A hydrogel for improving satiety and its preparation method and application

Abstract

The present invention discloses a kind of hydrogel that improves satiety and its preparation method and application, relate to the technical field of polymer gel preparation.The preparation method of the hydrogel that improves satiety of the present invention includes:Cellulose derivative and water are mixed, cross-linking auxiliary agent is added, fully mix, obtain the first solution;Pectin is added to the first solution, fully mix, and pH is adjusted to 7.5 8.0 to obtain the second solution;The second solution is physically cross-linked under ultrasonic treatment to obtain the first cross-linked product;In the first cross-linked product, pectin is added, continuous stirring is carried out to obtain gel;Remove moisture, obtain the hydrogel that improves satiety.The hydrogel prepared by the present invention has good mechanical properties and strong water absorption capacity, improves satiety by water absorption and expansion, achieves good weight loss effect, and meanwhile, the hydrogel has the effect of good regulation of intestinal flora.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer gel preparation, and in particular to a hydrogel for improving satiety, a preparation method and an application thereof. Background Art

[0002] Gel is a semi-solid substance formed by absorbing liquid through a network structure. It has high water retention and volume expansion properties. If used for satiety purposes, it can expand in the stomach after ingestion, taking up space and reducing hunger.

[0003] Currently, methods for preparing carboxymethyl cellulose-based hydrogels include ionic crosslinking, radiation crosslinking, freeze-thaw, free radical polymerization, and interpenetrating network polymerization. Ionic crosslinking utilizes the numerous carboxyl groups in carboxymethyl cellulose molecules to generate electrostatic interactions with divalent or trivalent metal cations, thereby forming a three-dimensional network structure. Radiation crosslinking involves the formation of chemical bonds between linear molecular backbones after irradiation. This method avoids the addition of crosslinking agents and eliminates impurities, reducing reaction complexity and byproduct generation while ensuring the non-toxicity of the resulting hydrogel. Freeze-thaw involves freezing a polymer solution and freezing the molecular chains at a specific point in time. Physical interactions such as van der Waals forces and hydrogen bonds cause adjacent chains to form entanglements, tightly binding them within a specific microregion to form "entanglement points." Free radical polymerization involves the continuous growth of free radicals. Interpenetrating network polymerization involves blending two or more polymers, interweaving and entangled polymer chains, with only physical interactions between them.

[0004] Currently, the mainstream preparation of hydrogels is mostly through chemical cross-linking. Hydrogels prepared by pure physical cross-linking have more advantages in terms of safety, biocompatibility, and preparation cost. They also have dynamic reversibility and can regulate the gel state through external stimuli (such as temperature and pH), providing a design basis for smart responsive materials. However, hydrogels prepared by physical cross-linking are weak in strength and stability.

[0005] Chinese patent CN119409994A discloses a hydrogel that absorbs oil and fat, and its preparation method and application. After mixing polysaccharide glue with water, wet ultrafine grinding is performed to obtain an ultrafine polysaccharide glue solution. High shear mixing is used to make the polysaccharide glue evenly penetrate into the interior of cellulose or its derivatives to form micelles. Microwave vacuum drying is used to promote the formation of a honeycomb structure in the micelles. Finally, ultrapure water atomized by high pressure is sprayed on the honeycomb micelles and dried to obtain a hydrogel that absorbs oil and fat. The hydrogel prepared by this method has a water absorption multiple of more than 100 times, a storage modulus of more than 1350Pa, and can efficiently absorb oil and fat. It has broad development prospects in the field of weight-loss drugs or foods. However, this method requires steps such as wet ultrafine grinding, high-pressure atomization spraying, and microwave vacuum drying. The overall production process is relatively complex, and the requirements for equipment and production conditions are high, making it difficult to achieve large-scale production. Therefore, on the basis of ensuring the performance of the gel, this method still needs to be further optimized. Summary of the Invention

[0006] The purpose of the present invention is to provide a hydrogel that enhances satiety, as well as its preparation method and application. By adding specific additives and cross-linking in two steps, the prepared hydrogel has good mechanical properties and strong water absorption capacity. It improves satiety by swelling through water absorption and achieves a good weight loss effect. At the same time, the hydrogel also has a good effect of regulating intestinal flora.

