Bacterial cellulose high-swelling-rate edible hydrogel sheet and preparation method thereof

Abstract

The invention relates to a bacterial cellulose high-swelling-rate edible hydrogel sheet and a preparation method thereof. The bacterial cellulose high-swelling-rate edible hydrogel sheet comprises bacterial cellulose, kappa-carrageenan, glucomannan and microgel composite components. The bacterial cellulose, the kappa-carrageenan and the glucomannan are compounded to construct a three-dimensional network with high strength and high porosity, so that the hydrogel sheet can be quickly swelled in gastric juice, provides satiety and is finally disintegrated into a fiber suspension which is easy to discharge. By introducing a microgel composite component constructed by beta-cyclodextrin including epsilon-polylysine, kappa-carrageenan and soya bean lecithin, multiple functions of bacteriostasis, oxidation resistance, loading of fat-soluble active components and the like are further realized, and the taste and stability of the product are remarkably improved.

Description

Technical Field

[0001] This application relates to the field of hydrogel materials, and in particular to an edible hydrogel sheet with high swelling rate of bacterial cellulose and a method for preparing the same. Background Technology

[0002] Hydrogels, as a class of functional materials with a three-dimensional network structure, possess the core characteristic of being able to absorb large amounts of water while remaining insoluble in water. This property has led to their widespread application in various fields such as agricultural water retention, food processing, and medical dressings. However, existing hydrogel products generally suffer from technical bottlenecks: most hydrogels are prepared using chemical cross-linking agents or non-food-grade substrates to meet mechanical properties or water absorption efficiency requirements, making it difficult to balance edible safety with high swelling performance. This significantly limits their application in the field of food functionalization.

[0003] With the rapid development of synthetic biology technology, the synthesis of food-grade raw materials through microbial fermentation has become a new industry trend. Among them, bacterial cellulose (BC), as a fermentation product of *Acetobacter xylinum*, is considered an ideal edible functional material substrate due to its high water content, pure natural food-grade properties, excellent biocompatibility, and three-dimensional fibrous network structure. Currently, the application forms of bacterial cellulose products on the market are relatively limited, mainly concentrated in coconut jelly granules (for improved taste) or food thickeners (for enhanced system stability). The potential of its unique three-dimensional fibrous network structure in terms of "high swelling function" has not yet been explored, and there are no highly swelling edible hydrogel products prepared with bacterial cellulose as the core substrate, indicating a significant market gap and technological challenge. Summary of the Invention

[0004] To address the aforementioned issues, this application provides an edible hydrogel sheet with high swelling rate of bacterial cellulose and its preparation method.

[0005] In the first aspect, this application provides an edible hydrogel sheet with a high swelling rate of bacterial cellulose, which adopts the following technical solution: An edible hydrogel sheet with high swelling rate of bacterial cellulose, comprising bacterial cellulose, κ-carrageenan, glucomannan and microgel composite components.

[0006] By adopting the above technical solution, a novel bacterial cellulose hydrogel tablet product is prepared by combining glucomannan, κ-carrageenan, bacterial cellulose, and microgel composite components. After consumption, the bacterial cellulose hydrogel tablet can quickly absorb water and swell, providing a feeling of fullness. Under the action of gastric juice, the bacterial cellulose hydrogel tablet is finally dispersed into a fiber suspension for easy excretion. After providing a feeling of fullness, this product can reduce the amount of food consumed, thereby controlling weight, promoting bowel movements, regulating blood sugar and blood lipids, and protecting the gastric mucosa. The addition of microgel composite components also improves the taste.

[0007] Preferably, the mass ratio of bacterial cellulose, κ-carrageenan and glucomannan is 1:(2.8-3.2).

[0008] By adopting the above technical solution, the mass ratio between bacterial cellulose, κ-carrageenan and glucomannan is preferably within the above range. The rigid gel properties of κ-carrageenan and the thickening and synergistic effect between glucomannan are balanced, and the resulting hydrogel network structure is stable and uniform with a consistent swelling rate. It can also give the gel sheet good mechanical strength, thereby making the prepared hydrogel sheet have a good taste.

