Oral release microgel particles, methods of making and using the same

Abstract

This invention discloses an oral-release microgel particle, its preparation method, and its application. The oral-release microgel particle comprises a core and a shell. The core includes essential oils, which in turn include fragrances and oils. The shell coats the surface of the core and comprises proteins and polysaccharides. This oral-release microgel particle exhibits sufficient stability in the external environment, preventing aroma evaporation before ingestion, thus achieving aroma loading and protection. Upon entering the oral cavity, it rapidly disintegrates and releases the aroma, achieving targeted aroma delivery and enhancing the oral aroma experience.

Description

Technical Field

[0001] This invention belongs to the field of food science and technology, specifically relating to an oral release microgel particle, its preparation method, and its application. Background Technology

[0002] Aroma, as a crucial sensory experience in food, plays a key role in food consumption choices, acceptance, and preferences. The human body perceives aroma primarily through two independent pathways: anterior nasal olfaction and posterior nasal olfaction. Anterior nasal olfaction refers to the perception of environmental odors through nasal respiration, commonly known as "smelling" the aroma. Posterior nasal olfaction refers to the perception of aromas during chewing, as they are transferred from the oral cavity to the nasal cavity along with swallowing and respiration; it's more like "eating" the aroma. With changes in lifestyles and dietary structures, industrialized foods are increasingly trending towards rapid consumption, leading people to perceive aromas through posterior nasal olfaction in more and more consumption scenarios. However, most volatile flavor substances and fragrances used in flavor enhancement are hydrophobic and exhibit poor stability in high-moisture-activity food systems. Therefore, designing appropriate delivery systems to load, protect, and deliver target aromas, and targeting and controlling their disintegration and release in the oral environment, is of great significance for achieving characteristic flavor stabilization.

[0003] With the development of aroma delivery technology, natural or synthetic polymer wall materials are widely used in the preparation of flavor inclusion compounds to enhance stability, reduce volatility, and prolong aroma retention. Unlike oral products, the chewing process in food is brief. Therefore, improving the stability of flavor inclusion compounds before ingestion, delaying aroma dissipation before ingestion, reducing the stability of flavor inclusion compounds after ingestion, and promoting aroma release are key issues that need to be addressed in food flavor inclusion compounds. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to provide an oral-release microgel particle, its preparation method, and its application. This oral-release microgel particle exhibits sufficient stability in the external environment, and its aroma does not easily volatilize before ingestion, achieving aroma loading and protection. After entering the oral cavity, it can rapidly disintegrate and release aroma, achieving targeted aroma delivery and enhancing the oral aroma experience.

[0005] In one aspect of the invention, an oral-release microgel particle is provided. According to an embodiment of the invention, it comprises:

[0006] The core includes essential oils, which include fragrances and oils;

[0007] The outer shell covers the surface of the core and comprises proteins and polysaccharides.

[0008] According to an embodiment of the present invention, oral release microgel particles include a core and a shell. The core includes essential oil, which includes fragrance and oil. The shell coats the surface of the core and includes protein and polysaccharide. The protein and polysaccharide form a protein-polysaccharide shell through electrostatic adsorption, and the shell coats the essential oil. This shell (1) acts as a physical barrier at the water-oil interface or gas-oil interface, enhancing the mass transfer resistance of aroma compounds from the essential oil to the liquid food or food headspace environment, and reducing the mass transfer rate of aroma compounds at the interface; (2) the hydrophobic groups in the protein and polysaccharide are arranged on the inner interface of the shell, and the aroma compounds released from the essential oil will undergo non-covalent association with the hydrophobic groups here, hindering the aroma from escaping to the aqueous phase or gas phase through the protein-polysaccharide shell, and reducing the matrix-air partition coefficient of the aroma compounds; (3) the protein-polysaccharide shell makes the surface of the microgel particles have a negative value of more than 30mV. The charge provides sufficient electrostatic repulsion to prevent the aggregation of microgel particles, ensuring uniform dispersion of the particles in the food matrix phase; (4) As food is chewed in the mouth, the microgel particles mix with saliva (pH≈7) to form a bolus. The change in pH environment causes proteins and polysaccharides to change from electrostatic adsorption to electrostatic repulsion, and the protein-polysaccharide shell structure depolymerizes, thereby rapidly releasing essential oils; (5) The aroma compounds that escape into the headspace environment of the oral cavity are transferred to the nasal cavity via the nasal olfactory pathway during swallowing and breathing, and are captured by olfactory cells to achieve the perception of the target aroma, thus enhancing the aroma experience during the oral chewing process. Therefore, the oral release microgel particles have sufficient stability in the external environment, and the aroma is not easily volatilized before entering the mouth, thus achieving aroma loading and protection. After entering the oral cavity, they can quickly disintegrate and release aroma, thus achieving the target transmission and perception of aroma.

[0009] In addition, the oral-release microgel particles according to the above embodiments of the present invention may also have the following technical features:

[0010] In some embodiments of the present invention, the particle size of the core is 0.5 μm to 1.0 μm. This improves the stability of the oral-release microgel particles.

[0011] In some embodiments of the present invention, the thickness of the outer shell is 2.0 μm to 4.0 μm. This improves the stability of the oral-release microgel particles and their rapid release upon ingestion.

[0012] In some embodiments of the present invention, the mass ratio of the protein to the polysaccharide in the shell is (3-1):1. This improves the taste and aroma retention.

[0013] In some embodiments of the present invention, the protein includes at least one of pea protein, soy protein isolate, whey protein, rice protein, and flaxseed protein.

[0014] In some embodiments of the present invention, the polysaccharide includes at least one of pectin, chitosan, sodium alginate, and carboxymethyl cellulose.

[0015] In some embodiments of the present invention, an encapsulation shell is further included, the encapsulation shell covering the surface of the outer shell, the encapsulation shell comprising at least one alkaline material layer covering the surface of the outer shell, the alkaline material layer being a polybasic amino acid layer or a basic protein layer. This improves the stability of the oral-release microgel particles.

[0016] In some embodiments of the present invention, the encapsulation shell comprises multiple layers of the alkaline material and multiple layers of polysaccharide, with the alkaline material layers and the polysaccharide layers spaced apart along a direction away from the shell. This improves the stability of the oral-release microgel particles.

