Asparagus extract with α-glucosidase activity regulating function, its preparation method and application

Abstract

The present invention discloses an asparagus extract with the activity of regulating α-glucosidase, its preparation method and application, belonging to the technical fields of food and medicine. The aqueous extract of asparagus is taken, after centrifugation filtration and microfiltration treatment, ultrafiltration membranes with different molecular weight cut-offs are used to separate and prepare asparagus extracts with different regulatory effects on the activity of α-glucosidase from the active sites that simultaneously contain the promotion and inhibition of α-glucosidase activity. Among them, the extracts with molecular weights greater than 3 KD, 6 KD, 10 KD, and 30 KD are asparagus extracts that promote the activity of α-glucosidase, and the extracts with molecular weights less than 3 KD, 6 KD, 10 KD, and 30 KD are asparagus extracts that inhibit the activity of α-glucosidase. The product of the preparation method of the present invention has high activity, saves energy, is simple and easy to operate, and is suitable for industrial production. The present invention separates the active sites that naturally coexist in asparagus and have the effects of promoting and inhibiting α-glucosidase, making the action of the asparagus extract more specific and powerful.

Description

Technical Field

[0001] The present invention belongs to the technical fields of food and medicine. More specifically, it relates to a method for separating and preparing asparagus extracts with different regulatory effects on α-glucosidase activity from the active sites that simultaneously promote and inhibit α-glucosidase activity in asparagus extracts, as well as the asparagus extracts and their applications. Background Art

[0002] α-Glucosidase, also known as glucosyltransferase, is systematically named α-D-glucosylglucose hydrolase. α-Glucosidase is mainly distributed on the small intestinal mucosa and can hydrolyze carbohydrates containing α-1,4-glycosidic bonds to release α-D-glucose to regulate the glucose concentration in the intestine.

[0003] Promoting the activity of α-glucosidase can enhance the ability to digest starch, which helps people with weak digestive ability improve starch digestion and obtain more glucose nutrition.

[0004] Inhibiting the activity of α-glucosidase can reduce the production rate of glucose and lower the glycemic index (GI) of food. The International Diabetes Federation and the American Association of Clinical Endocrinologists have regarded natural α-glucosidase inhibitors as the first-line therapy for type 2 diabetes, and screening natural α-glucosidase inhibitors from foods or plants has attracted much attention. In addition, α-glucosidase inhibitors can also inhibit the conversion of blood glucose into fat in the liver by reducing blood glucose. Therefore, α-glucosidase inhibitors can also be used for weight loss.

[0005] Asparagus (Asparagus officinalis L.), also known as asparagus, is a perennial herbaceous plant of the genus Asparagus in the family Asparagaceae. It is a king of vegetables with special nutritional and therapeutic effects. Asparagus contains essential amino acids, minerals and many other nutrients for the human body, and is rich in various active ingredients, such as asparagus polysaccharide, non-protein nitrogen substances mainly composed of asparagine and aspartic acid, saponin compounds, flavonoid substances, etc., and has various biological functions such as lipid-lowering, cancer prevention and anti-cancer, anti-fatigue, anti-aging, and immune regulation. However, there is still no clear and unified understanding of the effect of asparagus on the activity of α-glucosidase at present.

[0006] The inventors have found through research that asparagus contains active sites that both promote and inhibit the activity of α-glucosidase. Although the mass proportion of the active site that promotes the activity of α-glucosidase is relatively small, its promoting activity is very strong. Therefore, due to different ratios between the two, the action trends and efficacies of asparagus extracts on α-glucosidase are very different. In particular, the freshly squeezed asparagus juice and the water extract of asparagus prepared by the existing technology as a whole show a trend of promoting the activity of α-glucosidase, and their promoting effects vary with the ratios of the active sites that inhibit and promote the activity of α-glucosidase, and the active effects are unstable. After the water extract of asparagus is treated with ultrafiltration membrane modules with different cut-off molecular weights, asparagus extracts in different molecular weight ranges are obtained, and these asparagus extracts with different molecular weights have different trends in regulating the activity of α-glucosidase. There is a literature report that the extract obtained by treating the old stems of asparagus with ZTC 1+1 clarifying agent has the effect of inhibiting the activity of α-glucosidase, with a half inhibitory concentration of only 62.50 mg / mL and a maximum inhibition rate of 53.71 ± 3.05%. Compared with the asparagus extract with the activity of inhibiting α-glucosidase obtained in the present invention, both are more than half lower in terms of inhibiting the activity of α-glucosidase, indicating that the extract obtained by the literature technology may still contain two active sites that promote and inhibit the activity of α-glucosidase. Although the old stems of asparagus belong to the agricultural production waste of asparagus that is not for consumption and are different from the edible tender stems of asparagus described in the present invention in terms of chemical composition and active functions, the water extract of asparagus prepared by the method of using the ZTC 1+1 clarifying agent in this literature also shows a weak promoting effect on the activity of α-glucosidase, which is consistent with the action trend of the water extract of asparagus obtained by other processes such as juicing, ultrasonic treatment, and heating extraction. Summary of the Invention

[0007] The object of the present invention is to provide an asparagus extract that can simultaneously prepare asparagus extracts with the activities of inhibiting and promoting α-glucosidase from the water extract of asparagus, and the preparation method has a simple production process and high product activity.

[0008] The object of the present invention is to separate the two active sites that naturally coexist in asparagus and have the effects of promoting and inhibiting α-glucosidase, so that the asparagus extracts with the promoting and inhibiting effects are more specific and powerful.

