Edible aerogel from flammulina velutipes and preparation method and application thereof

Abstract

This invention discloses an edible aerogel derived from *Flammulina velutipes*, its preparation method, and its applications. The preparation method includes the following steps: dispersing dried *Flammulina velutipes* powder in an aqueous sodium hydroxide solution, reacting, separating, and washing to obtain a precipitate; dispersing the precipitate in an aqueous sodium hypochlorite solution for bleaching, separating, washing, and freeze-drying to obtain an extract; dissolving polyphenols in an aqueous NaOH solution to obtain a NaOH / polyphenol dissolution system; dispersing the extract in the NaOH / polyphenol dissolution system, and shaking to promote CGC swelling; cycling the obtained suspension through freeze-thaw cycles 2-4 times; centrifuging the suspension, and partially dialyzing the solution to remove NaOH to obtain a hydrogel-like CGC-polyphenol complex; freeze-drying and grinding the hydrogel-like CGC-polyphenol complex to obtain an edible aerogel derived from *Flammulina velutipes*. This invention provides the application of the aforementioned edible aerogel derived from *Flammulina velutipes* in the preparation of weight-loss drugs or dietary supplements.

Description

Technical Field

[0001] This invention relates to the field of biotechnology, specifically to a method for preparing edible aerogel derived from enoki mushrooms based on polyphenol regulation, the obtained edible aerogel derived from enoki mushrooms, and its application in the preparation of weight-loss drugs or dietary supplements. Technical Background

[0002] Due to changes in lifestyle and dietary habits, the prevalence of metabolic diseases such as obesity, diabetes, fatty liver, and hyperlipidemia is rapidly increasing globally. The prevention and treatment of these diseases have become major public health issues in the 21st century. With continuously improving living standards, people have increasingly higher requirements for food safety and nutrition, driving the in-depth development of healthy eating. Developing safe and effective fat absorption inhibition strategies, and reducing the actual absorption of lipids from high-fat diets through the design of novel food structural components, has become a promising and important direction in innovative food research and development.

[0003] Chitin has been shown to effectively improve glucose and lipid metabolism disorders through lipid adsorption, promoting lipid excretion in feces, and regulating gut microbiota. Currently, commercially available chitin is mainly extracted from the shells of crustaceans such as shrimp and crab, which is subject to limitations due to geographical and seasonal factors. Furthermore, chitin extracted from seafood is often unacceptable to vegetarians and those with seafood allergies. Edible fungi (such as enoki mushrooms) are another important source of dietary chitin. Chitin in the cell walls of edible fungi is cross-linked with dextran chains through covalent glycosidic bonds, existing as a copolymer called chitin-dextran complex (CGC). CGC possesses the bioactivity of both chitin and dextran and has a stable structure. In addition, enoki mushrooms have a wide availability, large yield, fewer geographical and seasonal limitations, and are inexpensive. As a non-animal-derived food, they typically do not contain allergens such as tropomyosin, expanding their application range. However, the relatively dense structure of extracted CGCs hinders the exposure of active groups, limiting their adsorption capacity for lipids, especially at the water-oil interface.

