A thermosensitive plant fiber-based emulsion gel, oil gel and preparation method and application thereof

Abstract

The invention discloses a thermosensitive plant fiber-based emulsion gel, an oil gel, and a preparation method and application thereof. The invention mixes a citrus fiber-glycyrrhizic acid fiber aqueous composite solution with liquid oil, heats the mixture until the mixed system is completely dissolved, homogenizes the mixture while hot, and then cools it to obtain a thermosensitive plant fiber-based emulsion gel. The emulsion gel of the invention has excellent mechanical properties, thixotropic properties and temperature sensitivity, can effectively load and protect hydrophilic / hydrophobic active substances, and realize the controlled release of flavor substances. The emulsion gel is dried to obtain a plant fiber-based oil gel with uniform appearance and stable properties. The process conditions of the invention are simple and mild, the raw materials are natural, healthy and safe, and it is easy to mass produce. It can be used as a traditional plastic fat substitute in future food processing, daily chemicals, biomedicine and other fields such as artificial meat.

Description

Technical Field

[0001] The invention belongs to the technical field of emulsion gels, and in particular relates to a temperature-sensitive plant fiber-based emulsion gel, an oil gel, and a preparation method and application thereof. Background Art

[0002] Plastic fats are a mixture of liquid oil and solid fats, which play an important role in the formation of food network structure and sensory characteristics. However, these plastic fats contain trans fatty acids or more saturated fatty acids, which increase the health risks of the final product. Some studies have confirmed the direct link between trans fatty acid intake and increased risk of cardiovascular disease. Therefore, people have focused on improving the health properties of food and reducing the intake of plastic fats. In addition, the unavoidable hydrogenation process in food processing also produces saturated fatty acids and trans fatty acids, which increases the risk of cardiovascular disease, metabolic syndrome and type II diabetes. Therefore, consumers are eager to demand low-calorie, zero trans fatty acids and more nutritious and healthy unsaturated fatty acids to reduce the incidence of related chronic diseases. In recent years, the development of new soft solid oils rich in polyunsaturated fatty acids through oil structuring technology has become a research hotspot in the field of food science.

[0003] Emulsion gel is a semi-solid emulsion system with a gel network structure. It has good thixotropic and shear-thinning properties, and has the ability to load and release active substances. Therefore, it has attracted widespread attention from scholars at home and abroad. Animal fat is a structural organization in which fat cells are combined with reticular connective fiber bundles. Its essence is an emulsion-filled gel. Emulsion gel is a relatively simple and highly operable method to achieve the structuring of liquid oils. It realizes the plasticity of liquid vegetable oil by constructing a gel network structure in the emulsion system, which can simulate the lubricating taste and functionality of animal fat, while providing better nutritional ingredients, thereby obtaining plant fat with similar performance to traditional animal fat. Therefore, emulsion gel has obvious advantages in the preparation of animal fat substitutes. Especially for the quality of artificial meat such as plant meat and cell cultured meat, adding plant-based structured fat substitutes with similar characteristics to animal fat is extremely critical, which can significantly improve the taste texture (such as juiciness and real meat taste), meat flavor release, nutrient delivery and final product sensory acceptance of artificial meat products.

[0004] Glycyrrhizic acid is a natural edible small molecule saponin with a hydrophilic glucuronic acid structure and a hydrophobic triterpene aglycone. It can self-assemble to form nanofibers and gel network structures when it reaches a certain concentration in water. In patent CN105686974A, a semi-solid shape and good plasticity and spreadability emulsion gel is obtained by utilizing the self-assembly characteristics of natural food-grade small molecule glycyrrhizic acid, which can be used as a plastic fat substitute. However, it does not have a controllable temperature response behavior, and it is impossible to achieve effective regulation of its own structural characteristics by temperature; in addition, in patent CN105686974A, the concentration of glycyrrhizic acid fiber alone needs to reach 2-6wt% to achieve the structuring of liquid vegetable oil. As a food additive, the amount of glycyrrhizic acid added in the food system is limited. How to stabilize the emulsion gel with a lower glycyrrhizic acid concentration is the main technical problem currently existing.