[0017] In some embodiments of the present invention, the thickness of the encapsulation shell is no greater than 4.0 μm. This allows for the rapid release of the microgel particles in the oral cavity.

[0018] In some embodiments of the present invention, the number of polysaccharide layers is no more than two. This improves the stability of the oral-release microgel particles.

[0019] In some embodiments of the present invention, the polybasic amino acid layer comprises at least one of polylysine, polyhistidine, and polyarginine.

[0020] In some embodiments of the present invention, the basic protein in the basic protein layer includes at least one of salmon protamine and herring protamine.

[0021] In some embodiments of the present invention, the polysaccharide in the polysaccharide layer includes at least one of pectin, chitosan, sodium alginate, and carboxymethyl cellulose.

[0022] In another aspect, the present invention provides a method for preparing the above-mentioned oral release microgel particles. According to an embodiment of the present invention, the method includes:

[0023] (1) Mix the fragrance and oil to obtain the essential oil;

[0024] (2) Dissolve the protein and polysaccharide in water and adjust the pH to 4.4-4.8 respectively to obtain a protein solution and a first polysaccharide solution;

[0025] (3) The essential oil and the protein solution are mixed to obtain a fragrance emulsion;

[0026] (4) The flavor emulsion and the first polysaccharide solution are mixed to obtain oral release microgel particles.

[0027] According to the method for preparing oral-release microgel particles according to the above embodiments of the present invention, firstly, a fragrance and an oil are mixed to dissolve the fragrance in the oil, thereby obtaining a fragrance oil. Protein and polysaccharide are dissolved in water and the pH is adjusted to 4.4–4.8 to obtain a protein solution and a first polysaccharide solution. In an environment with a pH of 4.4–4.8, the protein surface carries a positive charge, and the polysaccharide surface carries a negative charge. The fragrance oil and the protein solution are mixed. Due to its natural amphiphilicity, the protein spontaneously migrates to the water-oil interface during high-speed shearing, acting as a surfactant, thereby forming an oil-in-water emulsion, allowing the oil droplets to be uniformly and stably dispersed in the aqueous phase. Finally, the fragrance emulsion and the first polysaccharide solution are mixed. The protein and polysaccharide form a shell through electrostatic adsorption, encapsulating the fragrance oil, thus forming a core of the fragrance oil and a protein-polysaccharide shell covering the core surface. This outer shell acts as a physical barrier at the water-oil or gas-oil interface, increasing mass transfer resistance at the interface while simultaneously forming hydrophobic associations with aroma compounds escaping from essential oils, reducing the release rate and extent of these compounds. However, during food chewing, changes in the pH environment of the food bolus cause the proteoglycan shell structure to depolymerize, disintegrating and releasing the essential oils. The released aroma compounds are then perceived via the retronasal olfactory pathway, thus achieving the delivery and perception of the target aroma. Therefore, this method can be used to prepare orally released microgel particles that exhibit sufficient stability in the external environment, with minimal aroma volatilization before ingestion, but rapidly disintegrate and release aroma upon entering the oral cavity.

[0028] Pea protein is a natural amphiphilic substance. During the high-speed shearing process of essential oil and pea protein solution, pea protein spontaneously migrates to the water-oil interface to act as a surfactant, causing oil droplets to be evenly distributed in the aqueous phase, forming an oil-in-water emulsion. In an environment of pH 4.4-4.8, the surface of pea protein carries a positive charge, while the surface of pectin carries a negative charge. During the mixing of pectin solution and emulsion, pectin and pea protein form microgel particles through electrostatic adsorption, binding the essential oil inside the particles. At this time, the surface of the microgel particles carries a negative charge. In the corresponding pH environment, the surfaces of ε-polylysine and pectin carry positive and negative charges, respectively. Through a layer-by-layer self-assembly structured design, ε-polylysine and pectin are alternately adsorbed on the surface of microgel particles, forming microgel particles with different encapsulation layers on their surfaces.

[0029] In addition, the method for preparing oral release microgel particles according to the above embodiments of the present invention may also have the following technical features:

[0030] In some embodiments of the present invention, in step (1), the mass percentage of the fragrance in the essential oil is no more than 50%. This facilitates the release and volatilization of the aroma upon ingestion.

[0031] In some embodiments of the present invention, in step (2), the pH of the water is 4 to 5. This is beneficial for proteins and polysaccharides to carry positive and negative charges, respectively.

[0032] In some embodiments of the present invention, in step (2), the protein concentration in the protein solution is 0.005 g / mL to 0.02 g / mL. This improves the stability and texture of the shell.

[0033] In some embodiments of the present invention, in step (2), the polysaccharide concentration in the first polysaccharide solution is 0.005 g / mL to 0.02 g / mL. This allows for adjustment of the particle size of the microgel particles and the fragrance loading.

[0034] In some embodiments of the present invention, in step (3), the mass percentage of the essential oil in the fragrance emulsion is no more than 5%.

[0035] In some embodiments of the present invention, the method further includes: (5) dissolving the alkaline material and the polysaccharide in water and adjusting the pH value to 4.4 to 4.8 respectively to obtain an alkaline material solution and a second polysaccharide solution; (6) mixing the oral release microgel particles with the alkaline material solution to form an alkaline material layer on the surface of the oral release microgel particles; (7) mixing the oral release microgel particles with the alkaline material layer formed on the surface with the second polysaccharide solution to form a polysaccharide layer on the alkaline material layer; (8) repeating steps (6) and (7) to obtain an oral release microgel particle including an encapsulation shell having the alkaline material layer and the polysaccharide layer spaced apart. The alkaline material and polysaccharide are dissolved in water and the pH is adjusted to 4.4–4.8, so that the alkaline material and polysaccharide are positively and negatively charged, respectively. The oral release microgel particles are mixed with the alkaline material solution. Therefore, the oral release microgel particles prepared in step (4) have a negatively charged surface. Thus, the alkaline material and the oral release microgel particles form an alkaline material layer on the surface of the oral release microgel particles through electrostatic adsorption. The oral release microgel particles with the alkaline material layer on the surface are mixed with the second polysaccharide solution. Because the alkaline material layer is positively charged, it forms a polysaccharide layer on the alkaline material layer through electrostatic adsorption. Repeating the above steps (6) and (7), the oral release microgel particles can be formed by layer-by-layer self-assembly through electrostatic adsorption, including an encapsulation shell with an alkaline material layer and a polysaccharide layer spaced apart. Thus, by setting the encapsulation shell, the stability of the oral release microgel particles in the external environment is further improved while ensuring the disintegration of the microgel particles at the inlet.

