Burdock polyphenol and low-burden caffeine synergistic slow-release beverage and preparation method thereof

Abstract

The invention provides a burdock polyphenol synergistic low-burden caffeine slow-release beverage and a preparation method thereof. The beverage comprises the following raw materials in parts by weight: 55-65 parts of caffeine slow-release microcapsules, 20-30 parts of burdock polyphenol microspheres, 5-10 parts of a microencapsulated hovenia dulcis thunb extract and 0.5-2 parts of compound probiotic freeze-dried powder. The method comprises the following steps: S1, preparing caffeine sustained-release microcapsules; s2, preparing burdock polyphenol microspheres; s3, preparing a microencapsulated hovenia dulcis thunb extract; and S4, blending a final product. The burdock active ingredients and the coffee flavor are fused through a low-temperature coupling preparation technology, and flavor adaptation, nutrition preservation and function targeted release are synchronously achieved.

Description

Technical Field

[0001] The present invention relates to a burdock coffee beverage, in particular to a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage and a preparation method thereof, belonging to the technical field of functional foods. Background Art

[0002] Existing coffee beverages have a single ingredient, resulting in the following bottlenecks that need to be addressed: 1. Uncontrollable caffeine release rate: The caffeine release rate in traditional coffee drinks is as high as 0.8-1.2 mg / min, causing palpitations and metabolic disorders in sensitive people.

[0003] 2. The drawback of limited nutritional functionality: Commercially available coffee drinks generally contain less than 1g of dietary fiber per 100ml, and their antioxidant retention rate is less than 40%. While the addition of burdock's active ingredients (such as polyphenols and inulin) has the potential to regulate metabolism, existing formulas struggle to achieve a synergistic effect between coffee flavor and functionality.

[0004] 3. Competitive interference from flavor components: Burdock glucosinolate degradation products compete for adsorption with coffee aroma molecules (such as furanones), resulting in a significant earthy odor. Conventional flavor modification techniques (such as adding flavorings) can easily mask the natural active ingredients, reducing the product's health benefits.

[0005] 4. Severe nutrient loss during processing: High-temperature extraction results in an oxidation rate of over 60% for burdock polyphenols, leaving less than 45% of chlorogenic acid in the coffee. While low-temperature processing can reduce the destruction of heat-sensitive components in coffee, it also presents technical challenges such as low extraction efficiency of active ingredients and poor encapsulation stability.

[0006] Therefore, a low-temperature coupling process for burdock polyphenols and low-burden caffeine sustained-release beverages was developed to simultaneously achieve flavor adaptation, nutritional preservation and functional targeted release. Summary of the Invention

[0007] In response to the above-mentioned existing technical problems, the present invention provides a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage and its preparation process and application, so as to integrate the burdock active ingredients and coffee flavor through a low-temperature coupling preparation process, and achieve targeted release of caffeine through molecular encapsulation technology.

[0008] To achieve the above technical objectives, firstly, the present invention provides a burdock polyphenol synergistic low-burden caffeine sustained-release beverage, comprising the following raw materials and their weight portions: 55-65 parts of caffeine sustained-release microcapsules, 20-30 parts of burdock polyphenol microspheres, 5-10 parts of microencapsulated Hovenia dulcis extract, and 0.5-2 parts of composite probiotic freeze-dried powder.

[0009] Among them, the inclusion rate of the caffeine sustained-release microcapsules is ≥85-92%; the particle size of the burdock polyphenol microspheres is 50-80nm, and the drug loading capacity is 15-20%; the embedding rate of the microencapsulated Hovenia dulcis extract is ≥90%, and the drug loading capacity is 20%; the viable bacterial count of the composite probiotic freeze-dried powder is ≥1x10^10 CFU / g.

[0010] The beverage of the present invention further has the compound probiotic freeze-dried powder comprising the following raw materials and their weight portions: 40 parts of Bifidobacterium lactis, 30 parts of Lactobacillus acidophilus, and 30 parts of Lactobacillus plantarum.

[0011] In the above technical solution, the functions of each raw material are introduced as follows: (1) Caffeine sustained-release microcapsules use microencapsulation technology to extend the caffeine release cycle, similar to the design of the melatonin sustained-release system. They achieve gradient release by responding to different pH environments and provide caffeine at a concentration of 2.5-3.5%. The 2.5-3.5% concentration range can adapt to the metabolic characteristics of the Chinese population (about 60% have caffeine metabolism gene defects) while meeting basic refreshment needs.

[0012] (2) Burdock polyphenol microspheres have synergistic and prebiotic functions. Specifically, burdock polyphenols have antioxidant effects, inhibit a variety of food-related bacteria, and promote the growth of beneficial bacteria.

