Functional oral liquid containing dandelion extract and preparation method thereof

Abstract

The invention relates to the field of oral liquid, provides functional oral liquid containing dandelion extract and a preparation method of the functional oral liquid, and solves the problems that an existing product is unstable in component and bitter and astringent in taste. The method comprises the following steps: carrying out enzymolysis extraction, ultrasonic-assisted purification, ethanol precipitation and freeze drying on a dandelion extract to obtain purified polysaccharide, compounding carboxymethyl chitosan modified sodium alginate, pectin and whey protein, preparing a W / O type emulsion by combining calcium carbonate nanoparticles, and carrying out gelation and freeze drying to form the microcapsule. And finally, adding into an oral liquid matrix to prepare a product with good taste and high stability. The particle size of the obtained microcapsule is 8-12 [mu] m, the encapsulation efficiency is greater than or equal to 90%, the bitter taste can be effectively masked, the bitter taste value is reduced to 8.0-11.0 BU, the storage stability reaches 150-180 days, and the microcapsule has a relatively high application value.

Description

Technical Field

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

[0002] In the context where functional foods and nutritional health products are increasingly attracting market attention, the application of plant-derived active substances in oral liquid products has become an important direction for promoting food science and technology innovation. As a natural plant resource with a wide range of pharmacological activities, dandelion extract is rich in various bioactive components and has multiple functions such as anti-inflammatory, antioxidant, liver and stomach protection, etc. Therefore, it is widely used in the development of new functional oral liquids, especially suitable for the daily conditioning of sub-healthy people, those with low immunity and middle-aged and elderly people. However, to achieve its stable release and improved bioavailability in oral liquid products, the material system needs to have excellent component protection, good taste masking performance, excellent dispersion stability and appropriate storage stability, be able to maintain long-term functional activity under normal temperature conditions, and have good dissolution rate and absorption efficiency in the body. From an application perspective, the structural design of the material should not only ensure that the active ingredients are not easily degraded or inactivated, but also meet the comprehensive requirements of consumers for taste, color and fluidity in terms of sensory experience. Therefore, developing a microencapsulation material system that can both protect the active ingredients and significantly improve the taste is of great significance for enhancing the industrial competitiveness and market acceptance of plant functional beverages. Generally speaking, carrying out material innovation research on the stability and taste optimization of dandelion extract can not only significantly improve the functional performance and application expansion space of products, but also play a positive role in promoting the efficient utilization of natural products in the field of functional foods.

[0003] Although the oral liquid preparation technology for plant active ingredients has made certain 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 with publication 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 affects 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 to cause oxidation or polymerization, and lack of effective embedding 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 flavoring agents are difficult to achieve accurate masking of bitterness, and may cause abnormal viscosity of the system, precipitation, and even affect the synergistic effect of other ingredients under high concentration addition conditions. Existing preparation methods mostly focus on adjusting the formula ratio, lack of systematic design from the perspective of material structure and interface control, and are difficult to meet the comprehensive needs of functional foods for high stability, high bioavailability and excellent taste. Therefore, it is urgent to develop a new material system that can simultaneously achieve ingredient protection and bitterness regulation to support the efficient application of dandelion extracts in oral liquid products and promote the development of related products towards high quality and functionalization. Summary of the invention

[0004] (1) Technical issues solved 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.

[0005] (2) Technical solution In order to achieve the above object, the present invention provides the following technical solutions: A method for preparing a functional oral liquid containing dandelion extract comprises the following steps: A. Preparation of dandelion extract: A1. Mix dandelion powder with distilled water, add a compound enzyme solution prepared by α-amylase, pectinase, cellulase and papain in a mass ratio of (1.0-1.5):2:2:1 for enzymolysis, and heat to 80-85°C for inactivation for 5-8 minutes after the enzymolysis is completed; A2, ultrasonically treating the inactivated mixed solution and centrifuging to collect the supernatant; A3, concentrating the supernatant under reduced pressure, adding anhydrous ethanol for precipitation, collecting the precipitate and freeze-drying it to obtain crude polysaccharide; A4, purifying the crude polysaccharide through an anion exchange column and a 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 at a mass ratio of 70 - 90:10 - 30; B2. Add calcium carbonate nanoparticles to the mixed solution, squeeze it into sunflower seed oil containing an emulsification aid through a syringe, and stir to form a W / O emulsion; B3. Add a mixture of sunflower seed oil and acetic acid to the emulsion to form microcapsules, wash with ethanol and then freeze - dry; B4. Disperse the microcapsules in the oral liquid matrix to prepare a functional oral liquid.

[0006] Furthermore, in step A1, the particle size of the dandelion powder is 80 - 120 mesh, the solid - liquid ratio of the dandelion powder to distilled water is 1:25 - 1:35 g / mL; the total addition amount of the composite enzyme solution is 1.5 - 2.5% of the mass of the dandelion powder; the enzymatic hydrolysis temperature is 50 - 60 °C, and the enzymatic hydrolysis time is 20 - 30 minutes.

[0007] 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 centrifugation speed is 18000 - 22000×g, and the centrifugation time is 8 - 12 minutes.

[0008] Furthermore, in step A3, the temperature of vacuum 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; add absolute ethanol to make the final concentration reach 75 - 85%, and let it stand for precipitation at 2 - 6 °C for 10 - 14 hours; freeze - drying is carried out at - 45 - - 55 °C and a vacuum degree of 5 - 15 Pa for 18 - 24 hours.

[0009] Furthermore, in step A4, the crude polysaccharide is formulated into an aqueous solution with a concentration of 80 - 120 mg / mL; the anion - exchange column is a cellulose DE - 52 column, and gradient elution is carried out using a NaCl solution with a concentration of 0.1 - 0.3 M; the gel - filtration column is a Sephadex G - 75 column, and elution is carried out using a NaCl solution with a concentration of 0.08 - 0.12 M; the elution flow rate is controlled at 0.8 - 1.2 mL / min.

