Oil-absorbing edible aerogel based on micro-nano bubbles, and preparation method therefor and use thereof

Abstract

Disclosed in the present invention are an oil-absorbing edible aerogel based on micro-nano bubbles, and a preparation method therefor and the use thereof. The method comprises the following steps: (1) separately adding a regenerated silk fibroin and a gelling agent into water containing micro-nano bubbles, so as to obtain a regenerated silk fibroin solution and a gelling agent solution; and (2) uniformly mixing the regenerated silk fibroin solution and the gelling agent solution, and transferring the mixture to a mold for freeze-drying, so as to obtain the oil-absorbing edible aerogel. The oil-absorbing edible aerogel of the present invention has a porous structure, exhibits an excellent oil absorption rate and oil absorption capacity, and has broad application prospects in the fields of food products, materials, etc.

Description

Oil-absorbing edible aerogel based on micro / nano bubbles, its preparation method and application Technical Field

[0001] This invention relates to the field of aerogel technology, and in particular to an oil-absorbing edible aerogel based on micro-nano bubbles, its preparation method, and its application. Background Technology

[0002] Plastic fats (such as margarine and shortening) are widely used in the food industry due to their ideal texture, stability, and spreadability. However, plastic fats typically contain high levels of saturated and trans fatty acids, and long-term consumption may increase the risk of cardiovascular disease, obesity, and metabolic syndrome. With increasing demands for food safety and nutritional value, developing nutritious and healthy alternatives to plastic fats is of great significance. Against this backdrop, the solidification of liquid vegetable oils into oleogels to replace traditional plastic fats has gained increasing attention.

[0003] The construction of oleogels mainly involves two methods: direct and indirect methods. Most natural biopolymers are hydrophilic and difficult to disperse directly in oil; therefore, the indirect method is commonly used for oleogels. Indirect methods for oleogels can be further divided into emulsion template methods, foam template methods, solvent exchange methods, and aerogel template methods. Aerogels, due to their unique three-dimensional network structure, high specific surface area, and porosity, possess excellent oil absorption capacity, making them an ideal template material for oleogels. Chinese patent CN114586969A discloses an oleogel prepared using whey protein isolate and carboxymethyl chitosan as raw materials via an aerogel template method, which exhibits high mechanical strength and antioxidant capacity. Chinese patent CN118203113A discloses a method for preparing Antarctic krill oleogels by combining aerogel template methods and capillary suspensions. The oleogels obtained by this method are stable and biodegradable, making them ideal carriers for active substances. Cui Mengqi et al. (Cui Mengqi, Shan Guancheng, Sun Ruohan, et al. Properties of Soybean Protein-Fortified Sodium Carboxymethyl Cellulose Composite Oil Gel. Food Science) prepared sodium carboxymethyl cellulose / soy protein isolate composite aerogel through electrostatic interaction, which formed a highly elastic and high-strength oil gel after being impregnated with sunflower seed oil.

[0004] Although existing biomass aerogels have made some progress in the preparation of oleogels, some limitations still exist. Generally speaking, common aerogels have slow oil absorption rates due to their non-uniform pore structure, and their preparation methods are complex and costly, which limits their feasibility in the efficient preparation of oleogels and sustainable development applications. Summary of the Invention

[0005] This invention provides an oil-absorbing edible aerogel based on micro-nano bubbles and its preparation method. The aerogel has a porous structure and exhibits excellent oil absorption rate and oil absorption capacity.

[0006] The technical solution of the present invention is as follows:

[0007] A method for preparing an oil-absorbing edible aerogel based on micro / nanobubbles includes the following steps:

[0008] (1) Regenerated silk fibroin and gelling agent were added to water containing micro-nano bubbles respectively to obtain regenerated silk fibroin solution and gelling agent solution;

[0009] (2) Mix the regenerated silk fibroin solution and gelling agent solution evenly, transfer them to a mold for freeze drying, and obtain the oil-absorbing edible aerogel.

