Modified konjac glucomannan composite gel as well as preparation method and application thereof

Abstract

The invention provides modified konjac glucomannan composite gel as well as a preparation method and application thereof. The composite gel is of a core-shell double-phase structure, the outer layer is a daytime layer, the inner core is a night layer, and the daytime layer and the night layer are tightly combined through the crosslinking effect of soybean protein; the daytime interlayer is prepared by mixing and cross-linking a lactose modified konjac glucomannan solution, a daytime interlayer latch system and a soybean protein cross-linking solution; the nighttime layer is prepared by mixing and cross-linking soybean protein cross-linking liquid and a nighttime layer latch system, and the nighttime layer latch system is a compound formed by embedding lipoprotein lipase into V-shaped spiral starch. By constructing a core-shell double-phase structure and combining the targeting effect of the lactose modified konjac glucomannan and the active latching function of the V-shaped spiral starch, the day-night accurate drug release of the active component is realized, and meanwhile, the structural stability and intestinal tract adhesiveness of the gel are improved; the problems that existing gel is poor in targeting property, active ingredients are prone to losing, and the weight management effect is poor are solved.

Description

Technical Field

[0001] This invention relates to the field of functional product technology, specifically to a modified konjac glucomannan composite gel, its preparation method, and its application. Background Technology

[0002] Konjac glucomannan (KGM), a natural water-soluble dietary fiber, has attracted much attention in functional foods, weight management, and drug carriers due to its excellent hydrophilicity, gelling properties, and physiological functions such as delaying gastric emptying and enhancing satiety. Its molecular chains swell in water through hydrogen bonding to form a gel network, which can effectively regulate the rate of nutrient digestion and absorption. It exhibits unique advantages in lowering the glycemic index and improving gut microbiota balance, and has become one of the core raw materials for developing functional products.

[0003] However, pure KGM gel faces several technical bottlenecks in practical applications: First, the intermolecular forces of KGM molecules are singular, resulting in a loose gel network structure and poor thermal stability. It is prone to degradation, shrinkage, and water separation during heating, acidic digestion, or long-term storage, leading to deterioration in product texture and shortened shelf life. Second, KGM lacks intestinal targeting sites, resulting in a short gel retention time in the intestines and rapid loss of active ingredients with digestive fluids, leading to low bioavailability. Third, single KGM gel cannot achieve precise controlled release of active ingredients, limiting its effectiveness in functions such as weight management.

[0004] To improve the physicochemical and functional properties of KGM, existing technologies mostly employ binary composite modification strategies: KGM is combined with starch, utilizing the cross-linking effect after starch gelatinization to enhance the stability of the gel structure. However, the compatibility between the two is limited, the viscosity of the system increases sharply at high KGM content, resulting in poor processing flowability, and the composite gel is sensitive to temperature and pH, so the structural stability still needs to be optimized. KGM is combined with protein, enhancing the mechanical strength and thermal stability of the gel through hydrogen bonding and electrostatic interactions. However, this system is easily affected by ionic strength and heat treatment conditions, leading to phase separation or precipitation, making it difficult to balance structural uniformity and physiological function.

[0005] Furthermore, traditional composite gels are mostly single-phase structures, and their active ingredients are prone to burst release during the early stages of digestion, resulting in short-lived functional effects. Some modification processes rely on chemical cross-linking agents, posing potential biosafety risks and limiting their application in the food and pharmaceutical fields. Therefore, developing a multi-component composite gel that combines targeting, structural stability, and controlled-release functions has become crucial to overcoming the limitations of existing technologies. Summary of the Invention

[0006] Technical problems to be solved: To address the above-mentioned technical problems, the purpose of this invention is to provide a modified konjac glucomannan composite gel, its preparation method, and its application. By constructing a core-shell biphasic structure, combining the targeting effect of lactose-modified konjac glucomannan with the activity-locking function of V-helical starch, the invention achieves precise day and night release of active ingredients, while improving the structural stability and intestinal adhesion of the gel, thus solving the problems of poor targeting, easy loss of active ingredients, and poor weight management effect of existing gels.

[0007] Technical solution: A modified konjac glucomannan composite gel, wherein the composite gel has a core-shell biphase structure, with an outer daytime layer and an inner nighttime layer, and the daytime layer and the nighttime layer are tightly bound together by the cross-linking effect of soybean protein; The day layer is made by cross-linking a lactose-modified konjac glucomannan solution, a day layer lock-in system, and a soybean protein cross-linking solution; The night layer is made by mixing and cross-linking soybean protein cross-linking liquid with a night layer locking system, wherein the night layer locking system is a complex formed by embedding lipoprotein lipase into V-shaped helical starch.

[0008] Furthermore, the preparation method of the lactose-modified konjac glucomannan solution is as follows: (1) Take 6.0-7.0g of pretreated konjac glucomannan, add 40-50mL of cooled distilled water, place it on a magnetic stirrer, and stir for 15-20min at 500-600r / min to form a konjac glucomannan solution. (2) Take 2.5-3.5g of dried lactose and slowly add it to the konjac glucomannan solution. Continue stirring at 500-600r / min for 10-15min to obtain a mixed solution. (3) Keep the mixed solution at 55-65℃ for 2 hours, stirring for 4-5 minutes every 30 minutes to promote the glycosidic bond formation between lactose and konjac glucomannan. (4) After the reaction is complete, the mixture is naturally cooled to room temperature to obtain a lactose-modified konjac glucomannan solution.

[0009] Furthermore, the preparation method of the V-shaped spiral starch is as follows: (1) Take the pretreated mung bean starch, add 60%-70% ethanol aqueous solution and monoglyceride, and vortex at 3000-3500r / min for 5-6min to form a uniform starch suspension; (2) Place it in a high temperature and high pressure reactor, set the temperature to 90-100℃ and the pressure to 0.1MPa, start the reactor, and treat it at constant temperature and pressure for 18-22 minutes. Through the hydrophobic effect of the ethanol system and the molecular guiding effect of monoglycerides, the mung bean starch molecules are induced to rearrange to form a stable V-shaped helical structure. (3) After the reaction is complete, close the reactor, release the pressure naturally to atmospheric pressure, cool naturally to room temperature, let stand overnight at 4°C, collect the precipitate by centrifugation, wash several times with anhydrous ethanol, and dry at 40-45°C to obtain V-shaped spiral starch.

[0010] Furthermore, in step (1), the mass-to-volume ratio of the pretreated mung bean starch, ethanol aqueous solution, and monoglyceride is 1.5g:20mL:(0.024-0.03g).

[0011] Furthermore, the pretreatment method in step (1) is to pass the mung bean starch through an 80-mesh sieve to make the moisture content ≤8%.

[0012] The preparation method of the above-mentioned modified konjac glucomannan composite gel includes the following steps, by weight: Step 1: Take 0.7-0.8 parts of V-helix starch, add 10 parts of distilled water, vortex for 5-8 minutes to reconstitute, and obtain a V-helix starch suspension. Cool to 33-36℃, add 0.1-0.15 parts of soybean peptide, and stir at 400-450 r / min for 30-40 minutes to make the soybean peptide molecules uniformly embedded in the V-helix of starch, thus obtaining the interday layer lock-in system. Step 2: Take 0.7-0.8 parts of V-helix starch, add 10 parts of distilled water, vortex for 5-8 minutes to reconstitute, and obtain a V-helix starch suspension. Cool to 33-36℃, add 0.05-0.06 parts of lipoprotein lipase, and stir at 400-450 r / min for 30-40 minutes to allow the enzyme molecules to embed inside the V-helix of starch, thus obtaining a night layer lock-in system. Step 3: Take 1.5-2.5 parts of pretreated soy protein, add 10 parts of distilled water, stir at 500-550 r / min for 10-12 min, add 0.2-0.3 parts of sodium carbonate, continue stirring at 500-550 r / min for 10 min, adjust to 8.0-8.5, activate the cross-linking activity of soy protein, and obtain soy protein cross-linking solution; Step 4: Take the soybean protein cross-linking solution and mix it with the night layer lock-in system. Stir at 500-550 r / min for 5-6 min to form the night layer gel precursor. Slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold and let it stand at 24-26℃ for 1.5 h to allow the precursor to fully cross-link and form, thus obtaining the night layer core. Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add soybean protein cross-linking solution, stir at 500-550 r / min for 5-6 min to fully mix the three to form a day layer gel precursor. Slowly pour the day layer gel precursor into the outer layer cavity to cover the formed night layer core. Let it stand at 24-26℃ for 1 h to allow the day layer precursor to cross-link and form a tightly wrapped biphase structure of "core-outer layer". Step 6: Place the entire mold into a constant temperature water bath, heat to 93-97℃, and steam for 25-35 minutes to promote further bonding between the core and outer layer through the cross-linking effect of soybean protein, while stabilizing the V-shaped helical structure of starch. Remove the mold and allow it to cool naturally to room temperature. Then freeze it in a -20℃ freezer for 1 hour, and then thaw it at 25℃ room temperature for 2 hours to remove free water from the gel.