[0013] (3) Microencapsulated Hovenia dulcis extract has the function of sustained-release caffeine (release period 4h±10%). The encapsulation process delays the release rate of caffeine and exerts the traditional liver-protecting function of Hovenia dulcis, reducing the metabolic burden of caffeine.

[0014] (4) The compound probiotic freeze-dried powder has the function of decomposing tannins, reducing bitterness and improving the taste of beverages.

[0015] Secondly, the present invention provides a preparation process for a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage, comprising the following steps: S1. Preparation of caffeine sustained-release microcapsules: S1-1, roasting and grinding coffee beans to obtain coffee bean powder; S1-2, mixing coffee bean powder with purified water, performing ultrasonic-assisted extraction, centrifuging, and filtering to obtain a caffeine extract; S1-3, mixing the caffeine extract with a saturated solution of β-cyclodextrin, stirring, and spray drying to obtain caffeine sustained-release microcapsules.

[0016] The method of the present invention further comprises the following steps: selecting Brazilian sando beans, roasting them at 205° C. to a moisture content of ≤12%, and then air-grinding them to 80 mesh to obtain coffee bean powder.

[0017] In the above technical solution, roasting at 205°C promotes the Maillard reaction and caramelization within the coffee beans, producing unique coffee flavor. It also reduces the moisture content to ≤12%, facilitating subsequent grinding and storage. Furthermore, using airflow to grind the coffee beans to 80 mesh allows for controlled particle size, ensuring uniformity and efficiency in subsequent caffeine extraction.

[0018] The method of the present invention further comprises the following steps: adding purified water to the coffee bean powder at a solid-liquid ratio of 1:15, extracting with 300W ultrasonic waves at 55°C for 45 minutes, then centrifuging at 10,000 rpm for 15 minutes, and filtering the supernatant through a 0.45 μm filter membrane to obtain a caffeine extract.

[0019] In the above technical solution, a solid-liquid ratio of 1:15 ensures sufficient caffeine extraction, while a temperature of 55°C reduces the loss of heat-sensitive components in the coffee bean powder. Subsequently, ultrasonic-assisted extraction increases the dissolution rate of caffeine from the coffee bean powder and the amount of caffeine extracted. Furthermore, centrifugation at 10,000 rpm for 15 minutes effectively separates solid impurities from the extract, which is then filtered through a 0.45μm membrane to ensure the purity of the caffeine extract.

[0020] The method of the present invention further comprises the following steps: mixing the caffeine extract and the saturated solution of β-cyclodextrin in a mass ratio of 1:3, stirring at 40°C for 4 hours, and then spray drying at an inlet air temperature of 180°C to obtain caffeine sustained-release microcapsules.

[0021] In the above technical solution, β-cyclodextrin can fully incorporate into the caffeine extract, forming a stable inclusion complex. Stirring at 40°C for 4 hours ensures a smooth inclusion reaction while preventing high temperatures from damaging the caffeine and β-cyclodextrin structures. Furthermore, setting the inlet air temperature to 180°C not only allows the inclusion complex to dry quickly into microcapsules, but also maintains the structural stability and inclusion efficiency of the caffeine sustained-release microcapsules.

[0022] S2. Preparation of burdock polyphenol microspheres: S2-1, washing burdock root with ozone water, ultrasonically peeling, drying, and then crushing to obtain burdock root powder; S2-2, mixing burdock root powder with pH 4.5 phosphate buffer, adding a composite enzyme preparation for enzymatic hydrolysis, inactivating the enzyme, and filtering to obtain a burdock polyphenol extract; S2-3. Preparation of burdock polyphenol microspheres: burdock polyphenol extract and sodium alginate solution were mixed, and calcium chloride solution was added dropwise for solidification. The mixture was washed and spray-dried to obtain burdock polyphenol microspheres.

[0023] The method of the present invention further comprises the following steps: washing the burdock root with ozone water having a concentration of 5 ppm for 3 minutes, peeling the burdock root with the assistance of ultrasound, and then drying the burdock root with air at 40° C. until the moisture content is ≤10%, and then pulverizing the burdock root to obtain burdock root powder.

[0024] In the above technical solution, ozone water cleaning effectively sterilizes and disinfects the burdock root, removing microorganisms and impurities from its surface. Ultrasonic-assisted peeling separates the burdock root's epidermis from the flesh without damaging the internal tissue. Furthermore, forced air drying at 40°C prevents mold and deterioration during storage and subsequent processing, while ensuring the stability of its active ingredients and facilitating crushing into a uniform powder.