[0005] As consumers' demand for healthy functional and all-natural foods continues to grow, it is of great economic significance to select raw materials with clean labels to develop new high-quality, healthy functional foods. Therefore, compared with semi-synthetic or even synthetic lipid additives, some natural molecules with clean labels are more likely to be used as structuring aids for liquid oils due to their excellent bioavailability, biocompatibility and biodegradability. In the thermosensitive emulsion gel of the present invention, food-grade citrus fiber and glycyrrhizic acid fiber are obtained by top-down and bottom-up methods, respectively, and a tightly cross-linked double fiber network is constructed by the interaction of the two plant fibers in the emulsion gel. The synergistic combination of the gelation and emulsification functions of the two fibers can achieve efficient structuring of liquid vegetable oils, and can better simulate the structure and processing characteristics of animal fats (such as fat melting during cooking). Compared with the fiber network composed of two or more other cellulose polymers, citrus fiber and glycyrrhizic acid fiber have superior synergistic emulsification properties, can achieve simple, gentle and efficient emulsification, and have industrial and large-scale application value; compared with traditional emulsion gels, this type of thermosensitive emulsion gel stabilized by double plant fibers has natural health attributes, edibility and superior sensory properties, which greatly broadens the practical application of emulsion gels in future food (such as plant meat and cell-cultured meat), daily chemical products and other fields. Summary of the invention

[0006] The problems existing in the prior art are as follows: (1) Traditional emulsion gels are mostly stabilized by synthetic surfactants or proteins and liposomes from natural biomass, and do not have long-term storage stability and controllable temperature response behavior. These factors seriously restrict the practical application of emulsion gels. (2) Emulsion gels prepared from glycyrrhizic acid alone have problems such as poor thermal stability and too fast environmental response, and are difficult to resist the effects of heat treatment and mechanical damage in food processing. (3) As a food additive, the amount of glycyrrhizic acid added in the food system is limited. How to form a stable gel structure at a lower glycyrrhizic acid addition amount is the main technical problem currently existing. The purpose of the present invention is to provide a thermosensitive plant fiber-based emulsion gel, oil gel and its preparation method and application. The present invention introduces natural macromolecular citrus fiber, and constructs the emulsion interface through the "citrus fiber-glycyrrhizic acid fiber" double plant fiber. The emulsion gel is prepared by a green and simple one-step emulsification, and the liquid vegetable oil is structured, giving the emulsion gel high mechanical properties, sensitive temperature response behavior and double fiber network structure characteristics, thereby expanding its application in the fields of food, daily chemicals, etc. in the future. At the same time, the emulsion gel is dried and dehydrated to prepare a stable plant fiber-based oleogels. The oleogels are physical gels that do not change the chemical properties of the oil phase and do not generate trans fatty acids, and have good application prospects in the fields of food, medicine, and daily chemicals.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for preparing a temperature-sensitive plant fiber-based emulsion gel comprises the following steps:

[0009] (1) citrus fiber powder is uniformly dispersed in deionized water, and a uniform citrus fiber dispersion is obtained by physical modification;

[0010] (2) uniformly dispersing glycyrrhizic acid and / or glycyrrhizic acid derivatives in deionized water, heating and stirring to obtain a glycyrrhizic acid fiber solution;

[0011] (3) mixing the citrus fiber dispersion with the glycyrrhizic acid fiber solution to obtain a citrus fiber-glycyrrhizic acid fiber aqueous composite solution;

[0012] (4) The citrus fiber-glycyrrhizic acid fiber aqueous composite solution is mixed with liquid oil, heated until the mixed system is completely dissolved, homogenized while hot, and then cooled to obtain a temperature-sensitive plant fiber-based emulsion gel.

[0013] Preferably, the physical modification treatment in step (1) comprises one or more of high-pressure homogenization, high-intensity ultrasound, hydraulic cavitation, ultra-high-speed grinding, ball milling, and colloid milling;

[0014] Preferably, the physical modification treatment time in step (1) is 5-40 min;

[0015] Preferably, the concentration of the citrus fiber dispersion in step (1) is 0.1-10 wt %;

[0016] Preferably, the glycyrrhizic acid derivative in step (2) comprises one of glycyrrhizic acid ammonium salt, glycyrrhizic acid potassium salt and glycyrrhizic acid sodium salt.

