serine protease, bromelain and papain in a mass ratio of 3:1:2. mixture;

S5. Adjust the pH of the supernatant to 8.5, add the second compound enzyme of 2% soybean meal quality and continue enzymolysis for 6 hours. During the enzymolysis process, keep the temperature of the feed liquid at 60°C to obtain an enzymolysis solution, and put the enzymolysis solution in Centrifuge at 30,000 r/min for 20 min at 25°C to obtain a second supernatant, wherein the third composite enzyme is a mixture of trypsin, fungal protease, and flavor protease with a mass ratio of 2:2.5:0.2;

S5. The second supernatant is concentrated by using a multifunctional organic membrane pilot-scale equipment with a model of BONA-GM-1818H, wherein the membrane pore size is 500D, and the temperature of membrane filtration is 30°C, and then sprayed by a spray dryer. After drying, soybean peptides are obtained.

Example 3

A method for ultrasonic-assisted compound enzymolysis to extract soybean peptides with hypoglycemic activity, comprising the following steps:

S1. 1kg soybean meal flakes are ground and pulverized and then crossed a 70 mesh sieve to obtain soybean meal powder;

S2. Disperse the soybean meal powder in 20 times the mass of water, and place the suspension in a 300Mpa ultra-high pressure homogenizer for 2 times at 60°C to obtain a homogenized soybean meal solution;

S3. The homogenized soybean meal liquid is heated to 80°C and maintained for 60min;

S4. While sonicating the homogenized soybean meal liquid at a power of 400W, add the first compound enzyme of 1% soybean meal quality to carry out enzymatic hydrolysis of the homogenized soybean meal liquid. The pH of the enzymatic hydrolysis is 6.0, the temperature is 55° C. The time is 3h, and then centrifuged at 20000r/min for 10min at 25°C to separate, to obtain the residue and the first supernatant, wherein the first compound enzyme is serine protease, bromelain and papain with a mass ratio of 2:0.5:2 mixture;

S5. Adjust the pH of the feed solution to 8 with the above-mentioned supernatant, add the second compound enzyme of 1% soybean meal quality and continue enzymolysis for 4 hours. During the enzymolysis process, maintain the temperature of the feed solution at 55°C to obtain an enzymolysis solution, which is The enzymatic hydrolyzate was centrifuged at 20,000 r/min for 15 min at 25°C to obtain the second supernatant, and the third composite enzyme was a mixture of trypsin, fungal protease and flavor protease with a mass ratio of 1.5:2:0.1;

S6. The second supernatant is concentrated by using a multifunctional organic membrane pilot-scale equipment with a model of BONA-GM-1818H, wherein the membrane pore size is 300D, and the temperature of membrane filtration is 25°C, and then sprayed by a spray dryer. After drying, soybean peptides are obtained.

Comparative Example 1

The other steps are the same as in Example 1, the difference is that step S4 is replaced by the following steps: adjusting the pH of the supernatant to 7.5, adding 0.5% soybean meal quality second compound enzyme for 2h enzymatic hydrolysis, and maintaining the feed solution during the enzymatic hydrolysis process The temperature is 50 °C to obtain an enzymatic hydrolysis solution, and the enzymatic hydrolysis solution is centrifuged at 30,000 r/min for 10 min at 25 °C to separate, to obtain a second supernatant, wherein the second composite enzyme is a mass ratio of 2:2:0.2 Mixture of trypsin, fungal protease, flavored protease.

Comparative Example 2

The other steps are the same as in Embodiment 1, the difference is that step S3

S4 is replaced with a step: adding the homogenized soybean meal solution heated at 100 °C for 30 min to the first compound enzyme of 0.5% soybean meal quality to carry out enzymatic hydrolysis of the soybean meal solution, the pH of the enzymatic hydrolysis is 5, the temperature is 50 °C, and the enzymatic hydrolysis time is 4h, and then centrifuged at 30000r/min for 10min at 25°C to obtain the residue and the first supernatant, wherein the first compound enzyme is a mixture of trypsin, fungal protease and flavor protease with a mass ratio of 1:1:1 .