[0007] In order to achieve the above-mentioned purpose of the invention, the technical solution of the present invention is as follows:

[0008] In one aspect, the present invention provides a method for preparing a hydrogel for enhancing satiety, comprising the following steps:

[0009] (1) mixing a cellulose derivative and water, adding a crosslinking aid, and mixing thoroughly to obtain a first solution; wherein the first solution comprises 0.5% to 3% by weight of the cellulose derivative, and the crosslinking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:1 to 4, and the crosslinking aid has a mass content of 0.1% to 1%;

[0010] (2) adding pectin to the first solution obtained in step (1), mixing thoroughly, and adjusting the pH to 7.5-8.0 to obtain a second solution;

[0011] (3) physically cross-linking the second solution obtained in step (2) under ultrasonic treatment to obtain a first cross-linked product;

[0012] (4) adding pectin to the first cross-linked product obtained in step (3) and continuously stirring to obtain a gel;

[0013] (5) removing water from the gel obtained in step (4) to obtain the hydrogel for enhancing satiety.

[0014] Preferably, in step (1), the cellulose derivative is selected from at least one of sodium carboxymethyl cellulose (CMC), methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), and hydroxyethyl methyl cellulose (HEMC), and more preferably sodium carboxymethyl cellulose.

[0015] Preferably, in step (1), the molecular weight of the cellulose derivative is 100,000-200,000.

[0016] Preferably, in step (1), the mass content of the cellulose derivative in the first solution is 0.5%-2%, more preferably 1%.

[0017] Preferably, in step (1), in the first solution, the cross-linking auxiliary agent is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:2.

[0018] Preferably, in step (1), the mass content of the cross-linking aid in the first solution is 0.25%.

[0019] Preferably, in step (2), the mass ratio of the pectin to the cellulose derivative in step (1) is 7-9:0.5-1.5, more preferably 8:1.

[0020] Preferably, in step (2), the degree of esterification of the pectin is 58%-62%.

[0021] Preferably, in step (2), the pH is adjusted using sodium citrate.

[0022] Preferably, in step (2), the pH is adjusted to 7.5.

[0023] Preferably, in step (3), the conditions for the ultrasonic treatment are: ultrasonic power 500W-1200W, ultrasonic time 5min-40min; further preferably, the conditions for the ultrasonic treatment are: ultrasonic power 1000W, ultrasonic time 20min.

[0024] Preferably, in step (4), the mass ratio of the pectin to the cellulose derivative in step (1) is 7-9:0.5-2, more preferably 8:1.

[0025] Preferably, in step (4), the continuous stirring conditions are: stirring temperature 10°C-25°C, stirring speed 100r / min-800r / min, and stirring time 1h-3h. More preferably, the stirring temperature is 20°C, stirring speed 500r / min, and stirring time 2h.

[0026] In step (5), the water removal can be performed by any method that does not deteriorate the properties of the gel, thereby separating the gel obtained in step (4) from the solution. Examples of such methods include, but are not limited to, evaporative drying, freeze drying, precipitation, centrifugation, spray drying, critical point drying, and the like. As a specific example of the present invention, evaporative drying is used.

[0027] Preferably, in step (5), the evaporation drying conditions are: drying at 25°C-50°C for 24h-72h, more preferably: drying at 40°C for 48h.

[0028] Preferably, in step (5), before removing the moisture, the step further includes: adding water to the gel obtained in step (4) until saturated, washing with water 2-3 times, and filtering with an ultrafiltration membrane.

[0029] Preferably, the preparation method further comprises the step of crushing.

[0030] Furthermore, the pulverizing step is: pulverizing the hydrogel obtained in step (5) into 20-50 meshes.

