A functional beverage containing willowherb water extract, its preparation method and application

Abstract

This invention relates to the field of functional beverage technology, specifically to a functional beverage containing willowherb water extract, its preparation method, and its application. The beverage comprises the following components in the indicated mass-volume ratios: willowherb water extract dry extract 0.6-1.8 g / 30 mL, fructooligosaccharides 1.2-3.6 g / 30 mL, citric acid 0.06-0.18 g / 30 mL, xanthan gum 0.036-0.084 g / 30 mL, and L-ascorbic acid 0.03-0.15 g / 30 mL. While ensuring excellent color, flavor, and taste, the beverage achieves low sugar content, suitable acidity, and good stability, making it suitable for a wide range of consumers, including those with diabetes. The beverage preparation process is simple and reproducible, facilitating standardized production and large-scale promotion. It provides a feasible path for the high-value development of willowherb resources. Fructooligosaccharides hardly participate in sugar metabolism and do not raise blood sugar. The combination of willowherb's sleep-aiding function and low sugar content makes it suitable as a nighttime beverage for diabetic patients.

Description

Technical Field

[0001] This invention relates to the field of functional beverage technology, specifically to a functional beverage containing willowherb water extract, its preparation method, and its application. Background Technology

[0002] Sleep disorders have become a significant health issue affecting the global and Chinese populations. In recent years, the rate of sleep disturbance in China has remained high. According to the "2025 China Sleep Health Survey Report" released by the Chinese Sleep Research Society, the rate of sleep disturbance among people aged 18 and above in China is as high as 48.5%, with women and the elderly experiencing particularly prominent problems. Faced with this health challenge, existing market solutions have significant limitations. While mainstream sedative-hypnotic drugs are effective, they generally carry risks and side effects such as dependence, addiction, and limitations in the applicable population. Meanwhile, various sleep-aid beverages on the market mostly appear as ordinary food products with added sleep-aiding ingredients, offering limited actual effectiveness. Furthermore, some products may cause oral discomfort or health concerns due to sugar or other ingredients, failing to meet consumers' urgent need for natural, safe, and side-effect-free sleep aids.

[0003] Against this backdrop, plant extracts derived from traditional medicine are showing unique potential in improving sleep due to their gentle effects and multi-target regulation. The active ingredients in plants, such as flavonoids, terpenes, and alkaloids, can synergistically improve sleep quality through multiple pathways, including regulating neurotransmitters and alleviating oxidative stress. As consumers increasingly embrace the concept of "natural plants," the functional beverage market, particularly the sleep aid sub-segment, centered on natural plant ingredients, is experiencing rapid growth.

[0004] Willowherb (Epilobium angustifolium L.), as a traditional medicinal plant, has outstanding development value in this field. This perennial herb of the Onagraceae family is widely distributed in the Qinghai-Tibet Plateau of China, Siberia and Europe. Its application has a long history: Tibetan medical classics such as "Jingzhu Materia Medica" and "Four Medical Classics" record that it has the effect of "calming the mind and stabilizing the will", and is used to treat neurasthenia, insomnia and dreaminess; Russian folk medicine has a tradition of fermenting it into "Ivan Chai" to relieve anxiety and improve sleep[4]. Modern preliminary studies (including early mouse experiments) also support its anti-anxiety and sleep-aiding effects. The flavonoids (such as quercetin) and polyphenols (such as gallic acid) in willowherb are considered to be the material basis for its anti-inflammatory, antioxidant and neuromodulatory activities.

[0005] However, the resource development and industrialization of willowherb face the dilemma of "solid foundation but lagging industrialization." While domestic research has accumulated some expertise in chemical composition, pharmacology, and introduction and domestication, large-scale cultivation techniques (such as soil improvement and pest control) are still immature and lack systematic support. Product development largely remains at the traditional medicinal stage, with a scarcity of deep-processed products, resulting in low market awareness. Developing willowherb into a beverage formulation offers significant advantages such as convenient consumption, high patient compliance, and easily adjustable taste. Through modern food processing techniques, such as flavor modification using healthy sweeteners like fructooligosaccharides, low-sugar products that meet modern health needs can be prepared. This not only alleviates potential oral discomfort from drinking before bedtime, but the prebiotic properties of fructooligosaccharides and their minimal impact on blood sugar also broaden the product's applicability to a wider range of people, including diabetic patients.