[0036] In some embodiments of the present invention, in step (5), the concentration of the alkaline material in the alkaline material solution is 1 mg / mL to 4 mg / mL. This ensures that the microgel particles can carry the maximum amount of food flavoring without affecting the taste and texture of the food.

[0037] In some embodiments of the present invention, in step (5), the concentration of the polysaccharide in the second polysaccharide solution is 1 mg / mL to 4 mg / mL. Therefore, while delaying the loss of flavorings during food processing and storage, the aroma compounds can be released in the oral cavity at the maximum extent possible through disintegration.

[0038] In some embodiments of the present invention, in step (5), the pH of the water is 4 to 5. This facilitates the alkaline material and the polysaccharide carrying positive and negative charges, respectively.

[0039] In some embodiments of the present invention, the volume ratio of the alkaline material solution in step (6) to the second polysaccharide solution in step (7) is 1:(1-2). This delays the loss of flavoring during food processing and storage, while simultaneously releasing essential oils through structural breakdown in the oral cavity.

[0040] In a third aspect, the present invention provides a food product. According to embodiments of the present invention, the food product comprises the above-described oral-release microgel particles or oral-release microgel particles obtained by the above method. Thus, the food product achieves aroma and flavor stabilization, and provides a better sensory experience upon entering the oral cavity.

[0041] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0042] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0043] Figure 1 This is a schematic diagram of the structure of an oral release microgel particle according to an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of the structure of oral release microgel particles according to another embodiment of the present invention;

[0045] Figure 3 These are microscopic morphology images of the oral release microgel particles of Examples 1-5 of the present invention;

[0046] Figure 4These are disintegration performance diagrams of the oral release microgel particles prepared in Examples 1, 3 and 5 of this invention in an oral environment;

[0047] Figure 5 This is a particle size distribution diagram of the oral release microgel particles of Examples 6-9 of the present invention in the oral cavity environment;

[0048] Figure 6 This is a graph showing the release rate of hexanol in the oral cavity environment of the oral release microgel particles of Examples 6-8 of the present invention;

[0049] Figure 7 This is a graph showing the release rate of cis-3-hexenal in the oral-release microgel particles of Examples 6-8 of the present invention in the oral environment.

[0050] Figure 8 This is a graph showing the stability test results of the oral release microgel particles of Examples 10-13 of the present invention. Detailed Implementation

[0051] The embodiments of the present invention are described in detail below, and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0052] In one aspect of the invention, an oral-release microgel particle is provided. According to an embodiment of the invention, reference is made to... Figure 1 The oral release microgel particles consist of a core 100 and a shell 200.

[0053] According to an embodiment of the present invention, the core 100 includes essential oil, which comprises fragrance and oil; the outer shell 200 covers the surface of the core 100 and includes protein and polysaccharide. The outer shell 200, formed by protein and polysaccharide, encapsulates the essential oil, improving the stability of the oral-release microgel particles before ingestion. Simultaneously, because the protein and polysaccharide carry positive and negative charges respectively under a certain pH environment, they form the outer shell 200 through electrostatic adsorption. This protein-polysaccharide outer shell 200 ensures that the negative charge on the surface of the microgel particles is not less than 30mV, thereby providing sufficient electrostatic repulsion to prevent aggregation between microgel particles. This not only improves the dispersibility of the microgel particles in the external environment but also enhances their stability. On the other hand, during food chewing, the microgel particles mix with saliva (pH≈7) to form a bolus. The change in pH environment causes the protein and polysaccharide to change from electrostatic adsorption to electrostatic repulsion, which facilitates the microgel particles' response to pH stimulation in the oral environment, thereby disintegrating and releasing the essential oil. After the microgel particles enter the mouth, the oral cavity can quickly perceive the aroma. Therefore, the oral release microgel particles have sufficient stability in the external environment, and the aroma does not easily evaporate before entering the mouth, thus achieving aroma loading and protection. After entering the oral cavity, they can quickly disintegrate and release aroma, achieving the target delivery of aroma and improving the aroma experience in the oral cavity.

[0054] It should be noted that flavorings and oils are conventional materials in this field, and those skilled in the art can select them according to actual needs. For example, flavorings include raspberry flavoring, vanilla flavoring, orange flavoring, etc., and oils include vegetable oils, such as peanut oil, soybean oil, rapeseed oil, etc.

[0055] According to an embodiment of the present invention, the particle size of the core 100 is 0.5 μm to 1.0 μm. The inventors have found that if the particle size of the core 100 is too large, its dispersibility in the food matrix is ​​poor; if the particle size of the core 100 is too small, the loading of the encapsulated essential oil is low. Therefore, this application uses a core 100 with a particle size of 0.5 μm to 1.0 μm, which can improve the stability of orally releaseable microgel particles.

[0056] According to an embodiment of the present invention, the thickness of the outer shell 200 is 2.0 μm to 4.0 μm. The inventors have found that if the thickness of the outer shell 200 is too small, the aroma release performance in the external environment is poor; if the thickness of the outer shell 200 is too large, the aroma release performance in the oral cavity is poor. Therefore, this application uses an outer shell 200 with a thickness of 2.0 μm to 4.0 μm, which can improve the stability of the oral release microgel particles and their rapid release upon ingestion.

[0057] According to an embodiment of the present invention, the mass ratio of protein to polysaccharide in the shell 200 is (3-1):1. The inventors have found that if the mass ratio of protein to polysaccharide in the shell 200 is too large, the microgel particles will be too large, affecting the texture; if the mass ratio is too small, the aroma retention rate will be too low. Therefore, this application uses a shell 200 with a protein-to-polysaccharide mass ratio of (3-1):1, which can improve both texture and aroma retention.

[0058] According to embodiments of the present invention, the protein includes at least one of pea protein, soy protein isolate, whey protein, rice protein, and flaxseed protein. The inventors have discovered that the above-mentioned protein is an electronegative material within a preferred pH range (pH 4.4-4.8), capable of electrostatic self-assembly with electronegative materials to form microgel particle structures coated with essential oils. Its hydrophobic groups can undergo non-covalent association with aroma compounds, thereby delaying the aroma mass transfer process. Further, the polysaccharide includes at least one of pectin, chitosan, sodium alginate, and carboxymethyl cellulose. The inventors have discovered that the above-mentioned polysaccharide is an electronegative material within a preferred pH range (pH 4.4-4.8), capable of electrostatic self-assembly with electronegative materials to form microgel particles, and can capture aroma compounds through hydrophobic microdomains, thereby delaying the migration and diffusion of aroma.