[0010] The present invention adopts the design of composite enzyme synergistic enzymatic hydrolysis and multi-stage refining 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 a specific mass ratio in the enzymatic hydrolysis step, multi-site degradation can be carried out on the complex cell wall structure in dandelion powder, enabling more sufficient release of polysaccharides and other active ingredients and improving the initial extraction efficiency. The combination of composite enzymes not only plays a targeted hydrolysis role respectively, but also forms a synergistic effect during the enzymatic hydrolysis process, improving the solubility and enzymatic hydrolysis degree of the raw materials and providing a higher-quality starting material for the subsequent purification process. The subsequent ultrasonic-assisted treatment combines high-frequency vibration and temperature control system to further promote cell breakage and component release. At the same time, efficient liquid-solid separation is achieved under optimized centrifugation conditions to ensure the enrichment of target components in the supernatant. The steps of vacuum concentration and ethanol precipitation effectively remove impurities and enrich crude polysaccharides through mild dehydration and selective solvent action, reducing the risk of thermal degradation and maintaining the integrity of the active structure. Finally, through the two-stage purification and separation strategy of anion exchange column and gel filtration column, high-selectivity elution is achieved by using the differences in molecular charge and relative molecular mass to achieve the purpose of purifying the extract. Each step of the entire process flow from enzymatic hydrolysis to purification is interconnected and functionally complementary, forming a systematic extraction mechanism from structural wall breaking to functional separation. It not only enhances the extraction rate and purity of the target substance, but also enhances its stability and bioavailability in subsequent processing and applications, reflecting the significant improvement effect of multi-factor synergistic optimization on the extraction effect of complex natural products.

[0011] Further, in the step B1, by weight, 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; Further, the preparation method of the carboxymethyl chitosan modified sodium alginate is as follows: by weight, 1.0 part of sodium alginate, 0.3 - 1.0 part of carboxymethyl chitosan, and 80 - 120 parts of deionized water; dissolve sodium alginate in 50 - 70 parts of deionized water, stir at 60 - 80 °C for 30 - 60 minutes until completely dissolved; dissolve carboxymethyl chitosan in the remaining deionized water and adjust the pH value to 5.5 - 6.5; after cooling to room temperature, slowly drop the carboxymethyl chitosan solution into the sodium alginate solution, and the dropping time is 15 - 30 minutes; after the dropping is completed, continue to stir for 60 - 120 minutes to make it fully complexed, and then stand and ripen at 4 - 8 °C for 12 - 24 hours to obtain a carboxymethyl chitosan modified sodium alginate composite solution.

[0012] Further, in the step B2, by weight, 100 parts of the mixed solution obtained in the step B1, 1.0 - 3.0 parts of calcium carbonate nanoparticles, 150 - 200 parts of sunflower seed oil, 0.8 - 3.0 parts of an emulsification aid, and 3.0 - 6.0 parts of Tween 80 are used; first, the emulsification aid and Tween 80 are added to the sunflower seed oil, and stirred on a magnetic stirrer at 500 rpm for 1 - 2 minutes to obtain an oil phase, where the emulsifier is sorbitan monostearate; the calcium carbonate nanoparticles are slowly added to the mixed solution obtained in the step B1, and stirred for 2 - 5 minutes while adding until completely dispersed without agglomeration to obtain an aqueous phase; a 10 - 20 mL syringe is used to load the aqueous phase, and it is extruded into the stirring oil phase at a constant speed of 0.5 - 1.0 mL / min through a 16 - 24 gauge blunt stainless steel needle. During the extrusion process, the stirring speed is maintained at 500 - 800 rpm. After the extrusion is completed, stirring is continued for 10 - 20 minutes until a milky white, uniform, and stable W / O emulsion is formed.

[0013] Further, in the step B3, by weight, 30 - 50 parts of sunflower seed oil and 1.5 - 3.0 parts of acetic acid are mixed to obtain a mixture, and then this mixture is slowly added to the W / O emulsion obtained in the step B2, and the addition time is 15 - 25 minutes; after the microcapsules are formed, they are thoroughly washed with ethanol until there is no oil residue; the washed microcapsules are pre-frozen at -70 - -85 °C for 0.5 - 2 hours, and then transferred to a freeze dryer and freeze-dried at -45 - -55 °C and a vacuum degree of 0.8 - 1.5 Pa for 20 - 28 hours; the average particle size of the freeze-dried microcapsules is 8 - 12 μm, and the encapsulation efficiency is ≥90%.

[0014] The present invention adopts a composite embedding 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 microcapsules is more uniform, the buffering capacity of the carrier to the external environment is stronger, and the fixation and protection capacity of 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 being induced by a mixture of sunflower oil and acetic acid, the emulsion structure further cross-linked and solidified to form a microcapsule shell. With the help of low-temperature pre-freezing and freeze-drying processes, a dry microcapsule powder with a dense structure and reasonable particle size control was finally obtained. In the entire design, the synergistic effect between a variety of natural polymers and emulsified components significantly enhanced the encapsulation efficiency, structural stability and the ability of the microcapsule system to regulate the bitterness of the carrier. It not only improved the stable dispersion state of dandelion extract in a complex liquid matrix, but also achieved effective masking of its natural bitterness at the sensory level, providing reliable material support and structural design paths for the high-quality development of functional oral liquids.

[0015] The present invention also provides a functional oral liquid containing dandelion extract, which contains 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 in parts by weight. The bitterness masking effect of the oral liquid makes the bitterness 8.0-11.0 BU, and the stability is maintained for 150-180 days under the storage condition of 28°C.

[0016] The present invention also provides a functional oral liquid containing dandelion extract. Based on the consideration of the release of functional components and sensory acceptance, the formulation design realizes the coordinated unity of high stability and good taste. The oral liquid uses dandelion extract microcapsules as the core functional component. Through the microencapsulation technology, the stability and sustained-release ability of the dandelion extract in the liquid matrix are effectively improved, avoiding the degradation of active ingredients due to oxidation, hydrolysis or light, and at the same time significantly reducing the taste discomfort caused by its natural bitterness. In terms of excipients, the compound design of stevioside and sucralose not only ensures the natural coordination of sweetness, but also effectively masks the bitter and astringent flavor of dandelion itself, enhancing the oral pleasure; citric acid and sodium citrate jointly regulate the pH of the system and improve the flavor level; potassium sorbate and sodium benzoate jointly construct an anti-corrosion system to ensure the storage stability of the product at room temperature; xanthan gum and sodium carboxymethylcellulose, as rheological modifiers, jointly improve the viscosity and suspension of the system, preventing ingredient sedimentation or stratification; glycerol gives the product an appropriate taste 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 11.0 BU, fully meeting the multiple needs of consumers for functionality, taste and storage performance, and having broad market application prospects.

[0017] (3) Beneficial technical effects 1. The present invention adopts the compound enzyme synergistic enzymatic hydrolysis and multi-stage separation and purification technology to improve the extraction efficiency and component stability, form a synergistic mechanism of structural wall breaking and functional separation, and significantly enhance the purity and application performance of active ingredients.

[0018] 2. The present invention constructs a microcapsule system by chitosan-modified sodium alginate, pectin and whey protein in a coordinated manner to achieve efficient encapsulation and bitterness masking, significantly improve the taste and stability, solve the problems of ingredient release and acceptance, and has broad application prospects.