[0031] As an example of the present invention, the preparation method specifically includes the following steps:

[0032] (1) Sodium carboxymethyl cellulose is added to water and stirred until fully dissolved, and a crosslinking aid is added while stirring and mixed thoroughly to obtain a first solution; in the first solution, the mass content of sodium carboxymethyl cellulose is 0.5%-3%, and the crosslinking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:1-4, and the mass content of the crosslinking aid is 0.1%-1%;

[0033] (2) adding pectin to the first solution obtained in step (1), wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) is 7-9:0.5-1.5, and after fully mixing, adjusting the pH to 7.5-8.0 to obtain a second solution;

[0034] (3) placing the second solution obtained in step (2) into an ultrasonic instrument and performing physical crosslinking under ultrasonic treatment at an ultrasonic power of 500W-1200W and an ultrasonic time of 5min-40min to obtain a first crosslinked product;

[0035] (4) The first cross-linked product obtained in step (3) is taken out, and pectin is added, wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) is 7-9:0.5-2, and stirring is continued at a stirring temperature of 10°C-25°C, a stirring speed of 100 rpm-800 rpm, and a stirring time of 1 h-3 h to obtain a gel;

[0036] (5) Add water to the gel obtained in step (4) until saturated, wash with water 2-3 times, filter with a 10KDa ultrafiltration membrane to remove the additive, dry at 25°C-50°C for 24h-72h, and then crush to 20-50 mesh to obtain the hydrogel for enhancing satiety.

[0037] In another aspect, the present invention provides a hydrogel for enhancing satiety prepared by the above preparation method.

[0038] In another aspect, the present invention provides use of the above-mentioned hydrogel for enhancing satiety in the preparation of weight loss products.

[0039] Preferably, the weight loss product is food, medicine or health product, more preferably food.

[0040] In another aspect, the present invention provides use of the above-mentioned hydrogel for enhancing satiety in preparing a product having the function of regulating intestinal flora.

[0041] Preferably, the product having the function of regulating intestinal flora is food, medicine or health product, more preferably food.

[0042] The satiety-enhancing hydrogels of the present invention can be consumed in a dry, partially swollen, or fully swollen state, alone, in a mixture with liquid or dry food, or as a component of food or an edible substrate. They are preferably consumed in a substantially anhydrous state, that is, containing approximately 10% or less water by weight. When consumed in a substantially anhydrous form in combination with water, the hydrogel swells in the stomach and, upon transport to the small intestine, absorbs surrounding fluid and continues to swell. The swollen hydrogel then travels to the large intestine, where it degrades, releasing the absorbed water, and is subsequently excreted from the body.

[0043] When used for preparing medicines, the satiety-enhancing hydrogel of the present invention can be formulated into capsules, sachets, tablets or suspensions for oral administration.

[0044] The beneficial effects of the present invention are:

[0045] (1) The present invention adjusts the pH to a specific value and uses CaCl2 and ZnSO4 in a specific ratio as auxiliary agents to increase ionic crosslinking points, affect the stretching state of the molecular chains, promote physical entanglement, and improve the mechanical properties of the gel, thereby solving the problem of poor mechanical properties of physically crosslinked gels, which in turn affects storage, transportation, and fluidity in the body.

[0046] (2) The present invention adopts a two-step crosslinking method. The first step is ultrasonic treatment, which forms honeycomb-like pores within the crosslinked structure through the acoustic cavitation effect. The second step is to add pectin for secondary crosslinking. Throughout the whole process, the cavitation bubbles can act as a template to induce the formation of pores within the gel. Then, through the two-step physical crosslinking of cellulose derivatives and pectin under appropriate conditions, the pores formed by the bubbles are fixed to form a honeycomb porous structure. The resulting gel can significantly improve the water absorption capacity and can significantly improve the weight loss effect when used in weight loss products.

[0047] (3) The hydrogel prepared by the present invention can absorb water and swell, thereby improving satiety and achieving a good weight loss effect. At the same time, the hydrogel also has a good effect of regulating intestinal flora. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is the SEM image of the hydrogel prepared in Example 3 of the present invention.

[0049] Figure 2 Figure 2 is a schematic diagram of the weight changes of mice in the blank group, model group and example drug-treated group; in the figure, the model group is compared with the blank group. P<0.05, P<0.01; comparison between experimental group and model group, #P<0.05, ##P<0.01.

[0050] Figure 3 Schematic diagram of the weight changes of mice in the Example 3 and comparative example groups; in the figure, the comparative example group is compared with the Example 3 group. P<0.05, P<0.01. DETAILED DESCRIPTION

[0051] The following non-limiting examples are provided to enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. The following are merely illustrative of the scope of the present invention, and those skilled in the art may make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present invention.