[0025] The method of the present invention further comprises the following steps: adding a phosphate buffer solution with a pH of 4.5 to the burdock powder at a solid-liquid ratio of 1:8, then adding a composite enzyme preparation with a mass fraction of 0.5% of the burdock powder, performing enzymolysis at 40° C. for 90 minutes, inactivating the enzyme at 95° C. for 5 minutes, and then filtering through a 0.22 μm filter membrane to obtain a burdock polyphenol extract.

[0026] In the above technical solution, the addition of phosphate buffer to burdock powder and the setting of a solid-liquid ratio of 1:8 can provide a suitable reaction environment for the complex enzyme preparation, making burdock polyphenols more easily dissolve. Enzymatic hydrolysis at 40°C for 90 minutes is the optimal temperature and time for the enzymatic hydrolysis reaction, which can ensure high enzymatic hydrolysis efficiency and burdock polyphenol extraction rate. Enzyme inactivation at 95°C for 5 minutes can avoid excessive enzymatic hydrolysis from adversely affecting the structure and properties of burdock polyphenols. In addition, filtration through a 0.22μm filter membrane can remove solid residues and macromolecular impurities in the enzymatic hydrolysis solution, thereby improving the purity of the burdock polyphenol extract.

[0027] The method of the present invention is further characterized in that in S2-2, the complex enzyme preparation comprises cellulase and pectinase in a mass ratio of 3:1.

[0028] In the above technical solution, the burdock root cell wall is composed of a dense network of cellulose and pectin. Based on the natural content ratio of cellulose to pectin in the burdock root cell wall (about 2:1), the mass ratio of cellulase and pectinase is set to 3:1, and the penetration into the thick wall tissue is enhanced by increasing the proportion of cellulase, thereby ensuring a higher enzymatic hydrolysis efficiency and extraction rate of burdock polyphenols.

[0029] The method of the present invention further comprises the following steps: mixing the burdock polyphenol extract and the sodium alginate solution in a mass ratio of 1:2, dropping a 0.2 mol / L calcium chloride solution, and then solidifying by magnetic stirring for 2 hours, washing with distilled water three times, and then spray drying to obtain burdock polyphenol microspheres.

[0030] In the above technical solution, the calcium ions in the calcium chloride solution can undergo ion exchange with the sodium ions in the sodium alginate, causing the sodium alginate to form a gel network structure, encapsulating the burdock polyphenols therein to achieve solidification and molding. In addition, magnetic stirring for 2 hours can make the solidification reaction more uniform, ensuring the stability of the microsphere morphology and structure. Washing with distilled water three times can remove the residual calcium chloride and other impurities on the surface of the microspheres. In addition, spray drying can quickly dry the microspheres, forming a stable microsphere structure without destroying the activity of the burdock polyphenols.

[0031] S3. Preparation of microencapsulated Hovenia dulcis fruit extract: S3-1, grinding and sieving the Hovenia dulcis fruit to obtain Hovenia dulcis fruit powder; S3-2, mixing the Hovenia dulcis fruit powder with a 95% ethanol solution, extracting by heating, and concentrating and drying to obtain a Hovenia dulcis fruit extract; S3-3. The Hovenia dulcis fruit extract and the wall material powder are mixed and homogenized, and then spray-dried to obtain microencapsulated Hovenia dulcis fruit extract; the wall material comprises maltodextrin and gum arabic in a mass ratio of 1:1-2.

[0032] S4. Final product preparation: S4-1, mixing caffeine sustained-release microcapsules, burdock polyphenol microspheres, microencapsulated Hovenia dulcis fruit extract, and composite probiotic freeze-dried powder to obtain a mixed material; S4-2. Add 0.1% ascorbic acid by weight of the mixed material, homogenize, pasteurize, and then fill to obtain a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage.

[0033] In summary, the present invention provides a composite health drink that combines burdock active ingredients with coffee flavor and a low-temperature coupling preparation process thereof, particularly a method for preparing a functional drink that achieves targeted caffeine release through molecular encapsulation technology. Compared with the prior art, the present invention has the following beneficial effects and technical advantages: (1) Caffeine, burdock polyphenols, and Hovenia dulcis fruit extracts were all encapsulated using molecular encapsulation technology, which extended the half-life of caffeine in the beverage to 4.2 hours (2.8 hours for traditional products) and reduced the metabolic load by 32% (P < 0.05).

[0034] (2) Synergistic antioxidant system: Burdock polyphenols form a hydrogen bond network with chlorogenic acid in coffee liquid, which increases the total antioxidant capacity of the beverage (ABTS method) to 180μmol TE / g.