[0009] Another object of the present invention is to apply the asparagus extracts with more specific and powerful promoting or inhibiting effects obtained to food, health food, and drugs. Among them, the asparagus extract with the activity of promoting α-glucosidase can enhance the body's ability to digest starch, help people with weak digestive ability improve the digestion of starch, and obtain more glucose nutrition; the asparagus extract with the activity of inhibiting α-glucosidase can reduce the glucose production rate, help control blood sugar, and assist in weight loss.

[0010] The object of the present invention is achieved by the following technical solutions:

[0011] The present invention provides a preparation method of an asparagus extract with the activity of regulating α-glucosidase, comprising the following steps: taking an aqueous extract of asparagus, obtaining an aqueous asparagus extract after centrifugal filtration and microfiltration treatment, and respectively using ultrafiltration membranes with different molecular weight cut-offs to prepare an asparagus extract with the activity of regulating α-glucosidase, wherein:

[0012] (1) The aqueous asparagus extract passes through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Dalton, and the retentate with a molecular weight greater than 30,000 Dalton collected is an asparagus extract that promotes the activity of α-glucosidase, and the permeate with a molecular weight less than 30,000 Dalton is an asparagus extract that inhibits the activity of α-glucosidase;

[0013] (2) The aqueous asparagus extract passes through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Dalton, and the retentate with a molecular weight greater than 10,000 Dalton collected is an asparagus extract that promotes the activity of α-glucosidase, and the permeate with a molecular weight less than 10,000 Dalton is an asparagus extract that inhibits the activity of α-glucosidase;

[0014] (3) The aqueous asparagus extract passes through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Dalton, and the retentate with a molecular weight greater than 6,000 Dalton collected is an asparagus extract that promotes the activity of α-glucosidase, and the permeate with a molecular weight less than 6,000 Dalton is an asparagus extract that inhibits the activity of α-glucosidase;

[0015] (4) The aqueous asparagus extract passes through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Dalton, and the retentate with a molecular weight greater than 3,000 Dalton collected is an asparagus extract that promotes the activity of α-glucosidase, and the permeate with a molecular weight less than 3,000 Dalton is an asparagus extract that inhibits the activity of α-glucosidase;

[0016] (5) Taking the permeate with a molecular weight less than 30,000 Dalton, passing it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Dalton, and the filtrate with a molecular weight less than 30,000 and greater than 10,000 Dalton collected is an asparagus extract that promotes the activity of α-glucosidase;

[0017] (6) Taking the permeate with a molecular weight less than 10,000 Dalton, passing it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Dalton, and the filtrate with a molecular weight less than 10,000 and greater than 6,000 Dalton collected is an asparagus extract that promotes the activity of α-glucosidase;

[0018] (7) Taking the permeate with a molecular weight less than 6,000 Dalton, passing it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Dalton, and the filtrate with a molecular weight less than 6,000 and greater than 3,000 Dalton collected is an asparagus extract that promotes the activity of α-glucosidase;

[0019] The asparagus extract obtained by the above ultrafiltration can be concentrated and dried to obtain asparagus extracts with different dry matter contents.

[0020] Furthermore, the water extract of asparagus is obtained by juicing fresh asparagus.

[0021] Furthermore, the water extract of asparagus is obtained by crushing dried asparagus, adding 10 - 15 times water, and heating at 60°C for extraction for 0.5 - 2 hours.

[0022] Furthermore, the water extract of asparagus is obtained by crushing dried asparagus, adding 10 - 15 times water, and extracting with medium and low frequency ultrasonic waves for 1 hour.

[0023] Furthermore, the organic composite membrane material used for ultrafiltration is aromatic polyamide, poly(piperazine amide) or polyethersulfone, and the molecular weight cut-off range is 30,000 Daltons, 10,000 Daltons, 6,000 Daltons, 3,000 Daltons.

[0024] Furthermore, among the asparagus extracts with inhibitory activity against α-glucosidase, the one with the strongest inhibitory activity is the asparagus extract with a molecular weight less than 3,000 Daltons.

[0025] Furthermore, among the asparagus extracts with promoting activity against α-glucosidase, the one with the strongest promoting activity is the asparagus extract with a molecular weight greater than 30,000 Daltons.

[0026] Furthermore, the various asparagus extracts with the activity of regulating α-glucosidase can be made into known dosage forms in the fields of food and medicine, including lozenges, granules, ointments, oral liquids, beverages, powders, tablets or capsules, by using conventional preparation methods and excipients and / or additives acceptable in the fields of food and medicine.

[0027] The present invention also provides an application of the asparagus extract prepared by the above preparation method in the preparation of food, and the asparagus extract is used as a component in the preparation of food.

[0028] The present invention also provides an application of the asparagus extract prepared by the above preparation method in the preparation of a medicine with the pharmacological activity of regulating α-glucosidase, and the asparagus extract is used as an active ingredient in the medicine with the pharmacological activity of regulating α-glucosidase.

[0029] The present invention has at least the following beneficial effects:

[0030] 1. The preparation method of an asparagus extract with the activity of regulating α-glucosidase provided by the present invention can simultaneously prepare asparagus extracts with inhibitory and promoting activities against α-glucosidase respectively. The product of this preparation method has high activity, saves energy, is simple and easy to operate, and is suitable for industrial production.

[0031] 2. The preparation method of asparagus extract with the activity of regulating α-glucosidase provided by the present invention can separate two active parts in asparagus that naturally coexist and have the effects of promoting and inhibiting α-glucosidase, making the effects of asparagus extracts with promoting and inhibiting effects more specific and powerful respectively.