[0052] For numerical ranges in the present invention, it should be understood that unless otherwise specified herein, both endpoints of each numerical range and any value between the two endpoints may be used. For example, the numerical range "0.5%-3%" includes 0.5% and 3%, inclusive, and any real number therebetween, such as 0.5%, 0.51%, 0.511%, 0.6%, 0.65%, 0.7%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, etc.

[0053] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0054] The present invention will be further described below by way of specific examples. The various chemical reagents used in the examples of the present invention were obtained through conventional commercial channels unless otherwise specified. Unless otherwise specified, the contents described below are all by weight. Unless otherwise specified, it is understood that the experiments were conducted at room temperature.

[0055] In the following examples, the sodium carboxymethyl cellulose, hydroxyethyl cellulose, pectin, CaCl , ZnSO , sodium citrate, and citric acid used are preferably food grade or pharmaceutical grade materials. For example, sodium carboxymethyl cellulose, hydroxyethyl cellulose, pectin, CaCl , ZnSO , sodium citrate, and citric acid are all used as food additives and pharmaceutical excipients.

[0056] In the following examples, the average molecular weight of sodium carboxymethyl cellulose was 100,000-200,000, and the degree of pectin esterification was 58%-62%. Specifically, the sodium carboxymethyl cellulose in the following examples was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. under the product number C104983, with an average molecular weight of 100,000; hydroxyethyl cellulose was purchased from Shanghai Titan Technology Co., Ltd. under the product number 89157Q, with an average molecular weight of 200,000. Pectin was purchased from Dangshan Haisheng Pectin Co., Ltd. under the product number HSC105, with an esterification degree of 58%; and the product number HSC151B, with an esterification degree of 62%. The ultrasonic cell disruptor used was a Shanghai Yetuo YT-1800E, with a frequency range of 19.5 kHz to 20.5 kHz.

[0057] Example 1

[0058] (1) Sodium carboxymethyl cellulose is added to water and stirred until fully dissolved, and a cross-linking aid is added while stirring and mixed thoroughly to obtain a first solution; in the first solution, the mass content of sodium carboxymethyl cellulose is 0.5%, and the cross-linking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:1, and the mass content of the cross-linking aid is 0.1%;

[0059] (2) adding pectin (with a degree of esterification of 58%) to the first solution obtained in step (1), wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) is 7:1.5, and after thorough mixing, adjusting the pH to 7.5 with sodium citrate to obtain a second solution;

[0060] (3) placing the second solution obtained in step (2) into an ultrasonic instrument and performing physical crosslinking under ultrasonic treatment at an ultrasonic power of 500 W and an ultrasonic time of 40 min to obtain a first crosslinked product;

[0061] (4) The first cross-linked product obtained in step (3) was taken out, and pectin (with an esterification degree of 58%) was added, wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) was 7:2, and the mixture was stirred continuously at a temperature of 25°C, a stirring speed of 100 r / min, and a stirring time of 3 h to obtain a gel;

[0062] (5) Add water to the gel obtained in step (4) until saturated, wash with water three times, filter with a 10KDa ultrafiltration membrane to remove the additive, dry at 25°C for 72h, and then grind to 20-50 mesh to obtain the product.

[0063] Example 2

[0064] (1) Adding hydroxyethyl cellulose to water and stirring until fully dissolved, adding a crosslinking aid while stirring and mixing thoroughly to obtain a first solution; in the first solution, the mass content of hydroxyethyl cellulose is 3%, and the crosslinking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:4, and the mass content of the crosslinking aid is 1%;

[0065] (2) adding pectin (with a degree of esterification of 62%) to the first solution obtained in step (1), wherein the mass ratio of the pectin to the hydroxyethyl cellulose in step (1) is 9:0.5, and mixing thoroughly, adjusting the pH to 8.0 with sodium citrate to obtain a second solution;

[0066] (3) placing the second solution obtained in step (2) into an ultrasonic instrument and performing physical crosslinking under ultrasonic treatment at an ultrasonic power of 1200 W and an ultrasonic time of 5 min to obtain a first crosslinked product;

[0067] (4) The first cross-linked product obtained in step (3) was taken out, and pectin (with an esterification degree of 62%) was added, wherein the mass ratio of the pectin to the hydroxyethyl cellulose in step (1) was 9:0.5, and the mixture was stirred continuously at a stirring temperature of 10°C, a stirring speed of 800 r / min, and a stirring time of 1 h to obtain a gel;

[0068] (5) Add water to the gel obtained in step (4) until saturated, wash with water three times, filter with a 10KDa ultrafiltration membrane to remove the additive, dry at 50°C for 24h, and then grind to 20-50 mesh to obtain the product.

