CN115414398B

CN115414398B - Chestnut extract, preparation method thereof and application thereof in hypoglycemic products

Info

Publication number: CN115414398B
Application number: CN202211175515.6A
Authority: CN
Inventors: 牛奎; 王悦莹; 梁力曼; 杜彬; 彭飞; 杨越冬; 王同坤
Original assignee: Hebei Normal University of Science and Technology
Current assignee: Hebei Normal University of Science and Technology
Priority date: 2022-09-26
Filing date: 2022-09-26
Publication date: 2024-01-26
Anticipated expiration: 2042-09-26
Also published as: CN115414398A

Abstract

The invention relates to the technical field of extraction of effective components of Chinese chestnut, and discloses a Chinese chestnut extract, a preparation method thereof and application thereof in hypoglycemic products. The disclosed chestnut extract is obtained by extracting Yan Feng chestnut kernels as raw materials, and the chestnut extract comprises chestnut oligosaccharides and chestnut oligopeptides. The preparation method of the disclosed chestnut extract comprises the following steps: extracting Yan Feng semen Castaneae kernel with water as solvent, and collecting oligosaccharide and oligopeptide in the extractive solution. The application of said chestnut extract or chestnut kernel extract in preparing the nutritive product, health-care product and medicine with alpha-amylase inhibiting function, blood sugar reducing function and diabetes treating effect is disclosed. The chestnut extract has the remarkable blood sugar reducing effect, wherein the oligosaccharide and the oligopeptide have synergistic effect on blood sugar reducing effect.

Description

Chestnut extract, preparation method thereof and application thereof in hypoglycemic products

Technical Field

The invention relates to the technical field of extraction of effective components of Chinese chestnut, in particular to a Chinese chestnut extract, a preparation method thereof and application thereof in hypoglycemic products.

Background

According to the report of IDF world diabetes map (10 th edition) published by the International diabetes Union (IDF) in 2021, every 10 adults aged 20-79 years worldwide have 1 diabetic patient, and the total number of the diabetics reaches 5.37 hundred million people; 9% of the world's health expenditures are spent on diabetes, amounting to $9.66 billion. Diabetes has become a global public health problem, and the development of high-efficiency hypoglycemic agents has become urgent.

Chestnut (Castanea mollissima) is one of the ecological economic tree species in China, and is called woody grain and iron stalk crops. Chestnut is one of the homologous nuts with higher nutritive value, and the 'materia medica schema' records: "chestnut can treat kidney deficiency and weakness of waist and legs, can promote the circulation of kidney and qi, thicken intestines and stomach, kidney governs stool, chestnut can govern kidney". The Chinese medicine considers that the Chinese chestnut has sweet and warm taste, has the effects of nourishing stomach, strengthening spleen, tonifying kidney, strengthening tendons, promoting blood circulation, stopping bleeding, and relieving swelling, and is beneficial to the prevention and treatment of hypertension and coronary heart disease. Clinically, the Chinese chestnut can be singly used for treating symptoms such as regurgitation, diarrhea, weakness of waist and legs, hematemesis, hematochezia, golden sore and the like, and the Chinese chestnut can also be prepared into medicated diet by adding other traditional Chinese medicines or food raw materials, and can be used for treating diseases such as tracheitis, kidney deficiency, dyspepsia, diarrhea, apoplexy and the like. At present, related researches on nutritional active ingredients in chestnut kernels focus on chestnut starch, protein, polyphenol, dietary fiber, mineral elements, vitamins and the like, and researches on oligosaccharides and oligopeptides in chestnut are not reported.

In view of this, the present invention has been made.

Disclosure of Invention

The invention aims to provide a chestnut extract, a preparation method thereof and application thereof in hypoglycemic products.

The invention is realized in the following way:

in a first aspect, the invention provides a chestnut extract, which is obtained by extracting Yan Feng chestnut kernels as raw materials, wherein the chestnut extract comprises chestnut oligosaccharides and chestnut oligopeptides.