[0013] Furthermore, the soybean peptides mentioned in step 1 are passed through an 80-mesh sieve, have a molecular weight of 1-3 kDa, and a degree of hydrolysis of 15%-20%.

[0014] Furthermore, the pretreatment method for the pretreated soybean protein is to pretreat it through an 80-mesh sieve.

[0015] Furthermore, in step 4, the volume ratio of the soybean protein crosslinking solution to the night layer locking system is 1:(1.5-2.5).

[0016] Furthermore, in step 4, the diameter of the night layer kernel is 1.0 ± 0.05 mm.

[0017] Furthermore, in step 5, the volume ratio of the lactose-modified konjac glucomannan solution, the intercalary layer lock-in system, and the soybean protein crosslinking solution is (7-9):(1.5-2.5):1.

[0018] Furthermore, in step 5, the outer layer thickness in the tightly wrapped dual-phase structure of the "core-outer layer" is 0.3±0.05mm.

[0019] The above-mentioned modified konjac glucomannan composite gel is used in the preparation of food, functional carrier materials, drug sustained-release matrix or weight management functional food with high water retention, low water separation rate and adjustable texture properties.

[0020] Beneficial effects:

[0021] 1. This invention constructs a core-shell biphasic layered structure of "daytime layer-nighttime layer". It utilizes the spatial distribution characteristics of the outer daytime layer directly contacting the digestive environment and the inner nighttime layer being exposed in a delayed manner. Combined with the functional specificity of soybean peptides and lipoprotein lipase, it achieves time-sequential and precise drug release for controlling appetite during the day and regulating metabolism at night. It adapts to the human body's diurnal physiological rhythm and achieves a synergistic effect in weight management.

[0022] 2. This invention modifies the KGM by binding lactose to the glycosidic bonds of hydroxyl groups on the molecular chain of konjac glucomannan, introducing lactose targeting groups on the KGM surface. By utilizing the specific recognition and binding of lactose to receptors on the surface of intestinal mucosal epithelial cells, the adhesion ability of the gel to the intestinal mucosa is enhanced, the retention time of the gel in the intestine is prolonged, and the loss of active ingredients with digestive juices is reduced, thereby achieving the effect of full release of active ingredients and efficient function.

[0023] 3. This invention utilizes a composite modification technology involving ethanol-monoglyceride synergistic induction and high-temperature, high-pressure treatment. By leveraging the hydrophobic effect of ethanol to weaken the hydrogen bonds between starch molecules and the hydrophobic segments of monoglycerides to induce the directional alignment of starch molecules, combined with a high-temperature, high-pressure environment to promote the rearrangement of starch molecules, a highly crystalline V-shaped helical structure is formed. The hydrophobic microenvironment and steric hindrance effect of the helical cavity are used to fix soybean peptides and lipoprotein lipase, preventing their degradation by digestive enzymes such as pepsin and pancreatin, while reducing burst release during the initial digestion stage, thus achieving long-term preservation of the structure and function of the active ingredients.

[0024] 4. This invention uses sodium carbonate to adjust the pH of the system, activates the reactivity of amino acid residues in soybean protein molecules, and promotes the formation of multiple cross-linking effects such as disulfide bonds and hydrogen bonds between soybean protein molecules. On the one hand, it constructs a dense three-dimensional gel network, reducing the migration and loss of free water. On the other hand, it strengthens the interfacial bonding force of the core-shell structure, avoids the separation of the two-phase structure during digestion, and achieves the effect of improving the mechanical strength, structural stability and water retention performance of the gel.

[0025] 5. This invention optimizes the volume ratio of lactose-modified konjac glucomannan, V-helix starch locking system, and soybean protein crosslinking liquid to precisely control the pore size, crosslinking density, and pore connectivity of the gel network, balancing the flexibility and mechanical strength of the gel. This ensures that the gel is not easily broken during processing and that it can slowly degrade and release active ingredients in the intestinal digestive environment, achieving the effect of adapting to food processing technology and human digestive physiology.

[0026] 6. This invention employs a stepwise molding process, first cross-linking the nighttime layer precursor in a mold core, then encapsulating it with the daytime layer precursor and performing a second cross-linking. By leveraging the bridging effect of soybean protein cross-linking, a tight combination of the two-phase structure is achieved, while simultaneously forming independent functional zones. This avoids mutual interference between soybean peptides and lipoprotein lipase, ensuring that the two active ingredients are precisely released in their respective appropriate digestive stages (daytime stomach-upper small intestine, nighttime lower small intestine), achieving stable and highly efficient function.

[0027] 7. This invention selects food-grade natural macromolecular raw materials such as konjac glucomannan, mung bean starch, and soybean protein, and utilizes intermolecular non-covalent interactions (hydrogen bonds, hydrophobic interactions, and electrostatic interactions) to construct a gel network. This avoids the use of chemical cross-linking agents, reduces the biotoxicity of the gel, and improves biocompatibility and food safety. At the same time, the biodegradable properties of natural raw materials reduce the environmental burden, achieving the effect of being suitable for multiple applications such as functional foods, drug sustained-release matrices, and weight management formulas.

[0028] 8. This invention utilizes the spatial locking effect of V-shaped helical starch and the targeted adhesion effect of lactose-modified KGM to protect the active ingredients from premature degradation through the helical structure, and prolong the action time of the gel in the intestine through targeted adhesion, so that the active ingredients are continuously and stably released at the intestinal absorption site, thereby improving bioavailability and achieving the effect of strengthening physiological functions such as weight management and blood lipid regulation. Attached Figure Description

[0029] Figure 1 The images shown are scanning electron microscope (SEM) images of the core-outer layer crosslinking of the composite gels prepared in Example 6 and some comparative examples; where A is Example 6, B is Comparative Example 1, C is Comparative Example 2, D is Comparative Example 6, and E is Comparative Example 13. Figure 2 The graphs show the effects of the composite gel on food intake and body weight in mice from the normal diet group, high-fat diet group, positive control group, Example 1 group, Comparative Example 1 group, Comparative Example 2 group, Comparative Example 6 group, and Comparative Example 13 group; where: A is the body weight change graph of mice in each group; B is the average daily food intake graph of mice in each group; and C is the Lee's index graph of mice in each group. Figure 3 Histological analysis images of the effects of composite gels on the morphology of mouse adipose tissue in the normal diet group, high-fat diet group, positive control group, Example 1 group, Comparative Example 1 group, Comparative Example 2 group, Comparative Example 6 group, and Comparative Example 13 group; where A is the normal diet group, B is the high-fat diet group, C is the positive control group, D is Example 1 group, E is Comparative Example 1 group, F is Comparative Example 2 group, G is Comparative Example 6 group, and H is Comparative Example 13 group. Detailed Implementation

[0030] This invention proposes a modified konjac glucomannan composite gel, its preparation method, and its application. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following will provide a more detailed description of the invention with reference to specific examples. It should be understood that the specific examples described herein are only for explaining the invention and are not intended to limit the invention.

[0031] The following soybean peptides passed through an 80-mesh sieve, with a molecular weight of 1-3 kDa and a degree of hydrolysis of 15%-20%; the lipoprotein lipase activity is 20000 U / g (Yuanye Biotechnology).

[0032] Example 1 The preparation method of lactose-modified konjac glucomannan solution is as follows: (1) Take 6.0g of pretreated konjac glucomannan (passed through an 80-mesh sieve, with a moisture content of 4.6%), add 40mL of cooled distilled water, place it on a magnetic stirrer, and stir at 550r / min for 15min to form a konjac glucomannan solution. (2) Take 3.0g of dried lactose and slowly add it to the konjac glucomannan solution. Continue stirring at 550r / min for 10min to obtain a mixed solution. (3) Keep the mixed solution at 60°C for 2 hours, stirring for 4 minutes every 30 minutes during the process; (4) After the reaction is complete, the mixture is naturally cooled to room temperature to obtain a lactose-modified konjac glucomannan solution.