[0010] Micro- and nanobubbles, characterized by their small diameter, large specific surface area, and high absolute zeta potential, are widely used in surface cleaning, drug delivery, and nanomaterials. This invention generates micro- and nanobubbles during the aerogel preparation process, creating more open pores within the aerogel and thus improving the material's oil absorption rate and capacity. Furthermore, this invention utilizes micro- and nanobubble technology to optimize the aerogel's pore structure without requiring chemical modification or cross-linking, reducing the impact on the material's biocompatibility and better meeting the demand for environmentally friendly materials.

[0011] Preferably, the method for preparing regenerated silk fibroin includes:

[0012] The degummed silk fibroin was mixed with a ternary solution of CaCl2 / H2O / C2H5OH and heated at 80-100℃ to dissolve it in salt, thus obtaining a salt solution.

[0013] Centrifuge the salt solution and collect the supernatant; transfer the supernatant to a dialysis bag for dialysis, collect the dialysis fluid and freeze-dry it to obtain regenerated silk fibroin.

[0014] Preferably, in the ternary solution of CaCl2:H2O:C2H5OH, the molar ratio of CaCl2, H2O, and C2H5OH is 1:8:2; and the mass ratio of silk fibroin to the ternary solution of CaCl2:H2O:C2H5OH is 1:5-20.

[0015] Preferably, in water containing micro- and nano-bubbles, the average diameter of the micro- and nano-bubbles is 270-300 nm.

[0016] Micro- and nano-bubbles are generated using the gyratory shearing method.

[0017] Preferably, a micro-nano bubble generator is used to generate micro-nano bubbles in distilled water; the micro-nano bubble generator operates for 5-20 minutes, the water pump power is 500-1000W, and after stopping, it is allowed to stand until the liquid becomes clear to obtain water containing micro-nano bubbles.

[0018] Preferably, in step (1), the concentration of regenerated silk fibroin in the regenerated silk fibroin solution is 1-10%; and the concentration of gelling agent in the gelling agent solution is 1-5%.

[0019] The gelling agent is a polysaccharide or protein, preferably chitosan.

[0020] Preferably, the regenerated silk fibroin solution and the gelling agent solution are mixed in a volume ratio of 1:0.5-2.

[0021] The present invention also provides an oil-absorbing edible aerogel based on micro-nano bubbles prepared by the above preparation method.

[0022] The present invention also provides the application of the oil-absorbing edible aerogel in the preparation of oleogel, comprising: immersing the oil-absorbing edible aerogel in vegetable oil, and after the absorption is balanced, removing the excess vegetable oil on the surface to obtain oleogel.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) In this invention, the pore structure of the aerogel is adjusted by micro-nano bubble technology during the preparation process. Currently, there are no reports on increasing the aerogel flux by introducing micro-nano bubbles in the field of aerogel template preparation of olegels. Therefore, this invention opens up new possibilities for the scientific research and practical application of micro-nano bubble technology in the high-throughput preparation of olegels.

[0025] (2) The preparation method of the edible aerogel of the present invention is simple and the reaction conditions are mild. It has excellent rapid oil absorption performance and does not produce additional environmental pollutants. It conforms to the concept of green and sustainable development and has broad application prospects in the fields of food and materials. Attached Figure Description

[0026] Figure 1 shows the zeta potential diagrams of distilled water and micro / nano bubble water.

[0027] Figure 2 shows the particle size distribution of distilled water and micro / nano bubble water.

[0028] Figure 3 shows SEM images of the regenerated silk fibroin-chitosan aerogels prepared in Examples 1-3 and Comparative Examples 1-3, respectively. A-C represent Comparative Examples 1-3, and D-F represent Examples 1-3.

[0029] Figure 4 shows images of the Sudan Red staining and oil absorption process of the regenerated silk fibroin-chitosan aerogels prepared in Examples 1-3 and Comparative Examples 1-3.

[0030] Figure 5 shows the oil holding capacity of the regenerated silk fibroin-chitosan aerogels prepared in Examples 1-3 and Comparative Examples 1-3. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and do not limit it in any way.