[0035] (3) Low-temperature ultrasonic extraction process: The cell structure of coffee powder is destroyed by ultrasonic cavitation, and ultrasonic extraction is performed at a low temperature of 55°C to avoid the degradation of heat-sensitive components such as chlorogenic acid and caffeine.

[0036] (4) Low-temperature enzymatic hydrolysis process: 40°C is the optimal temperature for the enzymatic hydrolysis reaction of cellulase and pectinase, which can not only efficiently decompose the cell wall of burdock powder, but also release polyphenols (+35%) and oligosaccharides (prebiotics), thereby increasing the caffeine extraction rate and chlorogenic acid retention rate, improving the enzymatic hydrolysis efficiency, and avoiding the high-temperature gelatinization of burdock polysaccharides while maintaining the clarity of the beverage.

[0037] (5) Low-carbon preparation process: The extraction process for preparing caffeine sustained-release microcapsules saves 45% energy and reduces water consumption by 60% compared to traditional hot extraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Flow chart of the preparation process of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further explained below in conjunction with specific examples. It will be understood by those skilled in the art that the following examples are some examples of the present invention, rather than all examples, and are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. All reagents used are conventional products that can be purchased commercially.

[0040] Example 1: This example provides a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage, comprising the following raw materials and their weight portions: 55 parts of caffeine sustained-release microcapsules, 20 parts of burdock polyphenol microspheres, 5 parts of microencapsulated Hovenia dulcis extract, and 0.5 parts of composite probiotic freeze-dried powder.

[0041] The inclusion rate of the caffeine sustained-release microcapsules is ≥85%. The particle size of the burdock polyphenol microspheres is 50 nm, and the drug loading is 15%. The embedding rate of the microencapsulated Hovenia dulcis extract is ≥90%, and the drug loading is 20%. The viable count of the freeze-dried composite probiotic powder is ≥1x10^10 CFU / g. In specific implementations, the freeze-dried composite probiotic powder includes the following raw materials and their weight portions: 40 parts of Bifidobacterium lactis, 30 parts of Lactobacillus acidophilus, and 30 parts of Lactobacillus plantarum.

[0042] And, as Figure 1 As shown, this embodiment also provides a method for preparing a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage, comprising the following steps: S1. Preparation of caffeine sustained-release microcapsules: S1-1. Coffee bean processing: Brazilian Sando beans were selected and roasted at 205°C to a moisture content of ≤12%, and then air-milled to 80 mesh to obtain coffee bean powder.

[0043] S1-2. Preparation of caffeine extract: Purified water was added to coffee bean powder at a solid-liquid ratio of 1:15. The powder was extracted using 300W ultrasonic wave at 55°C for 45 minutes, followed by centrifugation at 10,000 rpm for 15 minutes. The supernatant was filtered through a 0.45 μm filter membrane to obtain a caffeine extract.

[0044] S1-3. Preparation of caffeine sustained-release microcapsules: Caffeine extract and β-cyclodextrin saturated solution were mixed in a mass ratio of 1:3, then stirred at 40°C for 4 hours, and then spray-dried (inlet air temperature 180°C) to obtain caffeine sustained-release microcapsules.

[0045] S2. Preparation of burdock polyphenol microspheres: S2-1. Burdock root treatment: The burdock root was washed with 5 ppm ozone water for 3 minutes, peeled with ultrasound assistance, and then dried with forced air at 40°C until the moisture content was ≤10%. The burdock root was then pulverized to obtain burdock root powder.

[0046] S2-2. Preparation of burdock polyphenol extract: add phosphate buffer solution with a pH of 4.5 to burdock powder at a solid-liquid ratio of 1:8, then add a complex enzyme preparation at a concentration of 0.5% by weight of burdock powder, perform enzymatic hydrolysis at 40°C for 90 minutes, inactivate the enzyme at 95°C for 5 minutes, and then filter through a 0.22 μm filter membrane to obtain a burdock polyphenol extract.

[0047] The composite enzyme preparation includes the following raw materials and their weight parts: 3 parts of cellulase and 1 part of pectinase.

[0048] S2-3. Preparation of burdock polyphenol microspheres: burdock polyphenol extract and sodium alginate solution were mixed in a mass ratio of 1:2, 0.2 mol / L calcium chloride solution was added dropwise, and then solidified by magnetic stirring for 2 h. The mixture was washed three times with distilled water and then spray-dried (inlet air temperature 180°C) to obtain burdock polyphenol microspheres.

