Functional oral liquid containing dandelion extract and preparation method thereof

Abstract

The present invention relates to the field of oral liquids, and provides a functional oral liquid containing dandelion extract and a preparation method thereof, which solves the problems of unstable ingredients and bitter taste of existing products. The method comprises enzymatic extraction of dandelion extract, ultrasound-assisted purification, ethanol precipitation and freeze-drying to obtain purified polysaccharides, and then modifying sodium alginate, pectin and whey protein by carboxymethyl chitosan, and combining with calcium carbonate nanoparticles to prepare a W / O type emulsion, which is then gelled and freeze-dried to form microcapsules, which are finally added to the oral liquid matrix to obtain a product with good taste and high stability. The obtained microcapsules have a particle size of 8 to 12 μm and an encapsulation rate of ≥90%. They can effectively mask bitterness, reduce the bitterness value to 8.0 to 11.0 BU, and have a storage stability of 150 to 180 days, thus having high application value.

Description

Technical Field

[0001] The present invention relates to the field of oral liquids, and in particular to a functional oral liquid containing dandelion extract and a preparation method thereof. Background Art

[0002] With functional foods and nutritional supplements gaining increasing market attention, the application of botanical active ingredients in oral liquid products has become a key area driving food technology innovation. Dandelion extracts, a natural plant resource with a wide range of pharmacological activities, are rich in bioactive components, exhibiting multiple functions, including anti-inflammatory, antioxidant, and hepatoprotective and stomach-protective properties. Consequently, they are widely used in the development of novel functional oral liquids, particularly for the daily well-being of individuals with sub-health conditions, those with compromised immune systems, and the elderly. However, to achieve stable release and enhanced bioavailability in oral liquid products, the material system must possess excellent ingredient protection, good taste-masking properties, excellent dispersion stability, and suitable storage stability. The material system must also maintain long-term functional activity at room temperature and exhibit a good dissolution rate and absorption efficiency in vivo. From an application perspective, the structural design of the material must not only ensure that the active ingredients are not easily degraded or inactivated, but also meet consumers' comprehensive sensory requirements for taste, color, and flowability. Therefore, developing a microencapsulation material system that both protects the active ingredients and significantly improves taste is crucial for enhancing the competitiveness and market acceptance of botanical functional beverages. Overall, conducting material innovation research around the stability and taste optimization of dandelion extracts can not only significantly improve the functional performance and application expansion space of the product, but also play a positive role in promoting the efficient use of natural products in the field of functional foods.

[0003] Although the technology for preparing oral liquids based on plant active ingredients has made some progress in recent years, there are still many limitations in practical applications, especially in terms of ingredient stability and sensory experience. For example, the Chinese patent application number CN106237130A discloses a method for preparing a dandelion oral liquid for clearing heat and relieving pain and its oral liquid. Although some functional improvements have been achieved, there are still phenomena such as degradation of active ingredients and stratification precipitation during long-term storage, and the problem of strong bitterness has not been effectively solved, which has affected the sensory acceptance and market application prospects of the product. The main reason is that the active ingredients such as polyphenols and flavonoids in dandelion extracts are easily affected by factors such as temperature, light and pH, resulting in oxidation or polymerization. At the same time, there is a lack of effective encapsulation and sustained-release carrier systems, resulting in poor stability and poor taste in the oral liquid matrix. In addition, traditional excipient systems such as simple sugar alcohols and bulk flavorings are difficult to achieve accurate masking of bitterness, and under high concentration addition conditions, they may cause abnormal viscosity of the system, precipitation, and even affect the synergistic effect of other ingredients. Existing preparation methods often focus on adjusting formulation ratios, lacking systematic design from the perspective of material structure and interface control, making it difficult to meet the comprehensive requirements of functional foods for high stability, high bioavailability, and excellent taste. Therefore, there is an urgent need to develop a new material system that can simultaneously achieve ingredient protection and bitterness regulation to support the efficient application of dandelion extract in oral liquid products and promote the development of related products towards high quality and functionalization. Summary of the Invention

[0004] (1) Technical problems solved

[0005] The purpose of the present invention is to provide a functional oral liquid containing dandelion extract and a preparation method thereof, so as to solve the problems of unstable ingredients and bitter taste of the current functional oral liquid containing dandelion extract.

[0006] (2) Technical solution

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing a functional oral liquid containing dandelion extract comprises the following steps:

[0009] A. Preparation of Dandelion Extract:

[0010] A1. Mix dandelion powder with distilled water and add a complex enzyme solution composed of α-amylase, pectinase, cellulase, and papain in a mass ratio of (1.0-1.5):2:2:1 for enzymatic hydrolysis. After enzymatic hydrolysis, heat to 80-85°C for 5-8 minutes to inactivate the solution.

[0011] A2. Ultrasonicate the inactivated mixed solution and centrifuge to collect the supernatant;

[0012] A3. The supernatant was concentrated under reduced pressure and then precipitated with anhydrous ethanol. The precipitate was collected and freeze-dried to obtain crude polysaccharide;

[0013] A4. Purifying the crude polysaccharide by anion exchange column and gel filtration column to obtain a purified dandelion extract;

[0014] B. Microencapsulation treatment:

[0015] B1, mixing carboxymethyl chitosan-modified sodium alginate, pectin and dandelion extract, and then mixing with whey protein in a mass ratio of 70-90:10-30;

[0016] B2, adding calcium carbonate nanoparticles to the mixed solution, squeezing it into sunflower oil containing an emulsifying aid through a syringe, and stirring to form a W / O emulsion;

[0017] B3, adding sunflower oil and acetic acid mixture to the emulsion to form microcapsules, and then washing with ethanol and freeze-drying;

[0018] B4. Disperse the microcapsules in the oral liquid matrix to prepare the functional oral liquid.

[0019] Furthermore, in step A1, the particle size of dandelion powder is 80-120 mesh, and the material-liquid ratio of dandelion powder to distilled water is 1:25-1:35 g / mL; the total amount of complex enzyme solution added is 1.5-2.5% of the mass of dandelion powder; the enzymolysis temperature is 50-60° C., and the enzymolysis time is 20-30 minutes.

[0020] Furthermore, in step A2, the ultrasonic frequency is 35-45 kHz, the ultrasonic power is 180-220 W, the ultrasonic temperature is 70-80° C., and the ultrasonic treatment time is 45-65 minutes; the centrifugal speed is 18,000-22,000×g, and the centrifugal time is 8-12 minutes.

[0021] Furthermore, in step A3, the temperature for reduced pressure concentration is 55-65° C., the vacuum degree is -0.08-0.095 MPa, and the supernatant is concentrated to 1 / 3-1 / 5 of the original volume; anhydrous ethanol is added to a final concentration of 75-85%, and the mixture is allowed to stand and precipitate at 2-6° C. for 10-14 hours; and freeze-drying is performed at -45-55° C. and a vacuum degree of 5-15 Pa for 18-24 hours.

[0022] Furthermore, in step A4, the crude polysaccharide is prepared into an aqueous solution with a concentration of 80~120 mg / mL; the anion exchange column is a cellulose DE-52 column, and a NaCl solution with a concentration of 0.1~0.3M is used for gradient elution; the gel filtration column is a Sephadex G-75 column, and a NaCl solution with a concentration of 0.08~0.12M is used for elution; the elution flow rate is controlled at 0.8~1.2mL / min.