[0004] Patent CN119770617B discloses a composition containing citrus polyphenols and citrus powder for fat burning and weight loss, its preparation method, and its application. The method uses raw materials such as enoki mushroom fiber and soy protein isolate to improve the stability of total polyphenols and vitamin C in the composition, effectively promoting fat burning and weight loss. This invention uses enoki mushroom fiber as a raw material for weight-loss foods, but the development and application of dietary fiber from enoki mushrooms are insufficient. Patent CN115477783B discloses a method for preparing chitosan-based superabsorbent materials, gels, and their applications. This method dissolves chitosan in an alkaline hydroxide / urea system, crosslinks it with epoxy crosslinking agents or guanidine inorganic salts, and after washing, drying, and pulverizing, obtains an edible gel with high expansion capacity, which can be applied to obesity control drugs. The material prepared by this method mainly achieves obesity control by absorbing water and expanding, enhancing satiety. The raw material's efficacy is relatively singular, and the use of urea, epoxy crosslinking agents, and other reagent residues may pose potential toxicity. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned shortcomings and propose a method for preparing edible aerogels derived from enoki mushrooms based on polyphenol regulation, the obtained edible aerogels derived from enoki mushrooms and their application in the preparation of weight-loss drugs or dietary supplements. The edible aerogels derived from enoki mushrooms prepared by this invention can effectively inhibit the digestion and absorption of lipids, and at the same time have antioxidant activity, synergistically enhancing the lipid-lowering effect.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing edible aerogel derived from *Flammulina velutipes* based on polyphenol regulation. The method involves extracting and preparing a chitin-glucan complex (CGC) from *Flammulina velutipes*, introducing polyphenols into a sodium hydroxide solution system to promote CGC dissolution, and allowing random polymerization and cross-linking between polyphenols and CGC. After dialysis, drying, and pulverization, a high-porosity edible aerogel is formed. The preparation method includes the following steps: Step 1: Disperse the dried enoki mushroom powder in a 0.5-2wt% sodium hydroxide (NaOH) aqueous solution at a material-to-liquid ratio of 1 g: 20-50 mL. React in a water bath at 100-120 ℃ for 3-4 h. Then repeat the centrifugation and washing of the precipitate until the pH is neutral. Step 2: Disperse the precipitate obtained in Step 1 in a 0.2-0.5wt% sodium hypochlorite aqueous solution at a material-to-liquid ratio of 1g:20-30mL, bleach at room temperature for 1-2 hours, repeat centrifugation and washing of the precipitate until the pH is neutral, freeze-dry the precipitate to obtain the CGC extract of Enoki mushroom. Step 3: Dissolve the polyphenols at an addition rate of 0.2-0.4 wt% in a 10-12 wt% NaOH aqueous solution to obtain a NaOH / polyphenol dissolution system; Step 4: Disperse the CGC extract of *Flammulina velutipes* in a NaOH / polyphenol dissolution system at an addition rate of 2-5 wt%, and shake at 200-300 rpm for 1-2 h at room temperature to promote CGC swelling; freeze the resulting CGC / NaOH / polyphenol suspension at below -20°C for 2-3 h, then thaw the sample, shake thoroughly at 200-300 rpm at room temperature for 2-3 h, and freeze again at below -20°C for 2-3 h, repeating this freeze-thaw cycle 2-4 times; Step 5: After centrifuging the suspension obtained in Step 4 to remove undissolved precipitates, dialyze the solution portion in deionized water at room temperature using an 8-12 kDa MWCO membrane for 48-72 h to remove NaOH, and obtain a hydrogel-like CGC-polyphenol complex. Step 6: Freeze-dry the hydrogel-like CGC-polyphenol complex to obtain CGC-polyphenol aerogel. Grind and pulverize the CGC-polyphenol aerogel under liquid nitrogen protection to obtain edible aerogel derived from enoki mushroom.

[0007] Preferably, in step 1, the concentration of the sodium hydroxide aqueous solution is 1 wt%, the material-to-liquid ratio is 1 g: 50 mL, and the reaction is carried out in a water bath at 100 ℃ for 3 h.

[0008] Preferably, in step 2, the concentration of the sodium hypochlorite aqueous solution is 0.2 wt%, the material-to-liquid ratio is 1 g: 20 mL, and the bleaching is carried out at room temperature for 1 h.

[0009] Preferably, in step 3, the polyphenol is tannic acid, gallic acid, or catechin.

[0010] Preferably, in step 3, the amount of polyphenol added is 0.3 wt%, and the concentration of the NaOH aqueous solution is 11 wt%.

[0011] Preferably, in step 4, the amount of the enoki mushroom CGC extract added is 3 wt%.

[0012] Preferably, in step 4, the obtained CGC / NaOH / polyphenol suspension is frozen at -80°C for 2 h, then the sample is thawed, shaken thoroughly at 200 rpm at room temperature for 2 h, and then frozen again at -80°C for 2 h. This freeze-thaw cycle is repeated 3 times.

[0013] Secondly, the present invention provides an edible aerogel derived from enoki mushrooms prepared according to the preparation method described in the first aspect.

[0014] Thirdly, the present invention provides the application of the edible aerogel derived from enoki mushrooms as described in the second aspect in the preparation of weight-loss drugs or dietary supplements.

[0015] By employing the above-described technology, the beneficial effects of the present invention compared to the prior art are as follows: (1) In this invention, natural polyphenols are used instead of urea as the dissolving medium for chitin-glucan complex (CGC) from enoki mushroom. Through polyphenol-mediated multiple non-covalent interactions, CGC is induced to form a porous three-dimensional network structure with random polymerization and cross-linking, which can enhance the physical adsorption of CGC and effectively capture and fix oils.