[0006] Therefore, by comprehensively utilizing Tibetan medicine records, domestic and international folk application experience, and preliminary experimental evidence, and using willowherb water extract as the main functional ingredient, we can systematically research and develop a natural, safe, and effective willowherb sleep aid beverage. This will not only respond to the market's urgent demand for new healthy sleep aid products, but also provide important scientific basis and practical path for promoting the modernization and high-value development of this traditional Tibetan medicine resource. Summary of the Invention

[0007] The primary objective of this invention is to provide a functional beverage containing willowherb aqueous extract, comprising the following components in the indicated mass-volume ratios: willowherb aqueous extract dry extract 0.6-1.8 g / 30 mL, fructooligosaccharides 1.2-3.6 g / 30 mL, citric acid 0.06-0.18 g / 30 mL, xanthan gum 0.036-0.084 g / 30 mL, and L-ascorbic acid 0.03-0.15 g / 30 mL.

[0008] Preferably, the pH value of the beverage is 3.5-3.7.

[0009] Preferably, the willowherb water extract dry extract is prepared by the following method: dried and pulverized willowherb raw material is mixed with deionized water at a material-to-liquid ratio of 1:18-1:22 g / mL, soaked at 50-60℃ for 75-225 minutes, ultrasonically extracted for 35 minutes, filtered, the filtrate is collected and concentrated and dried to obtain the extract.

[0010] Preferably, the extraction process of the willowherb water extract is as follows: ultrasonic temperature 55℃, soaking time 150 minutes, and material-to-liquid ratio 1:20 g / mL.

[0011] A second objective of this invention is to provide a method for preparing the functional beverage, comprising the following steps:

[0012] (1) Preparation of water extract of willowherb: The dried and pulverized willowherb raw material was mixed with water at a material-liquid ratio of 1:18-1:22 g / mL, soaked at 50-60℃ for 75-225 minutes, and then ultrasonically extracted at the same temperature for 35 minutes. After filtration, the filtrate was concentrated and dried to obtain dry extract of willowherb water extract.

[0013] (2) Preparation: Based on 30 mL, weigh 0.6-1.2 g of dry extract of willowherb water, 1.8-3.0 g of fructooligosaccharides, 0.12-0.18 g of citric acid, 0.036-0.060 g of xanthan gum and 0.06-0.12 g of L-ascorbic acid, add water to 30 mL, and mix thoroughly until the solution is homogeneous and clear;

[0014] (3) Post-processing: The prepared beverage is bottled, sealed and sterilized to obtain the final product.

[0015] Preferably, the preferred formulation prepared in step (2) is: 0.9 g of willowherb water extract dry extract, 2.4 g of fructooligosaccharides, 0.15 g of citric acid, 0.048 g of xanthan gum and 0.09 g of L-ascorbic acid.

[0016] Preferably, the sterilization in step (3) is performed by pasteurization or high-temperature instantaneous sterilization.

[0017] Preferably, the power of the ultrasonic extraction in step (1) is 200-400W.

[0018] A third objective of this invention is to provide the use of the aforementioned functional beverage in the preparation of health foods for improving sleep or relieving anxiety.

[0019] The beneficial effects of this invention are as follows: By modifying the ratio of willowherb extract, fructooligosaccharides, xanthan gum, citric acid, and L-ascorbic acid, the optimized formula (willowherb extract, fructooligosaccharides, citric acid, xanthan gum, L-ascorbic acid) ensures excellent color, flavor, and taste while achieving low sugar content (due to the prebiotic effect of fructooligosaccharides), suitable acidity (pH 3.5-3.7), and good stability, making it suitable for a wide range of consumers, including those with diabetes. Furthermore, by exploring the effects of pH value and the amount of flavoring agents, the optimal conditions for preparing the willowherb sleep-aid beverage were determined. Quality and functional evaluation tests proved that the optimized ultrasonic-assisted extraction process (55℃, material-to-liquid ratio 1:20, soaking for 150 min) is highly efficient and easy to operate. The beverage preparation process is simple, reproducible, and facilitates standardized production and large-scale promotion, providing a feasible path for the high-value development of willowherb resources. In addition, fructooligosaccharides (FOS) are internationally recognized as "bifidus factors" that can significantly increase beneficial bacteria such as Bifidobacteria in the gut. Furthermore, FOS can promote the absorption of minerals such as calcium, iron, and zinc, complementing the nutrients in willowherb and enhancing the overall health value of the beverage. FOS hardly participates in sugar metabolism and does not raise blood sugar. The sleep-aiding properties of willowherb combined with its low-sugar characteristics make it suitable as a nighttime beverage for diabetic patients. Attached Figure Description