[0049] S3. Preparation of microencapsulated Hovenia dulcis fruit extract: S3-1. Processing of Hovenia dulcis: removing impurities from the Hovenia dulcis, drying with forced air at 60° C., and then pulverizing and passing through an 80-mesh sieve to obtain Hovenia dulcis powder.

[0050] S3-2. Preparation of Hovenia dulcis extract: Hovenia dulcis powder was mixed with 95% ethanol solution at a solid-liquid ratio of 1:8, and extracted at 60-100°C for 3 hours. The mixture was then filtered, concentrated under vacuum, and dried under vacuum (to remove ethanol and water) to a constant weight to obtain the Hovenia dulcis extract.

[0051] S3-3. Preparation of microencapsulated Hovenia dulcis extract: maltodextrin and gum arabic were mixed in a mass ratio of 1:1-2 to obtain wall material powder, the Hovenia dulcis extract and the wall material powder were mixed in a mass ratio of 1:3, deionized water was added to form a homogeneous suspension, and then homogenized and emulsified at 8000-10000 rpm, and then spray-dried (inlet air temperature 160-165°C) to obtain microencapsulated Hovenia dulcis extract.

[0052] S4. Final product preparation: S4-1. Mix the caffeine sustained-release microcapsules, burdock polyphenol microspheres, microencapsulated Hovenia dulcis fruit extract, and compound probiotic freeze-dried powder in a mass ratio of 55-65:20-30:5-10:0.5-2 to obtain a mixed material.

[0053] S4-2. 0.1% ascorbic acid by weight of the mixture is added, and the mixture is homogenized twice at 50 MPa. The mixture is pasteurized at 72° C. for 15 seconds, and the mixture is filled to obtain a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage.

[0054] Example 2: This example provides a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage, comprising the following raw materials and their weight portions: 65 parts of caffeine sustained-release microcapsules, 30 parts of burdock polyphenol microspheres, 10 parts of microencapsulated Hovenia dulcis extract, and 2 parts of composite probiotic freeze-dried powder.

[0055] The inclusion rate of the caffeine sustained-release microcapsules is ≥92%. The particle size of the burdock polyphenol microspheres is 80 nm, and the drug loading is 20%. The embedding rate of the microencapsulated Hovenia dulcis extract is ≥90%, and the drug loading is 20%. The viable count of the freeze-dried composite probiotic powder is ≥1x10^10 CFU / g. In specific implementations, the freeze-dried composite probiotic powder includes the following raw materials and their weight portions: 40 parts of Bifidobacterium lactis, 30 parts of Lactobacillus acidophilus, and 30 parts of Lactobacillus plantarum.

[0056] Furthermore, the preparation method of the burdock polyphenols-synergistic low-burden caffeine sustained-release beverage is the same as that of Example 1.

[0057] Example 3: This example provides a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage, comprising the following raw materials and their weight portions: 62 parts of caffeine sustained-release microcapsules, 26 parts of burdock polyphenol microspheres, 8 parts of microencapsulated Hovenia dulcis extract, and 1.2 parts of composite probiotic freeze-dried powder.

[0058] The inclusion rate of the caffeine sustained-release microcapsules is ≥88%. The particle size of the burdock polyphenol microspheres is 65 nm, and the drug loading is 17%. The embedding rate of the microencapsulated Hovenia dulcis extract is ≥90%, and the drug loading is 20%. The viable count of the composite probiotic freeze-dried powder is ≥1x10^10 CFU / g. In specific implementations, the composite probiotic freeze-dried powder includes the following raw materials and their weight portions: 40 parts of Bifidobacterium lactis, 30 parts of Lactobacillus acidophilus, and 30 parts of Lactobacillus plantarum.

[0059] Furthermore, the preparation method of the burdock polyphenols-synergistic low-burden caffeine sustained-release beverage is the same as that of Example 1.

[0060] Comparative Example 1: This comparative example provides a burdock polyphenol-synergistic, low-burden caffeine sustained-release beverage, comprising the following ingredients by weight: 26 parts burdock polyphenol microspheres, 8 parts microencapsulated Hovenia dulcis fruit extract, and 1.2 parts freeze-dried composite probiotic powder. Compared to Example 3, this comparative example lacks 62 parts of the caffeine sustained-release microcapsules.

[0061] Comparative Example 2: This comparative example provides a burdock polyphenol-synergistic, low-burden caffeine sustained-release beverage, comprising the following ingredients by weight: 62 parts of caffeine sustained-release microcapsules, 8 parts of microencapsulated Hovenia dulcis fruit extract, and 1.2 parts of a freeze-dried composite probiotic powder. Compared to Example 3, this comparative example lacks 26 parts of burdock polyphenol microspheres.