[0016] Specifically, natural polyphenols (tannic acid, gallic acid, catechins, etc.) are introduced to replace urea in the construction of a sodium hydroxide / polyphenol dissolution system. During the dissolution process of CGC, the polyphenols form a high-density random polymer cross-linked structure with CGC through non-covalent interactions such as hydrogen bonding, ionic interactions, and hydrophobic interactions. This structure includes a strong chitin-chitin network and a weaker chitin-polyphenol network. Under the mediation of polyphenols, the solubility of CGC in the system is increased. After dialysis to remove sodium hydroxide, a high-strength CGC-polyphenol crystalline hydrate is formed. Freeze-drying yields an edible aerogel with a porous structure, a porosity of over 90%, a further increase in total pore surface area, and a decrease in pore size. This change in pore structure effectively enhances the physical adsorption and fixation of oils by the aerogel. The CGC-polyphenol edible aerogel exhibits enhanced water and oil holding capacity. Furthermore, this method avoids the potential toxicity caused by new covalent formation (polymer synthesis or chemical cross-linking) or the residue of toxic initiators and monomers.

[0017] (2) In the water-oil system, CGC-polyphenols can effectively adsorb bile salts, inhibit lipase activity, and lock, aggregate, and encapsulate lipids at the water-oil interface, effectively inhibiting lipid digestion and absorption. Moreover, polyphenols are gradually released during digestion, endowing edible aerogels with antioxidant activity and synergistically enhancing lipid-lowering effects.

[0018] Specifically, under the mediation of hydrophilic polyphenols, the dispersibility of aerogels in digestive juices is enhanced, but they are still not easily digested or dissolved. CGC-polyphenols, with their good solution dispersibility, can effectively adsorb bile salts through hydrogen bonds, van der Waals forces, and electrostatic interactions, inhibiting lipase activity. In a water-oil system simulating a high-fat diet, amphiphilic CGC-polyphenols can lock the water-oil interface, disrupting interfacial stability, promoting lipid (oils, cholesterol, etc.) aggregation and encapsulating lipids, reducing lipid emulsification and contact with lipases, thereby effectively inhibiting lipid digestion and absorption. Furthermore, during gastrointestinal digestion, polyphenols (tannic acid, gallic acid, catechins) in the aerogel are gradually released. These polyphenols not only synergistically inhibit water-oil interface migration but also exhibit excellent antioxidant activity in the gastrointestinal tract, possessing the potential to reduce oxidative stress in vivo. CGC-polyphenols can synergistically improve lipid metabolism disorders. Attached Figure Description

[0019] Figure 1a and b show the water-holding capacity and oil-holding capacity of the samples in the embodiments and comparative examples of the present invention; Figure 2 a and b show the bile salt adsorption and lipase inhibition capabilities of the samples in the embodiments and comparative groups of the present invention; Figure 3 a and b show the cholesterol adsorption and lipid acid release rates after simulated digestion of the samples in the embodiments and comparative groups of the present invention; Figure 4 Figures a and b show the polyphenol release and DPPH free radical scavenging capabilities of the samples in the embodiments and comparative groups of the present invention during simulated digestion. Detailed Implementation

[0020] The embodiments of the present invention are described in detail below to make the features of the present invention easily understandable to those skilled in the art, thereby providing a more detailed definition of the scope of protection of the present invention. However, the present invention is not limited to the following embodiments.

[0021] Sources of raw materials used in the examples and comparative examples: Enoki mushrooms: food grade, purchased from the local market; Sodium hydroxide: AR, purchased from Sinopharm Chemical Reagent Co., Ltd.; Sodium hypochlorite: AR, purchased from Sinopharm Chemical Reagent Co., Ltd.; Tannic acid: ≥99%, purchased from Shanghai Yuanye Biotechnology Co., Ltd.; Gallic acid: ≥98%, purchased from Shanghai Titan Technology Co., Ltd.; Catechins: ≥98%, purchased from Shaanxi Ruimao Biotechnology Co., Ltd.; Chitosan: practical grade, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Urea: ≥99%, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Artificial saliva: purchased from Shanghai Yuanye Biotechnology Co., Ltd., product number R22154; Artificial gastric fluid: purchased from Shanghai Yuanye Biotechnology Co., Ltd., product number R30386; Artificial small intestinal fluid: purchased from Shanghai Yuanye Biotechnology Co., Ltd., product number R22156; Example 1 (1) Disperse the dried enoki mushroom powder in a 1 wt% sodium hydroxide (NaOH) solution with a material-to-liquid ratio of 1 g: 50 mL. React for 3 h in a 100 ℃ water bath. Then repeat the centrifugation and washing of the precipitate until the pH is neutral.

[0022] (2) Disperse and soak the precipitate from (1) in a 0.2% sodium hypochlorite solution at a material-to-liquid ratio of 1 g: 20 mL. Bleach at room temperature for 1 h. Repeat centrifugation and washing of the precipitate until the pH is neutral. Freeze-dry the precipitate to obtain the CGC extract of Enoki mushroom.