[0019] 3. The present invention significantly improves the taste and stability through microencapsulation and multi-excipient coordinated design, solves the problems of ingredient instability and bitterness, realizes the coordination of structure and function through ratio optimization, and has broad application prospects. Description of the Drawings

[0020] Figure 1 It is a physical picture of freeze-dried dandelion prepared in Example 1 of the present invention.

[0021] Figure 2 It is a physical picture of the powdered dandelion obtained by crushing prepared in Example 1 of the present invention.

[0022] Figure 3 It is the mixed solution after enzymatic hydrolysis prepared in Example 1 of the present invention.

[0023] Figure 4 The extract after vacuum concentration prepared in Example 1 of the present invention.

[0024] Figure 5 The physical diagram of the purified dandelion extract prepared in Example 1 of the present invention.

[0025] Figure 6 The relationship diagram between the enzymolysis time and the extraction rate of dandelion extract of the present invention.

[0026] Figure 7 The relationship diagram between the enzymolysis temperature and the extraction rate of dandelion extract of the present invention.

[0027] Figure 8 The relationship diagram between the solid-liquid ratio and the extraction rate of dandelion extract of the present invention.

[0028] Figure 9 The morphology diagram of the solid-liquid ratio containing dandelion extract microcapsules prepared in Example 1 of the present invention.

[0029] Figure 10 The comparison diagram of the bitter taste masking effect of the oral liquid in the examples and comparative examples of the present invention.

[0030] Figure 11 The 6-month stability retention rate of the oral liquid products in the examples and comparative examples of the present invention.

[0031] Figure 12 The comparison diagram of the in vitro release behavior of the microcapsules in the examples and comparative examples of the present invention.

[0032] Figure 13 The evaluation results of the antioxidant activity of the oral liquid products in the examples and comparative examples of the present invention. Detailed implementation manners

[0033] To make the objectives, 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 with reference to the accompanying drawings of the present invention specification.

[0034] Example 1 A preparation method of a functional oral liquid containing dandelion extract, comprising the following steps: A. Preparation of dandelion extract: A1. Mix dandelion powder with distilled water, add a composite enzyme solution prepared from α-amylase, pectinase, cellulase and papain in a mass ratio of 1.0:2:2:1 for enzymolysis, and after the enzymolysis is completed, raise the temperature to 80 °C to inactivate for 5 minutes; specifically, the particle size of the dandelion powder is 80 mesh, the solid-liquid ratio with distilled water is 1:25 g / mL; the total addition amount of the composite enzyme solution is 1.5% of the mass of the dandelion powder; the enzymolysis temperature is 50 °C, and the enzymolysis time is 20 minutes.

[0035] A2. After ultrasonic treatment of the inactivated mixture, 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 centrifugation speed is 18,000×g, and the centrifugation time is 8 minutes.

[0036] A3. Concentrate the supernatant under reduced pressure and then add absolute ethanol for precipitation. Collect the precipitate and freeze-dry to obtain crude polysaccharide; the temperature for concentration under reduced pressure is 55 °C, the vacuum degree is -0.08 MPa, and the supernatant is concentrated to 1 / 3 of the original volume; add absolute ethanol to make the final concentration reach 75%, and let it stand for precipitation at 2 °C for 10 hours; the freeze-drying is carried out at -45 °C and a vacuum degree of 5 Pa for 18 hours.

[0037] A4. Purify the crude polysaccharide through an anion exchange column and a gel filtration column to obtain a purified dandelion extract; the crude polysaccharide is formulated into an aqueous solution with a concentration of 80 mg / mL; the anion exchange column is a cellulose DE-52 column, and gradient elution is carried out using a 0.1 M NaCl solution; the gel filtration column is a Sephadex G-75 column, and elution is carried out using a 0.08 M NaCl solution; the elution flow rate is controlled at 0.8 mL / min.

[0038] B. Microencapsulation treatment: B1. Mix carboxymethyl chitosan-modified sodium alginate, pectin and the dandelion extract, and then mix with whey protein according to a mass ratio of 76:24; by weight, 1.0 part of carboxymethyl chitosan-modified sodium alginate, 0.5 part of pectin, and 26 parts of the dandelion extract solution are mixed to obtain a mixed solution; the preparation method of carboxymethyl chitosan-modified sodium alginate is: by weight, 1.0 part of sodium alginate, 0.5 part of carboxymethyl chitosan, and 92 parts of deionized water; dissolve sodium alginate in 56 parts of deionized water, stir at 66 °C for 39 minutes until completely dissolved; dissolve carboxymethyl chitosan in the remaining deionized water, adjust the pH value to 5.8; after cooling to room temperature, slowly drip the carboxymethyl chitosan solution into the sodium alginate solution, and the dripping time is 20 minutes; after dripping, continue to stir for 78 minutes to make it fully complex, and then let it stand and ripen at 5 °C for 16 hours to obtain a carboxymethyl chitosan-modified sodium alginate composite solution.

[0039] B2. Add calcium carbonate nanoparticles to the mixed solution, and squeeze it into sunflower oil containing an emulsification aid through a syringe, then stir to form a W / O emulsion. 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 emulsification aid, and 3.9 parts of Tween 80 are used. First, add the emulsification aid and Tween 80 to the sunflower oil, and stir on a magnetic stirrer at 500 rpm for 1 minute to obtain the oil phase, where the emulsifier is sorbitan monostearate. Slowly add the calcium carbonate nanoparticles to the mixed solution obtained in step B1, and stir while adding for 3 minutes until completely dispersed without aggregation to obtain the water phase. Load the water phase with a 13 mL syringe, and squeeze it into the stirring oil phase through an 18-gauge blunt stainless steel needle at a constant speed of 0.65 mL / min. During the squeezing process, maintain the stirring speed at 590 rpm, and continue to stir for 13 minutes after the squeezing is completed until a milky white, uniform, and stable W / O emulsion is formed.

[0040] B3. Add a mixture of sunflower oil and acetic acid to the emulsion to form microcapsules, then wash with ethanol and freeze-dry. By weight, mix 36 parts of sunflower oil and 2.0 parts of acetic acid to obtain a mixture, and then slowly add this mixture to the W / O emulsion obtained in step B2 over 18 minutes. After the microcapsules are formed, wash them thoroughly with ethanol until there is no residual oil. Pre-freeze the washed microcapsules at -75 °C for 1.0 hour, and then transfer them to a freeze-dryer and freeze-dry at -48 °C and 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%.

[0041] B4. Disperse the microcapsules in the oral liquid matrix to obtain a functional oral liquid.