[0033] Example 2 The preparation method of lactose-modified konjac glucomannan solution is as follows: (1) Take 7.0g of pretreated konjac glucomannan (passed through an 80-mesh sieve, with a moisture content of 4.6%), add 40mL of cooled distilled water, place it on a magnetic stirrer, and stir at 550r / min for 15min to form a konjac glucomannan solution. (2) Take 2.5g of dried lactose and slowly add it to the konjac glucomannan solution. Continue stirring at 600r / min for 10min to obtain a mixed solution. (3) Keep the mixed solution at 60°C for 2 hours, stirring for 4 minutes every 30 minutes during the process; (4) After the reaction is complete, the mixture is naturally cooled to room temperature to obtain a lactose-modified konjac glucomannan solution.

[0034] Its viscosity was measured using a rotational viscometer; High-performance liquid chromatography (HPLC) was used for detection. The modification rate was calculated based on the unbound lactose content. The modification rate was calculated as follows: the sample solution was injected into the HPLC, the peak area of ​​free lactose was detected, and the result was substituted into the regression equation of the standard curve to calculate the mass (m1) of free lactose in the sample. Based on the initial total mass of lactose added to the reaction (m0 = 3.0 g), the lactose modification rate was calculated according to the following formula: Lactose modification rate (%) = (m0 - m1) / m0 × 100% In the formula: m0 is the total mass of lactose added at the beginning of the reaction (g); m1 is the mass of unbound free lactose in the sample (g).

[0035] The results are shown in Table 1: Table 1 Viscosity at 25℃ (mPa·s) Lactose modification rate (%) Example 1 3324 39.6 Example 2 3588 37.7

[0036] In summary, the lactose-modified konjac glucomannan solution prepared in Example 1 showed better results. Therefore, the following examples all used the lactose-modified konjac glucomannan solution prepared in Example 1.

[0037] Example 3 The preparation method of V-shaped spiral starch is as follows: (1) Take 1.5g of pretreated mung bean starch (passed through an 80-mesh sieve, with a moisture content of 6.8%), add 20mL of 60% ethanol aqueous solution and 0.024g of monoglyceride, and vortex at 3000r / min for 5min to form a uniform starch suspension; (2) Place it in a high-temperature and high-pressure reactor, set the temperature to 90℃ and the pressure to 0.1MPa, start the reactor, and treat it under constant temperature and pressure for 20 minutes; (3) After the reaction is complete, the reactor is closed, the pressure is naturally released to atmospheric pressure, and the reactor is naturally cooled to room temperature. The reactor is left to stand overnight at 4°C, the precipitate is collected by centrifugation, washed several times with anhydrous ethanol, and dried at 40°C to obtain V-shaped spiral starch.

[0038] Example 4 The preparation method of V-shaped spiral starch is as follows: (1) Take 1.5g of pretreated mung bean starch (passed through an 80-mesh sieve, with a moisture content of 6.8%), add 20mL of 70% ethanol aqueous solution and 0.03g of monoglyceride, and vortex at 3500r / min for 6min to form a uniform starch suspension; (2) Place it in a high-temperature and high-pressure reactor, set the temperature to 100℃ and the pressure to 0.1MPa, start the reactor, and treat it under constant temperature and pressure for 20 minutes; (3) After the reaction is complete, the reactor is closed, the pressure is naturally released to atmospheric pressure, and the reactor is naturally cooled to room temperature. The reactor is left to stand overnight at 4°C, the precipitate is collected by centrifugation, washed several times with anhydrous ethanol, and dried at 40°C to obtain V-shaped spiral starch.

[0039] 1. V-type crystallinity detection (X-ray diffraction, XRD) X-ray diffractometer (D8 Advance type) was used for detection. The parameters were: Cu target Kα rays, tube voltage 40kV, tube current 40mA, scanning range 2θ=5°-40°, scanning speed 5° / min, step size 0.02°. The diffraction pattern was analyzed using MDIJade 6.0 software, and the V-type crystallinity (the percentage of V-type crystal peak area to the total diffraction peak area) was calculated using the peak fitting method. 2. Verification of the integrity of the helical structure (XRD characteristic peaks) The XRD analysis showed that the characteristic diffraction peaks of V-helical starch were 2θ=17° and 19°. The intensity of the characteristic peaks reflects the structural integrity, and the higher the intensity, the more stable the helical structure. 3. Detection of soybean peptide embedding rate (high performance liquid chromatography, HPLC) Accurately weigh 0.75 g each of the products from Examples 3 and 4, and redissolve them in 10 mL of distilled water. After cooling to 35°C, add 0.12 g of soybean peptide (molecular weight 1-3 kDa) and stir at 400 r / min for 40 min. Then centrifuge at 8000 r / min for 10 min, and filter the supernatant through a 0.45 μm filter membrane. Detect the free soybean peptide content in the supernatant using HPLC. The embedding rate = (total mass of added soybean peptide - mass of free soybean peptide) / total mass of added soybean peptide × 100%. The results are shown in Table 2 below: Table 2 V-type crystallinity (%) Characteristic peak intensity (au) at 2θ=17° Characteristic peak intensity (au) at 2θ=19° Soybean peptide embedding rate (%) Example 3 62.3 1856 2132 89.5 Example 4 71.8 2468 2754 95.2

[0040] In summary, the V-shaped spiral starch prepared in Example 4 showed better results, so the V-shaped spiral starch prepared in Example 4 was used in all the following examples.

[0041] Example 5 A method for preparing a modified konjac glucomannan composite gel, comprising the following steps (parts by weight): Step 1: Take 0.7 parts of V-helix starch, add 10 parts of distilled water, vortex for 5 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 33℃, add 0.1 parts of soybean peptide, and stir at 400 r / min for 30 minutes to make soybean peptide molecules uniformly embedded in the V-helix of starch, thus obtaining the day layer lock-in system. Step 2: Take 0.7 parts of V-helix starch, add 10 parts of distilled water, vortex for 5 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 33°C, add 0.05 parts of lipoprotein lipase, and stir at 400 r / min for 30 minutes to allow enzyme molecules to embed into the V-helix of starch, thus obtaining the night layer lock-in system. Step 3: Take 1.5 parts of pretreated soybean protein (pretreated through an 80-mesh sieve), add 10 parts of distilled water, stir at 500 r / min for 10 min, add 0.2 parts of sodium carbonate, continue stirring at 500 r / min for 10 min, adjust to 8.0, and obtain soybean protein cross-linking solution; Step 4: Mix soybean protein crosslinking solution with night layer lock-in system at a volume ratio of 1:1.5, stir at 500 r / min for 5 min to form night layer gel precursor, slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold, and let it stand at 24℃ for 1.5 h to allow the precursor to fully crosslink and form, and obtain night layer core with a core diameter of 0.95 mm; Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add the soybean protein cross-linking solution, stir at 500 r / min for 5 min to ensure thorough mixing of the three components. The volume ratio of lactose-modified konjac glucomannan solution, day layer lock-in system and soybean protein cross-linking solution is 7:1.5:1 to form the day layer gel precursor. Slowly pour the day layer gel precursor into the outer cavity to cover the formed night layer core. Let it stand at 24℃ for 1 h to form a tightly wrapped biphase structure of "core-outer layer" with an outer layer thickness of 0.25 mm. Step 6: Place the mold into a constant temperature water bath, heat it to 93℃, keep it warm and steam for 25 minutes, remove it, let it cool naturally to room temperature, then put it in a -20℃ freezer for 1 hour, and then thaw it at 25℃ room temperature for 2 hours to obtain the product.

[0042] Example 6 A method for preparing a modified konjac glucomannan composite gel, comprising the following steps (parts by weight): Step 1: Take 0.75 parts of V-helix starch, add 10 parts of distilled water, vortex for 6 min to reconstitute, and obtain V-helix starch suspension. Cool to 34℃, add 0.12 parts of soybean peptide, and stir at 420 r / min for 35 min to make soybean peptide molecules uniformly embedded in the V-helix of starch, thus obtaining the day layer lock-in system. Step 2: Take 0.75 parts of V-helix starch, add 10 parts of distilled water, vortex for 6 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 34℃, add 0.055 parts of lipoprotein lipase, and stir at 420 r / min for 35 minutes to allow enzyme molecules to embed inside the V-helix of starch, thus obtaining the night layer lock-in system. Step 3: Take 2.0 parts of pretreated soybean protein (pretreated through an 80-mesh sieve), add 10 parts of distilled water, stir at 520 r / min for 11 min, add 0.25 parts of sodium carbonate, continue stirring at 520 r / min for 10 min, adjust to 8.2, and obtain soybean protein cross-linking solution; Step 4: Mix soybean protein crosslinking solution with night layer lock-in system at a volume ratio of 1:2.0, stir at 520 r / min for 5.5 min to form night layer gel precursor, slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold, and let it stand at 25℃ for 1.5 h to allow the precursor to fully crosslink and form, and obtain night layer core with a core diameter of 1.0 mm; Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add the soybean protein cross-linking solution, and stir at 520 r / min for 5.5 min to ensure thorough mixing. The volume ratio of lactose-modified konjac glucomannan solution, day layer lock-in system and soybean protein cross-linking solution is 8:2.0:1 to form the day layer gel precursor. Slowly pour the day layer gel precursor into the outer cavity to cover the formed night layer core. Let it stand at 25℃ for 1 h to form a tightly wrapped biphase structure of "core-outer layer" with an outer layer thickness of 0.3 mm. Step 6: Place the mold into a constant temperature water bath, heat it to 95℃, keep it warm and steam for 30 minutes, remove it, let it cool naturally to room temperature, then put it in a -20℃ freezer for 1 hour, and then thaw it at 25℃ room temperature for 2 hours to obtain the product.