[0032] 3. The preparation method of asparagus extract with the activity of regulating α-glucosidase provided by the present invention applies the asparagus extracts with more specific and powerful promoting or inhibiting effects obtained respectively to foods, health foods, and pharmaceuticals. Among them, the asparagus extract with the activity of promoting α-glucosidase can enhance the body's ability to digest starch, help people with weak digestive ability improve the digestion of starch, and obtain more glucose nutrition; the asparagus extract with the activity of inhibiting α-glucosidase can reduce the generation rate of glucose, help control blood sugar, and assist in weight loss. Detailed implementation mode

[0033] Example 1

[0034] Select 5000 grams of fresh edible asparagus, continuously wash it with running water, drain the water, crush and juice the processed asparagus, centrifuge and filter to obtain the juice, and microfilter it. The filtrate is the water extract of asparagus (the yield is 75.3% ± 0.21 of the weight of fresh asparagus).

[0035] Take the above-mentioned aqueous extract of asparagus, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 30,000 Da (asparagus extract that promotes the activity of α-glucosidase, and the yield is 1.8% of the weight of fresh asparagus) and the permeate with a molecular weight less than 30,000 Da (asparagus extract that inhibits the activity of α-glucosidase, and the yield is 73.5% of the weight of fresh asparagus); take the above-mentioned aqueous extract of asparagus, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 10,000 Da (asparagus extract that promotes the activity of α-glucosidase, and the yield is 2.6% of the weight of fresh asparagus) and the permeate with a molecular weight less than 10,000 Da (asparagus extract that inhibits the activity of α-glucosidase, and the yield is 72.7% of the weight of fresh asparagus); take the above-mentioned aqueous extract of asparagus, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 6,000 Da (asparagus extract that promotes the activity of α-glucosidase, and the yield is 2.8% of the weight of fresh asparagus) and the permeate with a molecular weight less than 6,000 Da (asparagus extract that inhibits the activity of α-glucosidase, and the yield is 72.5% of the weight of fresh asparagus); take the above-mentioned aqueous extract of asparagus, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 3,000 Da (asparagus extract that promotes the activity of α-glucosidase, and the yield is 2.8% of the weight of fresh asparagus) and the permeate with a molecular weight less than 3,000 Da (asparagus extract that inhibits the activity of α-glucosidase, and the yield is 72.3% of the weight of fresh asparagus); take the above-mentioned permeate with a molecular weight less than 30,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 30,000 Da and greater than 10,000 Da (asparagus extract that promotes the activity of α-glucosidase, and the yield is 0.75% of the weight of fresh asparagus); take the above-mentioned permeate with a molecular weight less than 10,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 10,000 Da and greater than 6,000 Da (asparagus extract that promotes the activity of α-glucosidase, and the yield is 0.26% of the weight of fresh asparagus); take the above-mentioned permeate with a molecular weight less than 6,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 6,000 Da and greater than 3,000 Da (asparagus extract that promotes the activity of α-glucosidase, and the yield is 0.15% of the weight of fresh asparagus).

[0036] The asparagus extract obtained by the above ultrafiltration can be concentrated and dried to obtain asparagus extracts with different dry matter contents.

[0037] Example 2

[0038] Select the dried asparagus, remove the parts with insects or spoilage, crush them with a pulverizer, and pass through a 60-mesh sieve.

[0039] Take 1000 grams of the above-mentioned asparagus powder, add 10 times the amount of water, extract at 60 °C for 0.5 h, centrifuge and filter, and collect the filtrate. Then add 10 times the amount of water to the obtained filter residue, extract at 60 °C for 0.5 h, centrifuge and filter, collect the filtrate, extract repeatedly 3 times, combine the obtained filtrates, and then perform microfiltration. The filtrate is the water extract of asparagus (the yield calculated based on the dry matter of asparagus is 3.64%).

[0040] Take the above-mentioned asparagus aqueous extract and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 30,000 Da (asparagus extract that promotes α-glucosidase activity, the yield of dry asparagus matter is 0.081%) and the permeate with a molecular weight less than 30,000 Da (asparagus extract that inhibits α-glucosidase activity, the yield of dry asparagus matter is 3.32%); take the above-mentioned asparagus aqueous extract and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 10,000 Da (asparagus extract that promotes α-glucosidase activity, the yield of dry asparagus matter is 0.12%) and the permeate with a molecular weight less than 10,000 Da (asparagus extract that inhibits α-glucosidase activity, the yield of dry asparagus matter is 3.21%); take the above-mentioned asparagus aqueous extract and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 6,000 Da (asparagus extract that promotes α-glucosidase activity, the yield of dry asparagus matter is 0.14%) and the permeate with a molecular weight less than 6,000 Da (asparagus extract that inhibits α-glucosidase activity, the yield of dry asparagus matter is 3.21%); take the above-mentioned asparagus aqueous extract and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 3,000 Da (asparagus extract that promotes α-glucosidase activity, the yield of dry asparagus matter is 0.15%) and the permeate with a molecular weight less than 3,000 Da (asparagus extract that inhibits α-glucosidase activity, the yield of dry asparagus matter is 3.18%); take the above-mentioned permeate with a molecular weight less than 30,000 Da and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 30,000 Da and greater than 10,000 Da (asparagus extract that promotes α-glucosidase activity, the yield of dry asparagus matter is 0.03%); take the above-mentioned permeate with a molecular weight less than 10,000 Da and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 10,000 Da and greater than 6,000 Da (asparagus extract that promotes α-glucosidase activity, the yield of dry asparagus matter is 0.01%); take the above-mentioned permeate with a molecular weight less than 6,000 Da and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 6,000 Da and greater than 3,000 Da (asparagus extract that promotes α-glucosidase activity, the yield of dry asparagus matter is 0.006%).