[0069] Example 3

[0070] (1) Sodium carboxymethyl cellulose is added to water and stirred until fully dissolved, and a cross-linking aid is added while stirring and mixed thoroughly to obtain a first solution; in the first solution, the mass content of sodium carboxymethyl cellulose is 1%, and the cross-linking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:2, and the mass content of the cross-linking aid is 0.25%;

[0071] (2) adding pectin (with a degree of esterification of 58%) to the first solution obtained in step (1), wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) is 8:1, and after thorough mixing, adjusting the pH to 7.5 with sodium citrate to obtain a second solution;

[0072] (3) placing the second solution obtained in step (2) into an ultrasonic instrument and performing physical crosslinking under ultrasonic treatment at an ultrasonic power of 1000 W and an ultrasonic time of 20 min to obtain a first crosslinked product;

[0073] (4) The first cross-linked product obtained in step (3) was taken out, and pectin (with an esterification degree of 58%) was added, wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) was 8:1, and the mixture was stirred continuously at a temperature of 20°C, a stirring speed of 500 r / min, and a stirring time of 2 h to obtain a gel;

[0074] (5) Add water to the gel obtained in step (4) until saturated, wash with water twice, filter with a 10KDa ultrafiltration membrane, remove the additive, dry at 45°C for 48h, and then crush to 20-50 mesh to obtain the product. The SEM image is as follows: Figure 1 .

[0075] Comparative Example 1

[0076] (1) Sodium carboxymethyl cellulose is added to water and stirred until fully dissolved, and a cross-linking aid is added while stirring and mixed thoroughly to obtain a first solution; in the first solution, the mass content of sodium carboxymethyl cellulose is 1%, and the cross-linking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:2, and the mass content of the cross-linking aid is 0.25%;

[0077] (2) adding pectin to the first solution obtained in step (1), wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) is 8:2, and after being fully mixed, adjusting the pH to 7.5 with sodium citrate to obtain a second solution;

[0078] (3) placing the second solution obtained in step (2) into an ultrasonic instrument and performing physical crosslinking under ultrasonic treatment at an ultrasonic power of 1000 W and an ultrasonic time of 20 min to obtain a first crosslinked product;

[0079] (4) The first cross-linked product obtained in step (3) was taken out and continued to be stirred at a stirring temperature of 20°C, a stirring speed of 500 r / min, and a stirring time of 2 h to obtain a gel;

[0080] (5) Add water to the gel obtained in step (4) until saturated, wash with water twice, filter with a 10KDa ultrafiltration membrane to remove the additive, dry at 45°C for 48h, and then grind to 20-50 mesh to obtain the product.

[0081] Compared with Example 3, in this method, the entire amount of pectin is added at one time for cross-linking.

[0082] Comparative Example 2

[0083] (1) Sodium carboxymethyl cellulose is added to water and stirred until fully dissolved, and a cross-linking aid is added while stirring and mixed thoroughly to obtain a first solution; in the first solution, the mass content of sodium carboxymethyl cellulose is 1%, and the cross-linking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:2, and the mass content of the cross-linking aid is 0.25%;

[0084] (2) adding pectin to the first solution obtained in step (1), wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) is 8:1, and after being fully mixed, adjusting the pH to 7.5 with sodium citrate to obtain a second solution, and continuously stirring at a stirring temperature of 20° C., a stirring speed of 500 r / min, and a stirring time of 0.5 h to obtain a first cross-linked product;

[0085] (3) adding pectin to the first cross-linked product obtained in step (2), wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) is 8:1, and continuously stirring at a stirring temperature of 20° C., a stirring speed of 500 r / min, and a stirring time of 2 h to obtain a gel;

[0086] (4) Add water to the gel obtained in step (3) until saturated, wash with water twice, filter with a 10KDa ultrafiltration membrane to remove the additive, dry at 45°C for 48 hours, and then grind to 20-50 mesh to obtain the product.