[0017] Preferably, the concentration of the glycyrrhizic acid fiber solution in step (2) is 0.1-10wt%;

[0018] Preferably, the temperature of the heating and stirring in step (2) is 60-95° C., and the time of the heating and stirring is 5-20 min.

[0019] Preferably, the liquid oil in step (3) comprises one or more of sunflower oil, rapeseed oil, soybean oil, corn oil, peanut oil, fish oil, algae oil, linseed oil, perilla seed oil, chia seed oil, olive oil, camellia oil, and rice bran oil;

[0020] Preferably, the liquid oil in step (3) also includes active substances.

[0021] Further preferably, the active substance is a fat-soluble active substance; and the content of the active substance in the liquid oil is 0.1-2 wt %.

[0022] Preferably, in the citrus fiber-glycyrrhizic acid fiber aqueous composite solution of step (3), the concentration of citrus fiber is 0.1-4wt%, and the concentration of glycyrrhizic acid fiber is 0.1-4wt%.

[0023] Preferably, in step (4), the ratio of the citrus fiber-glycyrrhizic acid fiber aqueous composite solution to the liquid oil is 90-20wt%:10-80wt%;

[0024] Preferably, the heating in step (4) is water bath heating; the heating temperature is 60-95° C., and the heating time is 5-30 min.

[0025] Preferably, the homogenization speed in step (4) is 4000-20000 rpm, and the homogenization time is 1-5 min;

[0026] Preferably, the cooling temperature in step (4) is 0-25° C., and the cooling time is 5-30 min.

[0027] The temperature-sensitive plant fiber-based emulsion gel is prepared by the above-mentioned preparation method.

[0028] A plant fiber-based oil gel is obtained by drying the above-mentioned temperature-sensitive plant fiber-based emulsion gel.

[0029] Preferably, the drying process includes freeze-drying or air-drying; the drying process lasts for 36-48 hours.

[0030] The application of the thermosensitive plant fiber-based emulsion gel as a fat substitute.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] (1) The present invention provides a method for preparing a temperature-sensitive plant fiber-based emulsion gel that can be used as a novel animal fat substitute. The emulsion gel has good temperature sensitivity, a wide temperature response range, and highly controllable behavior, which expands the application of the emulsion gel in the fields of food, cosmetics, and medicine. In particular, it can be used as an excellent substitute for plastic fats (such as traditional animal fats, saturated fats such as coconut oil and palm oil, and trans fatty acids, etc.) and a hydrophilic / hydrophobic active encapsulation and controlled release material.

[0033] (2) One of the materials used in the present invention is citrus fiber, which is obtained by grinding, washing, crushing, drying and other processes of the byproduct of citrus peel residue. It is an excellent raw material that can turn waste into treasure and has a natural clean label. The total dietary fiber content (TDF) of citrus fiber is 90.8%, which is higher than that of cereal fiber, and its water holding capacity is significantly higher than other commonly used fibers such as carrot fiber and oat fiber. Compared with other cellulose polymers commonly used in the food industry, citrus fiber not only has fiber functionality, but also has excellent food processability. It is a natural dietary fiber with both functionality and function.

[0034] (3) The emulsion gel described in the present invention has a temperature-sensitive double-fiber network structure constructed by high-molecular-weight cellulose citrus fiber and low-molecular-weight glycyrrhizic acid fiber. Compared with other similar composite cellulose networks, the preparation process is simple and the conditions are mild. It can achieve efficient emulsification in one step. At a relatively low concentration, synergistic emulsification occurs to form a stable double-fiber shell to protect the oil droplets. The mutual entanglement between the high-molecular-weight fibers and the small-molecular-weight fibers and the interaction between the oil droplet molecules jointly promote the stable formation of the emulsion gel.

[0035] (4) The materials used in the present invention, citrus fiber and glycyrrhizic acid, are both of plant origin, natural, safe, edible and easily available. The emulsion gel can be diversified and customized simply by adjusting the types and concentrations of raw materials and oil phases to meet the personalized needs of different consumers. It is a healthy, nutritious and sustainable plastic fat substitute.