In an alternative embodiment, the weight average molecular weight of the chestnut oligosaccharide is 500-680 Da, and the weight average molecular weight of the chestnut oligopeptide is 370-575 Da.

In alternative embodiments, the monosaccharide composition of the chestnut oligosaccharide includes Glc, gal, and Fru.

In an alternative embodiment, the amino acid composition of the chestnut oligopeptide is predominantly Asp, asn and Glu.

In an alternative embodiment, the total mass of Asp, asn and Glu after hydrolysis in the amino acid composition of the chestnut oligopeptide is more than 96%.

In a second aspect, the present invention provides a method for preparing a chestnut extract, comprising:

extracting Yan Feng semen Castaneae kernel with water as solvent, and collecting oligosaccharide and oligopeptide in the extractive solution.

In an alternative embodiment, the method of leaching comprises:

mixing Yan Feng semen Castaneae kernel powder with water, soaking, solid-liquid separating, and collecting leaching solution;

preferably, the solid-liquid ratio during leaching is 1:20-30;

preferably, the leaching temperature is 60-70 ℃;

preferably, the leaching is carried out for 2 to 3 hours under continuous stirring;

preferably, the solid-liquid separation is carried out by centrifugal separation, the centrifugal rotation speed is 6000-7000 rpm, and the time is 5-10 min.

In an alternative embodiment, the method further comprises filtering the resulting leach liquor to collect between 300 and 3000Da of extract.

In an alternative embodiment, the filtering method comprises:

filtering the leaching solution by using a microporous membrane with the diameter of 0.1 mu m to collect the penetrating fluid to obtain micro-filtrate;

filtering the micro-filtrate by using a 3000Da ultrafiltration membrane, and collecting the permeate to obtain the ultrafiltrate;

filtering the ultrafiltrate by using a nanofiltration membrane of 300Da to collect trapped fluid;

preferably, the method further comprises concentrating the trapped liquid under reduced pressure, and freeze drying to obtain solid extract.

In a third aspect, the present invention provides the use of the chestnut extract as defined in any one of the preceding embodiments or the chestnut kernel extract as defined in any one of the preceding embodiments for the preparation of a nutritional product, a health product and a medicament having an alpha-amylase inhibitory effect, a hypoglycemic function or a diabetes therapeutic effect.

The invention has the following beneficial effects:

the extract is prepared by extracting Yan Feng chestnut kernels as raw materials, wherein the chestnut oligosaccharides and the chestnut oligopeptides contained in the extract have synergistic effect on reducing blood sugar, and the cooperation of the chestnut oligosaccharides and the chestnut oligopeptides has remarkable blood sugar reducing activity; compared with extracts of other varieties of Chinese chestnut, the Yan Feng Chinese chestnut has obvious hypoglycemic activity; and the oligosaccharide and the oligopeptide can be extracted by taking water as a solvent, so that the oligosaccharide and the oligopeptide are not required to be extracted separately in the preparation process, and the extraction method is simple.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a gradient elution profile of chestnut oligosaccharide-oligopeptide composition on DEAE Sepharose FF column;

FIG. 2HPGPC method for determining molecular weight of semen Castaneae oligosaccharide-oligopeptide composition, semen Castaneae oligosaccharide and semen Castaneae oligopeptide;

FIG. 3IC method for determining monosaccharide composition of semen Castaneae oligosaccharide;

FIG. 4 is a graph showing the inhibitory effect of compositions, oligosaccharides, and oligopeptides on α -amylase.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

The chestnut extract, the preparation method and the application thereof in the hypoglycemic product are specifically described below.

The embodiment of the application provides a chestnut extract, which is obtained by extracting Yan Feng chestnut kernels serving as raw materials, wherein the chestnut extract comprises chestnut oligosaccharides and chestnut oligopeptides.

The inventor finds that the extract obtained by extracting Yan Feng chestnut kernels as raw materials has synergistic effect on reducing blood sugar, and the cooperation of the chestnut oligosaccharides and the chestnut oligopeptides has remarkable blood sugar reducing activity; compared with extracts of other varieties of Chinese chestnut, the Yan Feng Chinese chestnut has obvious hypoglycemic activity; and the oligosaccharide and the oligopeptide can be extracted by taking water as a solvent, so that the oligosaccharide and the oligopeptide are not required to be extracted separately in the preparation process, and the extraction method is simple.