[0087] Compared with Example 3, in this method, no ultrasonic treatment is performed during the cross-linking process.

[0088] Comparative Example 3

[0089] The difference from Example 3 is that the crosslinking aid is CaCl2. The other conditions are the same.

[0090] Comparative Example 4

[0091] The difference from Example 3 is that the crosslinking auxiliary agent is ZnSO4. The other conditions are the same.

[0092] Comparative Example 5

[0093] The difference from Example 3 is that the crosslinking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 2:1. The other conditions are the same.

[0094] Comparative Example 6

[0095] The difference from Example 3 is that citric acid is used to adjust the pH to 6.0. The other conditions are the same.

[0096] Comparative Example 7

[0097] The difference from Example 3 is that sodium citrate is used to adjust the pH to 8.5. The other conditions are the same.

[0098] Result detection

[0099] 1. Mechanical properties testing

[0100] 1.1 Tap density

[0101] Detection method: Weigh 40.0 g ± 0.1 g of each of the products prepared in Examples 1 to 3 and Comparative Examples 1 to 7, record the specific weight value M, put the weighed product into a dry 100 mL glass measuring cylinder, flatten the powder without compacting it, and vibrate the measuring cylinder 500 times with a mechanical tap density tester to read the tap volume V. 500 After vibrating the graduated cylinder 750 times, read the vibrated volume V 750 If the difference between the two volumes is less than 2%, then V 750 is the final compacted volume V f Otherwise, repeat in increments of 1250 taps as needed until the difference between subsequent measurements is less than 2%, giving the final V f .

[0102] The tap density DT is calculated using the following formula:

[0103] DT (g / mL) = M / V f .

[0104] Each sample was measured three times in parallel and the average value was taken.

[0105] 1.2 Elastic modulus

[0106] Testing method: Add 40.0 g ± 0.1 g of a medium solution (artificial gastric juice: water ratio of 1:8, prepared according to the Chinese Pharmacopoeia method) to a dry beaker and stir at room temperature. Weigh 0.250 g ± 0.005 g of each of the products prepared in Examples 1-3 and Comparative Examples 1-7 into a beaker and stir for 30 minutes. Drain the resulting material and perform a sweep frequency test on the material using a rheometer, measuring the value at an angular frequency of 10 rad / s. Perform three replicate tests on each sample, and take the average value.

[0107] The test results are shown in Table 1.

[0108] Table 1

[0109]

[0110] The results show that Examples 1 to 3 of the present invention and Comparative Example 2 have higher tap density and elastic modulus than other groups, proving that the present invention improves the mechanical properties of the gel and improves the shortcomings of physically cross-linked gel products through two-step cross-linking and the selection of cross-linking aids.

[0111] 2. Water absorption effect test

[0112] Detection method: Accurately weigh 1.0 g of the products prepared in Examples 1 to 3 and Comparative Examples 1 to 7, respectively, and place them in 200 mL of a medium with artificial gastric juice: water at a ratio of 1:8 (artificial gastric juice is prepared according to the Chinese Pharmacopoeia method). Place it in a 37°C incubator for 30 minutes, then take it out, filter out the water with a stainless steel sieve, and weigh it. The weight of the hydrogel after water absorption is m2.

[0113] Water absorption multiple = (m2-1) / 1.

[0114] Each sample was measured three times in parallel and the average value was taken.

[0115] The test results are shown in Table 2.

[0116] Table 2

[0117]

[0118] The results show that Examples 1-3 of the present invention have higher water absorption capacity. The results of Comparative Example 1 demonstrate that two-step crosslinking is a key step in the present invention. By completing crosslinking in two steps, the hydrogel structure can be improved and the water absorption capacity can be increased. The results of Comparative Example 2 show that the hydrogel without ultrasonic treatment lacks a good pore structure and has poor water absorption capacity. The results of Comparative Examples 3-7 demonstrate that the crosslinking agent and pH value also have a significant impact on water absorption capacity. By using appropriate agents and pH values, the molecular chain extension morphology during the physical crosslinking process is optimized, forming a good honeycomb structure, and the water absorption capacity of the hydrogel can also be improved.