[0036] (5) The present invention regulates the temperature-sensitive behavior, structure and functional properties of the system by changing the composition and concentration of the water phase and the oil phase in the emulsion gel. The emulsion gel can be used as a traditional animal fat substitute or a structured oil soft material in the fields of future food (such as plant meat and cell cultured meat), daily chemical products, biomedicine, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a stress scanning diagram of the emulsion gel with different glycyrrhizic acid concentrations in Example 1;

[0038] Figure 2 This is a frequency scanning diagram of the emulsion gel with different glycyrrhizic acid concentrations in Example 1;

[0039] Figure 3 This is the temperature scanning diagram of the emulsion gel with different glycyrrhizic acid concentrations in Example 1;

[0040] Figure 4 This is a diagram of the extrusion state of the emulsion gel with different glycyrrhizic acid concentrations in Example 2;

[0041] Figure 5 This is a graph showing the retention rate of β-carotene in the emulsion gel during storage at different glycyrrhizic acid concentrations in Example 3;

[0042] Figure 6a This is the flavor dynamic release diagram of the limonene loaded emulsion gel at different glycyrrhizic acid concentrations at 25°C in Example 4;

[0043] Figure 6b This is the flavor dynamic release diagram of the limonene loaded emulsion gel at different glycyrrhizic acid concentrations at 65°C in Example 4;

[0044] Figure 7 This is a state diagram of the oil gel prepared in Example 5;

[0045] Figure 8 This is the state diagram of the oil gel prepared in Example 6. DETAILED DESCRIPTION

[0046] In order to better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments, but the embodiments of the present invention are not limited thereto.

[0047] In the following examples, the rheological determination method is as follows:

[0048] Rheological measurement: Small deformation rheology analysis was used to analyze the rheological properties of the emulsion. On the HAAKE-MARS60 rheometer, the emulsion gel was placed on the sample stage of the rheometer, and parallel plates were used for testing. The gap between the sample stage and the parallel plate was 1 mm. First, a vibration experiment with amplitude scanning and frequency scanning was performed at 25°C to measure the changes in the yield stress (G′=G″), elastic modulus value (G′) and viscous modulus value (G″) of the sample. Then a temperature scan was performed on the sample.

[0049] Example 1

[0050] (1) The citrus fiber powder was uniformly dispersed in deionized water, pre-treated with a homogenizer at 10,000 rpm for 5 minutes, and then treated with high-pressure microfluidization at a microfluidization pressure of 100 MPa and 5 times to obtain a 1-2 wt% citrus fiber dispersion.

[0051] (2) The ammonium glycyrrhizinate powder was uniformly dispersed in deionized water and gently stirred for 5 min in a water bath at 80° C. to obtain a 1-10 wt % glycyrrhizic acid fiber solution.

[0052] (3) Three portions of glycyrrhizic acid fiber solution of different masses were respectively and evenly dispersed in the citrus fiber dispersion (and the concentration was adjusted with deionized water), and the resulting mixture was heated and stirred at 80°C for 10 min to obtain a citrus fiber-glycyrrhizic acid fiber aqueous phase of a composite stable system with a final citrus fiber concentration of 0.5wt% and glycyrrhizic acid fiber final concentrations of 0wt% (aqueous solution containing only 0.5wt% citrus fiber dispersion), 0.25wt%, 0.5wt% and 1wt%, respectively.

[0053] (4) A 60 wt% aqueous composite solution was mixed with a 40 wt% liquid oil (soybean oil), and the mixture was heated at 80°C for 5 min. The mixture was quickly homogenized at a speed of 8000 rpm for 2 min, and then cooled in an ice bath at 4°C for 10 min to obtain an emulsion gel prepared by combining citrus fiber and glycyrrhizic acid fiber.

[0054] The mechanical properties of emulsion gels are important indicators for evaluating whether they can be used as fat substitutes or in cosmetics, pharmaceuticals, etc. The rheological properties (ability to resist small deformations) can be reflected by the viscoelastic modulus of the product. The G′ value represents the energy stored in each deformation cycle, reflecting the elasticity and solid-like properties of the sample being tested, while the G″ value reflects the viscosity and liquid-like properties of the sample.

[0055] Figure 1It is a small amplitude stress scanning diagram of the latex gel prepared with glycyrrhizic acid fiber concentrations of 0wt%, 0.25wt%, 0.5wt% and 1wt%. It can be seen from the figure that the elastic modulus (G′) of all samples is significantly higher than the viscous modulus (G″), indicating that the latex gel exhibits elastic solid-like properties. With the increase of glycyrrhizic acid concentration, the elastic modulus and viscous modulus of the sample increase significantly, and the yield stress value increases. When the glycyrrhizic acid concentration increases from 0wt% to 1wt%, the elastic modulus increases from 66Pa to 702Pa, indicating that the sample has strong mechanical properties.