[0041] The above-mentioned asparagus extract obtained by ultrafiltration can be concentrated and dried to obtain asparagus extracts with different dry matter contents.

[0042] Example 3

[0043] Select the dried asparagus, remove the parts with insects or spoilage, crush them with a pulverizer, and sieve through a 60-mesh sieve.

[0044] Take 1000 grams of the above-mentioned asparagus powder, add 12 times the amount of water, extract at 60 °C for 1 h, centrifuge and filter, and collect the filtrate. Then add 12 times the amount of water to the obtained filter residue, extract at 60 °C for 1 h, centrifuge and filter, collect the filtrate, extract repeatedly 3 times, combine the obtained filtrates, and then perform microfiltration. The filtrate is the water extract of asparagus (the yield calculated based on the dry matter of asparagus is 4.3%).

[0045] Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 30,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.08%) and the permeate with a molecular weight less than 30,000 Da (asparagus extract inhibiting α-glucosidase activity, the yield of asparagus dry matter is 3.61%); Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 10,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.12%) and the permeate with a molecular weight less than 10,000 Da (asparagus extract inhibiting α-glucosidase activity, the yield of asparagus dry matter is 3.20%); Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 6,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.13%) and the permeate with a molecular weight less than 6,000 Da (asparagus extract inhibiting α-glucosidase activity, the yield of asparagus dry matter is 3.19%); Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 3,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.14%) and the permeate with a molecular weight less than 3,000 Da (asparagus extract inhibiting α-glucosidase activity, the yield of asparagus dry matter is 3.24%); Take the above-mentioned permeate with a molecular weight less than 30,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 30,000 Da and greater than 10,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.04%); Take the above-mentioned permeate with a molecular weight less than 10,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 10,000 Da and greater than 6,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.02%); Take the above-mentioned permeate with a molecular weight less than 6,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 6,000 Da and greater than 3,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.01%).

[0046] The above-mentioned asparagus extract obtained by ultrafiltration can be concentrated and dried to obtain asparagus extracts with different dry matter contents.

[0047] Example 4

[0048] Select the dried asparagus, remove the parts with insects or spoilage, crush them with a pulverizer, and pass through a 60-mesh sieve.

[0049] Take 1000 grams of the above-mentioned asparagus powder, add 14 times the amount of water, extract at 60 °C for 1.5 h, centrifuge and filter, and collect the filtrate. Then add 14 times the amount of water to the obtained filter residue, extract at 60 °C for 1.5 h, centrifuge and filter, collect the filtrate, extract repeatedly 3 times, combine the obtained filtrates, and then carry out microfiltration. The filtrate is the water extract of asparagus (the yield calculated based on the dry matter of asparagus is 4.1%).

[0050] Take the above-mentioned asparagus aqueous extract and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 30,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.09%) and the permeate with a molecular weight less than 30,000 Da (asparagus extract inhibiting α-glucosidase activity, yield of asparagus dry matter is 3.61%); Take the above-mentioned asparagus aqueous extract and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 10,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.12%) and the permeate with a molecular weight less than 10,000 Da (asparagus extract inhibiting α-glucosidase activity, yield of asparagus dry matter is 3.21%); Take the above-mentioned asparagus aqueous extract and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 6,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.13%) and the permeate with a molecular weight less than 6,000 Da (asparagus extract inhibiting α-glucosidase activity, yield of asparagus dry matter is 3.17%); Take the above-mentioned asparagus aqueous extract and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 3,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.14%) and the permeate with a molecular weight less than 3,000 Da (asparagus extract inhibiting α-glucosidase activity, yield of asparagus dry matter is 3.23%); Take the above-mentioned permeate with a molecular weight less than 30,000 Da and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 30,000 Da and greater than 10,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.04%); Take the above-mentioned permeate with a molecular weight less than 10,000 Da and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 10,000 Da and greater than 6,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.01%); Take the above-mentioned permeate with a molecular weight less than 6,000 Da and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 6,000 Da and greater than 3,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.01%).

[0051] The asparagus extract obtained by the above ultrafiltration can be concentrated and dried to obtain asparagus extracts with different dry matter contents.

[0052] Example 5

[0053] Select the dried asparagus, remove the parts with insects or spoilage, crush them with a pulverizer, and sieve through a 60-mesh sieve.

[0054] Take 1000 grams of the above-mentioned asparagus powder, add 15 times the amount of water, extract at 60 °C for 2 hours, centrifuge and filter, and collect the filtrate. Then add 15 times the amount of water to the obtained filter residue, extract at 60 °C for 2 hours, centrifuge and filter, collect the filtrate, extract repeatedly 3 times, combine the obtained filtrates, and then perform microfiltration. The filtrate is the water extract of asparagus (the yield calculated based on the dry matter of asparagus is 3.86%).