[0023] (3) Dissolve tannic acid in a 11 wt% NaOH solution at a dosage of 0.3 wt% to obtain a NaOH / tannic acid dissolution system.

[0024] (4) The CGC extract of *Flammulina velutipes* was dispersed in a NaOH / tannic acid dissolution system at an addition rate of 3 wt%, and shaken at 200 rpm for 1 h at room temperature to promote CGC swelling. The CGC / NaOH / tannic acid suspension was frozen at -80℃ for 2 h, then the sample was thawed, shaken thoroughly at 200 rpm for 2 h at room temperature, and then frozen again at -80℃ for 2 h. This freeze-thaw cycle was repeated 3 times.

[0025] (5) Centrifuge the suspension in (4) at 8000 rpm for 20 min to remove undissolved precipitate, and then dialyze the solution in deionized water at room temperature for 48 h to remove NaOH, so as to obtain hydrogel-like CGC-tannic acid complex.

[0026] (6) The hydrogel-like CGC-tannic acid complex was freeze-dried to obtain CGC-tannic acid aerogel. The aerogel was ground and pulverized under liquid nitrogen protection to obtain edible aerogel from enoki mushroom.

[0027] Example 2

[0028] (1) Disperse the dried enoki mushroom powder in a 1 wt% sodium hydroxide (NaOH) solution with a material-to-liquid ratio of 1 g: 50 mL. React for 3 h in a 100 ℃ water bath. Then repeat the centrifugation and washing of the precipitate until the pH is neutral.

[0029] (2) Disperse and soak the precipitate from (1) in a 0.2% sodium hypochlorite solution at a material-to-liquid ratio of 1 g: 20 mL. Bleach at room temperature for 1 h. Repeat centrifugation and washing of the precipitate until the pH is neutral. Freeze-dry the precipitate to obtain the CGC extract of Enoki mushroom.

[0030] (3) Gallic acid was uniformly dissolved in a 11 wt% NaOH solution at an addition amount of 0.3 wt% to obtain a NaOH / gallic acid dissolution system.

[0031] (4) The CGC extract of *Flammulina velutipes* was dispersed in a NaOH / gallic acid dissolution system at an addition rate of 3 wt%, and shaken at 200 rpm for 1 h at room temperature to promote CGC swelling. The CGC / NaOH / gallic acid suspension was frozen at -80℃ for 2 h, then the sample was thawed, shaken thoroughly at 200 rpm for 2 h at room temperature, and then frozen again at -80℃ for 2 h. This freeze-thaw cycle was repeated 3 times.

[0032] (5) Centrifuge the suspension in (4) at 8000 rpm for 20 min to remove undissolved precipitate, and then dialyze the solution in deionized water at room temperature for 48 h to remove NaOH, so as to obtain hydrogel-like CGC-gallic acid complex.

[0033] (6) The hydrogel-like CGC-gallic acid complex was freeze-dried to obtain CGC-gallic acid aerogel. The aerogel was ground and pulverized under liquid nitrogen protection to obtain edible aerogel from enoki mushroom.

[0034] Example 3

[0035] (1) Disperse the dried enoki mushroom powder in a 1 wt% sodium hydroxide (NaOH) solution with a material-to-liquid ratio of 1 g: 50 mL. React for 3 h in a 100 ℃ water bath. Then repeat the centrifugation and washing of the precipitate until the pH is neutral.

[0036] (2) Disperse and soak the precipitate from (1) in a 0.2% sodium hypochlorite solution at a material-to-liquid ratio of 1 g: 20 mL. Bleach at room temperature for 1 h. Repeat centrifugation and washing of the precipitate until the pH is neutral. Freeze-dry the precipitate to obtain the CGC extract of Enoki mushroom.

[0037] (3) Dissolve catechin in a 11 wt% NaOH solution at an addition rate of 0.3 wt% to obtain a NaOH / catechin dissolution system.

[0038] (4) The CGC extract of *Flammulina velutipes* was dispersed in a NaOH / catechin dissolution system at an addition rate of 3 wt%, and shaken at 200 rpm for 1 h at room temperature to promote CGC swelling. The CGC / NaOH / catechin suspension was frozen at -80℃ for 2 h, then the sample was thawed, shaken thoroughly at 200 rpm for 2 h at room temperature, and then frozen again at -80℃ for 2 h. This freeze-thaw cycle was repeated 3 times.