Comparative Example 3

The other steps are the same as in Example 1, the difference is that step S4 is replaced by a step: the homogenized and heated soybean meal solution at 100° C. for 30 min is sonicated at 400 W, and the first compound enzyme of 1% soybean meal quality is added to enzymatically hydrolyze the solution. The pH is 4.5, the temperature is 55°C, and the enzymolysis time is 3h, and then centrifuged at 20000r/min for 10min at 25°C to separate, to obtain the residue and the first supernatant, wherein, the first compound enzyme is a mass ratio of 2: 1:2 mixture of serine protease, bromelain and papain;

Replace step S4 with the step: adjust the pH of the supernatant 1 to 8, add the second compound enzyme of 1% residue mass to continue enzymatic hydrolysis for 4 h, during the enzymatic hydrolysis process, maintain the temperature of the feed liquid at 55 ° C to obtain enzymatic hydrolysis. The enzymatic hydrolysis solution was centrifuged at 20,000 r/min for 15 min at 25°C to obtain a second supernatant, wherein the second composite enzyme was a mixture of trypsin, fungal protease and flavor protease with a mass ratio of 1.5:2:0.1 .

Comparative Example 4

The other steps are the same as in Example 1, the difference is that step S4 is replaced by the step: the pH of the supernatant 1 is adjusted to 6, and the second compound enzyme of 3% soybean meal quality is added to carry out enzymatic hydrolysis for 4 hours. The enzymatic hydrolysis process In, maintain the temperature of feed liquid to be 60 ℃, obtain enzymolysis solution, centrifuge the enzymolysis solution for 20min at 30000r/min at 25 ℃ to separate, obtain the second supernatant, wherein, the first compound enzyme is mass ratio 3: 1:2 mixture of serine protease, bromelain and papain, and the second composite enzyme is a mixture of trypsin, fungal protease and flavor protease in a mass ratio of 2:2.5:0.2.

Comparative Example 5

Other steps are the same as those in Embodiment 1, the difference is that step S2 and step S3 are not included.

Comparative Example 6

Other steps are the same as in Embodiment 1, the difference is that step S3 is not included.

Comparative Example 7

The other steps are the same as those in Embodiment 1, the difference is that the sequence of steps S2-S4 is changed to step S4-step S2-step S3.

Comparative Example 8

Other steps are the same as in Example 1, the difference is that the pore size of the membrane in step S5 is 500D.

Comparative Example 9

1) 1kg soybean meal flakes are pulverized and sieved with 80 meshes to obtain dry soybean meal powder;

2) Add 15 times the mass of water, adjust the pH to 8-11 with NaOH, stir at 50°C for 1.5h, add and stir at 30-35r/min, and stop stirring after maintaining for 1h;

3) Centrifuge with a tubular centrifuge for 20 min at a rotational speed of 20000 r/min to obtain supernatant 1 and residue 1, and repeat steps 2 and 3 for residue 1 to obtain supernatant 2 and residue 2;

4) Combine the supernatants 1 and 2, and put them into the acid precipitation tank, slowly add 30% HCl solution while stirring, and adjust the pH to 5.4. When adding acid, it needs to be stirred continuously (the stirring speed is 30-40r/min), and at the same time, the pH of the solution should be continuously measured. When the whole solution reaches the isoelectric point, the stirring should be stopped immediately and let stand for 20-30min, so that the protein can form larger particles. settle down;

5) Centrifuge again with a tubular centrifuge for 20 min at a rotational speed of 20,000 r/min to obtain supernatant 3 and residue 3, and discard the supernatant;

6) Residue 3 was washed twice with 50°C water, 10 times of water was added, the pH was adjusted to 9.0 with 5% NaOH, the alkaline protease was added for enzymatic hydrolysis for 3 hours, the pH was adjusted to 6.5 with HCl, and the temperature was raised to above 90°C for 30 minutes. enzyme to obtain soybean peptide solution;

7) After passing the soybean peptide dilute feed liquid through the ceramic membrane, then pass through a 1000D ultrafiltration membrane, and the obtained filtrate is passed through a 300D concentrated membrane to obtain a product concentrate 1;