[0020] Figure 1. Standard curve of rutin

[0021] Figure 2 Effect of L-ascorbic acid on DPPH free radical scavenging rate

[0022] Figure 3 The effect of citric acid content on taste

[0023] Figure 4. Effect of fructooligosaccharide content on taste

[0024] Figure 5. Effect of xanthan gum content on mouthfeel

[0025] Figure 6. Comparison and analysis of pH value and sensory score

[0026] Figure 7 pH value intuitive analysis

[0027] Figure 8. Schematic diagram of pH value

[0028] Figure 9. Effect of willowherb extract concentration on taste

[0029] Figure 10 Range comparison sensory analysis of each component

[0030] Figure 11. Sensory analysis of each component by range comparison Detailed Implementation

[0031] The scope of protection of the present invention will be described in detail below with reference to specific embodiments. It should be noted that the scope of protection of the present invention is not limited by the following embodiments. Example 1

[0032] 1. Experimental materials

[0033] The willowherb specimens were mainly collected from Pandao Reservoir in Gonghe County, Huangzhong District, Xining City, Qinghai Province, at an altitude of 3000 m. They were identified by Professor Lin Pengcheng of the School of Pharmacy, Qinghai Nationalities University, as Willowherb (Chamaenerion angustifolium L.), a plant of the genus Chamaenerion in the family Onagraceae.

[0034] 1.1 Experimental Materials

[0035] Table 1 Main materials required for the experiment

[0036]

[0037] 1.2 Testing and Experiment Consumables

[0038] Microbial testing: Nutrient agar medium, Escherichia coli chromogenic medium, Salmonella selective medium (GB4789 standard).

[0039] Animal experiments: SPF-grade mice, jujube seed paste (a commercially available sleep drink), deionized water;

[0040] 2. Preparation of Willowherb Extract

[0041] Take 2 g of harvested, air-dried, and pulverized coarse willowherb powder sample, pour it into a 250 mL Erlenmeyer flask, add deionized water, and extract by ultrasonication. The ultrasonic water extract was first coarsely filtered through gauze and then vacuum filtered. Single-factor experiments were conducted and orthogonal experiments were used for verification. According to existing literature, the optimal extraction scheme is a soaking time of 150 min, a liquid-to-solid ratio of 1:20, and an extraction temperature of 55 ℃.

[0042] 2.1 Construction of the standard curve for total flavonoids

[0043] Standard solution: Weigh 0.25 mg of rutin into a 100 mL volumetric flask and dilute to volume with deionized water to obtain a 0.25 mg / mL rutin standard solution. Take six 10 mL volumetric flasks, numbered 1-6, and add 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 mL of the standard solution respectively. Make up to 5 mL with deionized water, shake well, and then add 1 mL of 5% sodium nitrite and 1 mL of 10% aluminum nitrate sequentially, allowing a 6-minute interval between each addition. Finally, add 2 mL of 4% sodium hydroxide solution, dilute to volume, and let stand for 15 minutes. Measure the absorbance at 507 nm, performing three parallel measurements to plot a standard curve.

[0044] 2.2 Single-factor experiment

[0045] The effects of soaking time, material-to-liquid ratio, and ultrasonic temperature on the total flavonoid content in the aqueous extract of *Willow Tree* were investigated.

[0046] 2.2.1 Effect of soaking time on the total flavonoid content in willowherb aqueous extract

[0047] Weigh 2.0 g of coarse willowherb powder and place it in a 250 mL Erlenmeyer flask. Set the ultrasonic temperature to 55 ℃ and the material-to-liquid ratio to 1:20 g / mL. Set the soaking times to 0 min, 75 min, 150 min, 225 min, and 300 min. Sonicate for 35 min at each soaking time, then filter. Seal the filtrate in a test tube for later use.