[0062] Comparative Example 3: This comparative example provides a burdock polyphenol-synergistic, low-burden caffeine sustained-release beverage, comprising the following ingredients and their weight proportions: 62 parts of caffeine sustained-release microcapsules, 26 parts of burdock polyphenol microspheres, and 1.2 parts of composite probiotic freeze-dried powder. Compared to Example 3, this comparative example lacks 8 parts of microencapsulated Hovenia dulcis fruit extract.

[0063] Comparative Example 4: This comparative example provides a burdock polyphenol-synergistic, low-burden caffeine sustained-release beverage, comprising the following ingredients by weight: 62 parts of caffeine sustained-release microcapsules, 26 parts of burdock polyphenol microspheres, and 8 parts of microencapsulated Hovenia dulcis fruit extract. Compared to Example 3, this comparative example lacks 1.2 parts of the composite probiotic freeze-dried powder.

[0064] Experiment 1: Verification of caffeine sustained-release performance.

[0065] Experimental principle: In vitro simulated digestion model: refer to the second method (paddle method) of the dissolution test method of the 2020 edition of the Chinese Pharmacopoeia.

[0066] Experimental conditions: Simulated gastric fluid (pH 1.2, containing 0.1% Tween 80) was stirred continuously at 37°C; after 2 hours, the simulated intestinal fluid (pH 6.8 phosphate buffer) was switched; samples were taken regularly to detect the free caffeine concentration.

[0067] Experimental Method: Coffee beans were roasted at 200°C to a moisture content of ≤12% and ground to 80 mesh to obtain coffee powder. 90°C hot water was then added to the coffee powder at a material-to-liquid ratio of 1:10 (g / mL). The mixture was soaked for 15 minutes and filtered to obtain a coffee extract. The coffee extract was then concentrated and spray-dried (inlet air temperature 180°C) to obtain traditional coffee powder.

[0068] Appropriate amounts of traditional coffee powder and the burdock polyphenol-synergistic, low-burden caffeine sustained-release beverage prepared in Example 3 were precisely weighed as samples for the traditional coffee group and the product group of the present invention, respectively, and placed into the dedicated hanging baskets provided with the dissolution cups. 900 mL of simulated gastric fluid, preheated to 37°C, was added to the dissolution cups. The hanging baskets containing the samples were slowly immersed in the simulated gastric fluid, ensuring that the samples were completely submerged and did not contact the cup walls or paddles. The dissolution tester was immediately started and set to 50 rpm to simulate gastric peristalsis. The timing was started. At predetermined time points, such as 0.5 h, 1 h, and 2 h, 5 mL of solution was aspirated from the dissolution cups and rapidly transferred to pre-chilled centrifuge tubes. The tubes were centrifuged at 10,000 rpm for 5 min. The supernatant was aspirated and filtered through a 0.22 μm filter membrane before being transferred to sample vials. The free caffeine concentration was determined by high-performance liquid chromatography (HPLC). Three replicate measurements were performed at each time point, and the average value was recorded.

[0069] When the digestion time reaches 2 hours, immediately stop the dissolution tester, carefully remove the sample basket, and rinse the simulated gastric fluid attached to the surface with a small amount of distilled water to minimize residual solution. Quickly discard the simulated gastric fluid from the dissolution vessel and rinse the dissolution vessel with distilled water to ensure that no residual simulated gastric fluid is present. Then, accurately add simulated intestinal fluid preheated to 37°C to the dissolution vessel. Re-immerse the sample basket in the simulated intestinal fluid and start the dissolution tester, maintaining the same speed to continue simulating the intestinal digestion process. Following the above sampling, centrifugation, filtration, and measurement process, continue to measure the free caffeine concentration in the simulated intestinal fluid at subsequent time points, such as 4 hours and 6 hours. Similarly, perform three replicate measurements at each time point and record the average value.

[0070] The experimental data are shown in Table 1 below.

[0071]

[0072] As can be seen from the above table, the caffeine concentration of the burdock polyphenols synergistic low-burden caffeine sustained-release beverage prepared in Example 3 is lower than that of traditional coffee powder at each time point, indicating that the product of the present invention can delay the release of caffeine, thereby extending the caffeine release period.

[0073] Experiment 2: Verification of burdock polyphenol retention rate.

[0074] Experimental Methods: Burdock polyphenol powder was prepared using a traditional hot extraction method: Burdock root slices were oven-dried at 90°C to a moisture content of ≤8%, then ground and passed through a 40-mesh sieve to obtain burdock root powder. An 80% ethanol solution was then added to the burdock root powder at a solid-liquid ratio of 1:10 (g / mL). The filtrates were reflux-extracted in an 85°C water bath twice for 1.5 hours each. The filtrates were then combined. The ethanol was then removed by rotary evaporation at 60°C to obtain a concentrated solution. Finally, the concentrated solution was spray-dried to obtain burdock polyphenol powder.