[0023] The present invention adopts the design of complex enzyme synergistic enzymatic hydrolysis and multi-stage refined extraction, which is mainly used to enhance the purification efficiency of dandelion extract and the stability performance of active ingredients. By introducing α-amylase, pectinase, cellulase and papain in the enzymatic hydrolysis step and acting synergistically in a specific mass ratio, it is possible to perform multi-site degradation on the complex cell wall structure in dandelion powder, so that polysaccharides and other effective ingredients are more fully released, thereby improving the initial extraction efficiency. The combination of complex enzymes not only exerts a targeted hydrolytic effect individually, but also forms a synergistic effect during the enzymatic hydrolysis process, improving the solubility and enzymatic hydrolysis degree of the raw materials, and providing higher quality starting materials for subsequent purification links. The subsequent ultrasonic assisted treatment is combined with high-frequency vibration and temperature control system to further promote cell disruption and component release, while achieving efficient liquid-solid separation under optimized centrifugal conditions to ensure the enrichment of target components in the supernatant. The reduced pressure concentration and ethanol precipitation steps effectively remove impurities and enrich crude polysaccharides through gentle dehydration and selective solvent action, reducing the risk of thermal degradation and maintaining the integrity of the active structure. Ultimately, a two-stage purification and separation strategy using anion exchange columns and gel filtration columns was employed, leveraging differences in molecular charge and relative molecular mass to achieve highly selective elution and ultimately purify the extract. The entire process flow, from enzymatic hydrolysis to purification, interconnects and complements each other, forming a systematic extraction mechanism from structural disruption to functional separation. This not only enhances the extraction rate and purity of the target substance, but also strengthens its stability and bioavailability in subsequent processing and applications, demonstrating the significant improvement in the extraction of complex natural products achieved through multi-factor synergistic optimization.

[0024] Furthermore, in step B1, 1.0 part of carboxymethyl chitosan-modified sodium alginate, 0.3-1.0 part of pectin, and 20-40 parts of dandelion extract solution are mixed to obtain a mixed solution, based on weight.

[0025] Furthermore, the preparation method of the carboxymethyl chitosan modified sodium alginate is as follows: in parts by weight, 1.0 part of sodium alginate, 0.3-1.0 part of carboxymethyl chitosan, and 80-120 parts of deionized water; dissolving the sodium alginate in 50-70 parts of deionized water, and stirring at 60-80° C. for 30-60 minutes until completely dissolved; dissolving the carboxymethyl chitosan in the remaining deionized water, and adjusting the pH value to 5.5-6.5; cooling to room temperature, and slowly adding the carboxymethyl chitosan solution dropwise to the sodium alginate solution for 15-30 minutes; after the dropwise addition is completed, continuing to stir for 60-120 minutes to fully complex, and then standing and aging at 4-8° C. for 12-24 hours to obtain a carboxymethyl chitosan modified sodium alginate composite solution.

[0026] Furthermore, in step B2, 100 parts of the mixed solution obtained in step B1, 1.0-3.0 parts of calcium carbonate nanoparticles, 150-200 parts of sunflower oil, 0.8-3.0 parts of emulsifying agent, and 3.0-6.0 parts of Tween 80 are added in parts by weight; first, the emulsifying agent and Tween 80 are added. 80 is added to sunflower seed oil, and stirred at 500 rpm on a magnetic stirrer for 1-2 minutes to prepare an oil phase, wherein the emulsifier is sorbitan monostearate; calcium carbonate nanoparticles are slowly added to the mixed solution obtained in step B1, and stirred for 2-5 minutes until completely dispersed without agglomeration, to prepare an aqueous phase; the aqueous phase is loaded into a 10-20 mL syringe and squeezed into the stirring oil phase through a 16-24 gauge blunt-tip stainless steel needle at a constant speed of 0.5-1.0 mL / min, maintaining the stirring speed at 500-800 rpm during the squeezing process. After the squeezing is completed, stirring is continued for 10-20 minutes until a milky white, uniform, and stable W / O emulsion is formed.

[0027] Furthermore, in step B3, 30 to 50 parts by weight of sunflower oil and 1.5 to 3.0 parts by weight of acetic acid are mixed to prepare a mixture, and then the mixture is slowly added to the W / O emulsion obtained in step B2 over a period of 15 to 25 minutes. After the microcapsules are formed, they are thoroughly washed with ethanol until no grease residue is left. The washed microcapsules are pre-frozen at -70 to -85°C for 0.5 to 2 hours, and then transferred to a freeze dryer and freeze-dried at -45 to -55°C and a vacuum degree of 0.8 to 1.5 Pa for 20 to 28 hours. The average particle size of the freeze-dried microcapsules is 8 to 12 μm, and the encapsulation efficiency is ≥90%.

[0028] The present invention adopts a composite encapsulation system design constructed by carboxymethyl chitosan modified sodium alginate, pectin, dandelion extract and whey protein, which is mainly used to enhance the encapsulation stability and bitterness masking performance of dandelion extract in functional oral liquid. By constructing a carrier material with carboxymethyl chitosan modified sodium alginate as the main skeleton, combining the rheological control properties of pectin and the interfacial activity characteristics of whey protein, the dispersibility and film-forming uniformity of the entire composite system in the aqueous phase are effectively improved, so that the distribution of active ingredients in the microcapsules is more uniform, the buffering capacity of the carrier to the external environment is stronger, and the fixation and protection capacity of the dandelion extract is improved. After adding calcium carbonate nanoparticles, the system strengthens the emulsification effect of the aqueous phase in the oil phase through a physical stabilization mechanism, forms a uniform and stable W / O emulsion structure under the synergistic conditions of stirring and constant-speed injection, and provides a stable precursor for subsequent microcapsule formation. After induction with a mixture of sunflower oil and acetic acid, the emulsion structure further crosslinks and solidifies to form a microcapsule shell. Using a low-temperature pre-freezing and freeze-drying process, a dry microcapsule powder with a dense structure and well-controlled particle size is ultimately obtained. Throughout the design, the synergistic effect between the various natural polymers and emulsifying components significantly enhances the microcapsule system's encapsulation efficiency, structural stability, and ability to regulate bitterness. This not only improves the stable dispersion of dandelion extract in complex liquid matrices but also effectively masks its natural bitterness at the sensory level, providing reliable material support and structural design paths for the high-quality development of functional oral solutions.

[0029] The present invention also provides a functional oral liquid containing dandelion extract, which contains, by weight, 8-15 parts of dandelion extract microcapsules, 75-85 parts of purified water, 0.3-0.8 parts of stevioside, 0.1-0.3 parts of sucralose, 0.8-1.5 parts of citric acid, 1.2-2.0 parts of sodium citrate, 0.05-0.15 parts of potassium sorbate, 0.02-0.08 parts of sodium benzoate, 0.2-0.5 parts of xanthan gum, 0.3-0.7 parts of sodium carboxymethyl cellulose, 2-5 parts of glycerol, and 0.01-0.05 parts of vitamin C. The oral liquid has a bitterness-masking effect so that the bitterness is 8.0-11.0 BU, and maintains stability for 150-180 days under storage conditions of 28°C.

[0030] The present invention also provides a functional oral liquid containing dandelion extract, whose formula design achieves a synergistic unity of high stability and good taste on the basis of taking into account the release of functional ingredients and sensory acceptance. The oral liquid uses dandelion extract microcapsules as the core functional ingredient. Through microencapsulation technology, it effectively improves its stability and sustained release ability in the liquid matrix, avoids degradation of the active ingredients due to oxidation, hydrolysis or light, and significantly reduces the taste discomfort caused by its natural bitterness. In terms of excipients, the compound design of steviol glycosides and sucralose effectively masks the bitter flavor of dandelion itself while ensuring a natural and harmonious sweetness, enhancing oral pleasure; citric acid and sodium citrate jointly adjust the pH of the system and enhance the flavor level; potassium sorbate and sodium benzoate synergistically construct an antiseptic system to ensure the storage stability of the product at room temperature; xanthan gum and sodium carboxymethyl cellulose act as rheology modifiers to jointly improve the viscosity and suspension of the system, preventing the components from settling or stratification; glycerol gives the product a suitable mouthfeel and smoothness; vitamin C not only has antioxidant function, but also further enhances the nutritional function of the product. The scientific and reasonable design of the overall ratio enables the oral liquid to maintain good stability for 150 to 180 days at 28°C, and the bitterness value is controlled between 8.0 and 11.0BU, fully meeting consumers' multiple demands for functionality, taste and storage performance, and has broad market application prospects.