[0056] Figure 2 It is a frequency scan diagram of 4 emulsion gels under 1Pa stress (determined according to the experimental results of stress scanning, within the linear viscoelastic region). The emulsion gel shows a low frequency dependence, and no yield stress point (G′=G″) appears at a higher frequency, indicating that the emulsion gel does not undergo gel-sol transition under high-rate deformation. Therefore, the mechanical properties of citrus fiber-glycyrrhizic acid fiber emulsion gel can be regulated by changing the concentration of glycyrrhizic acid fiber.

[0057] The excellent mechanical properties can maintain the structure of the emulsion gel, while the wide thermal responsiveness can expand the practical application range of the emulsion gel. Figure 3 The figure shows the change of modulus value of the emulsion gel prepared when the concentration of glycyrrhizic acid is 0wt%, 0.25wt%, 0.5wt%, and 1wt% during the heating and cooling cycle. It can be seen from the figure that the emulsion gel stabilized by pure citrus fiber has a certain thermal stability, and the temperature change has little effect on the texture of the pure citrus fiber-based emulsion gel, while the composite samples all show thermal sensitive behavior. The composite emulsion gel will undergo a gel-sol transition when heated to about 55°C, and the elastic modulus and viscous modulus will decrease, and gel will be formed during the cooling process to 25°C, indicating that the transition between the gel and sol states of the emulsion gel can be achieved by changing the temperature of the system. Therefore, the thermal sensitivity of the emulsion gel can be regulated by changing the concentration of citrus fiber-glycyrrhizic acid fiber, which is conducive to simulating the quality of animal fat and maintaining the "juicy" taste texture and melting properties.

[0058] The citrus fiber and glycyrrhizic acid fiber used in the experiment are all natural and safe raw materials, and reasonable use is beneficial to human health. In addition, from the preparation method, it can be seen that the emulsion gel of the present invention is easy to prepare, the conditions are mild, and no toxic and harmful waste is generated, and it can be used for industrial production.

[0059] Example 2

[0060] The emulsion gel fat substitute of Example 1 was extruded using a thick-tipped dropper to obtain an emulsion gel having an appearance as shown in Figure 4 When the emulsion gel is stored at room temperature, its appearance structure remains stable and has an ideal shape retention ability.

[0061] Figure 4 From left to right, the extrusion diagrams correspond to the addition of 0%, 0.25%, 0.5%, and 1% glycyrrhizic acid fiber. Figure 4 The emulsion gel in (1) is stabilized by citrus fiber alone, has no self-supporting and texture details, and presents a soft, viscous appearance; Figure 4 The emulsion gels in (2) and (3) can initially form slightly upright soft peaks, but the texture details are not fine enough; Figure 4 The latex gel of (4) has a clear texture, upright soft peaks, a glossy surface, and the best appearance. The above results prove that as the amount of glycyrrhizic acid fiber added increases, the sample has viscoelasticity and a finer extrusion texture, which is inferred to have good 3D printability.

[0062] Example 3

[0063] (1) The citrus fiber powder was uniformly dispersed in deionized water, pre-treated with a homogenizer at 10,000 rpm for 5 minutes, and then treated with high-pressure microfluidization at a microfluidization pressure of 100 MPa and 5 times to obtain a 1-2 wt% citrus fiber dispersion.

[0064] (2) The ammonium glycyrrhizinate powder was uniformly dispersed in deionized water and gently stirred for 5 min in a water bath at 80° C. to obtain a 1-10 wt % glycyrrhizic acid fiber solution.

[0065] (3) Three portions of glycyrrhizic acid fiber solution of different masses were respectively and evenly dispersed in the citrus fiber dispersion (and the concentration was adjusted with deionized water), and the resulting mixture was heated and stirred at 80°C for 10 min to obtain a citrus fiber-glycyrrhizic acid fiber aqueous phase of a composite stable system with a final citrus fiber concentration of 0.5wt% and glycyrrhizic acid fiber final concentrations of 0wt% (aqueous solution containing only 0.5wt% citrus fiber dispersion), 0.25wt%, 0.5wt% and 1wt%, respectively.