Further, in the Yan Feng chestnut kernels, the weight average molecular weight of the chestnut oligosaccharides is 500-680 Da, and the weight average molecular weight of the chestnut oligopeptides is 370-575 Da.

Further, the monosaccharide composition of chestnut oligosaccharides includes Glc, gal and Fru.

Further, the amino acid composition of the chestnut oligopeptide mainly comprises Asp, asn and Glu, and the mass ratio of the total amount of the chestnut oligopeptide, the Asn and the Glu after hydrolysis is more than 96%.

The preparation method of the chestnut extract provided by the embodiment of the application comprises the following steps:

The oligosaccharide and the oligopeptide are obtained by leaching Yan Feng chestnut kernels in water, and the oligosaccharide and the oligopeptide are not required to be extracted respectively, so that the preparation method of the chestnut extract is simple.

Specifically, the preparation method comprises the following steps:

s1, preparation of chestnut kernel powder

Peeling Yan Feng chestnut kernels to obtain chestnut kernels, drying the peeled chestnut kernels in an environment of 60-80 ℃ (for example, 60 ℃, 70 ℃ or 80 ℃) overnight to obtain dry chestnut, crushing dry chestnut, and sieving the crushed dry chestnut kernels with a 60-mesh sieve to obtain chestnut kernel powder.

S2, leaching

Uniformly mixing the chestnut kernel powder prepared in the last step with water, leaching under continuous stirring, and carrying out solid-liquid separation after leaching, and collecting leaching liquid.

To ensure adequate leaching, the preferred means employed may be, for example:

the solid-liquid ratio is 1:20-30 (1:20, 1:25 or 1:30) during leaching;

the temperature of the water mixed with the chestnut kernel powder is 60-70 ℃ (for example, 60 ℃, 65 ℃ or 70 ℃);

stirring and extracting for 2-3 h (such as 3h, 3.5h or 4 h).

Further, in order to ensure a good solid-liquid separation effect, the solid-liquid separation mode is centrifugal separation, the centrifugal rotation speed is 6000-7000 rpm (such as 6000rpm, 6500rpm or 7000 rpm), and the time is 5-10 min (such as 5min, 8min or 10 min), so as to obtain the water extract.

Preferably, in order to ensure that the oligosaccharides and oligopeptides in the chestnut are fully extracted, the obtained filter residue can be used as an extraction target for at least one time to be extracted by repeating the water extraction operation after solid-liquid centrifugal separation, and the obtained leaching solution is combined with the leaching solution obtained by the primary extraction.

S3, filtering

Filtering the leaching solution to collect the extract with the concentration of 300Da to 3000 Da.

The filtering mode is specifically as follows:

and (3) sequentially carrying out microfiltration, ultrafiltration and nanofiltration on the leaching solution obtained in the step S2.

One of the preferred ways of filtering may be:

firstly, filtering the leaching solution by adopting a microporous membrane with the thickness of 0.1 μm, controlling the pressure to be 8-12 bar (for example 8bar, 10bar or 12 bar), and collecting the permeate to obtain micro-filtrate;

then, filtering the micro-filtrate by using an ultrafiltration membrane with 3000Da, controlling the pressure to be 8-12 bar (for example 8bar, 10bar or 12 bar), and collecting the permeate to obtain the ultra-filtrate;

finally, filtering the ultrafiltrate by using a nanofiltration membrane of 300Da, controlling the pressure to be 10-14 bar (for example, 10bar, 12bar or 14 bar), and collecting the trapped fluid;

further, in each filtering step, when the filtering is performed at the later stage, in order to ensure sufficient filtering, ultrapure water can be added into the feed liquid barrel for filtering, and after the ultrapure water is added, the material liquid is filtered, and the material liquid can not completely pass through the membrane in theory, so that the filtering is stopped only when the osmotic liquid amount or the trapped liquid amount reaches a certain value according to experience, and in order to ensure that the subsequent three-phase purification is easier to perform, the filtered trapped liquid after the nanofiltration can be decompressed and concentrated to a proper amount and then the next step is continued. It should be noted that, the specific operation of filtering in the present application is a relatively conventional operation at present, and will not be described in detail herein.