[0039] (5) Centrifuge the suspension in (4) at 8000 rpm for 20 min to remove undissolved precipitate, and then dialyze the solution in deionized water at room temperature for 48 h to remove NaOH, so as to obtain hydrogel-like CGC-catechin complex.

[0040] (6) The hydrogel-like CGC-catechin complex was freeze-dried to obtain CGC-catechin aerogel. The aerogel was ground and pulverized under liquid nitrogen protection to obtain edible aerogel from enoki mushroom.

[0041] Comparative Example 1: Compared with Example 1, chitin from non-Flammulina velutipes sources was used.

[0042] Commercial chitosan powder.

[0043] Comparative Example 2: Compared with Example 1, no porosity regulation was performed on the CGC.

[0044] (1) Disperse the dried enoki mushroom powder in a 1 wt% sodium hydroxide (NaOH) solution with a material-to-liquid ratio of 1 g: 50 mL. React for 3 h in a 100 ℃ water bath. Then repeat the centrifugation and washing of the precipitate until the pH is neutral.

[0045] (2) The precipitate from (1) was dispersed and soaked in a 0.2% sodium hypochlorite solution at a material-to-liquid ratio of 1 g: 20 mL. The solution was bleached at room temperature for 1 h. The precipitate was then centrifuged and washed repeatedly until the pH was neutral. The precipitate was freeze-dried and pulverized to obtain the CGC extract of Enoki mushroom.

[0046] Comparative Example 3: Compared with Example 1, aerogels were prepared by dissolving CGCs in a NaOH / urea system.

[0047] (1) Disperse the dried enoki mushroom powder in a 1 wt% sodium hydroxide (NaOH) solution with a material-to-liquid ratio of 1 g: 50 mL. React for 3 h in a 100 ℃ water bath. Then repeat the centrifugation and washing of the precipitate until the pH is neutral.

[0048] (2) Disperse and soak the precipitate from (1) in a 0.2% sodium hypochlorite solution at a material-to-liquid ratio of 1 g: 20 mL. Bleach at room temperature for 1 h. Repeat centrifugation and washing of the precipitate until the pH is neutral. Freeze-dry the precipitate to obtain the CGC extract of Enoki mushroom.

[0049] (3) Dissolve urea at a concentration of 4 wt% in a 11 wt% NaOH solution to obtain a NaOH / urea dissolution system.

[0050] (4) The CGC extract of *Flammulina velutipes* was dispersed in a NaOH / urea solution system at an addition rate of 3 wt%, and shaken at 200 rpm for 1 h at room temperature to promote CGC swelling. The CGC / NaOH / urea suspension was frozen at -80℃ for 2 h, then the sample was thawed, shaken thoroughly at 200 rpm for 2 h at room temperature, and then frozen again at -80℃ for 2 h. This freeze-thaw cycle was repeated 3 times.

[0051] (5) Centrifuge the suspension in (4) at 8000 rpm for 20 min to remove undissolved precipitate. Then, dialyze the solution in deionized water at room temperature for 48 h using an 8-12 kDa MWCO membrane to remove NaOH and urea, and obtain hydrogel-like CGC.

[0052] (6) The hydrogel-like CGC was freeze-dried to obtain CGC aerogel. The aerogel was ground and pulverized under liquid nitrogen protection to obtain edible aerogel from enoki mushroom.

[0053] The CGC extracts from *Flammulina velutipes* prepared in the embodiments and comparative examples of this invention and their aerogel testing methods are as follows: (1) Analysis of porosity The porosity, total surface area, and average pore size of CGC aerogels derived from *Flammulina velutipes* were determined using a high-performance fully automated mercury porosimeter (Micromeritics AutoPore V 9620, USA).

[0054] Table 1. Pore structure of different CGC aerogels

[0055] The results are shown in Table 1: The results showed that the porosity of each group of aerogels was above 90%. More importantly, compared with the CGC aerogel prepared by the NaOH / urea system, the CGC-polyphenol composite aerogel prepared by the NaOH / polyphenol system had higher porosity and a larger total surface area, and the average pore size of the aerogel was reduced. In the polyphenol-mediated solution system, CGC forms a high-density random polymer cross-linked structure with polyphenols through non-covalent interactions such as hydrogen bonding, ionic interactions, and hydrophobic interactions. This structure includes a strong chitin-chitin network and a weaker chitin-polyphenol network, which promotes the complexity of the aerogel pore structure and may further promote the exposure of CGC active groups. The changes in the pore size of CGC-polyphenol aerogels mediated by polyphenols can effectively enhance the physical adsorption and fixation of oils by the aerogel.