[0031] (3) Beneficial technical effects

[0032] 1. This invention uses complex enzyme synergistic enzymatic hydrolysis and multi-stage separation and purification technology to improve extraction efficiency and ingredient stability, forming a synergistic mechanism of structural wall breaking and functional separation, significantly enhancing the purity and application performance of the active ingredients.

[0033] 2. This invention uses chitosan-modified sodium alginate, pectin, and whey protein to synergistically construct a microcapsule system, achieving efficient encapsulation and bitterness masking, significantly improving taste and stability, and solving the problems of ingredient release and acceptance, with broad application prospects.

[0034] 3. This invention significantly improves taste and stability through microcapsule encapsulation and multi-excipient collaborative design, solves the problems of unstable ingredients and bitterness, optimizes the ratio to achieve structural and functional synergy, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a photo of the freeze-dried dandelion prepared in Example 1 of the present invention.

[0036] Figure 2 This is a photo of the dandelion powder obtained by crushing in Example 1 of the present invention.

[0037] Figure 3 The enzymatically hydrolyzed mixed solution prepared in Example 1 of the present invention.

[0038] Figure 4 The extract prepared in Example 1 of the present invention after reduced pressure concentration.

[0039] Figure 5 This is a physical picture of the purified dandelion extract prepared in Example 1 of the present invention.

[0040] Figure 6 This is a relationship diagram between the enzymatic hydrolysis time and the extraction rate of dandelion extract of the present invention.

[0041] Figure 7 This is a relationship diagram between the enzymatic hydrolysis temperature and the extraction rate of dandelion extract of the present invention.

[0042] Figure 8 This is a relationship diagram between the solid-liquid ratio and the extraction rate of dandelion extract of the present invention.

[0043] Figure 9 This is a morphology diagram of the microcapsules containing dandelion extract prepared in Example 1 of the present invention with a solid-liquid ratio.

[0044] Figure 10 The diagram is a comparison of the bitter taste masking effects of the oral liquids of the embodiments of the present invention and the comparative examples.

[0045] Figure 11 The 6-month stability retention rate of the oral liquid products of the examples of the present invention and the comparative examples.

[0046] Figure 12 The figure is a comparison of the in vitro release behavior of the microcapsules of the examples of the present invention and the comparative examples.

[0047] Figure 13 The figures are the evaluation results of the antioxidant activity of the oral liquid products of the examples and comparative examples of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the specification of the present invention.

[0049] Example 1

[0050] A method for preparing a functional oral liquid containing dandelion extract comprises the following steps:

[0051] A. Preparation of Dandelion Extract:

[0052] A1. Dandelion powder was mixed with distilled water, and a complex enzyme solution composed of α-amylase, pectinase, cellulase, and papain in a mass ratio of 1.0:2:2:1 was added for enzymatic hydrolysis. After enzymatic hydrolysis, the mixture was heated to 80°C for 5 minutes to inactivate the mixture. Specifically, the dandelion powder particle size was 80 mesh, and the material-to-liquid ratio of the dandelion powder to distilled water was 1:25 g / mL. The total amount of the complex enzyme solution added was 1.5% of the mass of the dandelion powder. The enzymatic hydrolysis temperature was 50°C, and the enzymatic hydrolysis time was 20 minutes.

[0053] A2. Ultrasonicate the inactivated mixed solution and then centrifuge to collect the supernatant; the ultrasonic frequency is 35 kHz, the ultrasonic power is 180 W, the ultrasonic temperature is 70°C, and the ultrasonic treatment time is 45 minutes; the centrifugal speed is 18,000 × g, and the centrifugation time is 8 minutes.

[0054] A3. After the supernatant is concentrated under reduced pressure, anhydrous ethanol is added for precipitation. The precipitate is collected and freeze-dried to obtain crude polysaccharide; the temperature for reduced pressure concentration is 55°C and the vacuum degree is -0.08 MPa, and the supernatant is concentrated to 1 / 3 of the original volume; anhydrous ethanol is added to reach a final concentration of 75%, and the supernatant is allowed to settle at 2°C for 10 hours; freeze-drying is performed at -45°C and a vacuum degree of 5 Pa for 18 hours.

[0055] A4. Purify the crude polysaccharide by anion exchange column and gel filtration column to obtain a purified dandelion extract; the crude polysaccharide is prepared into an aqueous solution with a concentration of 80 mg / mL; the anion exchange column is a cellulose DE-52 column, and a 0.1 M NaCl solution is used for gradient elution; the gel filtration column is a Sephadex G-75 column, and a 0.08 M NaCl solution is used for elution; the elution flow rate is controlled at 0.8 mL / min.

[0056] B. Microencapsulation treatment:

[0057] B1. Mix carboxymethyl chitosan-modified sodium alginate, pectin and dandelion extract, and then mix with whey protein in a mass ratio of 76:24; in parts by weight, 1.0 part of carboxymethyl chitosan-modified sodium alginate, 0.5 part of pectin, and 26 parts of dandelion extract solution are mixed to obtain a mixed solution; the preparation method of carboxymethyl chitosan-modified sodium alginate is as follows: in parts by weight, 1.0 part of sodium alginate, 0.5 part of carboxymethyl chitosan, and 92 parts of deionized water; Sodium alginate was dissolved in 56 parts of deionized water and stirred at 66°C for 39 minutes until completely dissolved; carboxymethyl chitosan was dissolved in the remaining deionized water and the pH value was adjusted to 5.8; after cooling to room temperature, the carboxymethyl chitosan solution was slowly added dropwise to the sodium alginate solution for 20 minutes; after the addition was completed, stirring was continued for 78 minutes to ensure sufficient complexation, and then the solution was allowed to stand and mature at 5°C for 16 hours to obtain a carboxymethyl chitosan-modified sodium alginate composite solution.

[0058] B2, add calcium carbonate nanoparticles to the mixed solution, squeeze into the sunflower oil containing emulsifying aid through a syringe, and stir to form a W / O emulsion; in parts by weight, 100 parts of the mixed solution obtained in step B1, 1.6 parts of calcium carbonate nanoparticles, 165 parts of sunflower oil, 1.5 parts of emulsifying aids, and 3.9 parts of Tween 80; first, emulsifying aid and Tween 80 are added; 80 was added to sunflower oil and stirred at 500 rpm on a magnetic stirrer for 1 minute to prepare an oil phase, wherein the emulsifier was sorbitan monostearate; calcium carbonate nanoparticles were slowly added to the mixed solution obtained in step B1, and stirred for 3 minutes until completely dispersed without agglomeration, to prepare an aqueous phase; the aqueous phase was loaded into a 13 mL syringe and extruded into the stirring oil phase through an 18-gauge blunt-tipped stainless steel needle at a constant speed of 0.65 mL / min, maintaining the stirring speed at 590 rpm during the extrusion process. After the extrusion was completed, stirring was continued for 13 minutes until a milky white, uniform, and stable W / O emulsion was formed.