[0048] 2.2.2 Effect of material-to-liquid ratio on the total flavonoid content in willowherb aqueous extract

[0049] Weigh 2.0 g of coarse willowherb powder and place it in a 250 mL Erlenmeyer flask. Set the soaking time to 150 min and the ultrasonic temperature to 55 ℃. Change the material-to-liquid ratio to 1:16 g / mL, 1:18 g / mL, 1:20 g / mL, 1:22 g / mL, and 1:24 g / mL, and sonicate for 35 min at each ratio. Then filter the solution and seal the filtrate in a test tube for later use.

[0050] 2.2.3 Effect of ultrasonic temperature on the total flavonoid content in the aqueous extract of *Willow Tree*

[0051] Weigh 2.0 g of coarse willowherb powder and place it in a 250 mL Erlenmeyer flask. Set the soaking time to 150 min and the material-to-liquid ratio to 1:20 g / mL. Set the ultrasonic temperatures to 45 ℃, 50 ℃, 55 ℃, 60 ℃, and 65 ℃ respectively, and sonicate for 35 min at each temperature. Then filter the solution and place the filtrate in a test tube and seal it for later use.

[0052] 2.3 Orthogonal Experimental Design

[0053] Using the content of tea polyphenols in the aqueous extract of *Willow Tree* as the evaluation index, an orthogonal experiment was designed to obtain the optimal extraction scheme. Based on the data analysis of single-factor experiments, and combined with the orthogonal design concept, nine experimental schemes with three factors and three levels were designed, using ultrasonic temperature, soaking time, and material-to-liquid ratio as independent variables and the total flavonoid content of the aqueous extract of *Willow Tree* as the corresponding value.

[0054] Table 2 Factor Level Table

[0055]

[0056] 3. Research on the preparation process of Willowherb Beverage

[0057] This study investigated the preparation process of willowherb beverages by harvesting, air-drying, pulverizing, and ultrasonically extracting raw materials, using the water extract as the main raw material. Single-factor experiments were conducted to examine the effects of willowherb extract, fructooligosaccharides, citric acid, and xanthan gum on the willowherb beverage formulation. Orthogonal experiments were performed to optimize the preparation process. The quality and functional properties of the willowherb beverages were then evaluated.

[0058] 3.1 Single-factor experiment

[0059] The effects of controlling the proportions of fructooligosaccharides, citric acid, xanthan gum, L-ascorbic acid, and willowherb extract on the taste, flavor, and pH of sleep-aid beverages were investigated according to GB7101-2022 National Food Safety Standard for Beverages and GB 2760 Standard for the Use of Food Additives.

[0060] 3.1.1 Effects of xanthan gum on the taste, flavor, and pH of sleep-aid beverages

[0061] Prepare a beverage using 30 ml as a base. Weigh 0.9 g of willowherb extract and place it in a 50 mL transparent bottle. Set the dosage of fructooligosaccharides to 2.4 g / 30 mL, citric acid to 0.15 g / 30 mL, and L-ascorbic acid to 0.09 g. Set the xanthan gum dosage to 0.036 g, 0.048 g, 0.06 g, 0.072 g, and 0.084 g respectively. Add water to 30 ml and mix thoroughly with different dosages of xanthan gum until the solution is clear. Seal the bottle for later use.

[0062] 3.1.2 Effects of citric acid on the taste, flavor, and pH of sleep-aid beverages

[0063] Prepare a beverage using 30 ml as a base. Weigh 0.9 g of willowherb extract and place it in a 50 mL transparent bottle. Set the dosages as follows: fructooligosaccharides 2.4 g / 30 mL, xanthan gum 0.048 g / 30 mL, and L-ascorbic acid 0.09 g. Set the citric acid dosages as follows: 0.06 g, 0.09 g, 0.12 g, 0.15 g, and 0.18 g. Add water to a final volume of 30 ml. Mix thoroughly with different dosages of citric acid until the solution is clear. Seal the bottle for later use.

[0064] 3.1.3 Effects of fructooligosaccharides on the taste, flavor, and pH of sleep-aid beverages

[0065] Prepare a beverage using 30 ml as a base. Weigh 0.9 g of willowherb extract and place it in a 50 mL transparent bottle. Set the following dosages: xanthan gum 0.048 g / 30 mL, citric acid 0.15 g / 30 mL, and L-ascorbic acid 0.09 g. Set the dosages of fructooligosaccharides to 1.2 g, 1.8 g, 2.4 g, 3.0 g, and 3.6 g, respectively. Add water to 30 ml and mix thoroughly with different dosages of fructooligosaccharides until the solution is clear. Seal the bottle for later use.