[0066] (4) Add β-carotene (1 wt%) to sunflower oil and stir in a constant temperature water bath at 80° C. for 5 min until the β-carotene oil solution is evenly dispersed.

[0067] (5) A 60 wt % aqueous composite solution was mixed with a 40 wt % oil phase, heated at 80° C. for 5 min, and the mixture was quickly homogenized at a speed of 8000 rpm for 2 min while hot, and then cooled in an ice bath at 4° C. for 10 min to obtain an emulsion gel prepared by combining citrus fiber and glycyrrhizic acid fiber. The β-carotene content was measured on the 1st, 3rd, 5th, 7th, 15th, and 30th days to evaluate the protection ability of the system for hydrophobic bioactive substances.

[0068] Another important application of emulsion gel is as a delivery system for active ingredients in food, medicine and cosmetics. Therefore, we dissolved oil-soluble β-carotene in the oil phase before homogenization, and further constructed a functional emulsion gel of citrus fiber-glycyrrhizic acid fiber mixed system to explore the loading and release capacity of the system for hydrophobic bioactive substances. β-carotene can be uniformly loaded into the prepared emulsion gel, and the addition of β-carotene does not affect the formation of the emulsion gel, indicating that the emulsion gel has the potential use of loading active substances.

[0069] Figure 5 The figure is a graph of the retention rate of β-carotene encapsulated in the emulsion gel during storage at room temperature (25°C). It can be seen from the figure that at all glycyrrhizic acid fiber concentrations, more than 70% of the original β-carotene is still retained in the emulsion gel system after storage for 30 days. As the concentration of glycyrrhizic acid fiber increases, the retention rate of β-carotene in the emulsion gel increases from 73% to 76%, which shows that citrus fiber-glycyrrhizic acid fiber emulsion gel has the potential to protect and transport hydrophobic active substances.

[0070] Example 4

[0071] (1) The citrus fiber powder was uniformly dispersed in deionized water, pre-treated with a homogenizer at 10,000 rpm for 5 minutes, and then treated with high-pressure microfluidization at a microfluidization pressure of 100 MPa and 5 times to obtain a 1-2 wt% citrus fiber dispersion.

[0072] (2) The ammonium glycyrrhizinate powder was uniformly dispersed in deionized water and gently stirred for 5 min in a water bath at 80° C. to obtain a 1-10 wt % glycyrrhizic acid fiber solution.

[0073] (3) Two portions of glycyrrhizic acid fiber solution of different masses were respectively and evenly dispersed in the citrus fiber dispersion (and the concentration was adjusted with deionized water), and the resulting mixture was heated and stirred at 80°C for 10 min to obtain a citrus fiber final concentration of 0.5wt%, a glycyrrhizic acid fiber aqueous phase of a composite stable system having final concentrations of 0wt% (an aqueous solution containing only 0.5wt% of citrus fiber dispersion), 0.25wt%, and 1wt% of glycyrrhizic acid fiber, and an aqueous solution containing only 1wt% of glycyrrhizic acid fiber.

[0074] (4) Add limonene (1 wt%) to soybean oil and stir in a constant temperature water bath at 80° C. for 5 min until the β-carotene oil solution is evenly dispersed.

[0075] (5) A 60 wt% aqueous solution was mixed with a 40 wt% oil phase, and the mixture was heated at 80°C for 5 min. The mixture was quickly homogenized at a speed of 8000 rpm for 2 min, and then cooled in an ice bath at 4°C for 10 min to obtain an emulsion gel prepared by combining citrus fiber and glycyrrhizic acid fiber. The release of limonene in the emulsion gel every 5 minutes at 25°C and 65°C was measured by gas chromatography, and the release concentration of limonene at different time points was calculated based on a limonene standard curve prepared in advance to evaluate the potential of the emulsion gel as a flavor release system.