[0043] Example 7 A method for preparing a modified konjac glucomannan composite gel, comprising the following steps (parts by weight): Step 1: Take 0.8 parts of V-helix starch, add 10 parts of distilled water, vortex for 8 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 36℃, add 0.15 parts of soybean peptide, and stir at 450 r / min for 40 minutes to make soybean peptide molecules uniformly embedded in the V-helix of starch, thus obtaining the day layer lock-in system. Step 2: Take 0.8 parts of V-helix starch, add 10 parts of distilled water, vortex for 8 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 36℃, add 0.06 parts of lipoprotein lipase, and stir at 450 r / min for 40 minutes to allow enzyme molecules to embed inside the V-helix of starch, thus obtaining the night layer lock-in system. Step 3: Take 2.5 parts of pretreated soybean protein (pretreated through an 80-mesh sieve), add 10 parts of distilled water, stir at 550 r / min for 12 min, add 0.3 parts of sodium carbonate, continue stirring at 550 r / min for 10 min, adjust to 8.5, and obtain soybean protein cross-linking solution; Step 4: Mix soybean protein crosslinking solution with night layer lock-in system at a volume ratio of 1:2.5, stir at 550 r / min for 6 min to form night layer gel precursor, slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold, and let it stand at 26℃ for 1.5 h to allow the precursor to fully crosslink and form, and obtain night layer core with a core diameter of 1.05 mm; Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add the soybean protein cross-linking solution, and stir at 550 r / min for 6 min to ensure thorough mixing. The volume ratio of lactose-modified konjac glucomannan solution, day layer lock-in system and soybean protein cross-linking solution is 9:2.5:1 to form the day layer gel precursor. Slowly pour the day layer gel precursor into the outer cavity to cover the formed night layer core. Let it stand at 26℃ for 1 h to form a tightly wrapped biphase structure of "core-outer layer" with an outer layer thickness of 0.35 mm. Step 6: Place the mold into a constant temperature water bath, heat it to 97℃, keep it warm and steam for 35 minutes, remove it, let it cool naturally to room temperature, then put it in a -20℃ freezer for 1 hour, and then thaw it at 25℃ room temperature for 2 hours to obtain the product.

[0044] Example 8 A method for preparing a modified konjac glucomannan composite gel, comprising the following steps (parts by weight): Step 1: Take 0.7 parts of V-helix starch, add 10 parts of distilled water, vortex for 8 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 36℃, add 0.1 parts of soybean peptide, and stir at 450 r / min for 30 minutes to make soybean peptide molecules uniformly embedded in the V-helix of starch, thus obtaining the day layer lock-in system. Step 2: Take 0.7 parts of V-helix starch, add 10 parts of distilled water, vortex for 8 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 36℃, add 0.05 parts of lipoprotein lipase, and stir at 450 r / min for 30 minutes to allow enzyme molecules to embed inside the V-helix of starch, thus obtaining the night layer lock-in system. Step 3: Take 1.5 parts of pretreated soybean protein (pretreated through an 80-mesh sieve), add 10 parts of distilled water, stir at 550 r / min for 10 min, add 0.2 parts of sodium carbonate, continue stirring at 550 r / min for 10 min, adjust to 8.5, and obtain soybean protein cross-linking solution; Step 4: Mix soybean protein crosslinking solution with night layer lock-in system at a volume ratio of 1:1.5, stir at 550 r / min for 5 min to form night layer gel precursor, slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold, and let it stand at 26℃ for 1.5 h to allow the precursor to fully crosslink and form, and obtain night layer core with a core diameter of 0.95 mm; Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add soybean protein cross-linking solution, stir at 550 r / min for 5 min to ensure thorough mixing of the three components. The volume ratio of lactose-modified konjac glucomannan solution, day layer lock-in system and soybean protein cross-linking solution is 7:2.5:1 to form the day layer gel precursor. Slowly pour the day layer gel precursor into the outer cavity to cover the formed night layer core. Let it stand at 26℃ for 1 h to form a tightly wrapped biphase structure of "core-outer layer" with an outer layer thickness of 0.25 mm. Step 6: Place the mold into a constant temperature water bath, heat it to 93℃, keep it warm and steam for 35 minutes, remove it, let it cool naturally to room temperature, then put it in a -20℃ freezer for 1 hour, and then thaw it at 25℃ room temperature for 2 hours to obtain the product.

[0045] Example 9 A method for preparing a modified konjac glucomannan composite gel, comprising the following steps (parts by weight): Step 1: Take 0.8 parts of V-helix starch, add 10 parts of distilled water, vortex for 5 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 33℃, add 0.15 parts of soybean peptide, and stir at 400 r / min for 40 minutes to make soybean peptide molecules uniformly embedded in the V-helix of starch, thus obtaining the day layer lock-in system. Step 2: Take 0.8 parts of V-helix starch, add 10 parts of distilled water, vortex for 5 minutes to reconstitute, obtain V-helix starch suspension, cool to 33℃, add 0.06 parts of lipoprotein lipase, stir at 400 r / min for 40 minutes to allow enzyme molecules to embed inside the V-helix of starch, and obtain night layer lock-in system; Step 3: Take 2.5 parts of pretreated soybean protein (pretreated through an 80-mesh sieve), add 10 parts of distilled water, stir at 500 r / min for 12 min, add 0.3 parts of sodium carbonate, continue stirring at 500 r / min for 10 min, adjust to 8.0, and obtain soybean protein cross-linking solution; Step 4: Mix soybean protein crosslinking solution with night layer lock-in system at a volume ratio of 1:2.5, stir at 500 r / min for 6 min to form night layer gel precursor, slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold, and let it stand at 24℃ for 1.5 h to allow the precursor to fully crosslink and form, and obtain night layer core with a core diameter of 1.05 mm; Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add the soybean protein cross-linking solution, and stir at 500 r / min for 6 min to ensure thorough mixing. The volume ratio of lactose-modified konjac glucomannan solution, day layer lock-in system and soybean protein cross-linking solution is 9:1.5:1 to form the day layer gel precursor. Slowly pour the day layer gel precursor into the outer cavity to cover the formed night layer core. Let it stand at 24℃ for 1 h to form a tightly wrapped biphase structure of "core-outer layer" with an outer layer thickness of 0.35 mm. Step 6: Place the mold into a constant temperature water bath, heat it to 97℃, keep it warm and steam for 25 minutes, remove it, let it cool naturally to room temperature, then put it in a -20℃ freezer for 1 hour, and then thaw it at 25℃ room temperature for 2 hours to obtain the product.