S4, purifying

Concentrating the trapped fluid obtained in the step S3 under reduced pressure, and freeze-drying to obtain a solid extract.

The extraction rate of the extract prepared by the preparation method provided by the embodiment of the application is 3-4% (the ratio of the mass of the extract to the mass of the raw materials).

The embodiment of the application also provides application of the chestnut kernel extract in preparing nutrition, health care products and medicines with alpha-amylase inhibition effect, blood sugar reducing function or diabetes treatment effect.

The features and capabilities of the present invention are described in further detail below in connection with the examples.

Examples

The embodiment provides a preparation method of a Chinese chestnut extract, which specifically comprises the following steps:

peeling Yan Feng semen Castaneae to obtain semen Castaneae, drying at 60deg.C overnight to obtain dried semen Castaneae, pulverizing dried semen Castaneae, sieving with 60 mesh sieve to obtain semen Castaneae powder.

Extracting semen Castaneae powder in hot water with solid-liquid ratio of 1:25 and 70 deg.C under stirring for 3 hr, centrifuging at 6000rpm for 8min to obtain primary extractive solution.

Repeating the leaching steps to obtain secondary leaching liquor, and combining the primary leaching liquor and the secondary leaching liquor to obtain leaching liquor.

Loading a 0.1 mu m microporous filter membrane on the high-pressure flat membrane, pouring water extract into a feed liquid barrel, performing microfiltration under the pressure of 10bar, adding 400mL of ultrapure water into the feed liquid barrel when the trapped liquid is 500mL until the penetrating fluid is 1600mL, and collecting and combining the penetrating fluid to obtain the micro filtrate. Loading 3000Da ultrafiltration membrane on a high-pressure flat membrane, pouring micro-filtrate into a feed liquid barrel, performing ultrafiltration with the pressure set at 10bar, adding 400mL of ultrapure water into the feed liquid barrel when the trapped liquid is 500mL until the permeate liquid is 2000mL, and collecting and combining the ultrafiltration permeate liquid to obtain the ultrafiltrate. Loading a 300Da nanofiltration membrane on a high-pressure flat membrane, pouring ultrafiltrate into a feed liquid barrel, setting the pressure to be 12bar for nanofiltration, adding 600mL of ultrapure water into the feed liquid barrel when the trapped fluid is 500mL until the penetrating fluid is 3500mL, collecting the combined trapped fluid, and concentrating under reduced pressure to 100mL to obtain concentrated filtered trapped fluid.

Concentrating the filtered trapped fluid under reduced pressure, and lyophilizing to obtain solid semen Castaneae extract containing oligosaccharide and oligopeptide.

Experimental example 1

The chestnut extract prepared in the embodiment is dissolved into a sample to be detected of 5mg/mL, the sample to be detected is subjected to gradient elution on a DEAE Sepharose FF column, 490nm absorbance obtained by phenol-sulfuric acid method test is used as the ordinate of an elution curve, and an automatic part collector is connected with a test tube number as the abscissa to draw the elution curve, as shown in figure 1. 1 symmetrical elution peak can be obtained by using water and 0.1M NaCl solution as eluent, and obvious elution peak is not generated any more when the salt concentration is continuously increased. Collecting and combining the 5 th to 33 th tube eluates, and concentrating under reduced pressure and freeze-drying to obtain the oligosaccharide. Collecting and combining the eluent of the 74 th to 110 th tubes, and obtaining the oligopeptide after decompression concentration, full dialysis and freeze drying.

The yields of oligosaccharides and oligopeptides were 59% and 39%, respectively, with only 2% loss during separation, indicating that the extracts prepared by the methods of preparation of the extracts provided herein consisted almost entirely of oligosaccharides and oligopeptides.