[0056] (2) Water / oil holding capacity

[0057] The method for determining the adsorption capacity of the sample for water or soybean oil is as follows: Weigh 0.05 g of sample (W1) and 5 mL of water or soybean oil into a centrifuge tube, shake at 37℃ for 1 h, take it out and centrifuge (8000 r / min, 20 min), wipe the surface water or oil with filter paper and weigh it as W2. The water / oil holding capacity of the sample is calculated by formula (1).

[0058] (1)

[0059] The results are as follows Figure 1 As shown in a and b: The results showed that, compared to commercial chitosan, CGC derived from *Flammulina velutipes* exhibited superior water and oil retention capacity due to the presence of more active groups such as hydroxyl groups. Comparing Examples 1, 2, and 3 with Comparative Example 3, it was found that the aerogelation of CGC further enhanced the water and oil adsorption capacity of the samples. More importantly, Examples 1, 2, and 3 showed better adsorption and fixation effects on oils compared to Comparative Example 3.

[0060] (3) Bile salt adsorption

[0061] Add the sample (30 mg) to a 50 mL test tube, add 3 mL of artificial gastric juice, and digest at 37 ℃ with shaking for 1 h to simulate the gastric environment. Then, add 4 mL of artificial small intestinal juice and adjust the pH to 6.3 with 0.1 M NaOH solution. Subsequently, add 4 mL of 0.3 mmol / L sodium cholate solution (prepared with 0.1 mol / L PBS buffer at pH 6.3) to each sample and digest at 37 ℃ with shaking for 1 h to simulate the intestinal environment. After the reaction is complete, centrifuge at 8000 rpm for 20 min, take 2.5 mL of supernatant and put it in a 10 mL test tube, add 7.5 mL of 60 v / v% sulfuric acid, and place the test tube in a 70 ℃ water bath for 20 min. After that, take out the sample and cool it to room temperature. Measure the absorbance at 386 nm wavelength. Use a standard curve to determine the concentration of bile salts in the sample solution. The binding capacity of bile salts is shown in formula (2). (2) In the formula, C0 is the bile salt content before the adsorption reaction, mg; C1 is the bile salt content after the adsorption reaction, mg; and m is the sample mass, g.

[0062] The results are as follows Figure 2 As shown in a: The results showed that Examples 1, 2, 3 and Comparative Example 3 possessed excellent pore structures and exhibited superior bile salt binding capacity compared to Comparative Example 2, with the bile salt binding capacity of Examples 1, 2, 3, and 3 being significantly enhanced. CGC and polyphenols adsorbed onto bile salts through electrostatic attraction, hydrophobic interactions, and hydrogen bonding. Under polyphenol-mediated adsorption, the surface active groups of the CGC-polyphenol aerogel were further exposed, synergistically capturing and immobilizing bile salt molecules within the aerogel network structure. The adsorption of bile salts by the aerogel effectively reduced lipid emulsification and digestion efficiency during digestion, thereby exerting a lipid-lowering effect.

[0063] (4) Lipase inhibition

[0064] The sample was dispersed at a concentration of 0.2 mg / mL in Tris-HCl buffer solution at pH 7 to prepare a sample solution for later use; the lipase was dispersed at a concentration of 1 mg / mL in Tris-HCl buffer solution at pH 7 to prepare a lipase solution for later use. 120 µL of sample solution and 40 µL of lipase solution were mixed and reacted at 37 °C for 15 min. Then, 140 μL of p-nitrobenzene laurate-acetonitrile solution (2 mM) was added, and the reaction was continued at 37 °C for 15 min. The absorbance value A2 was recorded at 405 nm. The only difference is that 40 µL of lipase solution was replaced with 40 µL of Tris-HCl buffer at pH 7, and the absorbance value A1 was recorded at 405 nm. The only difference is that 120 µL of sample solution was replaced with 120 µL of Tris-HCl buffer solution with pH 7, and the absorbance value A3 was recorded at 405 nm. The only difference is that 40 µL of lipase solution was replaced with 40 µL of Tris-HCl buffer at pH 7, and 120 µL of sample solution was replaced with 120 µL of Tris-HCl buffer at pH 7. The absorbance value A4 was recorded at 405 nm. Calculate the lipase inhibition rate according to formula (3): (3) The results are as follows Figure 2 As shown in b: The results showed that the inhibition rate of lipase in the examples was significantly higher than that in the control group. Pancreatic lipase is synthesized by the pancreas and secreted into the duodenum through the pancreatobiliary system. It can hydrolyze approximately 50%-70% of fat and is a key enzyme regulating lipid absorption. Studies have shown that inhibiting pancreatic lipase activity is an effective strategy to reduce the breakdown and absorption of dietary fat, thereby improving obesity. The examples exhibited a higher lipase inhibition effect, indicating that the porous structure increased the binding affinity between the sample and the enzyme by increasing the number of available active sites. In addition, dietary active polyphenols such as tannic acid, gallic acid, and catechins also possess strong lipase inhibitory capabilities. The synergistic effect of polyphenols and the aerogel porous structure can significantly enhance the lipase inhibition effect, thereby improving lipid-lowering activity.