[0055] Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 30,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.07%) and the permeate with a molecular weight less than 30,000 Da (asparagus extract inhibiting α-glucosidase activity, the yield of asparagus dry matter is 3.61%); Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 10,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.11%) and the permeate with a molecular weight less than 10,000 Da (asparagus extract inhibiting α-glucosidase activity, the yield of asparagus dry matter is 3.19%); Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 6,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.118%) and the permeate with a molecular weight less than 6,000 Da (asparagus extract inhibiting α-glucosidase activity, the yield of asparagus dry matter is 3.19%); Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 3,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.13%) and the permeate with a molecular weight less than 3,000 Da (asparagus extract inhibiting α-glucosidase activity, the yield of asparagus dry matter is 3.21%); Take the above-mentioned permeate with a molecular weight less than 30,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 30,000 Da and greater than 10,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.03%); Take the above-mentioned permeate with a molecular weight less than 10,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 10,000 Da and greater than 6,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.005%); Take the above-mentioned permeate with a molecular weight less than 6,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 6,000 Da and greater than 3,000 Da (asparagus extract promoting α-glucosidase activity, the yield of asparagus dry matter is 0.007%).

[0056] The above-mentioned asparagus extract obtained by ultrafiltration can be concentrated and dried to obtain asparagus extracts with different dry matter contents.

[0057] Example 6

[0058] Select the dried asparagus, remove the parts with insects or spoilage, crush them with a pulverizer, and sieve through a 60-mesh sieve.

[0059] Take 1000 grams of the above-mentioned asparagus powder, add 10 times the amount of water, extract with medium and low-frequency ultrasonic waves for 1 hour, centrifuge and filter, and collect the filtrate. Then add 10 times the amount of water to the obtained filter residue, extract with medium and low-frequency ultrasonic waves for 1 hour, centrifuge and filter, collect the filtrate, extract repeatedly 3 times, combine the obtained filtrates, and then perform microfiltration. The filtrate is the water extract of asparagus (the yield calculated based on the dry matter of asparagus is 4.43%).

[0060] Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 30,000 Da (asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.081) and the permeate with a molecular weight less than 30,000 Da (asparagus extract that inhibits α-glucosidase activity, and the yield of asparagus dry matter is 3.65%); Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 10,000 Da (asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.12%) and the permeate with a molecular weight less than 10,000 Da (asparagus extract that inhibits α-glucosidase activity, and the yield of asparagus dry matter is 3.21%); Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 6,000 Da (asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.119%) and the permeate with a molecular weight less than 6,000 Da (asparagus extract that inhibits α-glucosidase activity, and the yield of asparagus dry matter is 3.24%); Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 3,000 Da (asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.15%) and the permeate with a molecular weight less than 3,000 Da (asparagus extract that inhibits α-glucosidase activity, and the yield of asparagus dry matter is 3.24%); Take the above-mentioned permeate with a molecular weight less than 30,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 30,000 Da and greater than 10,000 Da (asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.05%); Take the above-mentioned permeate with a molecular weight less than 10,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 10,000 Da and greater than 6,000 Da (asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.007%); Take the above-mentioned permeate with a molecular weight less than 6,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 6,000 Da and greater than 3,000 Da (asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.01%).

[0061] The above-mentioned asparagus extract obtained by ultrafiltration can be concentrated and dried to obtain asparagus extracts with different dry matter contents.

[0062] Example 7

[0063] Select the dried asparagus, remove the parts with insects or spoilage, crush them with a pulverizer, and sieve through a 60-mesh sieve.

[0064] Take 1000 grams of the above-mentioned asparagus powder, add 12 times the amount of water, extract with medium and low-frequency ultrasonic waves for 1 hour, centrifuge and filter, and collect the filtrate. Then add 12 times the amount of water to the obtained filter residue, extract with medium and low-frequency ultrasonic waves for 1 hour, centrifuge and filter, collect the filtrate, extract repeatedly 3 times, combine the obtained filtrates, and then carry out microfiltration. The filtrate is the water extract of asparagus (the yield calculated based on the dry matter of asparagus is 4.67%).

[0065] Take the above-mentioned asparagus aqueous extract and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 30,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.09%) and the permeate with a molecular weight less than 30,000 Da (asparagus extract inhibiting α-glucosidase activity, yield of asparagus dry matter is 3.63%); take the above-mentioned asparagus aqueous extract and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 10,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.13%) and the permeate with a molecular weight less than 10,000 Da (asparagus extract inhibiting α-glucosidase activity, yield of asparagus dry matter is 3.23%); take the above-mentioned asparagus aqueous extract and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 6,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.126%) and the permeate with a molecular weight less than 6,000 Da (asparagus extract inhibiting α-glucosidase activity, yield of asparagus dry matter is 3.24%); take the above-mentioned asparagus aqueous extract and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the retentate with a molecular weight greater than 3,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.15%) and the permeate with a molecular weight less than 3,000 Da (asparagus extract inhibiting α-glucosidase activity, yield of asparagus dry matter is 3.25%); take the above-mentioned permeate with a molecular weight less than 30,000 Da and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 30,000 Da and greater than 10,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.06%); take the above-mentioned permeate with a molecular weight less than 10,000 Da and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 10,000 Da and greater than 6,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.01%); take the above-mentioned permeate with a molecular weight less than 6,000 Da and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Collect the filtrate with a molecular weight less than 6,000 Da and greater than 3,000 Da (asparagus extract promoting α-glucosidase activity, yield of asparagus dry matter is 0.01%).

[0066] The above-mentioned asparagus extract obtained by ultrafiltration can be concentrated and dried to obtain asparagus extracts with different dry matter contents.

[0067] Example 8

[0068] Select the dried asparagus, remove the parts with insects or spoilage, crush them with a pulverizer, and pass through a 60-mesh sieve.