[0046] Example 10 A method for preparing a modified konjac glucomannan composite gel, comprising the following steps (parts by weight): Step 1: Take 0.75 parts of V-helix starch, add 10 parts of distilled water, vortex for 5 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 36℃, add 0.1 parts of soybean peptide, and stir at 450 r / min for 30 minutes to make soybean peptide molecules uniformly embedded in the V-helix of starch, thus obtaining the day layer lock-in system. Step 2: Take 0.75 parts of V-helix starch, add 10 parts of distilled water, vortex for 5 min to reconstitute, obtain V-helix starch suspension, cool to 36℃, add 0.05 parts of lipoprotein lipase, stir at 450 r / min for 30 min to allow enzyme molecules to embed inside the V-helix of starch, and obtain night layer lock-in system; Step 3: Take 2.0 parts of pretreated soybean protein (pretreated through an 80-mesh sieve), add 10 parts of distilled water, stir at 550 r / min for 10 min, add 0.2 parts of sodium carbonate, continue stirring at 550 r / min for 10 min, adjust to 8.5, and obtain soybean protein cross-linking solution; Step 4: Mix soybean protein crosslinking solution with night layer lock-in system at a volume ratio of 1:2.0, stir at 550 r / min for 5 min to form night layer gel precursor, slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold, and let it stand at 24℃ for 1.5 h to allow the precursor to fully crosslink and form, and obtain night layer core with a core diameter of 1.0 mm; Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add the soybean protein cross-linking solution, and stir at 550 r / min for 5 min to ensure thorough mixing. The volume ratio of lactose-modified konjac glucomannan solution, day layer lock-in system and soybean protein cross-linking solution is 8:1.5:1 to form the day layer gel precursor. Slowly pour the day layer gel precursor into the outer cavity to cover the formed night layer core. Let it stand at 24℃ for 1 h to form a tightly wrapped biphase structure of "core-outer layer" with an outer layer thickness of 0.3 mm. Step 6: Place the mold into a constant temperature water bath, heat it to 95℃, keep it warm and steam for 25 minutes, remove it, let it cool naturally to room temperature, then put it in a -20℃ freezer for 1 hour, and then thaw it at 25℃ room temperature for 2 hours to obtain the product.

[0047] Example 11 A method for preparing a modified konjac glucomannan composite gel, comprising the following steps (parts by weight): Step 1: Take 0.75 parts of V-helix starch, add 10 parts of distilled water, vortex for 8 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 33℃, add 0.15 parts of soybean peptide, and stir at 400 r / min for 40 minutes to make soybean peptide molecules uniformly embedded in the V-helix of starch, thus obtaining the day layer lock-in system. Step 2: Take 0.75 parts of V-helix starch, add 10 parts of distilled water, vortex for 8 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 33°C, add 0.06 parts of lipoprotein lipase, and stir at 400 r / min for 40 minutes to allow enzyme molecules to embed into the V-helix of starch, thus obtaining the night layer lock-in system. Step 3: Take 2.0 parts of pretreated soybean protein (pretreated through an 80-mesh sieve), add 10 parts of distilled water, stir at 500 r / min for 12 min, add 0.3 parts of sodium carbonate, continue stirring at 500 r / min for 10 min, adjust to 8.0, and obtain soybean protein cross-linking solution; Step 4: Mix soybean protein crosslinking solution with night layer lock-in system at a volume ratio of 1:2.0, stir at 500 r / min for 6 min to form night layer gel precursor, slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold, and let it stand at 26℃ for 1.5 h to allow the precursor to fully crosslink and form, and obtain night layer core with a core diameter of 1.0 mm; Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add the soybean protein cross-linking solution, and stir at 500 r / min for 6 min to ensure thorough mixing. The volume ratio of lactose-modified konjac glucomannan solution, day layer lock-in system and soybean protein cross-linking solution is 8:2.5:1 to form the day layer gel precursor. Slowly pour the day layer gel precursor into the outer cavity to cover the formed night layer core. Let it stand at 26℃ for 1 h to form a tightly wrapped biphase structure of "core-outer layer" with an outer layer thickness of 0.3 mm. Step 6: Place the mold into a constant temperature water bath, heat it to 95℃, keep it warm and steam for 35 minutes, remove it, let it cool naturally to room temperature, then put it in a -20℃ freezer for 1 hour, and then thaw it at 25℃ room temperature for 2 hours to obtain the product.

[0048] Example 12 A method for preparing a modified konjac glucomannan composite gel, comprising the following steps (parts by weight): Step 1: Take 0.7 parts of V-helix starch, add 10 parts of distilled water, vortex for 6 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 35℃, add 0.13 parts of soybean peptide, and stir at 430 r / min for 32 minutes to make soybean peptide molecules uniformly embedded in the V-helix of starch, thus obtaining the day layer lock-in system. Step 2: Take 0.7 parts of V-helix starch, add 10 parts of distilled water, vortex for 6 minutes to reconstitute, and obtain V-helix starch suspension. Cool to 35°C, add 0.052 parts of lipoprotein lipase, and stir at 430 r / min for 32 minutes to allow enzyme molecules to embed inside the V-helix of starch, thus obtaining the night layer lock-in system. Step 3: Take 1.8 parts of pretreated soybean protein (pretreated through an 80-mesh sieve), add 10 parts of distilled water, stir at 530 r / min for 10.5 min, add 0.22 parts of sodium carbonate, continue stirring at 530 r / min for 10 min, adjust to 8.3, and obtain soybean protein cross-linking solution; Step 4: Mix soybean protein crosslinking solution with night layer lock-in system at a volume ratio of 1:1.8, stir at 530 r / min for 5.2 min to form night layer gel precursor, slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold, and let it stand at 25℃ for 1.5 h to allow the precursor to fully crosslink and form, and obtain night layer core with a core diameter of 0.95 mm; Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add the soybean protein cross-linking solution, and stir at 530 r / min for 5.2 min to ensure thorough mixing. The volume ratio of lactose-modified konjac glucomannan solution, day layer lock-in system and soybean protein cross-linking solution is 7.5:1.8:1 to form the day layer gel precursor. Slowly pour the day layer gel precursor into the outer cavity to cover the formed night layer core. Let it stand at 25℃ for 1 h to form a tightly wrapped biphase structure of "core-outer layer" with an outer layer thickness of 0.25 mm. Step 6: Place the mold into a constant temperature water bath, heat it to 94℃, keep it warm and steam for 28 minutes, remove it, let it cool naturally to room temperature, then put it in a -20℃ freezer for 1 hour, and then thaw it at 25℃ room temperature for 2 hours to obtain the product.

[0049] Comparative Example 1 The difference between this comparative example and Example 6 is that unmodified conventional mung bean starch was used instead of V-shaped spiral starch in steps 1 and 2.

[0050] Comparative Example 2 The difference between this comparative example and Example 6 is that in step 5, a regular konjac glucomannan solution without lactose modification is used instead of the lactose-modified konjac glucomannan solution.

[0051] Comparative Example 3 The difference between this comparative example and Example 6 is that soybean peptides were not added in step 1.

[0052] Comparative Example 4 The difference between this comparative example and Example 6 is that lipoprotein lipase was not added in step 2.

[0053] Comparative Example 5 The difference between this comparative example and Example 6 is that in step 1, soybean peptides with a molecular weight of 4-6 kDa are used instead of soybean peptides with a molecular weight of 1-3 kDa.

[0054] Comparative Example 6 The difference between this comparative example and Example 6 is that sodium carbonate was not added in step 3 to adjust the pH.

[0055] Comparative Example 7 The difference between this comparative example and Example 6 is that the volume ratio of the soybean protein crosslinking solution to the night layer locking system in step 4 is 1:1.

[0056] Comparative Example 8 The difference between this comparative example and Example 6 is that the volume ratio of the soybean protein crosslinking solution to the night layer locking system in step 4 is 1:3.

[0057] Comparative Example 9 The difference between this comparative example and Example 6 is that the volume ratio of the lactose-modified konjac glucomannan solution, the intercalary layer lock-in system, and the soybean protein crosslinking solution in step 5 is 5:1.5:1.

[0058] Comparative Example 10 The difference between this comparative example and Example 6 is that the volume ratio of the lactose-modified konjac glucomannan solution, the intercalary layer lock-in system, and the soybean protein crosslinking solution in step 5 is 11:2.5:1.

[0059] Comparative Example 11 The difference between this comparative example and Example 6 is that the cooking temperature in step 6 is 85°C.

[0060] Comparative Example 12 The difference between this comparative example and Example 6 is that the cooking temperature in step 6 is 105°C.

[0061] Comparative Example 13 The difference between this comparative example and Example 6 is that the core-shell molded process was not used; instead, the daytime and nighttime precursors were directly mixed and molded in one step, without a day-night biphasic drug release structure.

[0062] Performance testing: 1. Freeze the above gel at -20℃ for 1.5h, then thaw it at room temperature of 25℃ for 2h, then soak the gel in 0.5% (w / v) citric acid solution for 1h, wipe off the surface moisture, and wait for testing.

