Oil-absorbing edible aerogel based on micro-nano bubbles as well as preparation method and application of oil-absorbing edible aerogel

Abstract

The invention discloses oil-absorbing edible aerogel based on micro-nano bubbles and a preparation method and application of the oil-absorbing edible aerogel based on the micro-nano bubbles, and the preparation method comprises the following steps: (1) respectively adding regenerated silk fibroin and a gel into water containing the micro-nano bubbles to obtain a regenerated silk fibroin solution and a gel solution; and (2) uniformly mixing the regenerated silk fibroin solution and the gel solution, transferring into a mold, and freeze-drying to obtain the oil-absorbing edible aerogel. The oil-absorbing edible aerogel has a porous structure, has excellent oil absorption rate and oil absorption capacity, and has wide application prospects in the fields of food, materials and the like.

Description

Technical Field

[0001] The invention relates to the technical field of aerogels, and in particular to an oil-absorbing edible aerogel based on micro-nano bubbles, a preparation method and an application thereof. Background Art

[0002] Plastic fats (such as margarine and shortening) are widely used in the food industry because of their ideal texture, stability and ductility. However, plastic fats usually contain a large amount of saturated fatty acids and trans fatty acids, and long-term consumption may increase the risk of cardiovascular disease, obesity and metabolic syndrome. As people have higher and higher requirements for food safety and nutrition, it is of great significance to develop nutritious and healthy plastic fat substitutes. In this context, solidifying liquid vegetable oils to form oil gels to replace traditional plastic fats has gradually attracted attention.

[0003] The construction of oil gel mainly includes two methods, which are divided into direct method and indirect method. Most natural biopolymers are hydrophilic and not easy to disperse directly into oil, so the indirect method is a common method for preparing oil gel. The indirect method for preparing oil gel can be divided into emulsion template method, foam template method, solvent exchange method, aerogel template method, etc. Aerogel has excellent oil absorption capacity due to its unique three-dimensional network structure, high specific surface area and porosity, and is an ideal template material for making oil gel. The Chinese patent with publication number CN114586969A discloses an oil gel prepared by aerogel template method using whey protein isolate and carboxymethyl chitosan as raw materials, and the oil gel has high mechanical strength and antioxidant capacity. The Chinese patent with publication number CN118203113A discloses a method for preparing Antarctic krill oil gel by combining aerogel template method and capillary suspension. The oil gel prepared by this method has stable properties and good biodegradability, and is an ideal carrier of active substances. Cui Mengqi et al. (Cui Mengqi, Shan Guancheng, Sun Ruohan, et al. Properties of Soy Protein Reinforced Sodium Carboxymethyl Cellulose Composite Oil Gel. Food Science) prepared sodium carboxymethyl cellulose / soy protein isolate composite aerogels through electrostatic interaction, and formed high elasticity and high strength oil gels after being immersed in sunflower oil.

[0004] Although existing biomass aerogels have made some progress in the preparation of oil gels, there are still some limitations. Generally speaking, common aerogels have a low oil absorption rate due to their uneven pore structure, complex preparation methods and high costs, which limits their feasibility in the efficient preparation of oil gels and sustainable development applications. Summary of the invention

[0005] The invention provides an oil-absorbing edible aerogel based on micro-nano bubbles and a preparation method thereof. The aerogel has a porous structure and has 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-nano bubbles comprises the following steps:

[0008] (1) adding regenerated silk fibroin and a gelling agent into water containing micro-nano bubbles to obtain a regenerated silk fibroin solution and a gelling agent solution;

[0009] (2) The regenerated silk fibroin solution and the gelling agent solution are mixed evenly, and the mixture is transferred to a mold for freeze drying to obtain the oil-absorbing edible aerogel.

[0010] Micro-nano bubbles have the characteristics of small diameter, large specific surface area and high absolute zeta potential, and are widely used in the fields of surface cleaning, drug transportation and nanomaterials. The present invention can form more open pores inside the aerogel by generating micro-nano bubbles during the aerogel preparation process, thereby improving the oil absorption rate and oil absorption capacity of the material. In addition, the present invention uses micro-nano bubble technology to optimize the aerogel pore structure without chemical modification or cross-linking, reducing the impact on the biocompatibility of the material, and can better meet the demand for environmentally friendly materials.

[0011] Preferably, the preparation method of regenerated silk fibroin comprises:

[0012] The silk fibroin after degumming is mixed with a CaCl2 / H2O / C2H5OH ternary solution, and heated at 80-100°C for salt dissolution to obtain a salt solution;

[0013] The salt solution is centrifuged to obtain a supernatant; the supernatant is transferred to a dialysis bag for dialysis, and the dialysate is collected for freeze-drying to obtain regenerated silk fibroin.