[0119] 3. Fat and weight loss experiment

[0120] Detection method:

[0121] SPF grade Kunming mice, male weighing 18g-22g, were randomly divided into groups according to body weight, with 8 mice in each group. The experimental groups were respectively gavaged once a day with the products prepared by Example 1-Example 3 and Comparative Example 1-Comparative Example 7 at a fixed time, with a dosage of 100 mg / kg and a gavage volume of 15 mL / kg. The model group and the blank group were gavaged with an equal volume of distilled water once a day. Except for the blank group, the mice in the other groups were fed with the same high-fat feed, and the blank group was maintained on normal feed. Feeding conditions: humidity 40%-70%, feeding temperature 22℃-26℃, dark and light environment for 12 hours each, and free drinking water and diet.

[0122] The experimental period was 6 weeks, and the mice were weighed at a fixed time every week. Figure 2 and Figure 3 shown.

[0123] Figure 2 The results showed that the weight of the model group mice showed a significantly faster growth trend compared with the blank group mice. After calculation, there was a significant difference after 3 weeks, indicating that the obesity model mice were successfully established. Figure 2 It shows that the hydrogels prepared in Examples 1 to 3 of the present invention can effectively inhibit the weight gain of mice caused by high-fat feed. Figure 3 The results showed that compared with Example 3, the hydrogel prepared in the comparative example performed relatively poorly in terms of weight loss effect.

[0124] After 6 weeks, all mice were fasted for 12 hours with or without water. Their body weights were recorded, and they were anesthetized with ether and sacrificed by cervical dislocation. The mice were rapidly dissected, and peritesticular and perirenal fat were completely separated and weighed (fat weight), and the fat body ratio was calculated. Intestinal contents were collected for analysis of the intestinal microbiota.

[0125] Fat-to-body ratio = fat weight / body weight × 100%.

[0126] SPSS 21 statistical software was used for data processing, and experimental data are presented as mean ± SD (standard deviation). The results of the lipid body ratio test are shown in Table 3.

[0127] Table 3

[0128]

[0129] Note: In the table, the model group is compared with the blank group. P<0.01; comparison between experimental group and model group, #P<0.05, ##P<0.01.

[0130] The results showed that the hydrogels prepared in Examples 1 to 3 of the present invention significantly reduced the fat body ratio of obese mice. The hydrogels prepared in the examples of the present invention achieved significant fat reduction effects by increasing water absorption capacity and enhancing satiety.

[0131] The results of intestinal flora detection are shown in Table 4.

[0132] Table 4

[0133]

[0134] The results in Table 4 show that the abundance of Bacteroidetes in the model group induced by a high-fat diet was significantly reduced, while the abundance of Firmicutes was significantly increased compared to the blank group. Firmicutes and Proteobacteria have been shown to occupy a larger proportion of intestinal microorganisms in obese patients. The test results show that, compared with Comparative Examples 1 to 7, the hydrogels prepared in Examples 1 to 3 significantly reduced the abundance of Firmicutes, increased the abundance of Bacteroidetes, improved the balance of bacterial colonies in the intestine of mice, and reduced the abundance of related bacterial phyla in obese model mice. Therefore, the hydrogel prepared by the present invention has the effect of regulating intestinal flora and can be used for the improvement and prevention of symptoms related to dysbiosis.

Claims

1. A method for preparing a hydrogel for improving satiety, characterized in that: The following steps are involved: (1) mixing a cellulose derivative and water, adding a crosslinking aid, and thoroughly mixing to obtain a first solution; wherein the first solution comprises 0.5% to 3% by weight of the cellulose derivative, and the crosslinking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:1-4, and the crosslinking aid has a mass content of 0.1% to 1%; and the cellulose derivative is selected from at least one of sodium carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, and hydroxyethyl methyl cellulose; (2) adding pectin to the first solution obtained in step (1), mixing thoroughly, and adjusting the pH to 7.5-8.0 to obtain a second solution; (3) physically cross-linking the second solution obtained in step (2) under ultrasonic treatment to obtain a first cross-linked product; (4) adding pectin to the first cross-linked product obtained in step (3) and continuously stirring to obtain a gel; (5) removing water from the gel obtained in step (4) to obtain the hydrogel for enhancing satiety.

2. The preparation method according to claim 1, characterized in that In step (1), the cellulose derivative is sodium carboxymethyl cellulose.