[0063] Texture parameters: The texture properties of the composite gel were evaluated using a texture analyzer (EZ-SX500N, Shimadzu, Japan). A P / 36 circular probe was used, specifically configured as follows: texture profile analysis mode; sample compression deformation to 50% of original height; probe speeds before, during, and after testing were 2.0 mm / s, 0.5 mm / s, and 2.0 mm / s, respectively; trigger force was 10 g; the interval between two compressions was 2 s; each sample was measured in parallel eight times; parameters such as hardness, cohesion, elasticity, chewiness, adhesiveness, and resilience were recorded. The results are shown in Table 3 below. Table 3 Texture properties Hardness (g) cohesion elasticity Adhesiveness (g) Chewable (g) Resilience Example 5 1723±85 0.81±0.02 0.88±0.01 1406±78 1238±69 0.40±0.01 Example 6 1856±92 0.83±0.02 0.90±0.01 1541±85 1387±78 0.42±0.01 Example 7 1789±88 0.82±0.02 0.89±0.01 1473±81 1311±72 0.41±0.01 Example 8 1698±82 0.80±0.02 0.87±0.01 1359±75 1182±65 0.39±0.01 Example 9 1812±90 0.82±0.02 0.89±0.01 1506±83 1341±75 0.41±0.01 Example 10 1835±91 0.83±0.02 0.90±0.01 1527±84 1364±76 0.42±0.01 Example 11 1805±89 0.82±0.02 0.89±0.01 1498±82 1333±74 0.41±0.01 Example 12 1756±86 0.81±0.02 0.88±0.01 1432±79 1260±70 0.40±0.01 Comparative Example 1 1243±76 0.71±0.03 0.78±0.02 883±62 689±54 0.31±0.02 Comparative Example 2 1628±88 0.79±0.02 0.85±0.01 1286±73 1093±65 0.38±0.01 Comparative Example 3 1769±87 0.81±0.02 0.88±0.01 1438±80 1268±71 0.40±0.01 Comparative Example 4 1782±88 0.82±0.02 0.89±0.01 1461±81 1290±72 0.40±0.01 Comparative Example 5 1683±83 0.80±0.02 0.87±0.01 1347±76 1163±66 0.39±0.01 Comparative Example 6 957±63 0.65±0.03 0.72±0.02 622±48 448±41 0.27±0.02 Comparative Example 7 1356±79 0.73±0.02 0.80±0.02 989±68 791±58 0.33±0.01 Comparative Example 8 1312±77 0.72±0.03 0.79±0.02 945±65 747±56 0.32±0.02 Comparative Example 9 1563±85 0.78±0.02 0.84±0.01 1220±71 1025±62 0.37±0.03 Comparative Example 10 1645±89 0.79±0.02 0.85±0.01 1300±74 1105±66 0.38±0.01 Comparative Example 11 1287±78 0.70±0.03 0.77±0.02 901±63 694±55 0.30±0.02 Comparative Example 12 1089±69 0.67±0.03 0.74±0.02 727±54 538±47 0.28±0.02 Comparative Example 13 892±58 0.62±0.02 0.68±0.03 553±42 376±36 0.25±0.01

[0064] As shown in Table 3, the textural parameters of all embodiments are significantly better than those of the comparative examples, with Example 6 exhibiting the best performance. The hardness of the embodiments ranges from 1698 to 1856 g, with cohesion of 0.80 to 0.83 and resilience of 0.39 to 0.42, demonstrating good mechanical strength and flexibility. In contrast, Comparative Example 13 has a hardness of only 892 g, cohesion of 0.62, and resilience of 0.25, exhibiting a loose and easily broken structure. Therefore, the raw material ratio and preparation process of this invention can effectively construct a stable three-dimensional network structure and improve the textural properties of the gel.

[0065] 2. The structures of the gels from Example 6, Comparative Example 2, Comparative Example 6, and Comparative Example 13 were observed using a scanning electron microscope (SEM). Figure 1 As shown, Figure 1 In Example 6, the cross-linking site of A presents a continuous and dense network layer. The molecular bridge formed by the cross-linking of soybean protein connects the outer KGM layer and the core starch, and the interface is free of cracks and pores. Figure 1 In the example B (Comparative Example 1), there is no clear cross-linking interface, only scattered molecular agglomeration areas, no continuous binding layer, and the outer layer and core components are mixed, resulting in a loose structure. Figure 1 In the C (Comparative Example 2) cross-linking interface, there is no complete cross-linking interface. Only a thin and broken bonding area exists in some areas. In most areas, the outer layer is in direct contact with the core and there is no cross-linking layer. Figure 1 The cross-linking interface of D (Comparative Example 6) in the sample has obvious cracks, and the bonding layer has voids with a width >500nm, resulting in low strength and easy separation of the core and shell. Figure 1 E (Comparative Example 13) has no cross-linking interface, and the whole structure is an irregular mixture with no outer / core partitions, and naturally no cross-linking bonding layer.

[0066] 3. Determination of water separation rate (%) and water holding rate (%): Wipe off the surface moisture of the cooled gel with test paper and record the gel mass as a. Freeze at -20℃ for 1.5h, then thaw at 25℃ for 2h. Wipe off the surface moisture and record the gel mass as b. Then place the gel in a centrifuge tube and centrifuge at 10000r / min for 15min. Wipe off the surface moisture and record the gel mass as c. Calculate the water holding rate and water separation rate according to formulas (1) and (2).

[0067] 4. Intestinal mucosal adhesion rate: detected using an in vitro Caco-2 cell model; 5. Soybean peptide sustained-release rate (2h / 12h): Detection under simulated gastric (2h) and intestinal (12h) environmental conditions; 6. Lipoprotein lipase activity retention rate: detected after simulating a digestive environment; The results are shown in Table 4 below: Table 4 Water separation rate (%) Water holding capacity (%) Intestinal mucosal adhesion rate (%) Soybean peptide sustained release rate (2h / 12h, %) Lipoprotein lipase activity retention rate (%) Example 5 8.5 90.8 76.2 12.5 / 89.3 88.6 Example 6 6.3 93.5 82.5 10.2 / 92.6 91.8 Example 7 7.1 91.4 78.8 11.8 / 90.5 89.5 Example 8 8.8 90.2 75.5 13.1 / 88.7 87.9 Example 9 6.9 92.3 79.1 12.0 / 91.2 90.2 Example 10 6.5 93.1 81.3 10.8 / 92.1 91 Example 11 6.7 92.8 80.7 11.5 / 91.5 90.5 Example 12 7.5 91.3 77.9 12.2 / 89.8 88.9 Comparative Example 1 18.6 75.3 65.3 35.8 / 62.5 45.2 Comparative Example 2 7 90.5 42.5 11.0 / 88.9 89 Comparative Example 3 6.8 92 79.8 - / - 90.5 Comparative Example 4 6.5 92.5 81 10.5 / 92.0 - Comparative Example 5 7.2 88.7 78.5 28.6 / 75.2 88.8 Comparative Example 6 22.3 72.8 68.9 15.3 / 82.1 76.5 Comparative Example 7 15.7 83.5 72.3 14.8 / 85.6 82.3 Comparative Example 8 16.2 82.9 70.5 13.5 / 84.2 80.1 Comparative Example 9 9.5 87.5 55.8 12.1 / 87.5 88.2 Comparative Example 10 11.2 89.3 79.5 11.0 / 89.0 89.1 Comparative Example 11 19.7 76.4 78.2 16.5 / 83.3 85.6 Comparative Example 12 21.5 73.6 77.5 22.3 / 78.5 62.3 Comparative Example 13 25.3 68.9 69.8 29.5 / 68.8 71.5

[0068] As shown in Table 4, the examples exhibited excellent performance in terms of water separation rate, water holding rate, intestinal mucosal adhesion rate, and sustained release / retention rate of active ingredients. Example 6 had the lowest water separation rate (6.3%), the highest water holding rate (93.5%), an intestinal mucosal adhesion rate of 82.5%, a 2-hour sustained release rate of only 10.2% for soybean peptides (low burst release), a 12-hour release rate of 92.6% (sufficient release), and a lipoprotein lipase activity retention rate of 91.8%. In contrast, Comparative Example 1 showed a 2-hour sustained release rate of 35.8% for soybean peptides and a enzyme activity retention rate of only 45.2%; Comparative Example 2 showed an intestinal mucosal adhesion rate of only 42.5%; and Comparative Example 13 showed a water separation rate of 25.3% and a water holding rate of only 68.9%.