[0076] Figure 6a and Figure 6b is the dynamic release curve of limonene in emulsion gel at different temperatures, Figure 6a It can be seen that at 25°C, for all samples, a rapid limonene release rate was shown in the first 15 min, followed by a slower release rate. As the concentration of glycyrrhizic acid fiber increased, the amount of limonene released decreased; Figure 6b It can be seen that when the temperature reaches 65°C (the cooking temperature of medium-rare steak), all samples show a rapid limonene release rate within the first 25 minutes, followed by a slower release rate. At this time, with the increase in glycyrrhizic acid fiber concentration, the tight network of the emulsion gel gradually melts and becomes sparse, which increases the release of limonene. This shows that citrus fiber-glycyrrhizic acid fiber emulsion gel has the potential to become a new aroma delivery system for improving food flavor perception, and its flavor release rate can be well controlled by simply changing the glycyrrhizic acid fiber concentration and temperature.

[0077] Example 5

[0078] (1) The citrus fiber powder was uniformly dispersed in deionized water, pre-treated with a homogenizer at 10,000 rpm for 5 minutes, and then treated with high-pressure microfluidization at a microfluidization pressure of 100 MPa and 5 times to obtain a 1-2 wt% citrus fiber dispersion.

[0079] (2) The ammonium glycyrrhizinate powder was uniformly dispersed in deionized water and gently stirred for 5 min in a water bath at 80° C. to obtain a 1-10 wt % glycyrrhizic acid fiber solution.

[0080] (3) Three portions of glycyrrhizic acid fiber solution of different masses were uniformly dispersed in the citrus fiber dispersion (and the concentration was adjusted with deionized water), and the resulting mixture was heated and stirred at 80°C for 10 min to obtain a citrus fiber final concentration of 0.5wt%, a citrus fiber-glycyrrhizic acid fiber aqueous phase of a composite stable system having glycyrrhizic acid fiber final concentrations of 0wt% (an aqueous solution containing only 0.5wt% of citrus fiber dispersion), 0.25wt%, 0.5wt% and 1wt%, and an aqueous solution containing only 1wt% of glycyrrhizic acid fiber.

[0081] (4) A 60 wt% aqueous composite solution was mixed with 40 wt% liquid oil (soybean oil), heated at 80°C for 5 min, and the mixture was quickly homogenized at a speed of 8000 rpm for 2 min while hot, and then cooled in an ice bath at 4°C for 10 min to obtain an emulsion gel prepared by a composite of citrus fiber and glycyrrhizic acid fiber, which was then freeze-dried for 48 h to obtain a fiber-based oil gel.

[0082] Figure 7 The citrus fiber dispersion is prepared by high-pressure microfluidization mechanical treatment, and the oil gel is prepared by freeze drying. The oil gel has certain strength and flexibility. Experiments show that the emulsion gel stabilized by less than 1wt% glycyrrhizic acid fiber cannot form a self-standing oil gel after drying (control 1%), and the oil gel prepared by the citrus fiber emulsion gel alone has obvious oil leakage on the surface (0%). The double-fiber composite emulsion gel can form a self-standing oil gel with uniform appearance after drying.

[0083] Example 6

[0084] (1) The citrus fiber powder was uniformly dispersed in deionized water, pre-treated with a homogenizer at 10,000 rpm for 5 min, and then treated with a hydraulic cavitation machine at a cavitation temperature of 25° C. for 30 min to obtain a 1-2 wt% citrus fiber dispersion.

[0085] (2) The ammonium glycyrrhizinate powder was uniformly dispersed in deionized water and gently stirred for 5 min in a water bath at 80° C. to obtain a 1-10 wt % glycyrrhizic acid fiber solution.

[0086] (3) Three portions of glycyrrhizic acid fiber solution of different masses were uniformly dispersed in the citrus fiber dispersion (and the concentration was adjusted with deionized water), and the resulting mixture was heated and stirred at 80°C for 10 min to obtain a citrus fiber final concentration of 0.5wt%, a citrus fiber-glycyrrhizic acid fiber aqueous phase of a composite stable system having glycyrrhizic acid fiber final concentrations of 0wt% (an aqueous solution containing only 0.5wt% of citrus fiber dispersion), 0.25wt%, 0.5wt% and 1wt%, and an aqueous solution containing only 1wt% of glycyrrhizic acid fiber.