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

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

[0016] Micro-nano bubbles were generated by gyroscopic shearing method.

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

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

[0019] The gelling agent is 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 use of the oil-absorbing edible aerogel in preparing oleogel, comprising: immersing the oil-absorbing edible aerogel in vegetable oil, and removing excess vegetable oil on the surface after absorption equilibrium is reached to obtain the oleogel.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention uses micro-nano bubble technology to adjust the pore structure of aerogel during the preparation process. At present, there is no report on increasing the aerogel flux by introducing micro-nano bubbles in the field of preparing oil gel by aerogel template method, so the present invention opens up new possibilities for scientific research and practical application of micro-nano bubble technology in high-throughput preparation of oil gel.

[0025] (2) The preparation method of the edible aerogel of the present invention is simple and the reaction conditions are mild. It has excellent performance of rapid oil absorption and does not produce additional environmental pollutants. It is in line with the concept of green and sustainable development and has broad application prospects in the fields of food, materials, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the zeta potential diagram of distilled water and micro-nano bubble water.

[0027] Figure 2 This is the particle size diagram of distilled water and micro-nano bubble water.

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

[0029] Figure 4 The Sudan red dyeing and oil absorption process images of the regenerated silk fibroin-chitosan aerogels prepared in Examples 1 to 3 and Comparative Examples 1 to 3.

[0030] Figure 5Graph showing the oil holding capacity of the regenerated silk fibroin-chitosan aerogels prepared in Examples 1 to 3 and Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention.

[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 sizes 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 and fixed on the sample stage with conductive glue. The surface morphology of the sample was observed after gold spraying.

[0038] Test method 4: Oil absorption process

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

[0040] Test Method 5: Oil Holding Capacity Analysis

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

[0042]

[0043] Where: m1 is the mass of oil gel before centrifugation / g; m2 is the mass of oil gel after centrifugation / g.

[0044] Test method 6: Texture test

[0045] Texture analysis was performed using a cylindrical probe with a diameter of 21 mm. The samples were compressed using the TPA mode, with a rate of 2.0 mm / s before the test, 1.0 mm / s during the test, 2.0 mm / s after the test, a trigger force of 2.0 g, and a compression level of 50%.

[0046] Comparative Example 1

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

[0048] Weigh a certain amount of silk fibroin powder, add CaCl2 / H2O / C2H5OH ternary solution (CaCl2 / H2O / C2H5OH molar ratio is 1:8:2) according to the material-liquid mass ratio of 1:10, and heat at 95°C for 2 hours for salt dissolution. After cooling, centrifuge the salt solution, take the supernatant and transfer it to a dialysis bag for 48 hours. Collect the dialysate and freeze-dry it to obtain regenerated silk fibroin powder.

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

[0050] Comparative Example 2

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

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

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

[0054] Comparative Example 3

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

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

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

[0058] Example 1

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

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

[0061] A micro-nano bubble generator was used to generate micro-nano bubbles in a container containing distilled water to obtain water containing micro-nano bubbles. 5 g of regenerated silk fibroin and 2 g of chitosan were dissolved in 100 mL of the above-prepared bubble water and 100 mL of acetic acid solution (1%, v / v), respectively. The regenerated silk fibroin solution and the chitosan solution were then fully mixed in a ratio of 2:1, and then transferred to a mold for freeze drying 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 comprises the following steps:

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

[0065] A micro-nano bubble generator was used to generate micro-nano bubbles in a container containing distilled water to obtain water containing micro-nano bubbles. 5 g of regenerated silk fibroin and 2 g of chitosan were dissolved in 100 mL of the above-prepared bubble water and 100 mL of acetic acid solution (1%, v / v), respectively. The regenerated silk fibroin solution and the chitosan solution were then fully mixed in a ratio of 1:1, and then transferred to a mold for freeze drying 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 comprises the following steps:

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

[0069] A micro-nano bubble generator was used to generate micro-nano bubbles in a container containing distilled water to obtain water containing micro-nano bubbles. 5 g of regenerated silk fibroin and 2 g of chitosan were dissolved in 100 mL of the above-prepared bubble water and 100 mL of acetic acid solution (1%, v / v), respectively. The regenerated silk fibroin solution and the chitosan solution were then fully mixed in a ratio of 1:2, and then transferred to a mold for freeze drying to obtain a regenerated silk fibroin-chitosan aerogel.