[0069] 7. Samples prepared in Example 6, Comparative Example 1, Comparative Example 2, Comparative Example 6, and Comparative Example 13 were used to replace the corresponding maltodextrin in the high-fat diet at a dosage of 4% (w / w). Inulin was used as a positive control. The ingredient list of the 60% high-fat diet is as follows: Table 5 High-fat dietary formula Component Name MD12033 (a high-fat diet developed by Medison), proportion Casein 25.84% maltodextrin 16.15% sucrose 8.89% Cellulose 6.46% soybean oil 3.23% lard 31.66% Toppings 7.77% total 100%

[0070] (1) Laboratory animals: Six-week-old male C57BL / 6 mice underwent a 7-day acclimatization period in an SPF-grade animal facility (with free access to feed). The mice were then randomly divided into eight groups: a normal diet group (NCD group, n=10), a high-fat diet group (HFD group, n=10), a positive control group (inulin group, n=10), Example 1 group (n=10), Comparative Example 1 group (n=10), Comparative Example 2 group (n=10), Comparative Example 6 group (n=10), and Comparative Example 13 group (n=10), with five mice per cage in each group. From the start of the experiment, all mice were fed their own prepared feed, with feed changed twice weekly and body weight measured twice. The experiment lasted for 12 weeks. After 12 weeks, the animals were fasted for 12 hours, weighed, and euthanized by cervical dislocation after blood collection via the orbital vein. Tissue samples were rapidly collected, flash-frozen in liquid nitrogen, transported on dry ice, and stored at -80°C. Serum was obtained by centrifuging whole blood samples at 3000 rpm and 4°C for 10 min.

[0071] (2) Determination of basic biochemical indicators Food intake and weight changes in mice: The general condition of each group of experimental animals, including their mental state, diet, excrement, and activity level, was observed and recorded daily. The weight and food intake of each animal were weighed and recorded at the same time point at a fixed frequency (twice a week). Based on the recorded weight data, a weight gain curve for the experimental animals was plotted. After the experiment, the weight gain and average food intake of each group of experimental animals were calculated based on the recorded data.

[0072] Lee's Index: Measure the mouse's body length (length from nose to anus) and weight, and calculate the Lee's Index according to formula (3):

[0073] (3) Blood lipid level analysis Using kits from Nanjing Jiancheng Bioengineering Institute and following their instructions, the concentrations of triglycerides (TG), total cholesterol (TCHO), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in mouse serum samples were measured.

[0074] (4) Appetite hormone levels during fasting To determine the levels of specific hormones in serum, this experiment employed enzyme-linked immunosorbent assay (ELISA). Specifically, the concentrations of glucagon-like peptide-1 (GLP-1), leptin, and tyrosine peptide (PYY) in serum samples were quantitatively analyzed.

[0075] (5) Biochemical analysis of the liver (MDA, AST, ALT) Accurately weigh at least 50 mg of tissue and add it to pre-cooled pH 7.3 phosphate buffer at a ratio of 1 g: 9 mL. Homogenize the mixture in liquid nitrogen and centrifuge at 5000 rpm for 15 minutes at 4°C. Collect the supernatant and store it at -80°C for later use. This supernatant was then used for subsequent assays: malondialdehyde (MDA) content was determined using a commercially available ELISA kit; alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were determined using a Nanjing Jiancheng Biochemical assay kit.

[0076] (6) Histological observation of fat Mouse adipose tissue observation was performed using hematoxylin-eosin staining. The complete procedure included: First, fresh tissue samples were fixed with 4% paraformaldehyde at 4°C for at least 3 days. After rinsing with running water, they were dehydrated with a series of ethanol solutions, cleared with xylene, impregnated with paraffin, and embedded. The tissue samples were then cut into 4μm thick sections. Subsequently, the paraffin sections were stained with H&E staining, which involved dewaxing to water with xylene and a series of ethanol solutions, staining with hematoxylin for 3-5 minutes, differentiating with hydrochloric acid alcohol, re-blueing with ammonia, and counterstaining with eosin for 5 minutes. Finally, the stained sections were dehydrated and cleared with anhydrous ethanol, n-butanol, and xylene, mounted with neutral resin, and observed and photographed under an optical microscope.

[0077] Experimental results: The effects of the above embodiments and comparative examples on food intake and weight changes in mice: By recording the baseline weight, weight changes during the feeding process, and final weight of the mice, the antagonistic effect of the gel prepared in this invention on obesity induced by a high-fat diet was investigated. During the 12-week experiment, the weight of mice in each group increased over time, and their mental state was good, indicating that the experiment did not have any abnormal effects on the mice. Figure 2 As shown in A and B, before dietary intervention, there was no statistically significant difference in the initial weight of mice in each group. However, after 12 weeks of dietary intervention, the weight of mice in each group gradually showed significant differences. At the end of the experiment, compared with the low-fat control group (NCD) mice, the average weight of mice in the high-fat diet group (HFD) was significantly higher, indicating that the high-fat diet successfully induced an obesity model. Compared with the HFD group, the final weight of mice in Example 6 group (28.5g) was significantly lower, with a weight gain rate of only 28.3%, and the average daily food intake (2.7g / mouse) was the lowest among all groups; while the weight of the comparative groups was higher than that of Example 6 group, with the final weight of comparative group 13 reaching 40.2g and a weight gain rate of 65.4%, close to that of the HFD group (43.8g, growth rate of 71.7%). It can be seen that the core-shell biphasic structure and the active ingredients of the present invention work synergistically to effectively enhance satiety, reduce food intake, and inhibit weight gain, with significantly better effects than the comparative group.

[0078] Lee's index is commonly used to measure obesity in mice, similar to body mass index (BMI) in humans. By recording the body length and weight of mice, Lee's index is calculated to assess the impact of different dietary interventions on obesity. Generally, a higher Lee's index indicates a higher degree of obesity. Figure 2As shown in C, the Lee's index of the HFD group was significantly higher than that of the other groups (p<0.05), successfully establishing an obesity model. The Lee's index of the Example 6 group was 3.2, consistent with the NCD group (3.2), and significantly lower than that of the inulin group (3.8) and all comparative examples; the Lee's index of comparative examples 1 and 2 was 3.7-3.8, and that of comparative examples 6 and 13 was 3.9-4.0, close to that of the HFD group (4.2). This further demonstrates that the composite gel of the present invention can effectively inhibit obesity induced by a high-fat diet, and the obesity improvement effect is better than that of the positive control and comparative examples.

[0079] Table 6. Serum lipid levels in mice Triglycerides (TG, mmol / L) Total cholesterol (TCHO, mmol / L) High-density lipoprotein cholesterol (HDL-C, mmol / L) Low-density lipoprotein cholesterol (LDL-C, mmol / L) NCD Group 1.12 2.65 1.38 0.85 HFD group 3.78 5.23 0.92 2.96 Inulin group 2.56 3.87 1.15 1.89 Example 1 Group 1.45 2.98 1.42 0.98 Comparative Example 1 2.89 4.12 1.08 2.15 Comparative Example 2 2.73 3.95 1.12 2.03 Comparative Example 6 Groups 3.25 4.56 1.01 2.48 Comparative Example 13 3.47 4.89 0.97 2.72

[0080] As shown in Table 6, the HFD group mice exhibited disordered lipid metabolism, with significantly elevated levels of TG, TCHO, and LDL-C, and decreased levels of HDL-C. The lipid indicators of the Example 6 group were similar to those of the NCD group, with TG at only 1.45 mmol / L, TCHO at 2.98 mmol / L, LDL-C at 0.98 mmol / L, and HDL-C at 1.42 mmol / L (higher than the NCD group), demonstrating a significantly better lipid regulation effect than the inulin group and the comparative group. In contrast, the comparative group 13 had TG of 3.47 mmol / L and TCHO of 4.89 mmol / L, similar to the HFD group. Therefore, the composite gel of this invention can effectively regulate lipid metabolism and improve lipid abnormalities induced by a high-fat diet.

[0081] Table 7 Serum appetite hormone concentrations in mice Glucagon-like peptide-1 (GLP-1, pmol / L) Leptin (ng / mL) Pyropeptide (PYY, pg / mL) NCD Group 7.85 3.25 232.6 HFD group 4.32 12.86 178.5 Inulin group 6.15 8.53 205.8 Example 1 Group 8.96 4.12 256.3 Comparative Example 1 5.78 9.68 198.4 Comparative Example 2 5.92 9.15 202.7 Comparative Example 6 Groups 5.13 10.87 189.6 Comparative Example 13 4.86 11.54 183.2

[0082] As shown in Table 7, the HFD group mice exhibited disordered appetite hormone secretion, with decreased GLP-1 and PYY concentrations and increased leptin concentration. In Example 6, the GLP-1 concentration reached 8.96 pmol / L (higher than the NCD group), the PYY concentration was 256.3 pg / mL (significantly higher than other groups), and the leptin concentration was only 4.12 ng / mL (close to the NCD group). This demonstrates that the composite gel of this invention can effectively regulate appetite hormone balance, enhance satiety, and suppress appetite. In contrast, the hormone regulation effects of the comparative groups were not as good as those of Example 6. For example, in Comparative Example 13, GLP-1 was only 4.86 pmol / L and leptin was 11.54 ng / mL, close to the HFD group. Therefore, the composite gel of this invention has a significant advantage in appetite regulation.