[0069] Take 1000 grams of the above-mentioned asparagus powder, add 15 times the amount of water, extract with medium and low-frequency ultrasonic waves for 1 hour, centrifuge and filter, and collect the filtrate. Then add 15 times the amount of water to the obtained filter residue, extract with medium and low-frequency ultrasonic waves for 1 hour, centrifuge and filter, collect the filtrate, extract repeatedly 3 times, combine the obtained filtrates, and then perform microfiltration. The filtrate is the water extract of asparagus (the yield based on dry matter of asparagus is 3.97%).

[0070] Take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 30,000 Da (an asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.07%) and the permeate with a molecular weight less than 30,000 Da (an asparagus extract that inhibits α-glucosidase activity, and the yield of asparagus dry matter is 3.62%); take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 10,000 Da (an asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.12%) and the permeate with a molecular weight less than 10,000 Da (an asparagus extract that inhibits α-glucosidase activity, and the yield of asparagus dry matter is 3.21%); take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 6,000 Da (an asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.10%) and the permeate with a molecular weight less than 6,000 Da (an asparagus extract that inhibits α-glucosidase activity, and the yield of asparagus dry matter is 3.20%); take the above-mentioned asparagus aqueous extract, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa. Respectively collect the retentate with a molecular weight greater than 3,000 Da (an asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.14%) and the permeate with a molecular weight less than 3,000 Da (an asparagus extract that inhibits α-glucosidase activity, and the yield of asparagus dry matter is 3.24%); take the above-mentioned permeate with a molecular weight less than 30,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da, with a filtration pressure of 0.12 Mpa, and collect the filtrate with a molecular weight less than 30,000 Da and greater than 10,000 Da (an asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.05%); take the above-mentioned permeate with a molecular weight less than 10,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da, with a filtration pressure of 0.12 Mpa, and collect the filtrate with a molecular weight less than 10,000 Da and greater than 6,000 Da (an asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.006%); take the above-mentioned permeate with a molecular weight less than 6,000 Da, and then pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da, with a filtration pressure of 0.12 Mpa, and collect the filtrate with a molecular weight less than 6,000 Da and greater than 3,000 Da (an asparagus extract that promotes α-glucosidase activity, and the yield of asparagus dry matter is 0.07%).

[0071] The asparagus extracts obtained by the above ultrafiltration can be concentrated and dried to obtain asparagus extracts with different dry matter contents.

[0072] Example 9

[0073] Take an appropriate amount of the asparagus extract with an α-glucosidase inhibitory activity and a molecular weight less than 3 kDa prepared in Example 1, concentrate it to a relative density of about 1.08, spray it into a fluidized bed granulator, use sorbitol as an auxiliary material, and granulate it by fluidized bed to obtain granular asparagus extract.

[0074] Example 10

[0075] Take an appropriate amount of the asparagus extract with an α-glucosidase promoting activity and a molecular weight greater than 30 kDa prepared in Example 1, concentrate it to a relative density of about 1.15 - 1.20, add 0.2% acesulfame potassium and 0.1% citric acid for flavoring, mix well, fill it into cans and seal them, then put them into an autoclave and sterilize them at 121 °C for 15 min to obtain oral liquid of asparagus extract.

[0076] Example 11

[0077] Take an appropriate amount of the asparagus extract with an α-glucosidase inhibitory activity and a molecular weight less than 6 kDa prepared in Example 1, concentrate it to a relative density of about 1.25 - 1.35, fill it while it is hot and pasteurize it to obtain asparagus paste.

[0078] Example 12

[0079] Take an appropriate amount of the asparagus extract with an α-glucosidase inhibitory activity and a molecular weight less than 6 kDa prepared in Example 1, concentrate it and then spray-dry it to obtain asparagus extract powder, and obtain powdery asparagus extract after sterilization and bagging.

[0080] Example 13

[0081] Take the powdery asparagus extract prepared in Example 13 above, add 4 times the amount of xylitol and mix well, and obtain asparagus tablets after tabletting.

[0082] Example 14

[0083] Take the powdery asparagus extract prepared in Example 13 above, fill it into capsules to make asparagus capsules.

[0084] Example 15

[0085] Take the powdery asparagus extract prepared in Example 13 above, add it to 25 times the amount of milk powder, mix well, fill it and bag it after blending to obtain asparagus extract milk powder.

[0086] Example 16

[0087] Take 200 g of the asparagus extract powder obtained by concentrating and then spray-drying the asparagus extract with an α-glucosidase promoting activity and a molecular weight greater than 10 kDa prepared in Example 2 above, add it to 800 g of pre-treated chocolate paste and other ingredients and mix evenly, pour the mixed slurry into a mold, form it and cool it to obtain chocolate products.

[0088] Example 17

[0089] Take 200 grams of the concentrated asparagus extract with α-glucosidase inhibitory activity and a molecular weight of less than 6 kDa prepared in Example 3 above, add it to 1% agar, 1% sodium alginate, and 1% carrageenan that have been pre-soaked in water, then add 0.2% aspartame, 0.1% edible essence, and 0.2% edible acid, heat to completely dissolve, fill into plastic cups of a certain specification, seal, sterilize, cool, conduct commercial sterility inspection, package, and obtain the finished asparagus extract jelly after passing the inspection.

[0090] Example 18

[0091] Take 200 grams of the asparagus extract powder obtained by spray drying the concentrated asparagus extract with α-glucosidase promoting activity and a molecular weight of more than 10 kDa prepared in Example 2 above, add appropriate amounts of pre-treated 30% maltose, 2% citric acid, 0.05% essence, 0.05% pigment, and 0.2% cream to make cream soft candy, sub-pack, pack into boxes, and obtain the finished asparagus extract cream soft candy after passing the inspection.