[0065] (5) Cholesterol and lipid locking ability in water-oil system

[0066] Cholesterol-locking capacity: Fresh egg yolk liquid was homogenized into an emulsion by stirring with 9 times the volume of deionized water. Then, 0.2 g of sample was thoroughly mixed with 5 mL of egg yolk emulsion, and the pH was adjusted to 2 with glacial acetic acid. The mixture was shaken at 37°C for 2 h. Subsequently, the pH was adjusted to 7 with 0.1 M NaOH, and the mixture was shaken at 37°C for another 2 h to simulate the digestive process of the stomach and small intestine. After adsorption, the mixture was centrifuged at 5000 rpm for 20 min, and 100 μL of supernatant was mixed with 300 μL of glacial acetic acid. 1.5 mL of phthalaldehyde-glacial acetic acid reagent (phthalaldehyde concentration 1 mg / mL) was added and the mixture was reacted for 10 min. Then, 1 mL of concentrated sulfuric acid was added, and the absorbance was measured at 550 nm. The cholesterol concentration was calculated using a standard curve. The calculation method for cholesterol adsorption capacity is as shown in formula (4): (4) In the formula, C0 is the cholesterol content before the adsorption reaction, mg; C1 is the cholesterol content after the adsorption reaction, mg; and m is the sample mass, g.

[0067] Oil-in-water emulsion: A 10% w / w soybean oil / water mixture was homogenized into an oil-in-water emulsion. 0.3 g of sample was mixed with 9.7 mL of the emulsion, and 2 mL of artificial saliva was added. The mixture was shaken at 37°C for 1 min to simulate the oral administration stage. Subsequently, 10 mL of artificial gastric juice was added, and the pH was adjusted to 2.5 with 0.1 M HCl. The mixture was shaken at 37°C for 2 h to simulate the gastric digestion stage. Finally, 20 mL of artificial small intestinal juice was added to the above simulated solution, and the pH was adjusted to 7 with 0.1 M NaOH. The mixture was shaken at 37°C for 2 h. After the reaction, the solution was titrated to pH 7 with 0.25 M NaOH solution, and the volume of NaOH consumed was recorded. The fatty acid (FFA) release rate was calculated according to formula (5): (5) In the formula, V NaOH The final volume of NaOH consumed is in mL; m NaOH Molar concentration of NaOH, 0.25M; M 大豆油 The lipid molecular weight of soybean oil is 860 g / mol; W 大豆油 Initial weight of soybean oil, in grams.

[0068] The results are as follows Figure 3 As shown in a and b: The results showed that the example groups exhibited the best cholesterol adsorption effect, and the fatty acid release rate after simulated gastrointestinal digestion was lower than that of the comparative groups. Among the comparative groups, Comparative Example 3 showed better cholesterol adsorption and fat digestion inhibition effects than Comparative Examples 1 and 2. The amphiphilic CGC-polyphenol can lock lipids (oils, cholesterol, etc.) in the porous structure through physical adsorption. It can also effectively inhibit lipid digestion and absorption by disrupting the stability of the water-emulsion interface, promoting lipid aggregation and encapsulating lipids, reducing lipid emulsification and contact with lipases.

[0069] (6) Polyphenol release and antioxidant activity

[0070] Polyphenol release: 0.3 g of sample was placed in a 50 mL Erlenmeyer flask, 2 mL of artificial saliva was added, and the mixture was shaken at 37 °C for 1 min to simulate the oral administration stage; then 10 mL of artificial gastric juice was added, the pH was adjusted to 2.5 with 0.1 M HCl, and the mixture was shaken at 37 °C for 2 h to simulate the gastric digestion stage; finally, 20 mL of artificial small intestinal juice was added to the above simulated digestive solution, the pH was adjusted to 7 with 0.1 M NaOH, and the mixture was shaken at 37 °C for 2 h. The total phenol content (expressed as gallic acid equivalent) in the digestive solution at each stage was determined by the Folin-Ciocalteu method to monitor the polyphenol release from the CGC-polyphenol composite aerogel during digestion.