[0009] Preferably, the product also includes a microgel composite component, wherein the raw materials of the microgel composite component include a κ-carrageenan composite component and soybean lecithin, and the raw materials of the κ-carrageenan composite component include β-cyclodextrin, κ-carrageenan and ε-polylysine.

[0010] By adopting the above technical solution, the κ-carrageenan composite component serves as a carrier, and soybean lecithin, a natural amphiphilic molecule, plays a good stabilizing role. The combination of the two can construct and encapsulate water-soluble and oil-soluble components, and has good interfacial activity, thereby improving the overall stability of the system. The κ-carrageenan composite component is prepared by β-cyclodextrin, κ-carrageenan and ε-polylysine. β-cyclodextrin encapsulates ε-polylysine, thereby improving the stability of ε-polylysine and enabling ε-polylysine to have a controllable release effect.

[0011] Preferably, the κ-carrageenan composite component is prepared by the following method: β-Cyclodextrin was mixed with water to obtain a β-cyclodextrin solution. Ethanol was mixed with ε-polylysine to obtain an ε-polylysine solution. The ε-polylysine solution was added to the β-cyclodextrin solution, stirred and mixed, and then subjected to ultrasonic treatment. Finally, it was freeze-dried to obtain an antibacterial inclusion complex powder. κ-Carrageenan was mixed with water to obtain a κ-carrageenan solution. β-Cyclodextrin, the antibacterial inclusion complex powder and the carrageenan solution were mixed, stirred, and then glycerol was added. Stirring was continued to obtain a κ-carrageenan complex component.

[0012] By adopting the above technical solution, when β-cyclodextrin is used to encapsulate ε-polylysine, the ε-polylysine is adsorbed to reduce the oxidation and volatilization of ε-polylysine, thereby improving the stability of the prepared hydrogel sheet. Glycerol is also added during the preparation process, which further improves the flexibility of κ-carrageenan and enhances its compatibility with soybean lecithin, further improving the stability of the edible hydrogel sheet.

[0013] Preferably, the mass ratio of β-cyclodextrin to ε-polylysine in the antibacterial inclusion complex powder is 1:(0.11-0.13).

[0014] By adopting the above technical solution, and optimizing the mass ratio between β-cyclodextrin and ε-polylysine within the above range, the encapsulation efficiency of β-cyclodextrin can be effectively improved, and ε-polylysine can play a sufficient antibacterial role without affecting the gel network structure, so that the prepared κ-carrageenan complex has good stability and antibacterial properties.

[0015] Preferably, in the κ-carrageenan composite component, the mass ratio between the antibacterial inclusion complex and κ-carrageenan is 1:(1.22-1.32).

[0016] By adopting the above technical solution, the mass ratio between the antibacterial inclusion complex and κ-carrageenan is preferably within the above range, so that the antibacterial inclusion complex can be fully encapsulated and fixed by a sufficient amount of κ-carrageenan. Furthermore, the cross-linking effect of κ-carrageenan can enhance the stability between the various components in the κ-carrageenan composite component. At the same time, it forms a porous gel network with bacterial cellulose and glucomannan, which can play a good role in antibacterial activity and enhance antioxidant activity without affecting the high swelling capacity of the hydrogel.

[0017] Preferably, the microgel composite component is prepared by the following method: Soybean lecithin was mixed with water to obtain a soybean lecithin solution. κ-carrageenan complex was added, stirred, allowed to stand, dried, cooled, washed to remove free lipids, and dried again to obtain a mixture. κ-carrageenan, guar gum, and water were mixed, freeze-dried, and a microgel was obtained. The microgel, mixture, and water were mixed, sheared, soybean oil was added, and sheared again to obtain the microgel complex.