[0059] According to embodiments of the present invention, the device further includes an encapsulation shell covering the surface of the outer shell. The encapsulation shell comprises at least one alkaline material layer covering the surface of the outer shell. The alkaline material layer is a polybasic amino acid layer or a basic protein layer. The outer shell of the oral-release microgel particles carries a negative charge, while the alkaline material in the alkaline material layer carries a positive charge. Through electrostatic adsorption, an alkaline material layer is formed on the surface of the outer shell. By encapsulating the outer shell of the oral-release microgel particles with an alkaline material layer, the stability of the oral-release microgel particles in the external environment can be further improved.

[0060] According to an embodiment of the present invention, reference Figure 2 The encapsulation shell comprises multiple layers of alkaline material 300 and multiple layers of polysaccharide 400, spaced apart along a direction away from the outer shell. The alkaline material layers 300 are positively charged, and the polysaccharide layers 400 are negatively charged. The polysaccharide layers 400 are formed on the alkaline material layers 300 through electrostatic adsorption, or the alkaline material layers 300 are formed on the polysaccharide layers 400. By forming an encapsulation shell comprising spaced alkaline material layers 300 and polysaccharide layers 400 on the outer shell of the oral-release microgel particles, the stability of the oral-release microgel particles can be improved.

[0061] According to embodiments of the present invention, the thickness of the encapsulation shell is no greater than 4.0 μm. The inventors have found that if the encapsulation shell is too thick, the microgel particles become too unstable in the oral cavity and cannot respond to pH stimulation in the oral environment to release the essential oil through structural disintegration. Therefore, this application uses an encapsulation shell with a thickness of no more than 4.0 μm, which allows for rapid release of the microgel particles in the oral cavity. Furthermore, the number of polysaccharide layers is no more than two.

[0062] According to embodiments of the present invention, the polybasic amino acid layer comprises at least one of polylysine, polyhistidine, and polyarginine. The basic protein layer comprises at least one of salmon protamine and herring protamine. The inventors have discovered that the aforementioned polybasic amino acids and basic proteins carry a negative charge in a preferred pH environment (pH 4.4-4.8), acting as electronegative encapsulating materials. They can form microgel particles through electrostatic self-assembly with electronegative encapsulating materials. Simultaneously, the proteins exhibit hydrophobic interactions with aroma compounds, which can delay the migration and diffusion of aroma. Further, the polysaccharide layer comprises at least one of pectin, chitosan, sodium alginate, and carboxymethyl cellulose. The inventors have discovered that the aforementioned polysaccharides carry a positive charge in a preferred pH environment (pH 4.4-4.8), acting as electronegative encapsulating materials. They can form microgel particles through electrostatic self-assembly with electronegative encapsulating materials. Simultaneously, the aforementioned polysaccharides exhibit hydrophobic interactions with aroma compounds, which can delay the migration and diffusion of aroma.

[0063] In another aspect, the present invention provides a method for preparing the above-mentioned oral release microgel particles. According to an embodiment of the present invention, the method includes:

[0064] S100: Mixing fragrance and oil

[0065] In this step, the fragrance and oil are vortexed for at least 1 minute to dissolve the fragrance in the oil, thus obtaining the essential oil. Furthermore, the mass percentage of fragrance in the essential oil is no more than 50%, thereby reducing the volatility of the aroma compounds.

[0066] S200: Dissolve the protein and polysaccharide in water separately and adjust the pH to 4.4–4.8.

[0067] In this step, the protein is dissolved in deionized water with a pH of 4–5, stirred until dissolved under refrigeration, and then the pH of the solution is adjusted to 4.4–4.8 to obtain the protein solution. The polysaccharide is also dissolved in deionized water with a pH of 4–5, stirred until dissolved under refrigeration, and then the pH of the solution is adjusted to 4.4–4.8 to obtain the first polysaccharide solution. The protein solution and the first polysaccharide solution have identical pH values. The refrigeration temperature is 0℃–4℃, the magnetic stirring speed is ≥400 rpm, and the stirring time is ≥12 hours. In an environment with a pH of 4.4–4.8, the protein surface carries a positive charge, and the polysaccharide surface carries a negative charge. It should be noted that using deionized water with a pH of 4–5 allows the protein to be fully hydrated in an environment close to the preferred pH (4.4–4.8), avoiding protein denaturation caused by significant pH adjustments during preparation. Specifically, the preparation method for deionized water with a pH value of 4-5 is as follows: accurately measure 500 mL of deionized water into a beaker, stir magnetically at room temperature, measure its pH value, and adjust the pH of the deionized water to the range of 4-5 using 1.0 M and 0.1 M hydrochloric acid solutions.

[0068] According to embodiments of the present invention, the protein concentration in the protein solution is 0.005 g / mL to 0.02 g / mL. The inventors have found that if the protein concentration in the protein solution is too high, the protein-polysaccharide shell thickness is too large, affecting the edible texture; if the protein concentration in the protein solution is too low, the flavor oil loading is low, affecting the yield of the coated flavor. Therefore, this application uses a protein solution with a protein concentration of 0.005 g / mL to 0.02 g / mL to improve the stability and texture of the shell. Further, the polysaccharide concentration in the first polysaccharide solution is 0.005 g / mL to 0.02 g / mL. By controlling the polysaccharide concentration in the polysaccharide solution within the above range, the particle size of the microgel particles and the flavor loading can be adjusted.