[0032] Test Method 1: zeta potential

[0033] The zeta potential of distilled water and water treated with micro / nano bubble technology was measured using a nanoparticle size potentiometer.

[0034] Test Method 2: Particle Size

[0035] The particle size of distilled water and water treated with micro / nano bubble technology were measured using a nanoparticle size potentiometer.

[0036] Test Method 3: SEM

[0037] A uniform area was cut out, fixed to the sample stage with conductive adhesive, and the surface morphology of the sample was observed after gold sputtering.

[0038] Test Method 4: Oil Absorption Process

[0039] Take aerogel samples of the same volume and immerse them in camellia oil containing dye. Simultaneously, use a camera to record the oil absorption process of the aerogel.

[0040] Test Method 5: Oil Holding Capacity Analysis

[0041] Place 1g of oleogel sample between two pieces of filter paper, then place it in a 10mL centrifuge tube and centrifuge at 10000r / min for 20min. Calculate the oil retention rate according to equation (1):

[0042]

[0043] In the formula: m1 is the mass of the oleogel before centrifugation (g); m2 is the mass of the oleogel after centrifugation (g).

[0044] Test Method 6: Texture Test

[0045] Texture analysis was performed using a cylindrical probe with a diameter of 21 mm. Compression tests were conducted on the samples using TPA mode, with a pre-test velocity of 2.0 mm / s, a test velocity of 1.0 mm / s, and a post-test velocity of 2.0 mm / s. The trigger force was 2.0 g, and the degree of compression was set to 50%.

[0046] Comparative Example 1

[0047] A method for preparing regenerated silk fibroin-chitosan aerogel includes the following steps:

[0048] A certain amount of silk fibroin powder was weighed and added to a ternary solution of CaCl2 / H2O / C2H5OH at a mass ratio of 1:10 (the molar ratio of CaCl2 / H2O / C2H5OH was 1:8:2). The solution was heated at 95℃ for 2 hours for salt dissolution. After cooling, the salt solution was centrifuged, and the supernatant was transferred to a dialysis bag and dialyzed for 48 hours. The dialysate was collected and freeze-dried to obtain regenerated silk fibroin powder.

[0049] 5g of regenerated silk fibroin and 2g of chitosan were dissolved in 100mL of distilled water and 100mL of acetic acid solution (1%, v / v), respectively. The regenerated silk fibroin solution and chitosan solution were then thoroughly mixed in a 2:1 ratio, transferred to a mold, and freeze-dried to obtain regenerated silk fibroin-chitosan aerogel.

[0050] Comparative Example 2

[0051] A method for preparing regenerated silk fibroin-chitosan aerogel includes the following steps:

[0052] The preparation method of regenerated silk fibroin powder is the same as that of Comparative Example 1.

[0053] 5g of regenerated silk fibroin and 2g of chitosan were dissolved in 100mL of distilled water and 100mL of acetic acid solution (1%, v / v), respectively. The regenerated silk fibroin solution and chitosan solution were then thoroughly mixed in a 1:1 ratio, transferred to a mold, and freeze-dried to obtain regenerated silk fibroin-chitosan aerogel.

[0054] Comparative Example 3

[0055] A method for preparing regenerated silk fibroin-chitosan aerogel includes the following steps:

[0056] The preparation method of regenerated silk fibroin powder is the same as that of Comparative Example 1.

[0057] 5g of regenerated silk fibroin and 2g of chitosan were dissolved in 100mL of distilled water and 100mL of acetic acid solution (1%, v / v), respectively. The regenerated silk fibroin solution and chitosan solution were then thoroughly mixed in a 1:2 ratio, transferred to a mold, and freeze-dried to obtain regenerated silk fibroin-chitosan aerogel.

[0058] Example 1

[0059] A method for preparing regenerated silk fibroin-chitosan aerogel based on micro / nano bubble technology includes the following steps:

[0060] The preparation method of regenerated silk fibroin powder is the same as that of Comparative Example 1.