[0042] A functional oral liquid containing dandelion extract in this example, by weight, contains 10 parts of dandelion extract microcapsules, 78 parts of purified water, 0.5 part of stevioside, 0.16 part of sucralose, 1.0 part of citric acid, 1.4 parts of sodium citrate, 0.08 part of potassium sorbate, 0.04 part of sodium benzoate, 0.29 part of xanthan gum, 0.42 part of sodium carboxymethylcellulose, 2.9 parts of glycerol, and 0.02 part of vitamin C. The bitter taste masking effect of this oral liquid reduces the bitterness value (BU) to 8.9, and its stability is maintained for 159 days under the storage condition of 28 °C.

[0043] From Figures 1 - 5 and Figure 9 the experimental results, it can be seen that the preparation method of the present invention can successfully realize the preparation of the dandelion functional oral liquid. Figure 1 It shows that the freeze-dried dandelion raw material maintains a good morphological structure, providing a high-quality raw material basis for subsequent processing. Figure 2The crushed dandelion powder is presented in a uniform and delicate powdery form, with a particle size meeting the requirements of 80 - 120 mesh, which is beneficial to improving the enzymatic hydrolysis efficiency and the release of active ingredients. Figure 3 The displayed mixed solution after enzymatic hydrolysis presents a uniform light brown liquid state, indicating that the composite enzyme solution can effectively break the cell wall structure of dandelion and fully release intracellular polysaccharides, flavonoids and other active ingredients. Figure 4 The concentration of the extract after vacuum concentration in significantly increases and the color deepens, confirming the effectiveness of the concentration process and laying a foundation for subsequent alcohol precipitation purification. Figure 5 The purified dandelion extract shown in presents a light yellow powdery form with uniform and delicate texture, indicating that gradient purification through anion exchange column and gel filtration column can effectively remove impurities such as proteins and pigments, and obtain a high - purity dandelion polysaccharide extract. Figure 9 The microscopic observation results in show that the prepared microcapsules present a regular spherical morphology, with a smooth and dense surface, uniform particle size distribution, and an average particle size in the range of 8 - 12 μm, proving that the composite carrier material of carboxymethyl chitosan - modified sodium alginate and whey protein can effectively encapsulate the dandelion extract to form microcapsules with stable structure, providing a strong guarantee for achieving bitter taste masking and controlled release effects.

[0044] Example 2 A preparation method of a functional oral liquid containing dandelion extract, comprising the following steps: A. Preparation of dandelion extract: A1. Mix the dandelion powder with distilled water, add a composite enzyme solution prepared from α - amylase, pectinase, cellulase and papain in a mass ratio of 1.2:2:2:1 for enzymatic hydrolysis, and after enzymatic hydrolysis, raise the temperature to 82°C to inactivate for 6 minutes; specifically, the particle size of the dandelion powder is 92 mesh, the material - liquid ratio of the dandelion powder to distilled water is 1:28 g / mL; the total addition amount of the composite enzyme solution is 1.8% of the mass of the dandelion powder; the enzymatic hydrolysis temperature is 53°C, and the enzymatic hydrolysis time is 23 minutes.

[0045] A2. Ultrasonically treat the inactivated mixed solution and then centrifuge to collect the supernatant; the ultrasonic frequency is 38 kHz, the ultrasonic power is 192 W, the ultrasonic temperature is 73°C, and the ultrasonic treatment time is 51 minutes; the centrifugation speed is 19200×g, and the centrifugation time is 9 minutes.

[0046] A3. Vacuum - concentrate the supernatant and then add absolute ethanol for precipitation, collect the precipitate and freeze - dry to obtain crude polysaccharide; the temperature of vacuum concentration is 58°C, the vacuum degree is - 0.085 MPa, and the supernatant is concentrated to 1 / 4 of the original volume; add absolute ethanol to make the final concentration reach 78%, and let it stand for precipitation at 3°C for 11 hours; freeze - drying is carried out at - 48°C and a vacuum degree of 8 Pa for 20 hours.

[0047] A4. Purify the crude polysaccharide through an anion exchange column and a gel filtration column to obtain a purified dandelion extract; prepare an aqueous solution of the crude polysaccharide with a concentration of 92 mg / mL; the anion exchange column is a cellulose DE-52 column, and gradient elution is performed using a 0.16 M NaCl solution; the gel filtration column is a Sephadex G-75 column, and elution is performed using a 0.09 M NaCl solution; the elution flow rate is controlled at 0.92 mL / min.

[0048] B. Microencapsulation treatment: B1. Mix carboxymethyl chitosan-modified sodium alginate, pectin and the dandelion extract, and then mix with whey protein in a mass ratio of 70:30; by weight, 1.0 part of carboxymethyl chitosan-modified sodium alginate, 0.3 part of pectin, and 20 parts of the dandelion extract solution are mixed to obtain a mixed solution; the preparation method of carboxymethyl chitosan-modified sodium alginate is: by weight, 1.0 part of sodium alginate, 0.3 part of carboxymethyl chitosan, and 80 parts of deionized water; dissolve sodium alginate in 50 parts of deionized water, and stir at 60 °C for 30 minutes until completely dissolved; dissolve carboxymethyl chitosan in the remaining deionized water, and adjust the pH value to 5.5; after cooling to room temperature, slowly drip the carboxymethyl chitosan solution into the sodium alginate solution, and the dripping time is 15 minutes; after dripping, continue to stir for 60 minutes to fully complex, and then stand and cure at 4 °C for 12 hours to obtain a carboxymethyl chitosan-modified sodium alginate composite solution.

[0049] B2. Add calcium carbonate nanoparticles to the mixed solution, and squeeze it into sunflower oil containing an emulsification aid through a syringe, and stir to form a W / O emulsion; 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 the emulsification aid, and 3.0 parts of Tween 80; first add the emulsification aid and Tween 80 to sunflower oil, and stir on a magnetic stirrer at 500 rpm for 1 minute to obtain an oil phase, where the emulsifier is sorbitan monostearate; slowly add calcium carbonate nanoparticles to the mixed solution obtained in step B1, and stir while adding for 2 minutes until completely dispersed without agglomeration to obtain an aqueous phase; use a 10 mL syringe to load the aqueous phase, and squeeze it into the stirring oil phase through a 16-gauge blunt stainless steel needle at a constant speed of 0.5 mL / min. During the squeezing process, keep the stirring speed at 500 rpm, and continue to stir for 10 minutes after squeezing until a milky white, uniform and stable W / O emulsion is formed.