[0092] The above only expresses the preferred embodiments of the present invention, and its description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications, improvements, and substitutions can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

[0093] Comparative Example 1

[0094] Select 5000 grams of fresh edible asparagus, continuously wash it with running water, drain the water, crush and juice the treated asparagus, centrifuge and filter to obtain the juice, and microfilter. The filtrate is the aqueous extract of asparagus. (Same as Example 1)

[0095] The above-obtained aqueous extract of asparagus can be concentrated and dried to obtain aqueous extracts of asparagus with different dry matter contents.

[0096] Comparative Example 2

[0097] Select 5000 grams of fresh edible asparagus, continuously wash it with running water, drain the water, blanch and then place it in a juicer to extract juice, and add ZTC to the asparagus juice 1+1The clarifying agent (8% component B, 4% component A) is used for clarifying treatment, and then filtration is carried out. The filtrate is the water extract of asparagus. (The extraction method is the same as that in the literature "Study on the in vitro antioxidant, cytotoxicity and α-glucosidase inhibitory activity of asparagus extract [J]. Natural Product Research and Development, 2011, 23(02): 356-360.", only changing the extraction object from old asparagus stems to asparagus. Old asparagus stems are the inedible waste parts of asparagus)

[0098] The obtained water extract of asparagus can be concentrated and dried to obtain water extracts of asparagus with different dry matter contents.

[0099] Experiment on the effect of samples on α-glucosidase activity

[0100] Take the asparagus extracts with molecular weights greater than 30,000 Da, greater than 10,000 Da, greater than 6,000 Da, greater than 3,000 Da, less than 30,000 Da and greater than 10,000 Da, and less than 6,000 Da and greater than 3,000 Da prepared in Example 1 of the present invention, and the water extracts of asparagus prepared in Comparative Examples 1 and 2 of the present invention, and respectively prepare sample solutions with a concentration of 0.2 mg / mL. According to the following experimental steps, measure the promoting effect of each sample on α-glucosidase and calculate the promotion rate; take the asparagus extracts with molecular weights less than 30,000 Da, less than 10,000 Da, less than 6,000 Da, and less than 3,000 Da prepared in Example 1 of the present invention and respectively prepare sample solutions with concentrations of 2.5, 5, 10, 20, and 40 mg / mL. According to the following experimental steps, measure the inhibitory effect of each sample on α-glucosidase and calculate the inhibition rate. Plot the concentration as the abscissa and the inhibition rate as the ordinate to calculate the IC50 (half inhibitory concentration) of each sample.

[0101] Experimental method:

[0102] (1) Reagent preparation: 0.2M sodium phosphate buffer PBS (pH = 6.8): Weigh appropriate amounts of disodium hydrogen phosphate dodecahydrate and sodium dihydrogen phosphate dihydrate respectively, and use distilled water to prepare 0.2M, and adjust the pH to 6.8; α-glucosidase: Weigh an appropriate amount of α-glucosidase (from yeast, Shanghai Yuanye, 50 U / mg), and use 0.2M sodium phosphate buffer PBS (pH = 6.8) to prepare 0.048 U / mL, place it at 4°C for later use, and prepare it freshly when in use; 5 mM p-nitrophenyl-α-D-glucopyranoside (pNPG): Weigh an appropriate amount of p-nitrophenyl-α-D-glucopyranoside, and use 0.2M sodium phosphate buffer PBS (pH = 6.8) to prepare 5 mM; 0.2M sodium carbonate solution: Weigh an appropriate amount of anhydrous sodium carbonate and use distilled water to prepare 0.2M.

[0103] (2) Experimental procedure: Mix 50 μL of the sample or 0.2 M PBS solution with 50 μL of α-glucosidase and incubate at 37 °C for 10 minutes. Then, add 50 μL of p-nitrophenyl-α-d-glucopyranoside solution to the mixture and incubate at 37 °C for another 20 minutes. Finally, add 100 μL of sodium carbonate solution to terminate the whole reaction, and measure the absorbance at 405 nm. Calculate the α-glucosidase inhibition rate and promotion rate according to the following formula

[0104]

[0105]

[0106] The experimental results are shown in Table 1. Compared with Comparative Examples 1 and 2, the asparagus extracts with molecular weights less than 30,000, 10,000, 6,000, and 3,000 daltons prepared by the method of the present invention all showed strong inhibitory effects on α-glucosidase activity. However, the samples of Comparative Example 1 (aqueous extract of asparagus) and Comparative Example 2 (aqueous extract of asparagus prepared by using ZTC clarifying agent according to the literature method), which were not treated by the method of the present invention, all showed weak α-glucosidase promoting effects, indicating that the present invention has successfully achieved the invention purpose of separating the two active sites in asparagus that naturally coexist and have the effects of promoting and inhibiting α-glucosidase, making the asparagus extract with the effect of inhibiting α-glucosidase more specific and powerful. 1+1 The aqueous extract of asparagus prepared by the clarifying agent) all showed weak α-glucosidase promoting effects, indicating that the present invention has successfully achieved the invention purpose of separating the two active sites in asparagus that naturally coexist and have the effects of promoting and inhibiting α-glucosidase, making the asparagus extract with the effect of inhibiting α-glucosidase more specific and powerful.