[0071] Antioxidant activity: The antioxidant activity of digestive juices after simulated gastric and intestinal digestion was determined using the DPPH free radical scavenging ability kit from Nanjing Jiancheng Biotechnology Institute.

[0072] The results are as follows Figure 4 As shown in a and b: The results showed that the polyphenols in the examples were gradually released during the oral, gastric, and intestinal digestion processes. After simulated gastric digestion, the free radical scavenging capacity of the simulated digestive fluid in the example groups remained above 80%, which was attributed to the gradual release of polyphenols in the samples. After simulated intestinal digestion, the free radical scavenging capacity in the digestive fluid decreased due to the large release and digestion of polyphenols. In contrast, the comparative groups did not show any antioxidant activity. The gradual release of polyphenols from CGC-polyphenol aerogel can not only synergistically inhibit lipid digestion and absorption during digestion, but also exert excellent antioxidant activity in the gastrointestinal tract, thus potentially reducing oxidative stress in vivo and synergistically improving lipid metabolism disorders.

Claims

1. A method for preparing edible aerogels derived from *Flammulina velutipes* based on polyphenol regulation, characterized in that: The preparation method includes the following steps: Step 1: Disperse the dried enoki mushroom powder in a 0.5-2wt% sodium hydroxide aqueous solution at a material-to-liquid ratio of 1 g: 20-50 mL. React in a water bath at 100-120 ℃ for 3-4 h. Then repeat the centrifugation and washing of the precipitate until the pH is neutral. Step 2: Disperse the precipitate obtained in Step 1 in a 0.2-0.5wt% sodium hypochlorite aqueous solution at a material-to-liquid ratio of 1 g: 20-30 mL, bleach at room temperature for 1-2 h, repeat centrifugation and washing of the precipitate until the pH is neutral, freeze-dry the precipitate to obtain the CGC extract of Enoki mushroom. Step 3: Dissolve the polyphenols at an addition rate of 0.2-0.4 wt% in a 10-12 wt% NaOH aqueous solution to obtain a NaOH / polyphenol dissolution system; Step 4: Disperse the CGC extract of *Flammulina velutipes* in a NaOH / polyphenol dissolution system at an addition rate of 2-5 wt%, and shake at 200-300 rpm for 1-2 h at room temperature to promote CGC swelling; freeze the resulting CGC / NaOH / polyphenol suspension at below -20°C for 2-3 h, then thaw the sample, shake thoroughly at 200-300 rpm at room temperature for 2-3 h, and freeze again at below -20°C for 2-3 h, repeating this freeze-thaw cycle 2-4 times; Step 5: After centrifuging the suspension obtained in Step 4 to remove undissolved precipitates, dialyze the solution portion in deionized water at room temperature using an 8-12 kDa MWCO membrane for 48-72 h to remove NaOH, and obtain a hydrogel-like CGC-polyphenol complex. Step 6: Freeze-dry the hydrogel-like CGC-polyphenol complex to obtain CGC-polyphenol aerogel. Grind and pulverize the CGC-polyphenol aerogel under liquid nitrogen protection to obtain edible aerogel derived from enoki mushroom.

2. The preparation method according to claim 1, characterized in that: In step 1, the concentration of the sodium hydroxide aqueous solution is 1 wt%, the material-to-liquid ratio is 1 g: 50 mL, and the reaction is carried out in a water bath at 100 ℃ for 3 h.

3. The preparation method according to claim 1, characterized in that: In step 2, the concentration of the sodium hypochlorite aqueous solution is 0.2 wt%, the material-to-liquid ratio is 1 g: 20 mL, and the bleaching is carried out at room temperature for 1 h.

4. The preparation method according to claim 1, characterized in that: In step 3, the polyphenol is tannic acid, gallic acid, or catechin.

5. The preparation method according to claim 1, characterized in that: In step 3, the amount of polyphenol added is 0.3 wt%, and the concentration of the NaOH aqueous solution is 11 wt%.

6. The preparation method according to claim 1, characterized in that: In step 4, the amount of the enoki mushroom CGC extract added is 3 wt%.

7. The preparation method according to claim 1, characterized in that: In step 4, the obtained CGC / NaOH / polyphenol suspension was frozen at -80℃ for 2 h. After that, the sample was thawed, shaken thoroughly at 200 rpm at room temperature for 2 h, and then frozen again at -80℃ for 2 h. This freeze-thaw cycle was repeated 3 times.

8. The present invention provides an edible aerogel derived from enoki mushroom prepared by the preparation method according to any one of claims 1-7.

9. The use of the edible aerogel derived from enoki mushrooms as described in claim 8 in the preparation of weight-loss drugs or dietary supplements.

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