8) passing the product concentrate 1 obtained in step 7) through a 0.22 μm aperture filter to remove microorganisms to obtain product concentrate 2;

9) Spray drying the product concentrate 2 obtained in step 8) (inlet air at 200±10° C. and outlet air at 90±5° C.) to obtain powdered soybean peptide.

test case

Extraction yield test: First, weigh the mass m of the soybean peptides obtained in each example or the comparative example, and then measure the purity w of the soybean peptide in each example and the comparative example according to "GB/T 22492-2008 soybean peptide powder" %, and finally according to "GB/T5009.5 Determination method of protein in food" to measure the total protein mass M in 1 kg of soybean meal in this example and the comparative example, according to the calculation formula: extraction yield=m*w%/M, for The extraction yield was calculated, and the results are shown in Table 1.

Table 1 Extraction yield results

project Yield % Example 1 35.00 Example 2 33.86 Example 3 32.42 Comparative Example 1 25.33 Comparative Example 2 27.53 Comparative Example 3 24.50 Comparative Example 4 21.11 Comparative Example 5 18.12 Comparative Example 6 25.97 Comparative Example 7 31.88 Comparative Example 8 32.68 Comparative Example 9 27.14

Hypoglycemic effect test: The soybean peptides obtained in Examples 1-3 and Comparative Examples 1-9 were diluted to 0.1 g/L as a sample solution, and 0.1 mL of α-glucosidase solution with a concentration of 0.2 U/mL was added to 2 mL of 0.1 mol/L α-glucosidase solution. L phosphate buffer (pH6.8), water bath at 37°C for 15min, add the sample solution to react for 10min, then add 0.25mL 25mmol/L substrate PNPG, after water bath for 30min, add 0.1mol/L 2mL Na ₂ CO ₃ to terminate the reaction, Measure the absorbance at 400nm (A2); replace the sample solution with 1 mL of phosphate buffer (pH 6.8) as a blank, and measure the absorbance value (A0); use 0.1 mL of phosphate buffer (pH 6.8) to replace the product in the product. The absorbance value of the enzyme solution was determined as (A1). Repeat the measurement 3 times, according to the formula: α-glucosidase inhibition rate/%=[1-(A2-A1)/A0]*100 to measure the inhibition rate of each product on α-glucosidase, the results are shown in Table 2 Show.

Table 2 Inhibition rate of α-glucosidase

project Inhibition rate(%) Example 1 55.39 Example 2 52.08 Example 3 50.72 Comparative Example 1 41.82 Comparative Example 2 49.63 Comparative Example 3 46.30 Comparative Example 4 45.98 Comparative Example 5 50.22 Comparative Example 6 52.32 Comparative Example 7 49.41 Comparative Example 8 40.23 Comparative Example 9 38.57

Soybean peptide hypoglycemic test: Take 140 SPF Kunming mice, half male and half male, 3-4w old, weighing 18-22g, and the mice were raised in a well-ventilated, relative humidity of 50%-60%, room temperature of 23-25 ℃, strict 12h light and 12h dark standardized rearing room. After the 3d acclimation period, the mice were randomly divided into pre-groups, and 12 mice were selected as the blank group (BG) and fed with common chow. All the remaining mice were fed a high-fat and high-sugar diet. After 1 month of feeding, the mice were fasted for 12 hours, and were intraperitoneally injected with streptozotocin (STZ) solution (pH 4.5, sodium citrate buffer) at a dose of 100 mg/kg body weight. The mice in the blank group were injected with the same amount of sodium citrate buffer solution, and the mice were restored to their diet immediately after the injection. Blood was collected from the tail vein 72 hours after the injection to measure the fasting blood glucose value. The fasting blood glucose was ≥11.1 mmol/L and The mice with symptoms of continuous polyphagia, polydipsia and polyuria were regarded as successful modeling. The mice with successful modeling were randomly divided into diabetes model group (MG), metformin group (PG), soybean peptide high-dose group (HDG), middle-dose group (MDG), and low-dose group (LDG), with 12 mice in each group. . The high, medium and low dose groups were administered with the soybean peptides prepared in Example 1 at doses of 600, 400, and 200 mg/kg; the metformin group was administered with metformin 200 mg/kg by intragastric administration; the model group and the blank group were administered the same dose of Ultra-pure water. Each group was given 0.2 mL/10 g by intragastric administration, once a day, for 14 consecutive days. The results are shown in Table 3.