[0059] B3, sunflower seed oil and acetic acid mixture are added to the emulsion to form microcapsules, and the microcapsules are then freeze-dried after washing with ethanol; in parts by weight, 36 parts of sunflower seed oil are mixed with 2.0 parts of acetic acid to prepare a mixture, and then the mixture is slowly added to the W / O emulsion obtained in step B2 over a period of 18 minutes; after the microcapsules are formed, they are thoroughly washed with ethanol until no grease residue is left; the cleaned microcapsules are pre-frozen at -75 ° C for 1.0 hour, and then transferred to a freeze dryer and freeze-dried at -48 ° C, under a vacuum of 1.0 Pa for 22 hours; the average particle size of the freeze-dried microcapsules is 9 μm, and the encapsulation efficiency is ≥90%.

[0060] B4. Disperse the microcapsules in the oral liquid matrix to prepare the functional oral liquid.

[0061] The functional oral liquid containing dandelion extract of this embodiment contains, by weight, 10 parts of dandelion extract microcapsules, 78 parts of purified water, 0.5 parts of stevioside, 0.16 parts of sucralose, 1.0 parts of citric acid, 1.4 parts of sodium citrate, 0.08 parts of potassium sorbate, 0.04 parts of sodium benzoate, 0.29 parts of xanthan gum, 0.42 parts of sodium carboxymethyl cellulose, 2.9 parts of glycerol, and 0.02 parts of vitamin C. The bitterness-masking effect of the oral liquid reduces the bitterness value (BU) to 8.9, and the stability is maintained for 159 days when stored at 28°C.

[0062] from Figure 1-Figure 5 and Figure 9 It can be seen from the experimental results that the preparation method of the present invention can successfully prepare dandelion functional oral liquid. Figure 1 It shows that the freeze-dried dandelion raw materials maintain a good morphological structure, providing a high-quality raw material basis for subsequent processing. Figure 2The dandelion powder after medium crushing is uniform and fine powder, and the particle size reaches the requirement of 80-120 mesh, which is conducive to improving the efficiency of enzymatic hydrolysis and the release of effective ingredients. Figure 3 The mixed liquid after enzymatic hydrolysis was shown to be a uniform brown-yellow liquid, indicating that the complex enzyme solution can effectively destroy the dandelion cell wall structure and fully release active ingredients such as intracellular polysaccharides and flavonoids. Figure 4 The concentration of the extract after vacuum concentration increased significantly and the color deepened, which confirmed the effectiveness of the concentration process and laid the foundation for subsequent alcohol precipitation purification. Figure 5 The purified dandelion extract shown is in the form of light yellow powder with a uniform and fine texture, indicating that gradient purification using an anion exchange column and a gel filtration column can effectively remove impurities such as proteins and pigments to obtain a high-purity dandelion polysaccharide extract. Figure 9 Microscopic observation results showed that the prepared microcapsules had a regular spherical morphology, a smooth and dense surface, a uniform particle size distribution, and an average particle size in the range of 8-12 μm. This proved that the carboxymethyl chitosan-modified sodium alginate and whey protein composite carrier material can effectively encapsulate dandelion extract to form structurally stable microcapsules, providing a strong guarantee for achieving bitterness masking and controlled release effects.

[0063] Example 2

[0064] A method for preparing a functional oral liquid containing dandelion extract comprises the following steps:

[0065] A. Preparation of Dandelion Extract:

[0066] A1. Dandelion powder was mixed with distilled water, and a complex enzyme solution consisting of α-amylase, pectinase, cellulase, and papain in a mass ratio of 1.2:2:2:1 was added for enzymatic hydrolysis. After enzymatic hydrolysis, the mixture was heated to 82°C for 6 minutes to inactivate the mixture. Specifically, the dandelion powder had a particle size of 92 mesh and the material-to-liquid ratio of distilled water was 1:28 g / mL. The total amount of the complex enzyme solution added was 1.8% of the mass of the dandelion powder. The enzymatic hydrolysis temperature was 53°C, and the enzymatic hydrolysis time was 23 minutes.

[0067] A2. Ultrasonic treatment of the inactivated mixed solution was performed, and the supernatant was collected by centrifugation; the ultrasonic frequency was 38 kHz, the ultrasonic power was 192 W, the ultrasonic temperature was 73° C., and the ultrasonic treatment time was 51 minutes; the centrifugal speed was 19200 × g, and the centrifugation time was 9 minutes.

[0068] A3. The supernatant was concentrated under reduced pressure and then anhydrous ethanol was added for precipitation. The precipitate was collected and freeze-dried to obtain crude polysaccharide; the temperature for reduced pressure concentration was 58°C and the vacuum degree was -0.085 MPa, and the supernatant was concentrated to 1 / 4 of the original volume; anhydrous ethanol was added to reach a final concentration of 78%, and the mixture was allowed to settle at 3°C ​​for 11 hours; and freeze-drying was performed at -48°C and a vacuum degree of 8 Pa for 20 hours.

[0069] A4. Purify the crude polysaccharide by anion exchange column and gel filtration column to obtain a purified dandelion extract; the crude polysaccharide is prepared into an aqueous solution with a concentration of 92 mg / mL; the anion exchange column is a cellulose DE-52 column, and a 0.16 M NaCl solution is used for gradient elution; the gel filtration column is a Sephadex G-75 column, and a 0.09 M NaCl solution is used for elution; the elution flow rate is controlled at 0.92 mL / min.

[0070] B. Microencapsulation treatment:

[0071] B1. Mix carboxymethyl chitosan-modified sodium alginate, pectin and dandelion extract, and then mix with whey protein at a mass ratio of 70:30; in parts by weight, 1.0 part of carboxymethyl chitosan-modified sodium alginate, 0.3 part of pectin, and 20 parts of dandelion extract solution are mixed to obtain a mixed solution; the preparation method of carboxymethyl chitosan-modified sodium alginate is as follows: in parts by weight, 1.0 part of sodium alginate, 0.3 part of carboxymethyl chitosan, and 80 parts of deionized water; Sodium alginate was dissolved in 50 parts of deionized water and stirred at 60°C for 30 minutes until completely dissolved; carboxymethyl chitosan was dissolved in the remaining deionized water and the pH value was adjusted to 5.5; after cooling to room temperature, the carboxymethyl chitosan solution was slowly added dropwise to the sodium alginate solution for 15 minutes; after the addition was completed, stirring was continued for 60 minutes to fully complex the solution, and then the solution was allowed to stand and mature at 4°C for 12 hours to obtain a carboxymethyl chitosan-modified sodium alginate composite solution.

[0072] B2, add calcium carbonate nanoparticles to the mixed solution, squeeze into the sunflower oil containing emulsifying aid through a syringe, and stir to form a W / O emulsion; in parts by weight, 100 parts of the mixed solution obtained in step B1, 1.0 part of calcium carbonate nanoparticles, 150 parts of sunflower oil, 0.8 part of emulsifying aid, and 3.0 parts of Tween 80; first, emulsifying aid and Tween 80 are added; 80 is added to sunflower oil and stirred at 500 rpm on a magnetic stirrer for 1 minute to prepare an oil phase, wherein the emulsifier is sorbitan monostearate; calcium carbonate nanoparticles are slowly added to the mixed solution obtained in step B1, and stirred for 2 minutes until completely dispersed without agglomeration, to prepare an aqueous phase; the aqueous phase is loaded into a 10 mL syringe and squeezed into the stirring oil phase at a constant speed of 0.5 mL / min through a 16-gauge blunt-tipped stainless steel needle, maintaining the stirring speed at 500 rpm during the squeezing process. After the squeezing is completed, stirring is continued for 10 minutes until a milky white, uniform, and stable W / O emulsion is formed.