[0069] S300: Mix essential oils and protein solution

[0070] In this step, the essential oil and protein solution are mixed and stirred, then subjected to high-speed shearing to form an oil-in-water emulsion. High-pressure homogenization further distributes the oil droplets more evenly in the aqueous phase, resulting in an oil-in-water emulsion with protein-coated essential oil. At this point, the oil droplets carry a positive charge due to the protein coating. Specifically, the high-speed shearing speed is ≥12000 rpm, the time is ≥2 min, the working pressure of the high-pressure homogenization is ≥10000 psi, and the number of homogenization cycles is ≥5. Furthermore, the mass percentage of essential oil in the flavor emulsion is no more than 5%. The inventors found that if the mass percentage of essential oil in the flavor emulsion is too high, the aroma release properties of the resulting microgel particles in the external environment are poor, failing to delay the loss of flavor during food processing and storage. Therefore, this application uses a flavor emulsion with an essential oil mass percentage of no more than 5%, which ensures the stability of the flavor in the food processing and storage environment while maintaining the sensitivity of the microgel particles to the oral environment, achieving the disintegration and release of the loaded flavor in the oral environment.

[0071] S400: Mix the fragrance emulsion and the first polysaccharide solution.

[0072] In this step, the fragrance emulsion and the first polysaccharide solution are mixed and magnetically stirred. Proteins and polysaccharides form a shell through electrostatic adsorption, encapsulating the fragrance oil. This creates a core of the fragrance oil and a protein-polysaccharide shell covering the core. After stirring for a period of time, the mixture is centrifuged, and the supernatant is discarded to remove excess protein and polysaccharides. The precipitate is then redissolved in an equal volume of deionized water at the same pH to obtain orally releaseable microgel particles. Specifically, the magnetic stirring speed is ≥400 rpm, the stirring time is 10 min–30 min, the centrifugation time is 1 min–3 min, and the centrifugal force is 800 × g–1200 × g.

[0073] Therefore, this method can be used to prepare orally released microgel particles that exhibit sufficient stability in the external environment, whose aroma does not easily volatilize before ingestion, but which rapidly disintegrate and release aroma upon entering the oral cavity. It should be noted that the characteristics and advantages described above for orally released microgel particles also apply to this method, and will not be repeated here.

[0074] According to embodiments of the present invention, the method for preparing oral release microgel particles further includes:

[0075] S500: Dissolve the alkaline material and polysaccharide in water separately and adjust the pH to 4.4–4.8.

[0076] In this step, an alkaline material is dissolved in deionized water with a pH of 4–5, and the pH of the solution is adjusted to 4.4–4.8 to obtain an alkaline material solution; a polysaccharide is dissolved in deionized water with a pH of 4–5, and the pH of the solution is adjusted to 4.4–4.8 to obtain a second polysaccharide solution. The alkaline material and the polysaccharide carry positive and negative charges, respectively, in an environment with a pH of 4.4–4.8.

[0077] S600: Mix oral-release microgel particles with an alkaline material solution.

[0078] In this step, the oral-release microgel particles prepared by S400 are vortex-mixed with an alkaline material solution, then centrifuged to remove the supernatant. Because the oral-release microgel particles have a negative charge on their surface, and the alkaline material in the alkaline material solution has a positive charge, the alkaline material will form an alkaline material layer on the surface of the oral-release microgel particles due to electrostatic adsorption. Specifically, the vortex mixing time is ≥1 min, the magnetic stirring speed is ≥400 rpm, and the stirring time is 5-10 min. Further, the concentration of the alkaline material in the alkaline material solution is 1 mg / mL to 4 mg / mL. The inventors found that if the concentration of the alkaline material in the alkaline material solution is too high, the protein-polysaccharide shell will be too thick, affecting the taste. If the concentration of the alkaline material in the alkaline material solution is too low, the flavor oil loading will be low, affecting the yield of coated flavor. Therefore, this application uses an alkaline material solution with a concentration of 1 mg / mL to 4 mg / mL, which can ensure that the microgel particles can carry the maximum amount of food flavor without affecting the taste of the food.

[0079] S700: A mixture of orally release microgel particles with an alkaline material layer on their surface and a second polysaccharide solution.

[0080] In this step, the oral-release microgel particles with an alkaline material layer on their surface obtained by S600 are mixed and stirred with a second polysaccharide solution, then centrifuged to remove the supernatant. The oral-release microgel particles with an alkaline material layer on their surface obtained by S600 carry a positive charge, while the polysaccharides in the second polysaccharide solution carry a negative charge. Through electrostatic adsorption, a polysaccharide layer is formed on the surface of the alkaline material layer. Further, the polysaccharide concentration in the second polysaccharide solution is 1 mg / mL to 4 mg / mL. The inventors found that if the polysaccharide concentration in the second polysaccharide solution is too high, the microgel particles are too stable in the oral environment, which is not conducive to their disintegration and aroma release. If the polysaccharide concentration in the second polysaccharide solution is too low, the aroma release is poor and cannot delay the loss of flavoring during food processing and storage. Therefore, this application uses a second polysaccharide solution with a polysaccharide concentration of 1 mg / mL to 4 mg / mL, which can maximize the disintegration and release of aroma compounds in the oral environment while delaying the loss of flavoring during food processing and storage.

[0081] According to an embodiment of the present invention, the volume ratio of the alkaline material solution in step (6) to the second polysaccharide solution in step (7) is 1:(1-2). The inventors have found that if the volume ratio of the alkaline material solution in step (6) to the second polysaccharide solution in step (7) is too small, the encapsulation layer thickness is too small, which is not conducive to delaying the loss of flavoring in the food processing and storage environment; if the volume ratio of the alkaline material solution in step (6) to the second polysaccharide solution in step (7) is too large, the encapsulation layer thickness is too large, which is not conducive to the disintegration and release of flavoring by the microgel particles in the oral environment. Therefore, the volume ratio of the alkaline material solution in step (6) to the second polysaccharide solution in step (7) of this application is 1:(1-2), which can delay the loss of flavoring in food processing and storage, and simultaneously release essential oils due to structural disintegration in the oral environment.

[0082] S700: Repeat S600 and S700

[0083] Repeat steps S600 and S700. Because the polysaccharide layer carries a negative charge, an alkaline material layer can be formed on the polysaccharide layer, i.e., repeat step S600. And because the alkaline material layer carries a positive charge, a polysaccharide layer can be formed on the alkaline material layer, i.e., repeat step S700. Repeat this process in sequence to form an encapsulation shell with an alkaline material layer and a polysaccharide layer spaced apart on the surface of the oral release microgel particles.

[0084] Therefore, by setting up an encapsulation shell, the stability of oral-release microgel particles in the external environment is further improved while ensuring the disintegration of microgel particles at the inlet.