[0083] Table 8 Biochemical indicators of mouse liver Malondialdehyde (MDA, nmol / mgprot) Aspartate aminotransferase (AST, U / mL) Alanine aminotransferase (ALT, U / mL) NCD Group 10.56 125.3 89.6 HFD group 18.72 246.8 198.5 Inulin group 14.35 189.6 142.8 Example 1 Group 11.23 138.5 97.4 Comparative Example 1 15.68 205.4 156.3 Comparative Example 2 15.12 198.7 149.6 Comparative Example 6 Groups 16.95 223.8 178.4 Comparative Example 13 17.83 235.2 189.7

[0084] Liver MDA is a core indicator for assessing the degree of lipid peroxidation in hepatocytes. Higher levels indicate more severe oxidative stress and cellular damage in the liver, and oxidative stress is a significant marker of obesity. Overweight or obesity is a key risk factor for hepatic steatosis, leading to significant liver dysfunction. AST and ALT are core biomarkers for assessing hepatocyte damage; elevated serum levels directly reflect impaired hepatocyte membrane integrity. To clarify the damaging effects of a long-term high-fat diet on the liver and to evaluate the intervention effect of the composite gel of this invention, this experiment measured ALT and AST levels in mouse livers. As shown in Table 8, the MDA content in the livers of mice in the HFD group was significantly increased, and the activities of AST and ALT were greatly enhanced, indicating severe oxidative and cellular damage to the liver. The MDA content in Example 6 group was only 11.23 nmol / mg prot (close to the NCD group), AST 138.5 U / mL, and ALT 97.4 U / mL, indicating very mild liver damage. The MDA, AST, and ALT levels in the comparative groups were higher than those in Example 6 group. Among them, the MDA in Comparative Example 13 group was 17.83 nmol / mg prot, AST was 235.2 U / mL, and ALT was 189.7 U / mL, which was close to the HFD group. It can be seen that the composite gel of the present invention can effectively reduce liver damage induced by high-fat diet and protect liver function.

[0085] Figure 3 The effects of the gel of the present invention on the morphology of adipocytes in mice were demonstrated. In the NCD group, adipocytes were smaller, more regular in shape, and uniform in size, with a tight cell arrangement. In contrast, adipocytes in the HFD group showed significant hypertrophy, with markedly larger cell volume, irregular shape, and varying sizes, and compressed intercellular spaces, indicating significant fat accumulation. After intervention with the gel of the present invention, the hypertrophy of adipocytes in each intervention group was improved to varying degrees. The adipocytes in Example 6 were the smallest, with morphology and size closest to the NCD group, and the cells were uniformly and tightly arranged. The adipocytes in the comparative groups were all larger than those in Example 6, and the adipocytes in Comparative Example 13 still showed significant hypertrophy, with little difference from the HFD group. This directly confirms that the composite gel of the present invention can effectively inhibit high-fat diet-induced adipocyte proliferation and hypertrophy, reduce fat accumulation, and thus play a role in weight management.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A modified konjac glucomannan composite gel, characterized in that, The composite gel has a core-shell biphase structure, with an outer daytime layer and an inner nighttime layer, and the daytime and nighttime layers are tightly bound together by the cross-linking effect of soybean protein. The day layer is made by cross-linking a lactose-modified konjac glucomannan solution, a day layer lock-in system, and a soybean protein cross-linking solution; The night layer is made by mixing and cross-linking soybean protein cross-linking liquid with a night layer locking system, wherein the night layer locking system is a complex formed by embedding lipoprotein lipase into V-shaped helical starch.

2. The modified konjac glucomannan composite gel according to claim 1, characterized in that, The preparation method of the lactose-modified konjac glucomannan solution is as follows: (1) Take 6.0-7.0g of pretreated konjac glucomannan, add 40-50mL of cooled distilled water and stir to form a konjac glucomannan solution; (2) Take 2.5-3.5g of dried lactose and slowly add it to the konjac glucomannan solution, continue stirring to obtain a mixed solution; (3) Keep the mixed solution at 55-65℃ for 2 hours, stirring for 4-5 minutes every 30 minutes during the process; (4) After the reaction is complete, the mixture is naturally cooled to room temperature to obtain a lactose-modified konjac glucomannan solution.

3. The modified konjac glucomannan composite gel according to claim 1, characterized in that, The preparation method of the V-shaped spiral starch is as follows: (1) Take the pretreated mung bean starch, add 60%-70% ethanol aqueous solution and monoglyceride, and vortex at 3000-3500r / min for 5-6min to form a uniform starch suspension; (2) Place it in a high-temperature and high-pressure reactor, set the temperature to 90-100℃ and the pressure to 0.1MPa, start the reactor, and treat it under constant temperature and pressure for 18-22 minutes; (3) After the reaction is complete, the reactor is closed, the pressure is naturally released to atmospheric pressure, and the reactor is naturally cooled to room temperature. The reactor is left to stand overnight at 4°C, the precipitate is collected by centrifugation, washed several times with anhydrous ethanol, and dried to obtain V-shaped spiral starch.

4. The modified konjac glucomannan composite gel according to claim 3, characterized in that, The pretreatment method in step (1) is to pass the mung bean starch through an 80-mesh sieve to make the moisture content ≤8%.

5. A method for preparing a modified konjac glucomannan composite gel according to any one of claims 1-4, characterized in that, By weight, the following steps are included: Step 1: Take 0.7-0.8 parts of V-helical starch, add 10 parts of distilled water, vortex to reconstitute, and obtain V-helical starch suspension. Cool to 33-36℃, add 0.1-0.15 parts of soybean peptide, and stir at 400-450r / min for 30-40min to obtain the interday layer lock-in system. Step 2: Take 0.7-0.8 parts of V-helical starch, add 10 parts of distilled water, vortex to reconstitute, and obtain V-helical starch suspension. Cool to 33-36℃, add 0.05-0.06 parts of lipoprotein lipase, and stir at 400-450r / min for 30-40min to obtain night layer lock-in system. Step 3: Take 1.5-2.5 parts of pretreated soybean protein, add 10 parts of distilled water, stir at 500-550 r / min for 10-12 min, add 0.2-0.3 parts of sodium carbonate, continue stirring at 500-550 r / min for 10 min, adjust to 8.0-8.5, and obtain soybean protein cross-linking solution; Step 4: Take the soybean protein cross-linking solution and mix it with the night layer lock-in system. Stir at 500-550 r / min for 5-6 min to form the night layer gel precursor. Slowly pour the night layer gel precursor into the inner core column cavity of the core-shell mold and let it stand at 24-26℃ for 1.5 h to obtain the night layer core. Step 5: Mix the lactose-modified konjac glucomannan solution with the day layer lock-in system, stir evenly, add soybean protein crosslinking solution, stir at 500-550 r / min for 5-6 min to fully mix the three to form a day layer gel precursor. Slowly pour the day layer gel precursor into the outer layer cavity to cover the formed night layer core. Let it stand at 24-26℃ for 1 h to form a tightly wrapped biphase structure of "core-outer layer". Step 6: Place the entire mold into a constant temperature water bath, heat to 93-97℃, keep warm and steam for 25-35 minutes, remove, let cool naturally to room temperature, then freeze in a -20℃ freezer for 1 hour, and then thaw at 25℃ room temperature for 2 hours to remove free water from the gel.

6. The method for preparing a modified konjac glucomannan composite gel according to claim 5, characterized in that, The soybean peptides mentioned in step 1 pass through an 80-mesh sieve, have a molecular weight of 1-3 kDa, and a degree of hydrolysis of 15%-20%.

7. The method for preparing a modified konjac glucomannan composite gel according to claim 5, characterized in that, In step 4, the volume ratio of the soybean protein crosslinking solution to the night layer locking system is 1:(1.5-2.5).

8. The method for preparing a modified konjac glucomannan composite gel according to claim 5, characterized in that, In step 5, the volume ratio of the lactose-modified konjac glucomannan solution, the intercalary layer lock-in system, and the soybean protein crosslinking solution is (7-9):(1.5-2.5):

1.

9. The application of the modified konjac glucomannan composite gel according to any one of claims 1-4 in the preparation of food, functional carrier material, drug sustained-release matrix or weight management functional food with high water retention, low water separation rate and adjustable texture properties.

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