[0073] B3, sunflower seed oil and acetic acid mixture are added to the emulsion to form microcapsules, and the microcapsules are then freeze-dried after washing with ethanol; in parts by weight, 30 parts of sunflower seed oil are mixed with 1.5 parts of acetic acid to prepare a mixture, and then the mixture is slowly added to the W / O emulsion obtained in step B2 over a period of 15 minutes; after the microcapsules are formed, they are thoroughly washed with ethanol until no grease residue is left; the cleaned microcapsules are pre-frozen at -70°C for 0.5 hour, and then transferred to a freeze dryer and freeze-dried at -45°C and a vacuum of 0.8 Pa for 20 hours; the freeze-dried microcapsule average particle size is 8 μm, and the encapsulation efficiency is ≥90%.

[0074] B4. Disperse the microcapsules in the oral liquid matrix to prepare the functional oral liquid.

[0075] The functional oral liquid containing dandelion extract of this embodiment contains, by weight, 8 parts of dandelion extract microcapsules, 75 parts of purified water, 0.3 parts of stevioside, 0.1 parts of sucralose, 0.8 parts of citric acid, 1.2 parts of sodium citrate, 0.05 parts of potassium sorbate, 0.02 parts of sodium benzoate, 0.2 parts of xanthan gum, 0.3 parts of sodium carboxymethyl cellulose, 2 parts of glycerol, and 0.01 parts of vitamin C. The bitterness-masking effect of the oral liquid reduces the bitterness value (BU) to 8.0, and the stability is maintained for 150 days when stored at 28°C.

[0076] Example 3

[0077] A method for preparing a functional oral liquid containing dandelion extract comprises the following steps:

[0078] A. Preparation of Dandelion Extract:

[0079] A1. Dandelion powder was mixed with distilled water, and a complex enzyme solution consisting of α-amylase, pectinase, cellulase, and papain in a mass ratio of 1.3:2:2:1 was added for enzymatic hydrolysis. After enzymatic hydrolysis, the mixture was heated to 83°C for 7 minutes to inactivate the mixture. Specifically, the dandelion powder had a particle size of 104 mesh and the material-to-liquid ratio of distilled water was 1:31 g / mL. The total amount of the complex enzyme solution added was 2.1% of the mass of the dandelion powder. The enzymatic hydrolysis temperature was 56°C, and the enzymatic hydrolysis time was 26 minutes.

[0080] A2. Ultrasonicate the inactivated mixed solution and then centrifuge to collect the supernatant; the ultrasonic frequency is 41 kHz, the ultrasonic power is 204 W, the ultrasonic temperature is 76°C, and the ultrasonic treatment time is 57 minutes; the centrifugal speed is 20400 × g, and the centrifugation time is 10 minutes.

[0081] A3. The supernatant was concentrated under reduced pressure and then anhydrous ethanol was added for precipitation. The precipitate was collected and freeze-dried to obtain crude polysaccharide; the temperature for reduced pressure concentration was 61°C and the vacuum degree was -0.089 MPa, and the supernatant was concentrated to 1 / 4 of the original volume; anhydrous ethanol was added to reach a final concentration of 81%, and the mixture was allowed to settle at 4°C for 12 hours; and freeze-drying was performed at -51°C and a vacuum degree of 11 Pa for 22 hours.

[0082] A4. Purify the crude polysaccharide by anion exchange column and gel filtration column to obtain a purified dandelion extract; the crude polysaccharide is prepared into an aqueous solution with a concentration of 104 mg / mL; the anion exchange column is a cellulose DE-52 column, and a 0.22 M NaCl solution is used for gradient elution; the gel filtration column is a Sephadex G-75 column, and a 0.10 M NaCl solution is used for elution; the elution flow rate is controlled at 1.04 mL / min.

[0083] B. Microencapsulation treatment:

[0084] B1. Mix carboxymethyl chitosan-modified sodium alginate, pectin and dandelion extract, and then mix with whey protein at a mass ratio of 90:10; in parts by weight, 1.0 part of carboxymethyl chitosan-modified sodium alginate, 1.0 part of pectin, and 40 parts of dandelion extract solution are mixed to obtain a mixed solution; the preparation method of carboxymethyl chitosan-modified sodium alginate is as follows: in parts by weight, 1.0 part of sodium alginate, 1.0 part of carboxymethyl chitosan, and 120 parts of deionized water; Sodium alginate was dissolved in 70 parts of deionized water and stirred at 80°C for 60 minutes until completely dissolved; carboxymethyl chitosan was dissolved in the remaining deionized water and the pH value was adjusted to 6.5; after cooling to room temperature, the carboxymethyl chitosan solution was slowly added dropwise to the sodium alginate solution for 30 minutes; after the addition was completed, stirring was continued for 120 minutes to fully complex the solution, and then the solution was allowed to stand and mature at 8°C for 24 hours to obtain a carboxymethyl chitosan-modified sodium alginate composite solution.

[0085] B2, add calcium carbonate nanoparticles to the mixed solution, squeeze into the sunflower oil containing emulsifying aid through a syringe, and stir to form a W / O emulsion; in parts by weight, 100 parts of the mixed solution obtained in step B1, 3.0 parts of calcium carbonate nanoparticles, 200 parts of sunflower oil, 3.0 parts of emulsifying aids, and 6.0 parts of Tween 80; first, emulsifying aid and Tween 80 are added to the mixture; 80 is added to sunflower oil and stirred at 500 rpm on a magnetic stirrer for 2 minutes to prepare an oil phase, wherein the emulsifier is sorbitan monostearate; calcium carbonate nanoparticles are slowly added to the mixed solution obtained in step B1, and stirred for 5 minutes until completely dispersed without agglomeration, to prepare an aqueous phase; the aqueous phase is loaded into a 20 mL syringe and squeezed into the stirring oil phase at a constant speed of 1.0 mL / min through a 24-gauge blunt-tipped stainless steel needle, maintaining the stirring speed at 800 rpm during the squeezing process. After the squeezing is completed, stirring is continued for 20 minutes until a milky white, uniform, and stable W / O emulsion is formed.

[0086] B3, sunflower seed oil and acetic acid mixture are added to the emulsion to form microcapsules, and the microcapsules are then freeze-dried after washing with ethanol; in parts by weight, 50 parts of sunflower seed oil are mixed with 3.0 parts of acetic acid to prepare a mixture, and then the mixture is slowly added to the W / O emulsion obtained in step B2 over a period of 25 minutes; after the microcapsules are formed, they are thoroughly washed with ethanol until no grease residue is left; the cleaned microcapsules are pre-frozen at -85°C for 2 hours, and then transferred to a freeze dryer and freeze-dried at -55°C and a vacuum of 1.5 Pa for 28 hours; the freeze-dried microcapsules have an average particle size of 12 μm and an encapsulation efficiency of ≥90%.

[0087] B4. Disperse the microcapsules in the oral liquid matrix to prepare the functional oral liquid.

[0088] The functional oral liquid containing dandelion extract of this embodiment contains, by weight, 15 parts of dandelion extract microcapsules, 85 parts of purified water, 0.8 parts of stevioside, 0.3 parts of sucralose, 1.5 parts of citric acid, 2.0 parts of sodium citrate, 0.15 parts of potassium sorbate, 0.08 parts of sodium benzoate, 0.5 parts of xanthan gum, 0.7 parts of sodium carboxymethyl cellulose, 5 parts of glycerol, and 0.05 parts of vitamin C. The bitterness-masking effect of the oral liquid reduces the bitterness value (BU) to 11.0, and the stability is maintained for 180 days when stored at 28°C.

[0089] Example 4

[0090] A method for preparing a functional oral liquid containing dandelion extract comprises the following steps:

[0091] A. Preparation of Dandelion Extract:

[0092] A1. Dandelion powder was mixed with distilled water, and a complex enzyme solution composed of α-amylase, pectinase, cellulase, and papain in a mass ratio of 1.5:2:2:1 was added for enzymatic hydrolysis. After enzymatic hydrolysis, the mixture was heated to 85°C for 8 minutes to inactivate the mixture. Specifically, the dandelion powder had a particle size of 120 mesh and the material-to-liquid ratio of distilled water was 1:35 g / mL. The total amount of the complex enzyme solution added was 2.5% of the mass of the dandelion powder. The enzymatic hydrolysis temperature was 60°C, and the enzymatic hydrolysis time was 30 minutes.