[0066] 3.1.4 Effects of L-Ascorbic Acid on the Taste, Flavor, and pH of Sleep Aid Beverages

[0067] Prepare a beverage using 30 ml as a base. Weigh 0.9 g of willowherb extract and place it in a 50 mL transparent bottle. Set the dosages as follows: xanthan gum 0.048 g / 30 mL, citric acid 0.15 g / 30 mL, and fructooligosaccharides 2.4 g / 30 mL. Set the dosages of L-ascorbic acid as follows: 0.03 g, 0.06 g, 0.09 g, 0.12 g, and 0.15 g. Add water to a final volume of 30 ml. Mix thoroughly with different dosages of L-ascorbic acid until the solution is clear. Seal the bottle for later use.

[0068] 3.1.5 Effects of Willowherb Extract on the Taste, Flavor, and pH of Sleep-Aid Beverages

[0069] Prepare a beverage using 30 ml as a base. Weigh 0.09 g of L-ascorbic acid and place it in a 50 mL transparent bottle. Set the following dosages for xanthan gum (0.048 g / 30 mL), citric acid (0.15 g / 30 mL), and fructooligosaccharides (2.4 g / 30 mL), and the dosages of willowherb extract (0.6 g, 0.9 g, 1.2 g, 1.5 g, and 1.8 g) respectively. Add water to a final volume of 30 ml. Mix thoroughly with different dosages of willowherb extract until the solution is clear, then seal and store for later use.

[0070] 3.2 Orthogonal Experimental Design

[0071] Using the pH range and taste / flavor of the willowherb sleep aid beverage as evaluation indicators, an orthogonal experiment was designed to obtain the optimal beverage formulation. Based on the data analysis of the single-factor experiments, and combined with the orthogonal design concept, five single factors—willowherb extract, fructooligosaccharides, citric acid, xanthan gum, and L-ascorbic acid—were used as independent variables, with sensory scores and pH values ​​of the willowherb sleep aid beverage as corresponding values, to design nine experimental schemes with five factors and three levels.

[0072] Table 3 Factor Level Table

[0073]

[0074] 3.3 Analysis of Physicochemical Properties of Willow Orchid Beverage

[0075] Free radical scavenging rates were measured under different L-ascorbic acid conditions. Three sets of data were measured in parallel, and the relationships are shown in the figure. Figure 2 As the dosage of ascorbic acid increased from 0.03 g / 30 ml to 0.15 g / 30 ml, the DPPH free radical scavenging rate gradually increased from 25.07% to 44.53%, showing a clear dose-dependent positive correlation. Repeat experiments were conducted at each dosage point, and the average value was close to the linear fitting value. Furthermore, the data points were relatively concentrated, indicating high stability and reliability of the experimental results. The rate of increase in scavenging rate gradually slowed down with increasing dosage, possibly indicating a scavenging saturation effect.

[0076] 3.3.1 Determination and analysis of acidity, sweetness, and viscosity

[0077] The determination of different acidity, sweetness, and viscosity was equivalent to the analysis of the dosage of citric acid, fructooligosaccharides, and xanthan gum. Three sets of data were measured in parallel, and the relationships between the sets are shown in the figure. Figure 3-5 .

[0078] As shown in Figure 3, when the amount of citric acid increased from 0.06 g to 0.18 g, the acidity of the beverage gradually increased, reaching the optimal acidity at 0.15 g, and then gradually decreased. Single-factor experiments showed that the optimal acidity was at 0.15 g.

[0079] Depend on Figure 4 It can be seen that as the amount of fructooligosaccharides increased from 1.2 g to 3.6 g, the sweetness of the beverage gradually increased, reaching the optimal sweetness at 2.4 g, and then gradually decreased. Single-factor experiments showed that the optimal sweetness was reached at 2.4 g.

[0080] Depend on Figure 5 It can be seen that as the amount of xanthan gum increased from 0.036 g to 0.084 g, the viscosity of the beverage gradually increased, reaching the optimal viscosity at 0.048 g, and then gradually decreased. Single-factor experiments showed that the optimal viscosity was 0.048 g.