[0018] By adopting the above technical solution, soybean lecithin and κ-carrageenan composite components are mixed to form a mixture with emulsifying and antibacterial functions. The microgel prepared by compounding kerogen and κ-carrageenan has a good three-dimensional network structure and acts as a stabilizer for Pickering emulsion. It is adsorbed at the oil-water interface. After shearing treatment, the mixture is fully dispersed with soybean oil to form a Pickering emulsion. After drying, the soybean oil leaves porous channels, which can synergistically enhance the swelling rate of the hydrogel with the fibrous network structure of bacterial cellulose.

[0019] Preferably, the mass ratio of the mixture to the microgel is 1:(0.3-0.5).

[0020] By adopting the above technical solution, and preferably within the above range the mass ratio between the mixture and the microgel, the prepared microgel composite component has good stability. The soybean lecithin and κ-carrageenan composite component in the mixture provides the basis for emulsification and antibacterial properties, while the microgel provides structural support. The two are synergistically adsorbed at the oil-water interface, thereby forming a stable layer and improving the stability of the Pickering emulsion system.

[0021] Preferably, the soybean lecithin solution in the mixture has a mass concentration of 4.8-5.6%.

[0022] By adopting the above technical solution, the mass concentration of soybean lecithin in the preferred soybean lecithin solution is within the above range, which allows the soybean lecithin to be fully dissolved and form a uniform solution. It can also effectively improve the interfacial tension between the κ-carrageenan composite component and the aqueous / oil phase, so as to promote the uniform dispersion of each component. At the same time, the emulsification effect is sufficient, the emulsion is uniformly dispersed, and it can be thoroughly stirred. Furthermore, it reduces the residue of soybean lecithin in the system, thereby further improving the stability of the prepared hydrogel sheet.

[0023] Secondly, this application provides a method for preparing edible hydrogel sheets with high swelling ratio of bacterial cellulose, using the following technical solution: A method for preparing an edible hydrogel sheet with high swelling ratio of bacterial cellulose includes the following steps: Bacterial cellulose is mixed with water and subjected to cell wall disruption treatment, followed by filling and sterilization to obtain a fermented fiber beverage. The fermented fiber beverage, κ-carrageenan, and glucomannan are mixed to obtain a fiber suspension, which is then dried after standing to obtain bacterial cellulose hydrogel sheets.

[0024] In summary, this application includes at least one of the following beneficial technical effects: By combining bacterial cellulose, κ-carrageenan and glucomannan, a stable three-dimensional network structure was prepared, which enabled the hydrogel tablets to swell rapidly and significantly in gastric juice after consumption, providing an immediate feeling of fullness. The resulting fiber suspension is easy to excrete, and while reducing food intake and helping to control weight, it has the potential health benefits of regulating blood sugar and blood lipids and protecting the gastric mucosa. The introduction of a microgel complex composed of κ-carrageenan and soybean lecithin enables the product to maintain high swelling capacity while achieving a more uniform and stable gel network and better texture, and realizes efficient encapsulation and loading of water-soluble and fat-soluble functional ingredients. By using β-cyclodextrin to encapsulate ε-polylysine and combining it with Pickering emulsion technology, a sustained-release and stable system was prepared. This not only improved the product's stability but also further enhanced its oxidative stability, antibacterial durability, and swelling rate through the composite structure of microgel and Pickering emulsion, thus comprehensively improving the product's functionality and storage stability. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments: Raw material description: All raw materials in the examples are commercially available; bacterial cellulose was selected as Acetobacter xylinum cellulose. Example 1

[0026] Preparation of edible hydrogel sheets with high swelling ratio of bacterial cellulose: Bacterial cellulose was mixed with purified water at a mass ratio of 1:1 and subjected to cell disruption at 11kW for 3 minutes. After filling, it was sterilized at 121℃ and 0.12MPa for 15 minutes and cooled to room temperature to obtain a fermented fiber beverage. κ-carrageenan (CAS No.: 9000-07-1), glucomannan (CAS No.: 11078-31-2), and purified water were mixed to obtain a premix. The mass concentration of κ-carrageenan in the premix was 0.8%, and the mass concentration of glucomannan was 0.3%. The fermented fiber beverage and the premix were mixed at a mass ratio of 1:3 to obtain a fiber suspension. After standing at 25℃ for 2 hours, the suspension was dried to obtain bacterial cellulose hydrogel sheets. Example 2