[0061] Micro-nanobubble generators were used to generate micro-nanobubbles in a container containing distilled water, resulting in water containing micro-nanobubbles. 5g of regenerated silk fibroin and 2g of chitosan were dissolved in 100mL of the prepared bubble water and 100mL of acetic acid solution (1%, v / v), respectively. The regenerated silk fibroin solution and chitosan solution were then thoroughly mixed in a 2:1 ratio, transferred to a mold, and freeze-dried to obtain a regenerated silk fibroin-chitosan aerogel.

[0062] Example 2

[0063] A method for preparing regenerated silk fibroin-chitosan aerogel based on micro / nano bubble technology includes the following steps:

[0064] The preparation method of regenerated silk fibroin powder is the same as that of Comparative Example 1.

[0065] Micro-nanobubble generators were used to generate micro-nanobubbles in a container containing distilled water, resulting in water containing micro-nanobubbles. 5g of regenerated silk fibroin and 2g of chitosan were dissolved in 100mL of the prepared bubble water and 100mL of acetic acid solution (1%, v / v), respectively. The regenerated silk fibroin solution and chitosan solution were then thoroughly mixed in a 1:1 ratio, transferred to a mold, and freeze-dried to obtain a regenerated silk fibroin-chitosan aerogel.

[0066] Example 3

[0067] A method for preparing regenerated silk fibroin-chitosan aerogel based on micro / nano bubble technology includes the following steps:

[0068] The preparation method of regenerated silk fibroin powder is the same as that of Comparative Example 1.

[0069] Micro-nanobubble generators were used to generate micro-nanobubbles in a container containing distilled water, resulting in water containing micro-nanobubbles. 5g of regenerated silk fibroin and 2g of chitosan were dissolved in 100mL of the prepared bubble water and 100mL of acetic acid solution (1%, v / v), respectively. The regenerated silk fibroin solution and chitosan solution were then thoroughly mixed at a 1:2 ratio, transferred to a mold, and freeze-dried to obtain a regenerated silk fibroin-chitosan aerogel.

[0070] Example 4

[0071] A method for preparing oleogels from edible aerogels includes the following steps:

[0072] The regenerated silk fibroin-chitosan aerogels prepared in Examples 1-3 and Comparative Examples 1-3 were respectively immersed in camellia oil. After reaching absorption equilibrium, the oil gel was removed and allowed to drip naturally for 30 seconds to remove excess oil from the surface, thus obtaining regenerated silk fibroin-chitosan-based oil gel.

[0073] As shown in Figure 1, the zeta potential of distilled water treated with micro / nano bubble technology was -32.53 ± 0.36 mV, while no zeta potential was detected in untreated distilled water. This demonstrates the presence of stable micro / nano bubbles in the system.

[0074] As shown in Figure 2, the average particle size of distilled water treated with micro / nano bubble technology was measured to be 280 ± 8.13 nm, while no nanoparticles were detected in untreated distilled water. This verifies the existence of stable micro / nano bubbles in the system.

[0075] As can be seen from Figure 3, the aerogel prepared after micro-nano bubble treatment has many uniformly distributed small pores on the pore channel walls, which increases the porosity and specific surface area of ​​the aerogel.

[0076] Figure 4 shows CR21, CR11, CR12, CR21 NBs, CR11 NBs, and CR12 NBs corresponding to aerogels prepared in proportions 1-3 and Examples 1-3, respectively. As can be seen from Figure 4, the aerogels prepared after micro / nano bubble treatment have a faster oil absorption rate than the untreated aerogels. The CR21 NBs sample completed oil absorption in 79 seconds, approximately one-third the time required for the CR21 sample.

[0077] Figure 5 shows CR21, CR11, CR12, CR21 NBs, CR11 NBs, and CR12 NBs corresponding to aerogels prepared in proportions 1-3 and Examples 1-3, respectively. As shown in Figure 5, the oil holding capacities of CR21, CR11, CR12, CR21 NBs, CR11 NBs, and CR12 NBs are 46.71±7.38%, 56.48±8.04%, 46.57±4.00%, 66.52±7.36%, 77.35±3.23%, and 67.46±5.46%, respectively. The aerogels treated with micro / nano bubble technology have significantly improved oil holding capacities compared to the untreated aerogels.