[0075] The burdock polyphenol powder prepared by traditional hot extraction and the burdock polyphenol synergistic low-burden caffeine sustained-release beverage prepared by low-temperature extraction in Example 3 were used as samples, and the total phenol content, DPPH scavenging rate, and chlorogenic acid retention rate of the samples were determined according to the following methods: 1) HPLC method for total phenol content (referring to GB / T 31740-2015); 2) DPPH free radical scavenging ability determination (TEAC method); 3) chlorogenic acid retention rate was determined by high performance liquid chromatography.

[0076] The experimental data are shown in Table 2 below.

[0077]

[0078] As can be seen from the above table, the low-temperature extraction process adopted in Example 3 can more effectively extract polyphenols from burdock. Compared with the burdock polyphenol powder prepared by the traditional hot extraction method, the product of the present invention has a higher total phenol content, a higher DPPH clearance rate, a higher chlorogenic acid retention rate, and a stronger antioxidant activity, and has more advantages in functionality and nutritional value.

[0079] Experiment 3: Refreshing effect.

[0080] Experimental subjects: 140 healthy adult subjects (aged 25-45 years old, half male and half female) were recruited and randomly divided into 7 groups (20 subjects in each group) to drink the beverages prepared in Examples 1-3 and Comparative Examples 1-4 respectively.

[0081] Experimental method: The subjects drank 200 mL of the corresponding beverage on an empty stomach in the morning. The subjective refreshing feeling was assessed using a visual analogue scale (VAS, 0-10 points, 0 points for no refreshing effect, 10 points for the strongest refreshing effect) 0.5h, 1h, 2h, 4h, and 6h after drinking. At the same time, the salivary cortisol level was tested to assess the degree of fatigue.

[0082] Determination of antioxidant activity: The total antioxidant capacity of the beverages was determined by the ABTS method, and the iron ion reducing capacity was determined by the FRAP method to evaluate the antioxidant properties of each formulation.

[0083] Liver function indicators: Venous blood was collected from the subjects 6 hours after drinking the beverage, and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) in the serum were measured to evaluate the protective effect of Hovenia dulcis extract on liver function.

[0084] Taste rating: Invite 10 professional food sensory evaluators to score the beverages based on the ISO 13299 standard in terms of aroma, flavor, mouthfeel, etc. (100-point system).

[0085] The experimental results are shown in Table 3 below.

[0086]

[0087] Note: * indicates P < 0.05 compared with Example 3.

[0088] Data analysis shows that compared to the other groups, the burdock polyphenol-co-caffeine slow-release beverage prepared in Example 3 exhibits the best refreshing effect, antioxidant capacity, liver protection, and taste. This demonstrates that Example 3 represents the optimal formulation of the present invention. Furthermore, the absence of any of the core ingredients in Comparative Examples 1-4 resulted in decreased performance in terms of refreshing, antioxidant, liver protection, and taste, fully demonstrating the synergistic effect of the formulation in Example 3.

[0089] Finally, it should be noted that the embodiments are merely preferred embodiments 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 aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A burdock polyphenol-synergistic low-burden caffeine sustained-release beverage, characterized in that: The preparation comprises the following raw materials and their weight portions: 55-65 parts of caffeine sustained-release microcapsules, 20-30 parts of burdock polyphenol microspheres, 5-10 parts of microencapsulated Hovenia dulcis fruit extract, and 0.5-2 parts of compound probiotic freeze-dried powder; The inclusion rate of the caffeine sustained-release microcapsules is ≥85-92%; The particle size of the burdock polyphenol microspheres is 50-80 nm, and the drug loading is 15-20%; The embedding efficiency of the microencapsulated Hovenia dulcis extract is ≥90%, and the drug loading is 20%; The viable bacterial count of the composite probiotic freeze-dried powder is ≥1x10^10 CFU / g.

2. The burdock polyphenols-synergistic low-burden caffeine sustained-release beverage according to claim 1, characterized in that: The composite probiotic freeze-dried powder comprises the following raw materials and their weight portions: 40 parts of Bifidobacterium lactis, 30 parts of Lactobacillus acidophilus, and 30 parts of Lactobacillus plantarum.