[0027] Preparation of κ-carrageenan composite components: 4.5 g of β-cyclodextrin (CAS No.: 7585-39-9) was mixed with 100 g of deionized water to obtain a β-cyclodextrin solution. 0.5 g of ε-polylysine (CAS No.: 28211-04-3) was mixed with 0.5 g of anhydrous ethanol to obtain an ε-polylysine solution. The ε-polylysine solution was added to the β-cyclodextrin solution, the mixture was heated to 60 °C, magnetically stirred for 3 h, then sonicated for 20 min, and finally freeze-dried in a freeze-drying oven at -80 °C for 48 hours. h, to obtain antibacterial inclusion complex powder; mix 2.75g of κ-carrageenan with 90g of water, heat to 80℃ and stir for 1h to obtain κ-carrageenan solution, add 2.25g of antibacterial inclusion complex powder and 3g of β-cyclodextrin to κ-carrageenan solution, stir at 60℃ for 30min, then add 15g of glycerol (CAS No.: 56-81-5), maintain the temperature and continue stirring for 30min, dry in an oven at 40℃ for 6h to obtain κ-carrageenan composite component.

[0028] Preparation of microgel composite components: Soybean lecithin (CAS No.: 8002-43-5) was mixed with water to obtain a 5g soybean lecithin solution with a mass concentration of 4.8%. 5g of κ-carrageenan was added to the soybean lecithin solution, and the mixture was stirred for 20 minutes until homogeneous. The mixture was then allowed to stand in a refrigerator at 4°C for 12 hours, followed by drying in an oven at 100°C for 4 hours. After naturally cooling to 25°C, the mixture was washed three times with anhydrous ethanol to remove free lipids, dried at 45°C, and ground to obtain a mixture. κ-carrageenan and curdlan gum (CAS No.: 54724-00-) were then mixed... 4) A two-gel system was obtained by mixing 2.78g of the two-gel system with 30g of deionized water. Then, 6.94g of the mixture and 0.28g of κ-carrageenan composite component were added. The mixture was heated in a water bath at 90℃ for 20min, then frozen in a freezer at -18℃ for 30min, and then sheared at 18000rpm for 4min to obtain microgels. The microgels were mixed with 3g of soybean oil and sheared at 14000rpm for 2min to obtain microgel composite components.

[0029] Preparation of edible hydrogel sheets with high swelling ratio of bacterial cellulose: Bacterial cellulose was mixed with purified water at a mass ratio of 1:1 and subjected to cell disruption at 11 kW for 3 minutes. After filling, it was sterilized at 121℃ and 0.12 MPa for 15 minutes and cooled to room temperature to obtain a fermented fiber beverage. κ-carrageenan, glucomannan, and microgel composite components were mixed with purified water to obtain a premix. The mass concentration of κ-carrageenan in the premix was 1.2%, the mass concentration of glucomannan was 0.5%, and the mass concentration of the microgel composite component was 0.5%. The fermented fiber beverage and the premix were mixed at a mass ratio of 1:3 to obtain a fiber suspension. After standing at 25℃ for 2 hours, it was dried to obtain bacterial cellulose hydrogel sheets. Example 3

[0030] Preparation of κ-carrageenan composite components: 4.42 g of β-cyclodextrin was mixed with 100 g of deionized water to obtain a β-cyclodextrin solution. 0.58 g of ε-polylysine was mixed with 0.5 g of anhydrous ethanol to obtain an ε-polylysine solution. The ε-polylysine solution was added to the β-cyclodextrin solution, heated to 60 °C, and magnetically stirred for 3 h. Then, the mixture was sonicated for 20 min and finally freeze-dried in a freeze-drying oven at -80 °C for 48 h to obtain an antibacterial inclusion complex powder. 2.84 g of κ-carrageenan was mixed with 90 g of water, heated to 80 °C, and stirred for 1 h to obtain a κ-carrageenan solution. 2.16 g of the antibacterial inclusion complex powder and 3 g of β-cyclodextrin were added to the κ-carrageenan solution, stirred at 60 °C for 30 min, then 15 g of glycerol was added. The temperature was maintained and stirring continued for 30 min. The mixture was dried in an oven at 40 °C for 6 h to obtain the κ-carrageenan composite component.