[0107] Table 1 Inhibitory effects of asparagus extracts with different molecular weights on α-glucosidase activity

[0108]

[0109] The experimental results are shown in Table 2. Compared with Comparative Examples 1 and 2, the asparagus extracts with molecular weights greater than 30,000, 10,000, 6,000, and 3,000 daltons; the asparagus extracts with molecular weights greater than 3,000 daltons; the asparagus extracts with molecular weights less than 30,000 and greater than 10,000 daltons; the asparagus extracts with molecular weights less than 6,000 and greater than 3,000 daltons prepared by the method of the present invention all showed strong promoting effects on α-glucosidase activity. Compared with Comparative Examples 1 and 2, the promoting activities were all significantly enhanced (p < 0.01). However, the samples of Comparative Example 1 (aqueous extract of asparagus) and Comparative Example 2 (aqueous extract of asparagus prepared by using ZTC 1+1The samples of the asparagus water extract prepared with the clarifying agent all showed a weak promoting effect on α-glucosidase. Although the promotion rate in Comparative Example 2 was significantly reduced compared with that in Comparative Example 1 (p < 0.05), the parts with promoting and inhibiting effects were still not separated, resulting in an inhibitory effect in Comparative Example 2. The present invention has successfully achieved the invention object of separating the two active parts in asparagus that naturally coexist and have promoting and inhibiting effects on α-glucosidase, making the asparagus extract with a promoting effect on α-glucosidase more specific and powerful.

[0110] Table 2 Promoting effect of asparagus extracts with different molecular weights on α-glucosidase activity

[0111]

[0112]

[0113] Compared with Comparative Example 1: * p < 0.05, ** p < 0.01, compared with Comparative Example 2: # p < 0.05, ## p < 0.01.

Claims

1. Preparation method of asparagus extract with regulated α-glucosidase activity, characterized in that, It includes the following steps: Take the aqueous extract of asparagus, and after centrifugal filtration and microfiltration treatment, obtain the aqueous extract of asparagus. Then, use ultrafiltration membranes with different molecular weight cut-offs to prepare asparagus extracts with the activity of regulating α-glucosidase. Among them: (1) The aqueous extract of asparagus passes through an ultrafiltration membrane with a molecular weight cut-off less than 30,000 Da. The retentate with a molecular weight greater than 30,000 Da collected is the asparagus extract that promotes the activity of α-glucosidase, and the permeate with a molecular weight less than 30,000 Da is the asparagus extract that inhibits the activity of α-glucosidase; (2) The aqueous extract of asparagus passes through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da. The retentate with a molecular weight greater than 10,000 Da collected is the asparagus extract that promotes the activity of α-glucosidase, and the permeate with a molecular weight less than 10,000 Da is the asparagus extract that inhibits the activity of α-glucosidase; (3) The aqueous extract of asparagus passes through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da. The retentate with a molecular weight greater than 6,000 Da collected is the asparagus extract that promotes the activity of α-glucosidase, and the permeate with a molecular weight less than 6,000 Da is the asparagus extract that inhibits the activity of α-glucosidase; (4) The aqueous extract of asparagus passes through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da. The retentate with a molecular weight greater than 3,000 Da collected is the asparagus extract that promotes the activity of α-glucosidase, and the permeate with a molecular weight less than 3,000 Da is the asparagus extract that inhibits the activity of α-glucosidase; (5) Take the permeate with a molecular weight less than 30,000 Da and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 10,000 Da. The filtrate with a molecular weight less than 30,000 Da and greater than 10,000 Da collected is the asparagus extract that promotes the activity of α-glucosidase; (6) Take the permeate with a molecular weight less than 10,000 Da and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 6,000 Da. The filtrate with a molecular weight less than 10,000 Da and greater than 6,000 Da collected is the asparagus extract that promotes the activity of α-glucosidase; (7) Take the permeate with a molecular weight less than 6,000 Da and pass it through an ultrafiltration membrane with a molecular weight cut-off less than 3,000 Da. The filtrate with a molecular weight less than 6,000 Da and greater than 3,000 Da collected is the asparagus extract that promotes the activity of α-glucosidase; The asparagus extracts obtained by the above ultrafiltration are respectively concentrated and dried to obtain asparagus extracts with different dry matter contents.

2. The preparation method of asparagus extract with regulated α-glucosidase activity according to claim 1, characterized in that: The aqueous extract of asparagus is obtained by juicing fresh asparagus.

3. The preparation method of the asparagus extract with regulated α-glucosidase activity according to claim 1, characterized in that, The aqueous extract of asparagus is obtained by crushing dried asparagus, adding 10 - 15 times of water, and heating and extracting at 60 °C for 0.5 - 2 hours.

4. The preparation method of asparagus extract with regulated α-glucosidase activity according to claim 1, characterized in that, The aqueous extract of asparagus is obtained by crushing dried asparagus, adding 10 - 15 times of water, and extracting with medium and low frequency ultrasonic waves for 1 h.

5. The preparation method of asparagus extract with regulated α-glucosidase activity according to claim 1, characterized in that, The organic composite membrane material used for the ultrafiltration membrane is aromatic polyamide, poly(piperazine amide) or polyethersulfone, and the molecular weight cut-off range of the ultrafiltration membrane is 30,000 Da, 10,000 Da, 6,000 Da, 3,000 Da.

6. Use of asparagus extract with regulated α-glucosidase activity, characterized in that: Use the asparagus extract prepared by the preparation method of the asparagus extract with the activity of regulating α-glucosidase according to any one of claims 1 to 5 as an ingredient in the preparation of food.

7. Use of asparagus extract with regulated α-glucosidase activity, characterized in that: The asparagus extract prepared by the preparation method of the asparagus extract with α-glucosidase activity regulating effect as claimed in any one of claims 1 to 5 is used as an active ingredient in a medicament with α-glucosidase pharmacological activity regulating effect.

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