[0093] A2. Ultrasonicate the inactivated mixed solution and then centrifuge to collect the supernatant; the ultrasonic frequency is 45 kHz, the ultrasonic power is 220 W, the ultrasonic temperature is 80°C, and the ultrasonic treatment time is 65 minutes; the centrifugal speed is 22,000 × g, and the centrifugation time is 12 minutes.

[0094] A3. The supernatant was concentrated under reduced pressure and then anhydrous ethanol was added for precipitation. The precipitate was collected and freeze-dried to obtain crude polysaccharide; the temperature for reduced pressure concentration was 65°C and the vacuum degree was -0.095 MPa, and the supernatant was concentrated to 1 / 5 of the original volume; anhydrous ethanol was added to reach a final concentration of 85%, and the mixture was allowed to settle at 6°C for 14 hours; and freeze-drying was performed at -55°C and a vacuum degree of 15 Pa for 24 hours.

[0095] A4. Purify the crude polysaccharide by anion exchange column and gel filtration column to obtain a purified dandelion extract; the crude polysaccharide is prepared into an aqueous solution with a concentration of 120 mg / mL; the anion exchange column is a cellulose DE-52 column, and a 0.3 M NaCl solution is used for gradient elution; the gel filtration column is a Sephadex G-75 column, and a 0.12 M NaCl solution is used for elution; the elution flow rate is controlled at 1.2 mL / min.

[0096] B. Microencapsulation treatment:

[0097] B1. Mix carboxymethyl chitosan-modified sodium alginate, pectin and dandelion extract, and then mix with whey protein in a mass ratio of 82:18; by weight, 1.0 part of carboxymethyl chitosan-modified sodium alginate, 0.7 part of pectin, and 32 parts of dandelion extract solution are mixed to obtain a mixed solution; the preparation method of carboxymethyl chitosan-modified sodium alginate is as follows: by weight, 1.0 part of sodium alginate, 0.7 part of carboxymethyl chitosan, and 104 parts of deionized water; Sodium alginate was dissolved in 62 parts of deionized water and stirred at 72°C for 48 minutes until completely dissolved; carboxymethyl chitosan was dissolved in the remaining deionized water and the pH value was adjusted to 6.1; after cooling to room temperature, the carboxymethyl chitosan solution was slowly added dropwise to the sodium alginate solution for 24 minutes; after the addition was completed, stirring was continued for 96 minutes to ensure sufficient complexation, and then the solution was allowed to stand and mature at 6°C for 19 hours to obtain a carboxymethyl chitosan-modified sodium alginate composite solution.

[0098] B2, add calcium carbonate nanoparticles to the mixed solution, squeeze into the sunflower oil containing emulsifying aid through a syringe, and stir to form a W / O emulsion; in parts by weight, 100 parts of the mixed solution obtained in step B1, 2.2 parts of calcium carbonate nanoparticles, 180 parts of sunflower oil, 2.1 parts of emulsifying aids, and 4.8 parts of Tween 80; first, emulsifying aid and Tween 80 are added; 80 is added to sunflower oil and stirred at 500 rpm on a magnetic stirrer for 2 minutes to prepare an oil phase, wherein the emulsifier is sorbitan monostearate; calcium carbonate nanoparticles are slowly added to the mixed solution obtained in step B1, and stirred for 4 minutes until completely dispersed without agglomeration, to prepare an aqueous phase; the aqueous phase is loaded into a 16 mL syringe and squeezed into the stirring oil phase at a constant speed of 0.8 mL / min through a 21-gauge blunt-tipped stainless steel needle, maintaining the stirring speed at 680 rpm during the squeezing process. After the squeezing is completed, stirring is continued for 16 minutes until a milky white, uniform, and stable W / O emulsion is formed.

[0099] B3, sunflower seed oil and acetic acid mixture are added to the emulsion to form microcapsules, and the microcapsules are then freeze-dried after washing with ethanol; in parts by weight, 42 parts of sunflower seed oil are mixed with 2.4 parts of acetic acid to prepare a mixture, and then the mixture is slowly added to the W / O emulsion obtained in step B2 over a period of 21 minutes; after the microcapsules are formed, they are thoroughly washed with ethanol until no grease residue is left; the cleaned microcapsules are pre-frozen at -79°C for 1.4 hours, and then transferred to a freeze dryer and freeze-dried at -51°C and a vacuum of 1.2 Pa for 25 hours; the freeze-dried microcapsule average particle size is 10 μm, and the encapsulation efficiency is ≥90%.

[0100] B4. Disperse the microcapsules in the oral liquid matrix to prepare the functional oral liquid.

[0101] The functional oral liquid containing dandelion extract of this embodiment contains, by weight, 12 parts of dandelion extract microcapsules, 81 parts of purified water, 0.6 parts of steviol glycosides, 0.22 parts of sucralose, 1.2 parts of citric acid, 1.7 parts of sodium citrate, 0.11 parts of potassium sorbate, 0.06 parts of sodium benzoate, 0.38 parts of xanthan gum, 0.54 parts of sodium carboxymethyl cellulose, 3.8 parts of glycerol, and 0.03 parts of vitamin C. The bitterness-masking effect of the oral liquid reduces the bitterness value (BU) to 9.8, and the stability is maintained for 168 days when stored at 28°C.

[0102] Figure 6-Figure 8 The experimental results of process parameter optimization show that the present invention can effectively improve the extraction efficiency of dandelion extract through systematic parameter regulation. Figure 6The results showed that the enzymatic hydrolysis time had a significant effect on the extraction rate. Within the range of 20-30 minutes, the extraction rate first increased rapidly and then leveled off with time, reaching a maximum of 3.2% at 26 minutes. Continuing to extend the time would lead to a decrease in the extraction rate. This is because excessive enzymatic hydrolysis may destroy some active ingredients or produce inhibitory products. Figure 7 The results showed the influence of enzymatic hydrolysis temperature. In the temperature range of 50-60℃, the extraction rate showed a trend of first increasing and then decreasing, reaching a peak of 3.8% at 56℃. When the temperature is too low, the enzyme activity is insufficient, resulting in insufficient extraction. When the temperature is too high, the enzyme may be inactivated or heat-sensitive components may be destroyed. Figure 8 This reflects the important role of the solid-liquid ratio on the extraction efficiency. As the solid-liquid ratio increases from 1:25 to 1:35 g / mL, the extraction rate gradually increases and reaches a maximum of 2.9% at 1:34 g / mL. The extraction rate decreases slightly with the subsequent increase in liquid dosage, indicating that there is an optimal solid-liquid ratio to achieve mass transfer balance and maximize enzymatic hydrolysis efficiency. Figure 10-13 The performance comparison experiment fully verifies the superiority of the technical solution of the present invention. Figure 10 The comparison of bitterness masking effect shows that the bitterness value of the embodiment of the present invention is significantly lower than that of the comparative example, proving that the microencapsulation technology can effectively encapsulate bitter components. Figure 11 The stability test results show that the retention rate of the examples is higher than 90% during the 6-month storage period and is significantly better than that of the comparative examples. Figure 12 The in vitro release behavior showed that the examples had good controlled release characteristics and avoided the sudden release of the active ingredient in the comparative examples. Figure 13 Antioxidant activity evaluation confirmed the IC of Example 50 A lower value indicates stronger antioxidant activity, which comprehensively shows that the preparation process and formula design of the present invention can produce a dandelion functional oral liquid product with excellent performance.