[0031] Preparation of microgel composite components: Soybean lecithin was mixed with water to obtain a 5g soybean lecithin solution with a mass concentration of 5.6%. 5g of κ-carrageenan was added to the soybean lecithin solution, and the mixture was stirred for 20 minutes until homogeneous. The solution was then allowed to stand in a refrigerator at 4°C for 12 hours, followed by drying in an oven at 100°C for 4 hours. After naturally cooling to 25°C, the mixture was washed three times with anhydrous ethanol to remove free lipids, dried at 45°C, and ground to obtain a mixture. κ-carrageenan and curdlan gum were then mixed at a mass ratio of 3:1 to obtain... To obtain the two-gel system, 2.74g of the two-gel system was mixed with 30g of deionized water. Then, 6.85g of the mixture and 0.41g of κ-carrageenan composite component were added. The mixture was heated in a water bath at 90℃ for 20min, then frozen in a freezer at -18℃ for 30min, and then sheared at 18000rpm for 4min to obtain microgels. The microgels were mixed with 3g of soybean oil and then sheared at 14000rpm for 2min to obtain the microgel composite component.

[0032] Preparation of edible hydrogel sheets with high swelling ratio of bacterial cellulose: Bacterial cellulose was mixed with purified water at a mass ratio of 1:1 and subjected to cell disruption at 11 kW for 3 minutes. After filling, it was sterilized at 121℃ and 0.12 MPa for 15 minutes and cooled to room temperature to obtain a fermented fiber beverage. κ-carrageenan, glucomannan, and microgel composite components were mixed with purified water to obtain a premix. The mass concentration of κ-carrageenan in the premix was 1%, the mass concentration of glucomannan was 0.4%, and the mass concentration of the microgel composite component was 2%. The fermented fiber beverage and the premix were mixed at a mass ratio of 1:3 to obtain a fiber suspension. After standing at 25℃ for 2 hours, it was dried to obtain bacterial cellulose hydrogel sheets. Example 4

[0033] Preparation of κ-carrageenan composite components: 4.46 g of β-cyclodextrin was mixed with 100 g of deionized water to obtain a β-cyclodextrin solution. 0.54 g of ε-polylysine was mixed with 0.5 g of anhydrous ethanol to obtain an ε-polylysine solution. The ε-polylysine solution was added to the β-cyclodextrin solution, heated to 60 °C, and magnetically stirred for 3 h. Then, the mixture was sonicated for 20 min and finally freeze-dried in a freeze-drying oven at -80 °C for 48 h to obtain an antibacterial inclusion complex powder. 2.8 g of κ-carrageenan was mixed with 90 g of water, heated to 80 °C, and stirred for 1 h to obtain a κ-carrageenan solution. 2.2 g of the antibacterial inclusion complex powder and 3 g of β-cyclodextrin were added to the κ-carrageenan solution, stirred at 60 °C for 30 min, then 15 g of glycerol was added. The temperature was maintained and stirring continued for 30 min. The mixture was dried in an oven at 40 °C for 6 h to obtain the κ-carrageenan composite component.

[0034] Preparation of microgel composite components: Soybean lecithin was mixed with water to obtain a 5g soybean lecithin solution with a mass concentration of 5.2%. 5g of κ-carrageenan was added to the soybean lecithin solution, and the mixture was stirred for 20 minutes until homogeneous. The solution was then allowed to stand in a refrigerator at 4°C for 12 hours, followed by drying in an oven at 100°C for 4 hours. After naturally cooling to 25°C, the mixture was washed three times with anhydrous ethanol to remove free lipids, dried at 45°C, and ground to obtain a mixture. κ-carrageenan and curdlan gum were then mixed at a mass ratio of 3:1 to obtain... To obtain the two-gel system, 2.76g of the two-gel system was mixed with 30g of deionized water. Then, 6.9g of the mixture and 0.34g of κ-carrageenan composite component were added. The mixture was heated in a water bath at 90℃ for 20min, then frozen in a freezer at -18℃ for 30min, and then sheared at 18000rpm for 4min to obtain microgels. The microgels were mixed with 3g of soybean oil and then sheared at 14000rpm for 2min to obtain the microgel composite component.