Experimental example 2

The oligosaccharide-oligopeptide extract prepared in the embodiment, the oligosaccharide and the oligopeptide prepared in the experimental example 1 are respectively dissolved into samples to be tested with the concentration of 3mg/mL and 5mg/mL, HPGPC elution is carried out on the samples to be tested, elution curves are obtained, as shown in figure 2, standard curves are respectively prepared by taking the dextran oligosaccharides with different weight average molecular weights and the oligopeptide standard substances as standard samples, the weight average molecular weight of the samples to be tested is 500-680 Da according to a standard curve linear equation, and the molecular weight of the samples to be tested is 370-575 Da.

Experimental example 3

The chestnut oligosaccharide prepared in the experimental example 1 is hydrolyzed by TFA, and the ion chromatogram after hydrolysis is shown in figure 3. Compared with the ion chromatogram of the mixed standard sample, 3 identifiable chromatographic peaks respectively correspond to Gal, glc and Fru appear in the ion chromatogram of the chestnut oligosaccharide.

Experimental example 4

The chestnut oligopeptide prepared in the experimental example 1 is hydrolyzed by hydrochloric acid, and then subjected to gel filtration and ultraviolet detection by a high performance liquid chromatograph, and is compared with a peptide standard substance solution to obtain an amino acid composition, wherein the amino acid composition is shown in table 1.

TABLE 1 amino acid composition of chestnut oligosaccharides

Amino acid name	Asparagine (Asn)	Aspartic acid (Asp)	Glutamic acid (Glu)
				Content (g/100 g)	43.27±1.68	35.68±1.59	17.40±0.93

From the table above, it can be seen that the chestnut oligopeptide mainly consists of Asn, asp and Glu, and the content of 3 amino acids is calculated to be more than 96%.

Experimental example 5

The chestnut extract consisting of oligosaccharides and oligosaccharides prepared in example 1 was verified for its inhibitory effect on alpha-amylase. The experimental mode is as follows:

1. preparing a solution: 1g of water-soluble starch was weighed into a 10g/L PBS buffer solution, and 5mg of alpha-amylase was weighed into the PBS solution and the volume was set to 10mL. The samples to be tested were formulated as solutions at concentrations of 0.156, 0.313, 0.625, 1.25, 2.5 and 5mg/mL, respectively.

2. Mixing 100 μl sample solution with 100 μl starch solution in test tube, culturing at 37deg.C for 10min, adding 100 μl alpha-amylase solution, culturing at 37deg.C for 10min, adding 100 μl DNS solution, and heating in boiling water bath for reaction for 5min. After cooling to room temperature and 50-fold dilution, the absorbance at 540nm was measured and the alpha-amylase inhibition was calculated using the following formula:

alpha-amylase inhibition ratio = [ (A1-A2) - (A3-A4) ]/(A1-A2) ×100%

Wherein, A1: water replaces the sample solution, i.e., water + starch solution + alpha-amylase solution measured absorbance value; a2: water replaces the sample solution, and PBS replaces the alpha-amylase solution, namely water + starch solution + PBS solution measured absorbance value; a3: the absorbance value of the sample on the inhibition effect of alpha-amylase, namely the absorbance value measured by the sample solution, the starch solution and the alpha-amylase solution; a4: the PBS solution replaces the alpha-amylase solution, i.e., the sample solution + the starch solution + the absorbance value measured by the PBS solution.

The experimental results are shown in FIG. 4.

As can be seen from FIG. 4, at 5X 2 ^-5 In the concentration range of 5mg/mL, the inhibition rate of the oligosaccharide and the oligopeptide to the alpha-amylase is increased along with the increase of the concentration, and the obvious concentration dependence is shown, but when the concentration is as high as 5mg/mL, the inhibition rate of the oligosaccharide and the oligopeptide to the alpha-amylase is still lower than 75%. Chinese chestnut oligosaccharide-oligopeptide composition at low concentration of 5×2 compared with single oligosaccharide and oligopeptide ^-5 When mg/mL, the inhibition rate of alpha-amylase reaches (75.50 +/-1.91)%, and the concentration is higher than 5 multiplied by 2 ^-2 At mg/mL, the inhibition rate of alpha-amylase is higher than 98%, which indicates that the composition of the oligosaccharide and the oligopeptide is obviously provided withHas more remarkable alpha-amylase inhibition activity and excellent blood sugar reducing effect.