[0103] Comparative Example 1

[0104] The method is basically the same as Example 1, except that in step A1, the ratio of the complex enzyme solution is changed to α-amylase, pectinase, cellulase and papain in a mass ratio of 3:2:2:1.

[0105] Comparative Example 2

[0106] The process is basically the same as Example 1, except that in step A1, the enzymolysis temperature is 30° C. and the enzymolysis time is 80 minutes.

[0107] Comparative Example 3

[0108] The process is basically the same as Example 1, except that in step A1, the enzyme inactivation temperature is 90° C. and the holding time is 15 minutes.

[0109] Comparative Example 4

[0110] The process is basically the same as Example 1, except that in step A2, the ultrasonic treatment temperature is 40° C. and the ultrasonic power is 100 W.

[0111] Comparative Example 5

[0112] The process is basically the same as Example 1, except that in step A2, the centrifugal speed is 8000×g and the centrifugal time is 20 minutes.

[0113] Comparative Example 6

[0114] The method is basically the same as Example 1, except that anhydrous ethanol is added in step A3 to a final concentration of 70%, and the mixture is allowed to stand and precipitate at 10° C. for 8 hours.

[0115] Comparative Example 7

[0116] The process is basically the same as Example 1, except that in step A3, the reduced pressure concentration temperature is 80° C. and the vacuum degree is -0.07 MPa.

[0117] Comparative Example 8

[0118] The method is basically the same as Example 1, except that in step A4, the anion exchange column uses a 0.5 M NaCl solution for gradient elution, and the elution flow rate is controlled at 3.0 mL / min.

[0119] Comparative Example 9

[0120] The method is basically the same as Example 1, except that in step B1, carboxymethyl chitosan-modified sodium alginate and whey protein are mixed in a mass ratio of 50:50.

[0121] Comparative Example 10

[0122] The method is basically the same as Example 1, except that in step B1, the sodium alginate is not modified with carboxymethyl chitosan.

[0123] Comparative Example 11

[0124] The method is basically the same as Example 1, except that in step B1, when preparing carboxymethyl chitosan-modified sodium alginate, the mass ratio of sodium alginate to carboxymethyl chitosan is 1.0:2.0, and the pH value is adjusted to 4.0.

[0125] Comparative Example 12

[0126] The method is basically the same as Example 1, except that the amount of dandelion extract microcapsules added to the oral liquid is 3 parts, the amount of purified water is 90 parts, and steviol glycoside and sucralose are not added.

[0127] Performance testing:

[0128] Bitterness Masking Evaluation: The bitterness intensity of the final functional oral liquid containing dandelion extract was quantitatively evaluated using an electronic tongue system (TS-5000Z) to verify the effectiveness of the microencapsulated taste-masking technology. Testing conditions were set at 25±1°C, and a standard curve was established using a quinine sulfate standard solution (1 mg / L = 10 BU). The final oral liquid product was tested, and triplicate measurements were performed on each sample. The mean and standard deviation of the bitterness values ​​were calculated to assess taste-masking efficiency.

[0129] In vitro release behavior assay: The release behavior of dandelion extract microcapsules in simulated digestive fluid was tested. The USP basket method was used to evaluate the release characteristics of the microcapsules in digestive fluids of varying pH values ​​and verify their controlled release efficacy. Three release media were used: simulated gastric fluid (pH 1.2, HCl-KCl buffer), simulated small intestinal fluid (pH 6.8, phosphate buffer), and simulated colonic fluid (pH 7.4, phosphate buffer). The temperature was 37 ± 0.5°C and the rotation speed was 50 rpm. Samples were collected at pre-set time points (0.5, 1, 2, 4, 6, 8, and 12 hours). The concentrations of the characteristic dandelion components in the release media were determined by HPLC. Cumulative release curves were plotted, and release kinetic parameters were calculated.

[0130] Accelerated product stability testing: Completely packaged dandelion functional oral liquid finished product. Three experimental conditions were set up: long-term test conditions (25±2°C / 60±5%RH), intermediate conditions (30±2°C / 65±5%RH), and accelerated test conditions (40±2°C / 75±5%RH). The following indicators were tested at 0, 1, 3, and 6 months: appearance (color, transparency, precipitation), pH, microbial limits, dandelion active ingredient content, bitterness, and preservative content. The Arrhenius equation was used to predict the product's shelf life at room temperature, verifying that stability could be maintained for 150-180 days when stored at 28°C.

[0131] Antioxidant activity assay: The antioxidant activity of dandelion functional oral liquid was tested. The antioxidant properties of the oral liquid were evaluated using the DPPH free radical scavenging activity assay. After centrifugation to remove insoluble matter, the oral liquid samples were diluted with deionized water to a concentration series (0.5, 1.0, 2.0, and 4.0 mg / mL). 0.5 mL of each sample at each concentration was mixed with 2.0 mL of 0.2 mM ethanolic DPPH solution, and the volume was adjusted to 3.0 mL by adding 0.5 mL of anhydrous ethanol. After shaking at 25 ± 2°C in the dark for 30 minutes, the absorbance change was measured at 517 nm using a UV-visible spectrophotometer. A blank control (ethanol-substituted sample), a positive control (vitamin C standard solution 10-100 μg / mL), and a sample blank (sample + ethanol, no DPPH added) were also prepared. Each concentration was measured three times in parallel, and the free radical scavenging rate was calculated according to the formula DPPH scavenging rate (%) = [(A0-A1+A2) / A0] × 100%. The concentration-scavenging rate curve was drawn and the IC 50 The antioxidant activity of dandelion extract in oral solution was evaluated by comparing the values ​​and verifying the biological activity retention of its functional components.

[0132] The properties of the oral liquids of Examples 1 to 4 and Comparative Examples 1 to 12 are summarized in Table 1. According to the experimental results and chart analysis, the effectiveness of the technical solution of the present invention was verified through systematic process optimization and performance evaluation. Figure 6 It shows that there is an optimal relationship between enzymatic hydrolysis time and the extraction rate of dandelion extract, and too short or too long enzymatic hydrolysis time will affect the extraction efficiency; Figure 7 The influence of enzymatic hydrolysis temperature on extraction rate was revealed. If the temperature is too low, the enzyme activity is insufficient, while if it is too high, the enzyme may be inactivated. There is an optimal temperature range. Figure 8 It shows that the solid-liquid ratio is a key parameter affecting the extraction effect, and an appropriate solid-liquid ratio can ensure sufficient mass transfer and reaction efficiency. Figure 9 The morphology observation of the microcapsules confirmed the success of the preparation process, showing the structural characteristics of microcapsules with regular spherical shape and uniform particle size. Figure 10 The bitterness masking effect comparison shows that the bitterness value of the embodiments of the present invention is controlled within the range of 8.5-10.2 BU, which is significantly better than the 11.5-35.6 BU of most comparative examples, especially compared with the 22.3-35.6 BU of comparative examples 11-12. Figure 11 The 6-month stability retention rate results show that the embodiment achieves a high retention rate of 92.3-96.8%, which is overall better than the range of 82.1-96.1% of the comparative example, demonstrating the effective protection of the active ingredient by microencapsulation technology. Figure 12The comparison of the in vitro release behaviors showed that the examples exhibited ideal sustained-release characteristics, with a 2-hour cumulative release rate of 18.3-25.6%, which effectively avoided the problems of excessive release (such as 65.8-78.2% for comparative examples 10-11) or insufficient release in some comparative examples, and achieved the expected controlled-release effect. Figure 13 The antioxidant activity evaluation results showed that the IC 50 The value is 1.58-1.85 mg / mL, which is comparable to the optimal control ratio but the overall performance is more stable and consistent, proving the advantage of microencapsulation in maintaining biological activity. Comprehensive data show that the functional oral liquid containing dandelion extract prepared by the present invention has achieved the expected results in key technical indicators such as bitterness masking, sustained-release performance, storage stability and biological activity retention.