[0035] Preparation of edible hydrogel sheets with high swelling ratio of bacterial cellulose: Bacterial cellulose was mixed with purified water at a mass ratio of 1:1 and subjected to cell disruption at 11 kW for 3 minutes. After filling, it was sterilized at 121℃ and 0.12 MPa for 15 minutes and cooled to room temperature to obtain a fermented fiber beverage. κ-carrageenan, glucomannan, and microgel composite components were mixed with purified water to obtain a premix. The mass concentration of κ-carrageenan in the premix was 1%, the mass concentration of glucomannan was 0.4%, and the mass concentration of the microgel composite component was 1.2%. The fermented fiber beverage and the premix were mixed at a mass ratio of 1:3 to obtain a fiber suspension. After standing at 25℃ for 2 hours, it was dried to obtain bacterial cellulose hydrogel sheets. Example 5

[0036] Example 5 is based on Example 4. In Example 5, when preparing the antibacterial inclusion complex, the amount of β-cyclodextrin added is 4.63g and the amount of ε-polylysine added is 0.37g. Example 6

[0037] Example 6 is based on Example 4. In Example 6, when preparing the antibacterial inclusion complex, the amount of β-cyclodextrin added is 4.31g and the amount of ε-polylysine added is 0.69g. Example 7

[0038] Example 7 is based on Example 4. In Example 7, when preparing the κ-carrageenan composite component, the antibacterial inclusion complex used was 2.5g and the κ-carrageenan was 2.5g. Example 8

[0039] Example 8 is based on Example 4. In Example 8, when preparing the κ-carrageenan composite component, the antibacterial inclusion complex used was 1.92 g and the κ-carrageenan was 3.08 g. Example 9

[0040] Example 9 is based on Example 4. In Example 9, when preparing the microgel composite component, the mixture used was 7.04g, the two-gel system was 2.82g, and the κ-carrageenan composite component was 0.14g. Example 10

[0041] Example 10 is based on Example 4. In Example 10, when preparing the microgel composite component, the mixture used was 6.67g, the two-gel system was 2.66g, and the κ-carrageenan composite component was 0.67g. Example 11

[0042] Example 11 is based on Example 4. In Example 11, the concentration of soybean lecithin in the soybean lecithin solution is 4% when preparing the microgel composite component. Example 12

[0043] Example 12 is based on Example 4. In Example 12, when preparing the microgel composite component, the concentration of soybean lecithin in the soybean lecithin solution is 6.5%. Example 13

[0044] Example 13 is based on Example 4, but no κ-carrageenan composite component was added when preparing the microgel composite component in Example 13.

[0045] Comparative Example 1 Comparative Example 1 is based on Example 1, but no κ-carrageenan was added when preparing the edible hydrogel sheet in Comparative Example 1.

[0046] Comparative Example 2 Comparative Example 2 is based on Example 1, in which no glucomannan was added during the preparation of the edible hydrogel sheet.

[0047] Performance testing The following performance tests were performed on the samples of Examples 1-13 and Comparative Examples 1-2: (1) Hardness The hardness of the samples was tested with reference to GB / T 34790-2017. Each sample was tested three times, and the average value was taken. The test results were recorded in Table 1.

[0048] (2) Swelling water absorption rate Place the sample in water for 48 hours and test the swelling volume ratio of the sample. Test each sample 3 times, take the average value, and fill in the test results in Table 1.

[0049] (3) Decomposition time (4) Antibacterial properties The antibacterial properties of the samples were tested with reference to GB / T 21510-2008. Escherichia coli was used as the test object. Each sample was tested 3 times, and the average value was taken. The test results were recorded in Table 1.