Experimental example 6

1. Normal mouse fasting blood glucose effect experiment

Healthy SD male rats are kept on the feed for 3 days, fasted for 3-5 hours, blood is collected from tail veins, and blood glucose levels are randomly divided into 2 groups: blank control and composition intervention groups. Rats in each group were fed normal drinking water and the blank group was filled with distilled water and the composition intervention group was filled with 0.50g/kg bw of composition solution 1 time daily for 30 days, and fasting blood glucose levels were measured using a glucometer. The experimental results are shown in table 2.

TABLE 2 Effect of chestnut extract on fasting blood glucose in rats

Group of	Initial fasting blood glucose (mmol/L)	Terminal fasting blood sugar (mmol/L)
			Blank control group	6.44±0.38	6.72±0.47
Composition intervention group	6.49±0.33	6.70±0.45
			P value	0.267	0.422

As can be seen from table 2, the blank control group and the composition intervention group have no significant difference (P > 0.05) in the initial fasting blood glucose, the final fasting blood glucose and their change rates, indicating that ingestion of the chestnut oligosaccharide-oligopeptide composition does not cause a decrease in blood glucose in normal rats.

2. Diabetes model rat fasting blood glucose influence experiment

Establishing a hyperglycemia rat model: after the rats were fasted for 24 hours, the tail vein was injected with tetraoxypyrimidine (120 mg/kg bw) for one molding, and after the injection, free feeding and drinking water were resumed, and the rats were kept for 5 days. After 5d of molding, the blood glucose concentration was measured by fasting for 5 hours. And (3) selecting rats with successful hyperglycemia modeling (blood sugar value is 10-25 mmol/L), respectively filling the Chinese chestnut oligosaccharide-oligopeptide composition in low, medium and high dose groups with 0.25, 0.5 and 1.0g/kg bw, filling the same volume of distilled water in a model group (diabetic model rats) and a blank group (normal rats) (without problems in the invention) with the same volume of the stomach, measuring the FBG value 1 time a day, and continuously for 30 days. The results are shown in Table 3.

TABLE 3 influence of chestnut extract on diabetes model rat FBG results

As can be seen from table 3, the FBG levels in the model group were elevated, significantly different (P < 0.01) from the blank group, and the FBG levels in the low, medium and high dose groups were reduced after 10d of intervention, and exhibited a good dose-response relationship. The FBG level of each dose group is obviously reduced (P < 0.01) compared with that of a model group after 10d to 30d intervention, which indicates that the chestnut oligosaccharide-oligopeptide composition can effectively control the increase of FBG and has better potential for treating diabetes.

3. Oral glucose tolerance test in diabetes model mice

The rats with hyperglycemia modeling success are selected to fasted for 5 hours, then the fasting blood glucose value is measured, then, chestnut oligosaccharide-oligopeptide composition with corresponding concentration is given to each dosage group, the model group (diabetic model rat) and the blank group (normal rat) are filled with the same volume of distilled water, after 15 minutes, each group is orally given glucose of 2.0g/kg bw, the blood glucose value of 0.5 hour and 2.0 hour after glucose is measured, and the area under the curve is calculated. The experimental results are shown in table 4.

TABLE 4 Effect of chestnut extract on diabetic model rat OGTT

As can be seen from table 4, the data show that the model group rats had an elevated glucose tolerance, a significant difference (P < 0.01) compared to the blank group rats, and both the medium and high dose groups were significantly reduced (P < 0.01) compared to the model group. The blood glucose value and the area under the blood glucose curve of the hyperglycemia model rats of each dosage group are lower than those of the model groups, which indicates that the chestnut oligosaccharide-oligopeptide composition not only can effectively reduce the FBG level of the rats, but also can obviously improve the tolerance of the rat organism to glucose.