[0050] B3. Add a mixture of sunflower oil and acetic acid to the emulsion to form microcapsules, wash with ethanol and then freeze-dry; by weight, mix 30 parts of sunflower oil with 1.5 parts of acetic acid to obtain a mixture, and then slowly add this mixture to the W / O emulsion obtained in step B2, with the addition time being 15 minutes; after the microcapsules are formed, thoroughly wash them with ethanol until no oil residue remains; pre-freeze the washed microcapsules at -70°C for 0.5 hours, and then transfer them to a freeze-dryer for freeze-drying at -45°C and a vacuum degree of 0.8 Pa for 20 hours; the average particle size of the freeze-dried microcapsules is 8 μm, and the encapsulation efficiency is ≥90%.

[0051] B4. Disperse the microcapsules in an oral liquid matrix to obtain a functional oral liquid.

[0052] A functional oral liquid containing dandelion extract in this example, by weight, contains 8 parts of dandelion extract microcapsules, 75 parts of purified water, 0.3 part of stevioside, 0.1 part of sucralose, 0.8 part of citric acid, 1.2 parts of sodium citrate, 0.05 part of potassium sorbate, 0.02 part of sodium benzoate, 0.2 part of xanthan gum, 0.3 part of sodium carboxymethylcellulose, 2 parts of glycerol, and 0.01 part of vitamin C; the bitter taste masking effect of this oral liquid reduces the bitterness value (BU) to 8.0, and the stability is maintained for 150 days under the storage condition of 28°C.

[0053] Example 3 A preparation method of a functional oral liquid containing dandelion extract, comprising the following steps: A. Preparation of dandelion extract: A1. Mix dandelion powder with distilled water, add a complex enzyme solution prepared from α-amylase, pectinase, cellulase, and papain in a mass ratio of 1.3:2:2:1 for enzymatic hydrolysis, and after the enzymatic hydrolysis is completed, raise the temperature to 83°C for inactivation for 7 minutes; specifically, the particle size of the dandelion powder is 104 mesh, the material-liquid ratio of the dandelion powder to distilled water is 1:31 g / mL; the total addition amount of the complex enzyme solution is 2.1% of the mass of the dandelion powder; the enzymatic hydrolysis temperature is 56°C, and the enzymatic hydrolysis time is 26 minutes.

[0054] A2. After ultrasonic treatment of the inactivated mixture, 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 centrifugation speed is 20400×g, and the centrifugation time is 10 minutes.

[0055] A3. Concentrate the supernatant under reduced pressure, add absolute ethanol for precipitation, collect the precipitate and freeze-dry to obtain crude polysaccharide; the temperature for reduced-pressure concentration is 61 °C, the vacuum degree is -0.089 MPa, and the supernatant is concentrated to 1 / 4 of the original volume; add absolute ethanol to make the final concentration reach 81%, and let it stand for precipitation at 4 °C for 12 hours; freeze-drying is carried out at -51 °C and a vacuum degree of 11 Pa for 22 hours.

[0056] A4. Purify the crude polysaccharide through an anion exchange column and a gel filtration column to obtain a purified dandelion extract; the crude polysaccharide is formulated into an aqueous solution with a concentration of 104 mg / mL; the anion exchange column is a cellulose DE-52 column, and gradient elution is carried out using a NaCl solution with a concentration of 0.22 M; the gel filtration column is a Sephadex G-75 column, and elution is carried out using a NaCl solution with a concentration of 0.10 M; the elution flow rate is controlled at 1.04 mL / min.

[0057] B. Microencapsulation treatment: B1. Mix carboxymethyl chitosan-modified sodium alginate, pectin and dandelion extract, and then mix with whey protein according to a mass ratio of 90:10; 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: by weight, 1.0 part of sodium alginate, 1.0 part of carboxymethyl chitosan, and 120 parts of deionized water; dissolve sodium alginate in 70 parts of deionized water, stir at 80 °C for 60 minutes until completely dissolved; dissolve carboxymethyl chitosan in the remaining deionized water, adjust the pH value to 6.5; after cooling to room temperature, slowly drop the carboxymethyl chitosan solution into the sodium alginate solution, and the dropping time is 30 minutes; after dropping, continue to stir for 120 minutes to make it fully complex, and then let it stand and ripen at 8 °C for 24 hours to obtain a carboxymethyl chitosan-modified sodium alginate composite solution.

[0058] B2. Add calcium carbonate nanoparticles to the mixed solution, and extrude it into sunflower oil containing an emulsification aid through a syringe, then stir to form a W / O emulsion. 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 emulsification aid, and 6.0 parts of Tween 80 are used. First, add the emulsification aid and Tween 80 to the sunflower oil, and stir on a magnetic stirrer at 500 rpm for 2 minutes to obtain the oil phase, where the emulsifier is sorbitan monostearate. Slowly add the calcium carbonate nanoparticles to the mixed solution obtained in step B1, and stir while adding for 5 minutes until completely dispersed without aggregation to obtain the water phase. Load the water phase with a 20 mL syringe, and extrude it into the stirring oil phase through a 24-gauge blunt stainless steel needle at a constant speed of 1.0 mL / min. During the extrusion process, keep the stirring speed at 800 rpm, and continue to stir for 20 minutes after extrusion until a milky white, uniform, and stable W / O emulsion is formed.

[0059] B3. Add a mixture of sunflower oil and acetic acid to the emulsion to form microcapsules, then wash with ethanol and freeze-dry. By weight, mix 50 parts of sunflower oil and 3.0 parts of acetic acid to obtain a mixture, and then slowly add this mixture to the W / O emulsion obtained in step B2 over 25 minutes. After the microcapsules are formed, wash them thoroughly with ethanol until there is no residual grease. Pre-freeze the washed microcapsules at -85°C for 2 hours, and then transfer them to a freeze-dryer for freeze-drying at -55°C and a vacuum of 1.5 Pa for 28 hours. The average particle size of the freeze-dried microcapsules is 12 μm, and the encapsulation efficiency is ≥90%.

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

[0061] A functional oral liquid containing dandelion extract in this example, by weight, contains 15 parts of dandelion extract microcapsules, 85 parts of purified water, 0.8 part of stevioside, 0.3 part of sucralose, 1.5 parts of citric acid, 2.0 parts of sodium citrate, 0.15 part of potassium sorbate, 0.08 part of sodium benzoate, 0.5 part of xanthan gum, 0.7 part of sodium carboxymethylcellulose, 5 parts of glycerol, and 0.05 part of vitamin C. The bitter taste masking effect of this oral liquid reduces the bitter value (BU) to 11.0, and its stability is maintained for 180 days under the storage condition of 28°C.