[0050] Table 1 Performance test results of Examples 1-13 and Comparative Examples 1-2

[0051] As shown in Table 1, the hardness of Examples 1-4 was between 1.0 and 1.5, the swelling water absorption rate was between 119.6 and 141.4 times, and the decomposition time was between 2.5 and 3.5 hours. This indicates that adjusting the ratio of glucomannan and κ-carrageenan can regulate the hardness, swelling water absorption rate, and decomposition time of the edible hydrogel sheets. The antibacterial rate of Examples 2-4 was 95% or higher, indicating that the edible hydrogel sheets prepared after adding the microgel composite component have good antibacterial properties.

[0052] In Examples 5 and 6, the mass ratio of β-cyclodextrin to ε-polylysine during the preparation of the antibacterial inclusion complex was not within the range specified in this application. When the amount of ε-polylysine added was too small and the amount of β-cyclodextrin was too large, the excess β-cyclodextrin existed in a free state, competing with the hydroxyl groups of κ-carrageenan and glucomannan for hydrogen bonds, and filled the gaps in the cross-linking network, blocking the porous channels of the Pickering emulsion, resulting in insufficient cross-linking and affecting the antibacterial rate. When there was too much ε-polylysine and too little β-cyclodextrin, the encapsulation rate of ε-polylysine was insufficient, and the agglomerated oil droplets blocked the interfiber gaps of bacterial cellulose, resulting in poor gel network stability and partial decomposition. Therefore, the performance of Examples 5 and 6 was reduced.

[0053] In Examples 7 and 8, the mass ratio between the antibacterial inclusion complex and κ-carrageenan during the preparation of the κ-carrageenan composite was not within the range specified in this application. When the amount of κ-carrageenan used was too small, it was difficult to encapsulate and fix all the inclusion complex particles, causing the inclusion complex particles to agglomerate, reducing the interfacial stability of the system, forming irregular particles, and affecting the long-term antibacterial performance. When the amount of κ-carrageenan used was too large, the resulting matrix was denser and excessively constrained the inclusion complex. This reduced the interfacial compatibility when it subsequently bound to lecithin, limited the swelling rate, prolonged the decomposition time, and delayed and reduced the antibacterial performance.

[0054] In Examples 9 and 10, when preparing the microgel composite components, if the amount of κ-carrageenan composite component used was too low, the particle distribution was sparse, the swelling was slow, and it acted as an inert filler in the system, resulting in a decrease in decomposition time and antibacterial performance. If the amount of κ-carrageenan composite component used was too high, it interfered with the formation of the network of the two-gel system, occupied too much of the interface, and due to the presence of hydrophilic inclusion complexes, the water absorption and swelling rate increased, but the stability was poor, it quickly disintegrated in the stomach, and the long-term antibacterial performance was affected.

[0055] In Examples 11 and 12, the concentration of soybean lecithin in the soybean lecithin solution was not within the range specified in this application. When the concentration of soybean lecithin was too low, it was difficult to form a stable and strong interfacial film, the overall particle strength decreased, hindering water penetration and swelling, and the fragile interfacial film was quickly destroyed in the stomach, accelerating the decomposition time and reducing stability, thus affecting the overall antibacterial performance of the system. When the concentration of soybean lecithin was too high, micelles formed in the interfacial layer, the fluidity decreased, and brittleness occurred, hindering water penetration, reducing the swelling rate, and affecting both the decomposition rate and antibacterial performance.

[0056] In Example 13, no κ-carrageenan composite component was added during the preparation of the microgel composite component. The microgel composite component lacked cross-linking sites and rigid support, making it difficult to further enhance the filler and achieve good antibacterial properties.

[0057] In Comparative Example 1, no κ-carrageenan was added during the preparation of the edible hydrogel sheet. Cross-linking was achieved only through hydrogen bonds of glucomannan, making it difficult to form a stable three-dimensional structure. As a result, the hardness decreased, and the product collapsed and deformed. The loose gel network was quickly digested in gastric juice, and microorganisms were easily attached, leading to a decrease in antibacterial properties.