Table 3 hypoglycemic test results

Sensory test: The soybean peptides prepared according to Examples 1-3 were sensory tested from three aspects of taste, color and smell. The results are shown in Table 4. The soybean peptides prepared in this scheme have good sensory quality.

Table 4 Sensory detection

Result analysis

It can be seen from Table 1 that the method used in this scheme has a higher extraction yield than other methods, and the addition of composite enzymes, ultra-high pressure homogenization treatment, and ultrasonic extraction synergistically affect the extraction yield;

It can be seen from Table 2 that the soybean peptide prepared in Examples 1-3 has a better inhibitory effect on α-glucosidase than Comparative Examples 1-9. It can be seen that the products prepared by the method of the present invention have extremely strong hypoglycemic effect.

The results in Table 2 were applied to animal experiments to verify, taking Example 1 as the research object, and comparing with the commercially available hypoglycemic drug metformin. It does have a blood sugar lowering effect.

It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own emphasis. For details not described in individual embodiments, reference may be made to descriptions in other embodiments.

The above examples only represent the embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be noted that, for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (8)

1. A method for extracting soybean peptide with hypoglycemic activity by ultrasonic-assisted composite enzymolysis is characterized by comprising the following steps:

s1, obtaining soybean meal powder;

s2, dispersing the soybean meal powder in water, and carrying out homogenization treatment to obtain homogenized soybean meal liquid;

s3, preheating the soybean meal liquid;

s4, carrying out enzymolysis on the homogenized soybean meal liquid by using a first compound enzyme under an ultrasonic condition, then centrifuging to obtain a supernatant 1, adding a second compound enzyme into the supernatant 1 for enzymolysis to obtain an enzymolysis liquid, and centrifuging the enzymolysis liquid to obtain a supernatant 2;

s5, concentrating and drying the supernatant 2 to obtain the soybean peptide;

the first compound enzyme is a mixture comprising serine protease, bromelain and papain, and the second compound enzyme is a mixture comprising trypsin, mould protease and flavourzyme; the pressure of the homogenization treatment is 200Mpa-300Mpa, the homogenization frequency is 1-2 times, and the homogenization temperature is 50-70 ℃.

2. The method for extracting the soybean peptide with the hypoglycemic activity by ultrasonic-assisted compound enzymolysis as claimed in claim 1, wherein in step S4, the enzymolysis pH of the first compound enzyme is 4-6, the enzymolysis temperature is 50-60 ℃, and the enzymolysis time is 2-4h.

3. The method for extracting soybean peptide with hypoglycemic activity by ultrasonic-assisted compound enzymolysis according to claim 1, wherein in step S4, the enzymolysis pH of the second compound enzyme is 7.5-8.5, the enzymolysis temperature is 50-60 ℃, and the enzymolysis time is 2-6h.

4. The method for extracting soybean peptide with hypoglycemic activity by ultrasonic-assisted complex enzymolysis as claimed in claim 1, wherein the mass ratio of serine protease, bromelain and papain is (2-3): (0.5-1): (2-2.5).

5. The method for extracting soybean peptide with hypoglycemic activity by ultrasonic-assisted complex enzymolysis as claimed in claim 1, wherein the mass ratio of trypsin, mould protease and flavourzyme is (1.5-2): (2-2.5): (0.1-0.2).

6. The method for extracting soybean peptide with hypoglycemic activity by ultrasonic-assisted compound enzymolysis according to claim 1, wherein in step S4, the power of the ultrasonic wave is 300-600W, and the time of the ultrasonic wave is 1-3h.

7. The method for extracting soybean peptide with hypoglycemic activity by ultrasonic-assisted composite enzymolysis according to claim 1, wherein in step S4, the concentration mode is membrane filtration.

8. Use of the soybean peptide extracted by the method of claims 1-7 in hypoglycemic agents.