3. A process for preparing the burdock polyphenols synergistic low-burden caffeine sustained-release beverage according to claim 1 or 2, characterized in that: The steps include: S1. Preparation of caffeine sustained-release microcapsules: S1-1, roasting and grinding coffee beans to obtain coffee bean powder; S1-2, mixing coffee bean powder with purified water, performing ultrasonic-assisted extraction, centrifuging, and filtering to obtain a caffeine extract; S1-3, mixing the caffeine extract with a saturated solution of β-cyclodextrin, stirring, and spray drying to obtain caffeine sustained-release microcapsules; S2. Preparation of burdock polyphenol microspheres: S2-1, washing burdock root with ozone water, ultrasonically peeling, drying, and then crushing to obtain burdock root powder; S2-2, mixing burdock root powder with pH 4.5 phosphate buffer, adding a composite enzyme preparation for enzymatic hydrolysis, inactivating the enzyme, and filtering to obtain a burdock polyphenol extract; S2-3, preparation of burdock polyphenol microspheres: mixing burdock polyphenol extract with sodium alginate solution, adding calcium chloride solution dropwise for solidification, washing, and spray drying to obtain burdock polyphenol microspheres; S3. Preparation of microencapsulated Hovenia dulcis fruit extract: S3-1, grinding and sieving the Hovenia dulcis fruit to obtain Hovenia dulcis fruit powder; S3-2, mixing the Hovenia dulcis fruit powder with a 95% ethanol solution, extracting by heating, and concentrating and drying to obtain a Hovenia dulcis fruit extract; S3-3, homogenizing the Hovenia dulcis fruit extract and the wall material powder, and spray-drying the mixture to obtain microencapsulated Hovenia dulcis fruit extract; the wall material comprises maltodextrin and gum arabic in a mass ratio of 1:1-2; S4. Final product preparation: S4-1, mixing caffeine sustained-release microcapsules, burdock polyphenol microspheres, microencapsulated Hovenia dulcis fruit extract, and composite probiotic freeze-dried powder to obtain a mixed material; S4-2. Add 0.1% ascorbic acid by weight of the mixed material, homogenize, pasteurize, and then fill to obtain a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage.

4. The preparation process of a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage according to claim 3, characterized in that: The S1-1 includes the following steps: Brazilian sando beans were selected and roasted at 205°C to a moisture content of ≤12%, and then air-milled to 80 mesh to obtain coffee bean powder.

5. The preparation process of a burdock polyphenols-synergistic low-burden caffeine sustained-release beverage according to claim 3, characterized in that: The S1-2 includes the following steps: Purified water was added to the coffee bean powder at a solid-liquid ratio of 1:

15. The powder was extracted with 300W ultrasonic wave at 55°C for 45 minutes, and then centrifuged at 10,000 rpm for 15 minutes. The supernatant was filtered through a 0.45 μm filter membrane to obtain a caffeine extract.

6. The preparation process of a burdock polyphenols-synergistic low-burden caffeine sustained-release beverage according to claim 3, characterized in that: The S1-3 comprises the following steps: The caffeine extract and the saturated solution of β-cyclodextrin were mixed in a mass ratio of 1:3, and then stirred at 40°C for 4 hours, and then spray-dried with an inlet air temperature of 180°C to obtain caffeine sustained-release microcapsules.

7. The preparation process of a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage according to claim 3, characterized in that: The S2-1 includes the following steps: The burdock root was washed with ozone water at a concentration of 5 ppm for 3 minutes, peeled with the assistance of ultrasound, and then dried with forced air at 40° C. until the moisture content was ≤10%, and then pulverized to obtain burdock root powder.

8. The process for preparing a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage according to claim 3, characterized in that: The S2-2 comprises the following steps: Phosphate buffer with a pH of 4.5 was added to the burdock powder at a solid-liquid ratio of 1:8, and then a complex enzyme preparation with a mass fraction of 0.5% of the burdock powder was added. The mixture was enzymolyzed at 40°C for 90 minutes, inactivated at 95°C for 5 minutes, and filtered through a 0.22 μm filter membrane to obtain a burdock polyphenol extract.

9. The process for preparing a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage according to claim 8, characterized in that: In the S2-2, the complex enzyme preparation includes cellulase and pectinase in a mass ratio of 3:

1.

10. The preparation process of a burdock polyphenol-synergistic low-burden caffeine sustained-release beverage according to claim 3, characterized in that: The S2-3 comprises the following steps: The burdock polyphenol extract and sodium alginate solution were mixed in a mass ratio of 1:2, 0.2 mol / L calcium chloride solution was added dropwise, and then solidified by magnetic stirring for 2 h, washed with distilled water three times, and spray-dried to obtain burdock polyphenol microspheres.

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