[0078] As shown in Table 1, CR21, CR11, CR12, CR21 NBs, CR11 NBs, and CR12 NBs correspond to proportions 1-3 and examples 1-3, respectively, with hardness values ​​of 320.20±29.34g, 373.67±11.68g, 216.50±16.10g, 245.67±5.69g, 269.83±9.93g, and 97.20±25.60g, respectively. The hardness of the oleogel prepared using micro-nano bubble technology is significantly lower than that of the untreated oleogel. By reducing the hardness of the oleogel, not only can its softness and fluidity be improved, thereby improving the taste, but it also helps to improve the release efficiency of active substances and enhance the spreadability of the product.

[0079] Table 1

[0080] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an oil-absorbing edible aerogel based on micro / nanobubbles, characterized in that, Includes the following steps: (1) Regenerated silk fibroin and gelling agent were added to water containing micro-nano bubbles respectively to obtain regenerated silk fibroin solution and gelling agent solution; (2) Mix the regenerated silk fibroin solution and gelling agent solution evenly, transfer them to a mold for freeze drying, and obtain the oil-absorbing edible aerogel.

2. The method for preparing oil-absorbing edible aerogel based on micro / nano bubbles according to claim 1, characterized in that, Methods for preparing regenerated silk fibroin include: The degummed silk fibroin was mixed with a ternary solution of CaCl2 / H2O / C2H5OH and heated at 80-100℃ to dissolve it in salt, thus obtaining a salt solution. Centrifuge the salt solution and collect the supernatant; transfer the supernatant to a dialysis bag for dialysis, collect the dialysis fluid and freeze-dry it to obtain regenerated silk fibroin.

3. The method for preparing oil-absorbing edible aerogel based on micro / nano bubbles according to claim 2, characterized in that, In the ternary solution of CaCl2:H2O:C2H5OH, the molar ratio of CaCl2, H2O, and C2H5OH is 1:8:2; the mass ratio of silk fibroin to the ternary solution of CaCl2:H2O:C2H5OH is 1:5-20.

4. The method for preparing the oil-absorbing edible aerogel based on micro / nano bubbles according to claim 1, characterized in that, In water containing micro- and nano-bubbles, the average diameter of the micro- and nano-bubbles is 270-300 nm.

5. The method for preparing the oil-absorbing edible aerogel based on micro / nanobubbles according to claim 1 or 4, characterized in that, Micro-nano bubble generators are used to generate micro-nano bubbles in distilled water. The working time of the micro-nano bubble generator is 5-20 minutes, and the water pump power is 500-1000W. After stopping, the water is left to stand until the liquid becomes clear, thus obtaining water containing micro-nano bubbles.

6. The method for preparing oil-absorbing edible aerogel based on micro / nanobubbles according to claim 1, characterized in that, In step (1), the concentration of regenerated silk fibroin in the regenerated silk fibroin solution is 1-10%; the concentration of gelling agent in the gelling agent solution is 1-5%.

7. The method for preparing oil-absorbing edible aerogel based on micro / nanobubbles according to claim 1 or 6, characterized in that, The regenerated silk fibroin solution and the gelling agent solution are mixed at a volume ratio of 1:0.5-2.

8. The method for preparing oil-absorbing edible aerogel based on micro / nano bubbles according to claim 1, characterized in that, The gelling agent is chitosan.

9. An oil-absorbing edible aerogel, characterized in that, It was prepared using the preparation method of claims 1-8.

10. The application of the oil-absorbing edible aerogel according to claim 9 in the preparation of oleogels, characterized in that, include: The oil-absorbing edible aerogel is immersed in vegetable oil. After the absorption is balanced, the excess vegetable oil on the surface is removed to obtain the oil gel.

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