[0062] Example 4 A preparation method of a functional oral liquid containing dandelion extract, comprising the following steps: A. Preparation of dandelion extract: A1. Mix the dandelion powder with distilled water, add a complex enzyme solution prepared from α-amylase, pectinase, cellulase, and papain in a mass ratio of 1.5:2:2:1 for enzymatic hydrolysis. After the enzymatic hydrolysis is completed, raise the temperature to 85 °C and inactivate for 8 minutes. Specifically, the particle size of the dandelion powder is 120 mesh, the material-liquid ratio of the dandelion powder to distilled water is 1:35 g / mL; the total addition amount of the complex enzyme solution is 2.5% of the mass of the dandelion powder; the enzymatic hydrolysis temperature is 60 °C, and the enzymatic hydrolysis time is 30 minutes.

[0063] A2. Ultrasonically treat the inactivated mixture 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 centrifugation speed is 22000×g, and the centrifugation time is 12 minutes.

[0064] A3. Concentrate the supernatant under reduced pressure and then add absolute ethanol for precipitation. Collect the precipitate and freeze-dry to obtain crude polysaccharide; the temperature for concentration under reduced pressure is 65 °C, the vacuum degree is -0.095 MPa, and the supernatant is concentrated to 1 / 5 of the original volume; add absolute ethanol to make the final concentration reach 85%, and let it stand for precipitation at 6 °C for 14 hours; freeze-drying is carried out at -55 °C and a vacuum degree of 15 Pa for 24 hours.

[0065] A4. Purify the crude polysaccharide through an anion exchange column and a gel filtration column to obtain a purified dandelion extract; the crude polysaccharide is formulated into an aqueous solution with a concentration of 120 mg / mL; the anion exchange column is a cellulose DE-52 column, and gradient elution is carried out using a 0.3 M NaCl solution; the gel filtration column is a Sephadex G-75 column, and elution is carried out using a 0.12 M NaCl solution; the elution flow rate is controlled at 1.2 mL / min.

[0066] B. Microencapsulation treatment: B1. Mix carboxymethyl chitosan-modified sodium alginate, pectin, and the 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 the 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; dissolve sodium alginate in 62 parts of deionized water, stir at 72 °C for 48 minutes until completely dissolved; dissolve carboxymethyl chitosan in the remaining deionized water, adjust the pH value to 6.1; after cooling to room temperature, slowly drip the carboxymethyl chitosan solution into the sodium alginate solution, and the dripping time is 24 minutes; after the dripping is completed, continue to stir for 96 minutes to make it fully complex, and then let it stand and ripen at 6 °C for 19 hours to obtain a carboxymethyl chitosan-modified sodium alginate composite solution.

[0067] B2. Add calcium carbonate nanoparticles to the mixed solution, and squeeze it into sunflower oil containing an emulsification aid through a syringe, then stir to form a W / O emulsion. 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 emulsification aid, and 4.8 parts of Tween 80 are used. First, add the emulsification aid and Tween 80 to the sunflower oil, and stir on a magnetic stirrer at 500 rpm for 2 minutes to obtain the oil phase, where the emulsifier is sorbitan monostearate. Slowly add the calcium carbonate nanoparticles to the mixed solution obtained in step B1, and stir while adding for 4 minutes until completely dispersed without agglomeration to obtain the water phase. Use a 16 mL syringe to load the water phase, and squeeze it into the stirring oil phase at a constant speed of 0.8 mL / min through a 21-gauge blunt stainless steel needle. During the squeezing process, maintain the stirring speed at 680 rpm, and continue to stir for 16 minutes after squeezing until a milky white, uniform, and stable W / O emulsion is formed.

[0068] B3. Add a mixture of sunflower oil and acetic acid to the emulsion to form microcapsules, then wash with ethanol and freeze-dry. By weight, mix 42 parts of sunflower oil and 2.4 parts of acetic acid to obtain a mixture, and then slowly add this mixture to the W / O emulsion obtained in step B2 over 21 minutes. After the microcapsules are formed, wash them thoroughly with ethanol until there is no residual grease. Pre-freeze the washed microcapsules at -79°C for 1.4 hours, and then transfer them to a freeze-dryer and freeze-dry at -51°C and a vacuum of 1.2 Pa for 25 hours. The average particle size of the freeze-dried microcapsules is 10 μm, and the encapsulation efficiency is ≥90%.

[0069] B4. Disperse the microcapsules in the oral liquid matrix to obtain a functional oral liquid.

[0070] For a functional oral liquid containing dandelion extract in this example, by weight, it contains 12 parts of dandelion extract microcapsules, 81 parts of purified water, 0.6 parts of stevioside, 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 carboxymethylcellulose, 3.8 parts of glycerol, and 0.03 parts of vitamin C. The bitter taste masking effect of this oral liquid reduces the bitter value (BU) to 9.8, and its stability is maintained for 168 days under the storage condition of 28°C.

[0071] Figures 6 - 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 6It shows that the enzymolysis time has a significant effect on the extraction rate. In the range of 20 - 30 minutes, the extraction rate first increases rapidly and then levels off with the extension of time, reaching the maximum value of 3.2% at 26 minutes. Continuing to extend the time will instead lead to a decrease in the extraction rate, which is because excessive enzymolysis may damage some active ingredients or produce inhibitory products. Figure 7 It shows the influence law of the enzymolysis temperature. In the temperature range of 50 - 60 °C, the extraction rate shows a trend of first increasing and then decreasing, reaching the peak value of 3.8% at 56 °C. 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 the thermosensitive components may be damaged. Figure 8 It 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 the highest value of 2.9% at 1:34 g / mL. Subsequently, increasing the liquid dosage leads to a slight decrease in the extraction rate, indicating that there is an optimal solid - liquid ratio to achieve mass transfer balance and maximize the enzymolysis efficiency. Figures 10 - 13 The performance comparison experiment fully verifies the superiority of the technical solution of the present invention. Figure 10 The comparison of the bitter - taste masking effect shows that the bitter - taste value of the embodiment of the present invention is significantly lower than that of the comparative example, proving that the micro - encapsulation technology can effectively encapsulate the bitter - taste components. Figure 11 The stability test results show that the retention rate of the embodiment is higher than 90% during the 6 - month storage period and is significantly better than that of the comparative example. Figure 12 The in - vitro release behavior shows that the embodiment has good controlled - release characteristics and avoids the burst release phenomenon of the active ingredients in the comparative example. Figure 13 The antioxidant activity evaluation confirms that the IC 50 value of the embodiment is lower, indicating stronger antioxidant activity. Generally speaking, the preparation process and formula design of the present invention can produce a dandelion functional oral liquid product with excellent performance.

[0072] Comparative Example 1 It is basically the same as Example 1, except that in step A1, the ratio of the composite enzyme solution is changed to be prepared according to the mass ratio of α - amylase, pectinase, cellulase, and papain of 3:2:2:1.