[0085] In a third aspect, the present invention provides a food product. According to embodiments of the present invention, the food product comprises the above-described oral-release microgel particles or oral-release microgel particles obtained by the above-described method. Thus, the food product achieves aroma and flavor stabilization, and provides a better sensory experience upon entering the oral cavity. It should be noted that the features and advantages described above for oral-release microgel particles and their preparation methods also apply to this food product, and will not be repeated here.

[0086] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0087] Example 1

[0088] (1) Accurately weigh 4g each of pea protein and pectin, add 200mL of deionized water with pH 4.5, stir at 600rpm for 12h at 4℃ to fully dissolve, and after returning to room temperature, accurately adjust the pH to 4.4 to obtain pea protein solution and pectin solution 1.

[0089] (2) Accurately weigh 8g of rapeseed oil and 2g of raspberry essence, vortex for 2 minutes to fully mix and dissolve, and obtain an essential oil with a mass percentage of 20%;

[0090] (3) Accurately measure 90 mL of the above pea protein solution, place it at room temperature and magnetically stir at 600 rpm, add 2.5 mL of essential oil, shear at 16000 rpm for 2 min, and homogenize at 15000 psi for 5 times to obtain the flavor emulsion.

[0091] (4) Accurately measure 60 mL of the above fragrance emulsion, place it at room temperature and stir magnetically at 600 rpm, add 20 mL of pectin solution 1, continue stirring for 30 min, centrifuge the mixture at 1000×g for 3 min, pour off the supernatant to remove excess protein and polysaccharide, redissolve the precipitate to obtain oral release microgel particles (LBL0) dispersion, spray dry to obtain oral release microgel particles (LBL0).

[0092] The essential oil in the prepared oral release microgel particles had a particle size of 0.61±0.03μm; the thickness of the pea protein-pectin shell was 3.37±0.02μm; and the mass ratio of pea protein to polysaccharide in the shell was 3:1.

[0093] Example 2

[0094] Steps (1) to (4) of Example 2 are the same as those of Example 1;

[0095] (5) Accurately weigh 0.5g each of ε-polylysine and pectin, add 200mL of deionized water with pH 4.5, stir at 600rpm for 12h at 4℃ to fully dissolve, and after returning to room temperature, accurately adjust the pH to 4.4 to obtain ε-polylysine solution and pectin solution 2.

[0096] (6) Accurately measure 10 mL of the LBL0 dispersion obtained in step (4), place it under magnetic stirring at 600 rpm at room temperature, add 10 mL of ε-polylysine solution, continue stirring for 5 min, centrifuge the mixture at 1000×g for 3 min, reconstitute the precipitate, and obtain a microgel particle dispersion (LBL1) with an alkaline material layer (encapsulation shell) on the surface of the oral release microgel particles. Spray dry to obtain oral release microgel particles (LBL1) including the encapsulation shell, with a thickness of 0.73 μm.

[0097] Example 3

[0098] Steps (1) to (6) of Example 3 are the same as those of Example 2;

[0099] (7) The microgel particle dispersion (LBL1) with a surface coated with an alkaline material layer prepared in step (6) is mixed with 10 mL of pectin solution 2 and stirred for 5 min. The mixture is centrifuged at 1000×g for 3 min, the precipitate is reconstituted, and the microgel particle dispersion (LBL2) with a pectin layer coated on the alkaline material layer is spray-dried to obtain oral release microgel particles (LBL2) including an encapsulation shell (alkaline material layer + pectin layer) with a thickness of 1.8 μm.

[0100] Example 4

[0101] In Example 4, based on the LBL2 prepared in Example 3, the method of step (6) was repeated. The LBL2 dispersion prepared in Example 3 was placed at room temperature and magnetically stirred at 600 rpm. 10 mL of ε-polylysine solution was added and stirred for 5 min. The mixture was centrifuged at 1000×g for 3 min, the precipitate was re-dissolved, and an alkaline material layer was formed on the basis of LBL2 to obtain a microgel particle dispersion (LBL3). After spray drying, oral release microgel particles (LBL3) including an encapsulation shell (alkaline material layer + pectin layer + alkaline material layer) were obtained, with the thickness of the encapsulation shell being 2.86 μm.

[0102] Example 5

[0103] In Example 5, based on the LBL3 prepared in Example 4, the method of step (7) was repeated, that is, the LBL3 dispersion prepared in Example 4 was mixed with 10 mL of pectin solution 2 and stirred for 5 min. The mixture was centrifuged at 1000×g for 3 min, the precipitate was reconstituted, and the microgel particle dispersion (LBL4) coated with the pectin layer on the alkaline material layer was spray-dried to obtain oral release microgel particles (LBL4) including an encapsulation shell (alkaline material layer + pectin layer + alkaline material layer + pectin layer), with an encapsulation shell thickness of 3.54 μm.

[0104] The micromorphology of the oral-release microgel particles obtained in Examples 1-5 was observed using cryo-scanning electron microscopy, such as... Figure 3 As shown, LBL0, LBL1, LBL2, LBL3, and LBL4 exhibit irregular spherical structures.

[0105] Essential oils, pea protein, and pectin were labeled with Nile Red, thioflavin T (ThT), and fluorescein isothiocyanate (FITC), respectively. The fluorescently labeled materials were used to prepare LBL0 (Example 1), LBL2 (Example 3), and LBL4 (Example 5). The effect of saliva on the microgel particles was observed using laser confocal microscopy. The results are shown in [Figure 1]. Figure 4 ,from Figure 4It can be seen that LBL0, LBL2 and LBL4 exhibit an "oil leakage" phenomenon, meaning that the oral release microgel particles prepared in Examples 1, 3 and 5 can disintegrate and release essential oils in the oral environment.

[0106] Example 6

[0107] (1) Accurately weigh 2g each of pea protein and pectin, add 200mL of deionized water with pH 4.5, stir at 400rpm for 12h at 4℃ to fully dissolve, and after returning to room temperature, accurately adjust the pH to 4.6 to obtain pea protein solution and pectin solution 1.

[0108] (2) Accurately weigh 9g of rapeseed oil and 1g of grass essence, vortex for 2 minutes to fully mix and dissolve, and obtain an essential oil with a mass percentage of 10%;

[0109] (3) Accurately measure 30 mL of the above pea protein solution, place it at room temperature and magnetically stir at 600 rpm, add 0.8 mL of essential oil, shear at 12000 rpm for 2 min, and homogenize at 12000 psi for 5 times to obtain the essential oil emulsion.