[0070] Example 4

[0071] A method for preparing oleogel from edible aerogel comprises the following steps:

[0072] Regenerated silk fibroin-chitosan aerogels prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were respectively taken and immersed in camellia oil. After reaching absorption equilibrium, the oil gel was taken out and naturally dripped for 30 seconds to remove excess oil on the surface, thereby obtaining regenerated silk fibroin-chitosan-based oil gel.

[0073] like Figure 1 As shown in the figure, the zeta potential of distilled water treated with micro-nano bubble technology was -32.53±0.36mV, while the zeta potential of untreated distilled water was not detected. This proves the existence of stable micro-nano bubbles in the system.

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

[0075] from Figure 3 It can be seen that in the aerogel prepared after micro-nano bubble treatment, many evenly distributed small holes appear on the pore channel walls, which increases the porosity and specific surface area of ​​the aerogel.

[0076] Figure 4 CR21, CR11, CR12, CR21 NBs, CR11 NBs, and CR12 NBs correspond to the aerogels prepared in Examples 1 to 3 and Examples 1 to 3, respectively. Figure 4 It can be seen that the aerogels prepared after micro-nano bubble treatment have a faster oil absorption rate than the untreated aerogels. The CR21 NBs sample completes the oil absorption behavior in 79 seconds, which is about one-third of the completion time of the CR21 sample.

[0077] Figure 5 CR21, CR11, CR12, CR21 NBs, CR11 NBs, and CR12 NBs correspond to the aerogels prepared in Examples 1 to 3 and Examples 1 to 3, respectively. Figure 5 As shown, 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 oil holding capacity of aerogels treated with micro-nano bubble technology is significantly improved compared with that of untreated aerogels.

[0078] As shown in Table 1, CR21, CR11, CR12, CR21 NBs, CR11 NBs, and CR12 NBs correspond to Examples 1 to 3 and Examples 1 to 3, respectively, and their hardnesses are 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 oil gel prepared by the micro-nano bubble technology is significantly lower than that of the untreated oil gel. By reducing the hardness of the oil gel, not only can its softness and fluidity be improved, thereby improving the taste, but it also helps to improve the release efficiency of the active substance and enhance the spreadability of the product.

[0079] Table 1

[0080]

[0081] The embodiments described above provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements and equivalent substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an oil-absorbing edible aerogel based on micro-nano bubbles, characterized in that: The following steps are involved: (1) adding regenerated silk fibroin and a gelling agent into water containing micro-nano bubbles to obtain a regenerated silk fibroin solution and a gelling agent solution; (2) The regenerated silk fibroin solution and the gelling agent solution are mixed evenly, and the mixture is transferred to a mold for freeze drying to obtain the oil-absorbing edible aerogel.

2. The method for preparing the oil-absorbing edible aerogel based on micro-nano bubbles according to claim 1, characterized in that: The preparation method of regenerated silk fibroin comprises: The silk fibroin after degumming is mixed with a CaCl2 / H2O / C2H5OH ternary solution, and heated at 80-100°C for salt dissolution to obtain a salt solution; The salt solution is centrifuged to obtain a supernatant; the supernatant is transferred to a dialysis bag for dialysis, and the dialysate is collected for freeze-drying to obtain regenerated silk fibroin.

3. The method for preparing the oil-absorbing edible aerogel based on micro-nano bubbles according to claim 2, characterized in that: In the CaCl2:H2O:C2H5OH ternary solution, the molar ratio of CaCl2, H2O, and C2H5OH is 1:8:2; the mass ratio of silk fibroin to the CaCl2:H2O:C2H5OH ternary solution 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-nano bubbles, the average diameter of the micro-nano bubbles is 270-300nm.

5. The method for preparing the oil-absorbing edible aerogel based on micro-nano bubbles according to claim 1 or 4, characterized in that: A micro-nano bubble generator is used to generate micro-nano bubbles in distilled water; the micro-nano bubble generator works for 5-20 minutes, the water pump power is 500-1000W, and after stopping, the liquid is allowed to stand until it becomes clear, thereby obtaining water containing micro-nano bubbles.

6. The method for preparing the oil-absorbing edible aerogel based on micro-nano bubbles 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%; and the concentration of gelling agent in the gelling agent solution is 1-5%.

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

8. The method for preparing the 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: The preparation is obtained by the preparation method of claims 1-8.

10. Use of the oil-absorbing edible aerogel according to claim 9 in the preparation of oleogel, characterized in that: include: The oil-absorbing edible aerogel is immersed in vegetable oil, and after absorption equilibrium is reached, excess vegetable oil on the surface is removed to obtain the oil gel.

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