[0073] Comparative Example 2 It 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.

[0074] Comparative Example 3 It 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.

[0075] Comparative Example 4 It is basically the same as Example 1, except that in step A2, the ultrasonic treatment temperature is 40 °C and the ultrasonic power is 100W.

[0076] Comparative Example 5 It is basically the same as Example 1, except that the centrifugation speed in step A2 is 8000×g and the centrifugation time is 20 minutes.

[0077] Comparative Example 6 It is basically the same as Example 1, except that anhydrous ethanol is added in step A3 to make the final concentration reach 70%, and the mixture is allowed to stand and precipitate at 10°C for 8 hours.

[0078] Comparative Example 7 It is basically the same as Example 1, except that the decompression concentration temperature in step A3 is 80°C and the vacuum degree is -0.07 MPa.

[0079] Comparative Example 8 It is basically the same as Example 1, except that in step A4, the anion exchange column is eluted with a NaCl solution with a concentration of 0.5 M by gradient elution, and the elution flow rate is controlled at 3.0 mL / min.

[0080] Comparative Example 9 It 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.

[0081] Comparative Example 10 It is basically the same as Example 1, except that in step B1, sodium alginate is not treated with carboxymethyl chitosan modification.

[0082] Comparative Example 11 It is basically the same as Example 1, except that in the preparation of carboxymethyl chitosan-modified sodium alginate in step B1, the mass ratio of sodium alginate to carboxymethyl chitosan is 1.0:2.0, and the pH value is adjusted to 4.0.

[0083] Comparative Example 12 It is basically the same as Example 1, except that the addition amount of dandelion extract microcapsules in the oral liquid is 3 parts, the purified water is 90 parts, and stevioside and sucralose are not added.

[0084] Performance Test: Evaluation Experiment on Bitter Taste Masking Effect: For the final product of the functional oral liquid containing dandelion extract, the bitter taste intensity of the oral liquid was quantitatively evaluated using an electronic tongue system (TS-5000Z type) to verify the effectiveness of the microencapsulation taste masking technology. The test 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 test samples were the final oral liquid products, and each sample was measured in parallel 3 times. The average value and standard deviation of the bitter taste values were calculated to evaluate the taste masking efficiency.

[0085] In vitro release behavior determination experiment: To test the release behavior of dandelion extract microcapsules in simulated digestive fluids, the USP basket method was used to evaluate the release characteristics of the microcapsules in digestive fluids with different pH values, and its controlled release effect was verified. Three release media were set: simulated gastric juice (pH 1.2, HCl-KCl buffer), simulated intestinal juice (pH 6.8, phosphate buffer), and simulated colonic juice (pH 7.4, phosphate buffer). The temperature was 37 ± 0.5 °C and the rotation speed was 50 rpm. Samples were taken at preset time points (0.5, 1, 2, 4, 6, 8, 12 hours), and the concentration of the characteristic components of dandelion in the release medium was determined by HPLC. The cumulative release curve was plotted and the release kinetic parameters were calculated.

[0086] Accelerated stability test of the product: The finished product of dandelion functional oral liquid with intact packaging. Three conditions were set for the experiment: long-term test condition (25 ± 2 °C / 60 ± 5% RH), intermediate condition (30 ± 2 °C / 65 ± 5% RH), and accelerated test condition (40 ± 2 °C / 75 ± 5% RH). The following indicators were detected at 0, 1, 3, and 6 months: appearance (color, transparency, precipitation), pH value, microbial limit, content of active components of dandelion, bitterness value, preservative content, etc. The shelf life of the product at room temperature was predicted by the Arrhenius equation to verify whether the stability could be maintained for 150 - 180 days under the storage condition of 28 °C.

[0087] Antioxidant activity determination experiment: To test the antioxidant active components of dandelion functional oral liquid. The DPPH free radical scavenging ability method was used to evaluate the antioxidant performance of the oral liquid. After centrifuging the oral liquid sample to remove insoluble substances, it was diluted with deionized water into a series of concentration gradients (0.5, 1.0, 2.0, 4.0 mg / mL). Take 0.5 mL of samples with different concentrations and mix them with 2.0 mL of DPPH ethanol solution (0.2 mM, freshly prepared), and add 0.5 mL of absolute ethanol to make the volume of the reaction system up to 3.0 mL. After reacting with shaking for 30 minutes under dark conditions at 25 ± 2 °C, the change in absorbance was measured at 517 nm using an ultraviolet-visible spectrophotometer. At the same time, blank control (ethanol replacing the sample), positive control (vitamin C standard solution 10 - 100 μg / mL), and sample blank (sample + ethanol, without adding DPPH) were set. Each concentration was measured in parallel 3 times, and the free radical scavenging rate was calculated according to the formula DPPH scavenging rate (%) = [(A0 - A1 + A2) / A0] × 100%, and the concentration-scavenging rate curve was plotted and the IC 50 value was calculated to evaluate the antioxidant activity intensity of the dandelion extract in the oral liquid and verify the retention of the biological activity of its functional components.

[0088] The performances of the oral liquids of Examples 1-4 and Comparative Examples 1-12 are summarized in Table 1. According to the experimental results and chart analysis, the present invention verifies the effectiveness of the technical solution through systematic process optimization and performance evaluation. Figure 6 It shows that there is an optimal relationship between the enzymolysis time and the extraction rate of dandelion extract. Too short or too long enzymolysis time will affect the extraction efficiency. Figure 7 It reveals the influence rule of enzymolysis temperature on the extraction rate. When the temperature is too low, the enzyme activity is insufficient, and when 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. An appropriate solid-liquid ratio can ensure sufficient mass transfer and reaction efficiency. Figure 9 The observation of the microcapsule morphology of [[]] Figure 9 [[]] confirms the success of the preparation process, showing the microcapsule structural characteristics of regular spherical shape and uniform particle size. Figure 10 The comparison of the bitter taste masking effects of [[]] Figure 10 [[]] shows that the bitter taste value of the examples of the present invention is controlled within the range of 8.5 - 10.2 BU, which is significantly better than 11.5 - 35.6 BU of most of the comparative examples, especially showing obvious improvement compared with 22.3 - 35.6 BU of Comparative Examples 11-12. Figure 11 The results of the 6-month stability retention rate of [[]] Figure 11 [[]] show that the examples reach a high retention rate of 92.3 - 96.8%, which is overall better than the range of 82.1 - 96.1% of the comparative examples, proving the effective protection of the microcapsule technology for active ingredients. Figure 12 The comparison of the in vitro release behaviors of [[]] Figure 12 [[]] shows that the examples exhibit ideal sustained-release characteristics, and the cumulative release rate at 2 hours is 18.3 - 25.6%, effectively avoiding the problems of too fast release (such as 65.8 - 78.2% for Comparative Examples 10-11) or insufficient release of some comparative examples, and achieving the expected controlled-release effect. Figure 13 The evaluation results of the antioxidant activity of [[]] Figure 13 [[]] show that the IC 50 value of the examples is 1.58 - 1.85 mg / mL, which is equivalent to that of the optimal comparative example but shows more stable and consistent overall performance, proving the advantages of microencapsulation in maintaining biological activity. The comprehensive data show that the functional oral liquid containing dandelion extract prepared by the present invention has achieved the expected effects in key technical indicators such as bitter taste masking, sustained-release performance, storage stability, and maintenance of biological activity.