[0110] (4) Accurately measure 15 mL of the above fragrance emulsion, place it at room temperature and magnetically stir at 600 rpm, add 5 mL of pectin solution 1, continue stirring for 10 min, centrifuge the mixture at 800×g for 2 min, pour off the supernatant to remove excess protein and polysaccharide, redissolve the precipitate to obtain oral release microgel particles (LBL0) dispersion, spray dry to obtain oral release microgel particles (LBL0).

[0111] The particle size of the essential oil in the prepared oral release microgel particles was 0.58±0.02μm; the thickness of the pea protein-pectin shell was 3.87±0.03μm; and the mass ratio of pea protein to polysaccharide in the shell was 2:1.

[0112] Example 7

[0113] Steps (1) to (4) of Example 7 are the same as those of Example 6;

[0114] (5) Accurately weigh 0.5g each of ε-polylysine and pectin, add 200mL of deionized water with pH 4.5, stir at 400rpm for 12h at 4℃ to fully dissolve, and after returning to room temperature, accurately adjust the pH to 4.6 to obtain ε-polylysine solution and pectin solution 2.

[0115] (6) Accurately measure 10 mL of the LBL0 dispersion obtained in step (4), place it at room temperature and stir magnetically at 400 rpm, add 10 mL of ε-polylysine solution, continue stirring for 5 min, centrifuge the mixture at 800×g for 2 min, reconstitute the precipitate, and obtain a microgel particle dispersion (LBL1) with an alkaline material layer (encapsulation shell) on the surface of the oral release type microgel particles.

[0116] (7) The microgel particle dispersion (LBL1) with a surface coated with an alkaline material layer prepared in step (6) was mixed with 10 mL of pectin solution 2 and stirred for 5 min. The mixture was centrifuged at 800×g for 2 min, the precipitate was reconstituted, and the microgel particle dispersion (LBL2) with a pectin layer coated on the alkaline material layer was spray-dried to obtain oral release microgel particles (LBL2) including an encapsulation shell (alkaline material layer + pectin layer) with a thickness of 0.32 μm.

[0117] Example 8

[0118] Based on the oral release microgel particles (LBL2) prepared in Example 7, steps (6) and (7) of Example 7 were repeated to obtain oral release microgel particles (LBL4) including an encapsulation shell (alkaline material layer + pectin layer + alkaline material layer + pectin layer), with the thickness of the encapsulation shell being 2.03 μm.

[0119] Example 9

[0120] Based on the oral release microgel particles (LBL4) prepared in Example 8, steps (6) and (7) of Example 7 were repeated multiple times to obtain oral release microgel particles (LBL8) including an encapsulation shell (alkaline material layer + pectin layer + alkaline material layer + pectin layer + alkaline material layer + pectin layer + alkaline material layer + pectin layer), with an encapsulation shell thickness of 8.15 μm.

[0121] The effect of saliva on the orally released microgel particles obtained in Examples 6-9 was characterized, and the results are shown in [the table below]. Figure 5 ,from Figure 5 It can be seen that LBL0, LBL2, and LBL4 showed a significant increase in particle size in the oral environment (p < 0.05), meaning that the essential oils released after disintegration aggregated to form larger oil droplets; LBL8 showed no significant change in particle size (p > 0.05), meaning that the microgel particles with 8 encapsulation layers on their surface were too stable in the oral environment and could not disintegrate to release essential oils.

[0122] Hexanal and cis-3-hexenal are aroma active substances in grass flavorings. The air-matrix partition coefficient (K) and retention rate (R) of the two substances in LBL0, LBL2 and LBL4 were determined by gas chromatography-mass spectrometry. The specific data are shown in Table 1.

[0123] Table 1

[0124]

[0125] As shown in Table 1, the K value is directly proportional to the number of encapsulation layers on the particle surface, while the R value is inversely proportional to the number of encapsulation layers. This means that the encapsulation shell on the particle surface acts as an interfacial barrier for aroma migration, effectively regulating the aroma release intensity. Compared to the 42.69% retention rate of unencapsulated fragrance, the retention rate of fragrance encapsulated using this invention is increased to over 80%. This indicates that the oral-release microgel particles of this application have a high aroma retention rate and excellent stability in the external environment.

[0126] The aroma release rates of Examples 6 (LBL0), 7 (LBL2), and 8 (LBL4) during oral processing were determined using dynamic headspace analysis. The results are shown in [Figure number missing]. Figure 6 and Figure 7 ,from Figure 6 and Figure 7 It can be seen that both hexanal and cis-3-hexenal, two representative aromas, can be released in the oral environment, and the release rate is inversely proportional to the number of encapsulation layers. That is, layer-by-layer self-assembly modification can effectively regulate the aroma release rate.

[0127] Example 10

[0128] (1) Accurately weigh 2g each of pea protein and pectin, add 200mL of deionized water with pH 4.5, stir at 400rpm for 12h at 4℃ to fully dissolve, and after returning to room temperature, accurately adjust the pH to 4.8 to obtain pea protein solution and pectin solution 1.

[0129] (2) Accurately weigh 6g of soybean oil and 4g of orange flavoring, vortex for 2 minutes to fully mix and dissolve, and obtain flavoring oil with a mass percentage of 40%;

[0130] (3) Accurately measure 30 mL of the above pea protein solution, place it at room temperature and magnetically stir at 500 rpm, add 1.0 mL of essential oil, shear at 15000 rpm for 3 min, and homogenize at 16000 psi for 5 times to obtain the flavor emulsion.

[0131] (4) Accurately measure 15 mL of the above fragrance emulsion, place it at room temperature and magnetically stir at 500 rpm, add 5 mL of pectin solution 1, continue stirring for 30 min, centrifuge the mixture at 1200×g for 1 min, pour off the supernatant to remove excess protein and polysaccharide, redissolve the precipitate to obtain oral release microgel particles (LBL0) dispersion, spray dry to obtain oral release microgel particles (LBL0).

[0132] The essential oil in the prepared oral release microgel particles had a particle size of 0.59±0.01μm; the thickness of the pea protein-pectin shell was 3.95±0.04μm; and the mass ratio of pea protein to polysaccharide in the shell was 1:1.