[0087] (4) A 60 wt% aqueous composite solution was mixed with 40 wt% liquid oil (soybean oil), heated at 80°C for 5 min, and the mixture was quickly homogenized at a speed of 8000 rpm for 2 min while hot, and then cooled in an ice bath at 4°C for 10 min to obtain an emulsion gel prepared by a composite of citrus fiber and glycyrrhizic acid fiber, which was then freeze-dried for 48 h to obtain a fiber-based oil gel.

[0088] Figure 8 The invention discloses a citrus fiber dispersion prepared by hydrodynamic cavitation mechanical treatment, and an oil gel prepared by freeze drying. The strength and flexibility of the oil gel are slightly lower than those of the oil gel formed by citrus fiber treated by high-pressure micro jet. The emulsion gel stabilized by only 1wt% glycyrrhizic acid fiber cannot form a self-supporting oil gel after drying (control 1%). The oil gel prepared by the citrus fiber emulsion gel alone has obvious oil leakage on the surface (0%). The composite emulsion gel can form a self-supporting oil gel with uniform appearance after drying.

[0089] The implementation methods of the present invention are not limited to the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement methods and shall be included in the protection of the present invention.

Claims

1. A method for preparing a temperature-sensitive plant fiber-based emulsion gel, characterized in that: The following steps are involved: (1) Dispersing citrus fiber powder evenly in deionized water, and obtaining a uniform citrus fiber dispersion by physical modification; the concentration of the citrus fiber dispersion is 0.1-10wt%; (2) Dispersing glycyrrhizic acid and / or glycyrrhizic acid derivatives uniformly in deionized water, heating and stirring to obtain a glycyrrhizic acid fiber solution; the concentration of the glycyrrhizic acid fiber solution is 0.1-10 wt%; (3) mixing the citrus fiber dispersion with the glycyrrhizic acid fiber solution to obtain a citrus fiber-glycyrrhizic acid fiber aqueous composite solution; the concentration of citrus fiber in the citrus fiber-glycyrrhizic acid fiber aqueous composite solution is 0.1-4 wt %, and the concentration of glycyrrhizic acid fiber is 0.1-4 wt %; (4) Mixing the citrus fiber-glycyrrhizic acid fiber aqueous composite solution with liquid oil, heating until the mixed system is completely dissolved, homogenizing the mixed solution while hot, and then cooling to obtain a temperature-sensitive plant fiber-based emulsion gel; the amount ratio of the citrus fiber-glycyrrhizic acid fiber aqueous composite solution to the liquid oil is 90-20 wt%:10-80 wt%.

2. The preparation method according to claim 1, characterized in that: The physical modification treatment in step (1) includes one or more of high-pressure homogenization, high-intensity ultrasound, hydraulic cavitation, ultra-high-speed grinding, ball milling, and colloid milling; the time of the physical modification treatment is 5-40 min.

3. The preparation method according to claim 1, characterized in that: The glycyrrhizic acid derivative in step (2) is selected from the group consisting of ammonium glycyrrhizinate, potassium glycyrrhizinate, and sodium glycyrrhizinate; The heating and stirring temperature in step (2) is 60-95°C, and the heating and stirring time is 5-20 min.

4. The preparation method according to claim 1, characterized in that: The liquid oil in step (3) includes one or more of sunflower oil, rapeseed oil, soybean oil, corn oil, peanut oil, fish oil, algae oil, linseed oil, perilla seed oil, chia seed oil, olive oil, camellia oil, and rice bran oil; The liquid oil in step (3) also includes active substances.

5. The preparation method according to claim 1, characterized in that: The heating in step (4) is water bath heating; the heating temperature is 60-95 ºC, and the heating time is 5-30 min.

6. The preparation method according to claim 1, characterized in that: The homogenization speed in step (4) is 4000-20000 rpm, and the homogenization time is 1-5 min; The cooling temperature is 0-25°C and the cooling time is 5-30 min.

7. Thermosensitive plant fiber-based emulsion gel prepared by the preparation method according to any one of claims 1 to 6.

8. A plant fiber-based oil gel, characterized in that: The thermosensitive plant fiber-based emulsion gel is obtained by drying the thermosensitive plant fiber-based emulsion gel according to claim 7.

9. The plant fiber-based oil gel according to claim 8, characterized in that The drying process includes freeze drying or air drying; the drying process time is 36-48 hours.

10. Use of the thermosensitive plant fiber-based emulsion gel according to claim 7 as a fat substitute.

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