[0089] Table 1 Summary of the Performances of the Oral Liquids of Examples 1-4 and Comparative Examples 1-12

[0090] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that any equivalent structural transformation made under the concept of the present invention using the content of the specification and drawings of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A preparation method of a functional oral liquid containing dandelion extract, characterized in that, It includes the following steps: A. Preparation of dandelion extract: A1. Mix dandelion powder with distilled water, add a complex enzyme solution prepared from α - amylase, pectinase, cellulase and papain in a mass ratio of (1.0 - 1.5):2:2:1 for enzymatic hydrolysis. After enzymatic hydrolysis, raise the temperature to 80 - 85°C and inactivate for 5 - 8 minutes; A2. Ultrasonically treat the inactivated mixture and then centrifuge to collect the supernatant; A3. Concentrate the supernatant under reduced pressure, add absolute ethanol for precipitation, collect the precipitate and freeze - dry to obtain crude polysaccharide; A4. Purify the crude polysaccharide through an anion - exchange column and a gel - filtration column to obtain purified dandelion extract; B. Microencapsulation treatment: B1. Mix carboxymethyl chitosan - modified sodium alginate, pectin with dandelion extract, and then mix with whey protein in a mass ratio of 70 - 90:10 - 30; B2. Add calcium carbonate nanoparticles to the mixed solution, squeeze it into sunflower seed oil containing an emulsification aid through a syringe, and stir to form a W / O emulsion; B3. Add a mixture of sunflower seed oil and acetic acid to the emulsion to form microcapsules, wash with ethanol and then freeze - dry; B4. Disperse the microcapsules in an oral liquid matrix to prepare a functional oral liquid.

2. The preparation method of a functional oral liquid containing dandelion extract according to claim 1, characterized in that, In the 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 addition amount of the complex enzyme solution is 1.5 - 2.5% of the mass of dandelion powder; the enzymatic hydrolysis temperature is 50 - 60°C, and the enzymatic hydrolysis time is 20 - 30 minutes.

3. The preparation method of a functional oral liquid containing dandelion extract according to claim 1, characterized in that, In the 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 centrifugation speed is 18000 - 22000×g, and the centrifugation time is 8 - 12 minutes.

4. The preparation method of a functional oral liquid containing dandelion extract according to claim 1, characterized in that, In the step A3, the temperature of 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; add absolute ethanol to make the final concentration reach 75 - 85%, and stand for precipitation at 2 - 6°C for 10 - 14 hours; freeze - drying is carried out at - 45 - - 55°C and a vacuum degree of 5 - 15 Pa for 18 - 24 hours.

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

6. The preparation method of a functional oral liquid containing dandelion extract according to claim 1, characterized in that, In the step B1, by weight, 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 preparation method of a functional oral liquid containing dandelion extract according to claim 1, characterized in that, The preparation method of carboxymethyl chitosan modified sodium alginate in step B1 is as follows: by weight, 1.0 part of sodium alginate, 0.3 - 1.0 part of carboxymethyl chitosan, and 80 - 120 parts of deionized water; dissolve sodium alginate in 50 - 70 parts of deionized water, stir at 60 - 80 °C for 30 - 60 minutes until completely dissolved; dissolve carboxymethyl chitosan in the remaining deionized water, adjust the pH value to 5.5 - 6.5; after cooling to room temperature, slowly drip the carboxymethyl chitosan solution into the sodium alginate solution, and the dripping time is 15 - 30 minutes; after dripping, continue to stir for 60 - 120 minutes to make them fully complex, and then stand and cure at 4 - 8 °C for 12 - 24 hours to obtain a carboxymethyl chitosan modified sodium alginate composite solution.

8. The preparation method of a functional oral liquid containing dandelion extract according to claim 1, characterized in that In step B2, by weight, 100 parts of the mixed solution obtained in step B1, 1.0 - 3.0 parts of calcium carbonate nanoparticles, 150 - 200 parts of sunflower seed oil, 0.8 - 3.0 parts of emulsification aid, and 3.0 - 6.0 parts of Tween 80; first add the emulsification aid and Tween 80 to the sunflower seed oil, stir on a magnetic stirrer at 500 rpm for 1 - 2 minutes to obtain an oil phase, and the emulsifier is sorbitan monostearate; slowly add the calcium carbonate nanoparticles to the mixed solution obtained in step B1, stir while adding for 2 - 5 minutes until completely dispersed without agglomeration to obtain an aqueous phase; load the aqueous phase with a 10 - 20 mL syringe, and extrude it into the stirring oil phase at a constant speed of 0.5 - 1.0 mL / min through a 16 - 24 gauge blunt stainless steel needle. During the extrusion process, keep the stirring speed at 500 - 800 rpm. After extrusion, continue to stir for 10 - 20 minutes until a milky white, uniform and stable W / O emulsion is formed.

9. The preparation method of a functional oral liquid containing dandelion extract according to claim 1, characterized in that, In step B3, by weight, mix 30 - 50 parts of sunflower seed oil and 1.5 - 3.0 parts of acetic acid to obtain a mixture, and then slowly add the mixture to the W / O emulsion obtained in step B2, and the addition time is 15 - 25 minutes; after the microcapsules are formed, wash them thoroughly with ethanol until there is no oil residue; pre-freeze the washed microcapsules at -70 - 85 °C for 0.5 - 2 hours, and then transfer them to a freeze dryer and freeze-dry at -45 - 55 °C and a vacuum degree of 0.8 - 1.5 Pa for 20 - 28 hours; the average particle size of the freeze-dried microcapsules is 8 - 12 μm, and the encapsulation efficiency is ≥90%.

10. The functional oral liquid containing dandelion extract obtained by the preparation method according to any one of claims 1-9, characterized in that, By weight parts, it contains 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 bitter taste masking effect of this oral liquid makes the bitter value 8.0 - 11.0 BU, and its stability can be maintained for 150 - 180 days under the storage condition of 28°C.

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