[0058] In Comparative Example 2, no glucomannan was added during the preparation of the edible hydrogel sheet. The κ-carrageenan ions were over-crosslinked, resulting in a dense but fragile gel network. Water could not easily penetrate into the gel, leading to insufficient water absorption capacity. Furthermore, the gel was difficult to be broken down by gastric digestive enzymes, resulting in a prolonged residence time in the body and easy invasion by microorganisms.

[0059] This specific embodiment is merely an explanation of this application and is not intended to limit it. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification but must be determined according to the scope of the claims.

Claims

1. An edible hydrogel sheet with high swelling rate of bacterial cellulose, characterized in that: It includes bacterial cellulose, κ-carrageenan, and glucomannan.

2. The edible hydrogel sheet with high swelling rate of bacterial cellulose according to claim 1, characterized in that: The mass ratio of bacterial cellulose, κ-carrageenan and glucomannan is 1:(2.8-3.2).

3. The edible hydrogel sheet with high swelling rate of bacterial cellulose according to claim 1, characterized in that: It also includes a microgel composite component, the raw materials of which include κ-carrageenan composite component and soybean lecithin, the raw materials of which include β-cyclodextrin, κ-carrageenan and ε-polylysine.

4. The edible hydrogel sheet with high swelling rate of bacterial cellulose according to claim 3, characterized in that: The κ-carrageenan composite component was prepared by the following method: β-Cyclodextrin was mixed with water to obtain a β-cyclodextrin solution. Ethanol was mixed with ε-polylysine to obtain an ε-polylysine solution. The ε-polylysine solution was added to the β-cyclodextrin solution, stirred and mixed, and then subjected to ultrasonic treatment. Finally, it was freeze-dried to obtain an antibacterial inclusion complex powder. κ-Carrageenan was mixed with water to obtain a κ-carrageenan solution. β-Cyclodextrin, the antibacterial inclusion complex powder and the carrageenan solution were mixed, stirred, and then glycerol was added. Stirring was continued to obtain a κ-carrageenan complex component.

5. The edible hydrogel sheet with high swelling rate of bacterial cellulose according to claim 4, characterized in that: In the antibacterial inclusion complex powder, the mass ratio between β-cyclodextrin and ε-polylysine is 1:(0.11-0.13).

6. The edible hydrogel sheet with high swelling ratio of bacterial cellulose according to claim 4, characterized in that: In the κ-carrageenan composite component, the mass ratio between the antibacterial inclusion complex and κ-carrageenan is 1:(1.22-1.32).

7. The edible hydrogel sheet with high swelling rate of bacterial cellulose according to claim 3, characterized in that: The microgel composite component was prepared using the following method: Soybean lecithin was mixed with water to obtain a soybean lecithin solution. κ-carrageenan complex was added, stirred, allowed to stand, dried, cooled, washed to remove free lipids, and dried again to obtain a mixture. κ-carrageenan, guar gum, and water were mixed, freeze-dried, and a microgel was obtained. The microgel, mixture, and water were mixed, sheared, soybean oil was added, and sheared again to obtain the microgel complex.

8. The edible hydrogel sheet with high swelling ratio of bacterial cellulose according to claim 7, characterized in that: The mass ratio of the mixture, the dual-gum system, and the κ-carrageenan composite component is 1:0.4:(0.04-0.06).

9. The edible hydrogel sheet with high swelling ratio of bacterial cellulose according to claim 7, characterized in that: In the mixture, the soybean lecithin solution has a soybean lecithin mass concentration of 4.8-5.6%.

10. A method for preparing the edible hydrogel sheet with high swelling ratio of bacterial cellulose as described in claim 1, characterized in that: Includes the following steps: Bacterial cellulose is mixed with water and subjected to cell wall disruption treatment, followed by filling and sterilization to obtain a fermented fiber beverage. The fermented fiber beverage, κ-carrageenan, and glucomannan are mixed to obtain a fiber suspension, which is then dried after standing to obtain bacterial cellulose hydrogel sheets.

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