Experimental example 7

The chestnut extracts of Yan Qiu, yan Li and big-leaf late variety were selected, the chestnut extracts were prepared by the same extraction method as in the example, the inhibition effect of these extracts on alpha-amylase at different concentrations was tested, and the results were recorded in table 5.

TABLE 5 inhibition of alpha-amylase by chestnut extracts of different varieties at different concentrations

As can be seen from the table above, the extract comprising oligosaccharides and oligopeptides extracted from the kernel extract of Yan Feng chestnut has significantly better alpha-amylase inhibitory activity than other chestnut varieties.

In summary, the chestnut extract provided by the application is a substance containing chestnut oligosaccharides and chestnut oligopeptides extracted from Yan Feng chestnut kernels serving as raw materials, and has the following characteristics:

1. a large number of experiments prove that the extract provided by the application has remarkable in-vitro and in-vivo hypoglycemic activity, can be applied to the fields of medicines and health-care foods, and promotes the high-value utilization of Chinese chestnut.

2. The oligosaccharide and the oligopeptide in the composition are separated, and the hypoglycemic activity of the composition is obviously higher than that of the single oligosaccharide and the oligopeptide through the comparative test of the hypoglycemic activity of the single oligosaccharide and the oligopeptide, so that the synergistic effect of the chestnut oligosaccharide and the oligopeptide is obviously improved, the oligosaccharide and the oligopeptide are not required to be further separated in practical application, and the low-cost and high-efficiency large-scale production of the active ingredient is facilitated.

3. The extraction and purification process uses water as a solvent, does not introduce toxic and harmful substances, accords with a food-grade extraction process, and has the characteristics of environmental protection. The whole preparation process of the composition is simple to operate, good in controllability, low in cost, and good in application prospect and commercial feasibility.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The application of the chestnut extract in preparing health care products and medicines with the function of reducing blood sugar is characterized in that the chestnut extract is obtained by extracting Yan Feng chestnut kernels as raw materials, and the chestnut extract comprises chestnut oligosaccharides and chestnut oligopeptides;

the weight average molecular weight of the chestnut oligosaccharide is 500-680 Da, and the weight average molecular weight of the chestnut oligopeptide is 370-575 Da;

the monosaccharide composition of the chestnut oligosaccharide comprises Glc, gal and Fru;

the amino acid composition of the chestnut oligopeptide mainly comprises Asp, asn and Glu;

in the amino acid composition of the chestnut oligopeptide, the mass ratio of the total amount of Asp, asn and Glu after hydrolysis is more than 96%.

2. The use according to claim 1, wherein the method for preparing chestnut extract comprises:

3. The use according to claim 2, wherein the method of leaching comprises:

mixing Yan Feng semen Castaneae kernel powder with water, soaking, solid-liquid separating, and collecting leaching solution.

4. The use according to claim 2, wherein the solid to liquid ratio during leaching is 1:20-30.

5. The use according to claim 2, wherein the leaching temperature is 60-70 ℃.

6. The use according to claim 2, characterized in that the leaching is carried out with stirring for a period of 2-3 hours.

7. The method according to claim 3, wherein the solid-liquid separation is performed by centrifugation at 6000 to 7000rpm for 5 to 10min.

8. The use according to claim 3, further comprising filtering the resulting extract to collect the extract between 300 and 3000 Da.

9. The use according to claim 8, wherein the filtering method comprises:

filtering the leaching solution by adopting a microporous filter membrane with the diameter of 0.1 mu m, and collecting a penetrating fluid to obtain a micro-filtrate;

filtering the micro-filtrate by using an ultrafiltration membrane of 3000Da, and collecting the permeate to obtain an ultrafiltrate;

the retentate was collected by filtration of the ultrafiltrate using a nanofiltration membrane of 300 Da.

10. The use according to claim 9, characterized in that the obtaining of the retentate further comprises concentrating it under reduced pressure and freeze-drying to obtain a solid extract.