3. The preparation method according to claim 1, characterized in that In step (1), the molecular weight of the cellulose derivative is 100,000-200,000; in step (2), the degree of esterification of the pectin is 58%-62%.

4. The preparation method according to claim 1, characterized in that In step (1), the mass content of the cellulose derivative in the first solution is 0.5%-2%.

5. The preparation method according to claim 4, characterized in that In step (1), the mass content of the cellulose derivative in the first solution is 1%.

6. The preparation method according to claim 1, characterized in that In step (1), in the first solution, the crosslinking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:

2.

7. The preparation method according to claim 1, characterized in that In step (1), the mass content of the cross-linking aid in the first solution is 0.25%.

8. The preparation method according to claim 1, characterized in that In step (2), the mass ratio of the pectin to the cellulose derivative in step (1) is 7-9:0.5-1.5; in step (4), the mass ratio of the pectin to the cellulose derivative in step (1) is 7-9:0.5-2.

9. The preparation method according to claim 8, characterized in that In step (2), the mass ratio of the pectin to the cellulose derivative in step (1) is 8:1; in step (4), the mass ratio of the pectin to the cellulose derivative in step (1) is 8:

1.

10. The preparation method according to claim 1, characterized in that In step (2), the pH is adjusted to 7.

5.

11. The preparation method according to claim 1, characterized in that In step (3), the conditions for the ultrasonic treatment are: ultrasonic power 500W-1200W, and ultrasonic time 5min-40min.

12. The preparation method according to claim 11, characterized in that The ultrasonic treatment conditions are: ultrasonic power 1000W, ultrasonic time 20min.

13. The preparation method according to claim 1, characterized in that In step (4), the conditions for continuous stirring are: stirring temperature 10°C-25°C, stirring speed 100r / min-800r / min, and stirring time 1h-3h.

14. The preparation method according to claim 1, characterized in that In step (5), the method for removing moisture is evaporative drying, and the conditions for evaporative drying are: drying at 25°C-50°C for 24h-72h.

15. The preparation method according to claim 1, characterized in that In step (5), before removing the water, the step further includes: adding water to the gel obtained in step (4) until saturated, washing with water 2-3 times, and filtering with an ultrafiltration membrane.

16. The preparation method according to claim 1, characterized in that The specific steps include: (1) Sodium carboxymethyl cellulose is added to water and stirred until fully dissolved, and a crosslinking aid is added while stirring and mixed thoroughly to obtain a first solution; in the first solution, the mass content of sodium carboxymethyl cellulose is 0.5%-3%, and the crosslinking aid is a combination of CaCl2 and ZnSO4 in a mass ratio of 1:1-4, and the mass content of the crosslinking aid is 0.1%-1%; (2) adding pectin to the first solution obtained in step (1), wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) is 7-9:0.5-1.5, and after fully mixing, adjusting the pH to 7.5-8.0 to obtain a second solution; (3) placing the second solution obtained in step (2) into an ultrasonic instrument and performing physical crosslinking under ultrasonic treatment at an ultrasonic power of 500W-1200W and an ultrasonic time of 5min-40min to obtain a first crosslinked product; (4) The first cross-linked product obtained in step (3) is taken out, and pectin is added, wherein the mass ratio of the pectin to the sodium carboxymethyl cellulose in step (1) is 7-9:0.5-2, and stirring is continued at a stirring temperature of 10°C-25°C, a stirring speed of 100 rpm-800 rpm, and a stirring time of 1 h-3 h to obtain a gel; (5) Add water to the gel obtained in step (4) until saturated, wash with water 2-3 times, filter with a 10KDa ultrafiltration membrane to remove the additive, dry at 25°C-50°C for 24h-72h, and then crush to 20-50 mesh to obtain the hydrogel for enhancing satiety.

17. A hydrogel for enhancing satiety prepared according to the preparation method according to any one of claims 1 to 16.

18. Use of the satiety-enhancing hydrogel according to claim 17 in the preparation of a weight loss product.

19. The use according to claim 18, characterized in that The weight loss product is food, medicine or health product.

20. Use of the satiety-enhancing hydrogel according to claim 17 in preparing a product having the function of regulating intestinal flora.

21. The use according to claim 20, characterized in that The product having the function of regulating intestinal flora is food, medicine or health product.

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