[0133] Table 1 Performance summary of oral liquids of Examples 1 to 4 and Comparative Examples 1 to 12

[0134]

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that any equivalent structural transformations made within the scope of the present invention using the contents of the present invention's description and drawings should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a functional oral liquid containing dandelion extract, characterized in that: The following steps are involved: A. Preparation of Dandelion Extract: A1. Mix dandelion powder with distilled water and add a complex enzyme solution composed of α-amylase, pectinase, cellulase, and papain in a mass ratio of (1.0-1.5):2:2:1 for enzymatic hydrolysis. After enzymatic hydrolysis, heat to 80-85°C for 5-8 minutes to inactivate the solution. A2. Ultrasonicate the inactivated mixed solution and centrifuge to collect the supernatant; A3. The supernatant was concentrated under reduced pressure and then precipitated with anhydrous ethanol. The precipitate was collected and freeze-dried to obtain crude polysaccharide; A4. Purifying the crude polysaccharide by anion exchange column and gel filtration column to obtain a purified dandelion extract; B. Microencapsulation treatment: B1. Mix carboxymethyl chitosan-modified sodium alginate, pectin, and dandelion extract, and then mix with whey protein in a mass ratio of 70-90:10-30; B2, adding calcium carbonate nanoparticles to the mixed solution, squeezing it into sunflower oil containing an emulsifying aid through a syringe, and stirring to form a W / O emulsion; B3, adding sunflower oil and acetic acid mixture to the emulsion to form microcapsules, and then washing with ethanol and freeze-drying; B4, dispersing the microcapsules in an oral liquid matrix to prepare a functional oral liquid; The preparation method of the carboxymethyl chitosan modified sodium alginate in step B1 is as follows: in parts by weight, 1.0 part of sodium alginate, 0.3-1.0 part of carboxymethyl chitosan, and 80-120 parts of deionized water; dissolving the sodium alginate in 50-70 parts of deionized water, and stirring at 60-80° C. for 30-60 minutes until completely dissolved; dissolving the carboxymethyl chitosan in the remaining deionized water, and adjusting the pH value to 5.5-6.5; cooling to room temperature, slowly adding the carboxymethyl chitosan solution dropwise to the sodium alginate solution for 15-30 minutes; and continuing to stir for 60-120 minutes after the dropwise addition is completed to fully complex the solution, and then standing and aging at 4-8° C. for 12-24 hours to obtain a carboxymethyl chitosan modified sodium alginate composite solution.

2. The method for preparing a functional oral liquid containing dandelion extract according to claim 1, characterized in that: In step A1, the particle size of dandelion powder is 80-120 mesh, and the material-liquid ratio of dandelion powder to distilled water is 1:25-1:35 g / mL; the total amount of the complex enzyme solution added is 1.5-2.5% of the mass of the dandelion powder; the enzymolysis temperature is 50-60° C., and the enzymolysis time is 20-30 minutes.

3. The method for preparing a functional oral liquid containing dandelion extract according to claim 1, wherein: In step A2, the ultrasonic frequency is 35-45 kHz, the ultrasonic power is 180-220 W, the ultrasonic temperature is 70-80° C., and the ultrasonic treatment time is 45-65 minutes; the centrifugal speed is 18,000-22,000×g, and the centrifugation time is 8-12 minutes.

4. The method for preparing a functional oral liquid containing dandelion extract according to claim 1, wherein: In step A3, the temperature for reduced pressure concentration is 55-65° C., the vacuum degree is -0.08-0.095 MPa, and the supernatant is concentrated to 1 / 3-1 / 5 of the original volume; anhydrous ethanol is added to a final concentration of 75-85%, and the mixture is allowed to settle at 2-6° C. for 10-14 hours; and freeze-drying is performed at -45-55° C. and a vacuum degree of 5-15 Pa for 18-24 hours.

5. The method for preparing a functional oral liquid containing dandelion extract according to claim 1, characterized in that: In step A4, the crude polysaccharide is prepared into an aqueous solution with a concentration of 80-120 mg / mL; the anion exchange column is a cellulose DE-52 column, and a NaCl solution with a concentration of 0.1-0.3 M is used for gradient elution; the gel filtration column is a Sephadex G-75 column, and a NaCl solution with a concentration of 0.08-0.12 M is used for elution; the elution flow rate is controlled at 0.8-1.2 mL / min.

6. The method for preparing a functional oral liquid containing dandelion extract according to claim 1, wherein: In the step B1, 1.0 part of carboxymethyl chitosan-modified sodium alginate, 0.3-1.0 part of pectin, and 20-40 parts of dandelion extract solution are mixed to obtain a mixed solution.

7. The method for preparing a functional oral liquid containing dandelion extract according to claim 1, wherein: In the step B2, 100 parts of the mixed solution obtained in step B1, 1.0-3.0 parts of calcium carbonate nanoparticles, 150-200 parts of sunflower oil, 0.8-3.0 parts of emulsifying agent, Tween The invention relates to a method for preparing an aqueous phase comprising: firstly adding an emulsifying aid and Tween 80 to sunflower oil, and stirring the mixture at 500 rpm on a magnetic stirrer for 1 to 2 minutes to prepare an oil phase, wherein the emulsifier is sorbitan monostearate; slowly adding calcium carbonate nanoparticles to the mixed solution obtained in step B1, and stirring the mixture for 2 to 5 minutes until the particles are completely dispersed without agglomeration, to prepare an aqueous phase; using a 10 to 20 mL syringe to load the aqueous phase, and squeezing the aqueous phase into the stirring oil phase through a 16 to 24 gauge blunt-tip stainless steel needle at a constant speed of 0.5 to 1.0 mL / min, maintaining the stirring speed at 500 to 800 rpm during the squeezing process, and continuing stirring for 10 to 20 minutes after the squeezing is completed, until a milky white, uniform, and stable W / O emulsion is formed.

8. The method for preparing a functional oral liquid containing dandelion extract according to claim 1, wherein: In step B3, 30 to 50 parts by weight of sunflower oil and 1.5 to 3.0 parts by weight of acetic acid are mixed to prepare a mixture, and then the mixture is slowly added to the W / O emulsion obtained in step B2 over a period of 15 to 25 minutes. After the microcapsules are formed, they are thoroughly washed with ethanol until no grease residue is left. The washed microcapsules are pre-frozen at -70 to -85°C for 0.5 to 2 hours, and then transferred to a freeze dryer and freeze-dried at -45 to -55°C and a vacuum degree of 0.8 to 1.5 Pa for 20 to 28 hours. The average particle size of the freeze-dried microcapsules is 8 to 12 μm, and the encapsulation efficiency is ≥90%.

9. The functional oral liquid containing dandelion extract obtained by the preparation method according to any one of claims 1 to 8, characterized in that: The oral liquid comprises 8-15 parts of dandelion extract microcapsules, 75-85 parts of purified water, 0.3-0.8 parts of stevioside, 0.1-0.3 parts of sucralose, 0.8-1.5 parts of citric acid, 1.2-2.0 parts of sodium citrate, 0.05-0.15 parts of potassium sorbate, 0.02-0.08 parts of sodium benzoate, 0.2-0.5 parts of xanthan gum, 0.3-0.7 parts of sodium carboxymethyl cellulose, 2-5 parts of glycerol, and 0.01-0.05 parts of vitamin C. The bitterness-masking effect of the oral liquid makes the bitterness value of the oral liquid 8.0-11.0 BU, and the stability is maintained for 150-180 days under storage conditions of 28°C.

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