[0133] Example 11

[0134] Steps (1) to (4) of Example 11 are the same as those of Example 10;

[0135] (5) Accurately weigh 0.5g each of ε-polylysine and pectin, add 200mL of deionized water with pH 4.5, stir at 500rpm for 12h at 4℃ to fully dissolve, and after returning to room temperature, accurately adjust the pH to 4.8 to obtain ε-polylysine solution and pectin solution 2.

[0136] (6) Accurately measure 10 mL of the LBL0 dispersion obtained in step (4), place it at room temperature and magnetically stir at 500 rpm, add 10 mL of ε-polylysine solution, continue stirring for 5 min, centrifuge the mixture at 1200×g for 1 min, reconstitute the precipitate, and obtain a microgel particle dispersion (LBL1) with an alkaline material layer (encapsulation shell) on the surface of the oral release type microgel particles.

[0137] (7) The microgel particle dispersion (LBL1) with a surface coated with an alkaline material layer prepared in step (6) is mixed with 10 mL of pectin solution 2 and stirred for 5 min. The mixture is centrifuged at 1200×g for 1 min, the precipitate is reconstituted, and the microgel particle dispersion (LBL2) with a pectin layer coated on the alkaline material layer is spray-dried to obtain oral release microgel particles (LBL2) including an encapsulation shell (alkaline material layer + pectin layer) with a thickness of 0.95 μm.

[0138] Example 12

[0139] Based on the oral release microgel particles (LBL2) prepared in Example 11, steps (6) and (7) of Example 11 were repeated to obtain oral release microgel particles (LBL4) including an encapsulation shell (alkaline material layer + pectin layer + alkaline material layer + pectin layer), with the thickness of the encapsulation shell being 2.12 μm.

[0140] Example 13

[0141] Based on the oral release microgel particles (LBL4) prepared in Example 12, steps (6) and (7) of Example 11 were repeated multiple times to obtain oral release microgel particles (LBL8) including an encapsulation shell (alkaline material layer + pectin layer + alkaline material layer + pectin layer + alkaline material layer + pectin layer + alkaline material layer + pectin layer), with an encapsulation shell thickness of 6.65 μm.

[0142] The juice matrix (deionized water, glucose, citric acid, pectin, etc.) was prepared according to commercially available orange juice, and the pH was adjusted to 3.0-5.0. The pH stability of the microgel particles was evaluated by changes in particle size. The results are shown in [Figure number missing]. Figure 8 ,from Figure 8 It can be seen that the microgel particles of Examples 10-13 all have good stability with fruit juice. In particular, the microgel particles with two or more encapsulation shells on their surface have better stability within the test range. The instability coefficient is inversely proportional to the number of encapsulation layers, indicating that the encapsulation shell helps to enhance the stability of oral release microgel particles in the food storage and transportation environment.

[0143] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0144] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An oral release microgel particle, characterized in that, include: The core comprises essential oil, which includes fragrance and oil, and the particle size of the core is 0.5μm~1.0μm; The shell, which covers the surface of the core, comprises a protein and a polysaccharide, and has a thickness of 2.0 μm to 4.0 μm. The mass ratio of the protein to the polysaccharide in the shell is (3 to 1):

1. The protein includes at least one of pea protein, soy protein isolate, whey protein, rice protein, and flaxseed protein; The polysaccharide includes at least one of pectin, sodium alginate and carboxymethyl cellulose; It also includes a packaging shell, which covers the surface of the outer shell. The thickness of the packaging shell is no more than 4.0 μm. The packaging shell includes an alkaline material layer and a polysaccharide layer, which are spaced apart in a direction away from the outer shell. The polysaccharides in the polysaccharide layer include at least one of pectin, sodium alginate, and carboxymethyl cellulose.

2. The microgel particles according to claim 1, characterized in that, The alkaline material layer is a polybasic amino acid layer or an alkaline protein layer.

3. The microgel particles according to claim 2, characterized in that, The number of polysaccharide layers is no more than 2; Optionally, the polybasic amino acid layer comprises at least one of polylysine, polyhistidine, and polyarginine. Optionally, the basic protein in the basic protein layer includes at least one of salmon protamine and herring protamine.

4. A method for preparing the oral release microgel particles according to any one of claims 1 to 3, characterized in that, include: (1) Mix the fragrance and oil to obtain the essential oil; (2) Dissolve the protein and polysaccharide in water and adjust the pH to 4.4-4.8 respectively to obtain a protein solution and a first polysaccharide solution; (3) The essential oil and the protein solution are mixed to obtain a fragrance emulsion; (4) The fragrance emulsion and the first polysaccharide solution are mixed to obtain oral release microgel particles; (5) Dissolve the alkaline material and polysaccharide in water and adjust the pH to 4.4~4.8 respectively to obtain an alkaline material solution and a second polysaccharide solution; (6) The oral release microgel particles are mixed with the alkaline material solution to form an alkaline material layer on the surface of the oral release microgel particles; (7) The oral release microgel particles on which the alkaline material layer is formed on the surface are mixed with the second polysaccharide solution to form a polysaccharide layer on the alkaline material layer; (8) Repeat steps (6) and (7) to obtain oral release microgel particles comprising an encapsulation shell having the alkaline material layer and the polysaccharide layer spaced apart.

5. The method according to claim 4, characterized in that, In step (1), the mass percentage of the fragrance in the essential oil is no more than 50%; Optionally, in step (2), the pH of the water is 4 to 5; Optionally, in step (2), the protein concentration in the protein solution is 0.005 g / mL to 0.02 g / mL; Optionally, in step (2), the polysaccharide concentration in the first polysaccharide solution is 0.005 g / mL to 0.02 g / mL; Optionally, in step (3), the mass percentage of the essential oil in the fragrance emulsion is no more than 5%.

6. The method according to claim 4, characterized in that, In step (5), the concentration of the alkaline material in the alkaline material solution is 1 mg / mL to 4 mg / mL; Optionally, in step (5), the concentration of the polysaccharide in the second polysaccharide solution is 1 mg / mL to 4 mg / mL; Optionally, in step (5), the pH of the water is 4 to 5; Optionally, the volume ratio of the alkaline material solution in step (6) to the second polysaccharide solution in step (7) is 1:(1~2).

7. A food product, characterized in that, Includes the oral-release microgel particles according to any one of claims 1-3 or oral-release microgel particles obtained by the method according to any one of claims 4-6.

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