[0081] 3.3.2 pH content determination

[0082] pH values ​​were measured at different ratios, with three sets of data obtained in parallel. The relationship between pH value and sensory scores is shown in [reference needed]. Figure 6 A comparative analysis of pH value and sensory scores revealed that when the pH value is in the range of 3.5-3.7, the sensory scores of the beverage are relatively high, and appropriate acidity helps to improve the taste and quality of the beverage.

[0083] The range of pH values ​​measured in three parallel experiments was calculated for intuitive analysis. The relationship between pH value and the distribution of materials in each group is shown in the figure. Figure 7 As the amount of citric acid increased, the pH value of the beverage gradually decreased, indicating that citric acid is the main factor affecting the acidity of the beverage; the greater the amount used, the stronger the acidity of the beverage. When the amount of fructooligosaccharides increased, the pH value decreased to some extent, but the effect was relatively smaller than that of citric acid. Willowherb extract, xanthan gum, and ascorbic acid: these three factors had a relatively small effect on the pH value, and the pH differences between different levels were not significant. Example 2: Quality Evaluation of Willow Orchid Beverage

[0084] 1. Sensory evaluation

[0085] According to the GB7101-2022 National Food Safety Standard, beverages are tested for color, odor, taste, and state by placing a uniformly mixed sample in a colorless, transparent container, observing the color under natural light, identifying the odor, rinsing the mouth with warm water, tasting the flavor, and checking for foreign matter to determine whether they meet the national standard.

[0086] According to GB 2760 "Standard for Use of Food Additives", the safe range of use for flavoring agents and stabilizers such as fructooligosaccharides, citric acid, xanthan gum and L-ascorbic acid is determined, and the optimal applicable ratio is determined based on sensory evaluation.

[0087] A panel of 10 members was formed to evaluate the beverages based on four aspects: color, aroma, taste, and mouthfeel. Each aspect was scored out of 2.5 points, for a total of 10 points. The specific scoring criteria are as follows:

[0088] 1.1 Evaluation criteria for the content and flavor of willowherb extract:

[0089] Color: 2-2.5 points for uniform and natural color that matches the expected color of the beverage; 1-2 points for relatively uniform color with slight deviation; 0-1 point for uneven color with obvious deviation.

[0090] Aroma: A rich, pure aroma with no off-odors scores 2-2.5 points; a faint aroma or a slight off-odor scores 1-2 points; a very faint aroma or a noticeable off-odor scores 0-1 points.

[0091] Taste: A rich, harmonious, and pleasant taste scores 2-2.5 points; a bland or slightly unharmonious taste scores 1-2 points; a bland taste or a distinctly unpleasant taste scores 0-1 points.

[0092] Texture: 2-2.5 points for a smooth and delicate texture; 1-2 points for a rough texture or a slightly astringent texture; 0-1 points for a very poor texture with obvious discomfort.

[0093] 1.2 Evaluation criteria for fructooligosaccharide content:

[0094] Sweetness 1.0 - 1.4: Too bland or too sweet; 1.5 - 1.9: Sweetness is generally appropriate but slightly off; 2.0 - 2.5: Sweetness is just right and suits the general public's taste.

[0095] Flavor harmony: 1.0 - 1.4: Significant conflict with other flavors; 1.5 - 1.9: Moderate harmony, sweetness is noticeably separated from other flavors; 2.0 - 2.5: Perfectly blended with other flavors, good harmony.

[0096] 1.3 Criteria for assessing citric acid content:

[0097] Acidity suitability: 1.0 - 1.4: Acidity is too high or too low; 1.5 - 1.9: Acidity is basically suitable but slightly unpleasant; 2.0 - 2.5: Acidity is just right, with a pleasant taste.

[0098] Refreshing taste: 1.0 - 1.4: Dull taste, no refreshing feeling; 1.5 - 1.9: Moderate refreshing taste, you can feel some freshness but it is not strong; 2.0 - 2.5: Very refreshing taste, comfortable in the mouth after drinking.

[0099] 1.4 Criteria for evaluating xanthan gum content:

[0100] Consistency suitability: 1.0 - 1.4: too thin or too thick; 1.5 - 1.9: consistency is basically suitable but slightly off; 2.0 - 2.5: consistency is just right, smooth texture.

[0101] Stability: 1.0 - 1.4: Precipitation or stratification occurs quickly after standing; 1.5 - 1.9: Slight precipitation or stratification occurs after standing for a period of time; 2.0 - 2.5: Remains stable after standing for a long time, with no obvious precipitation or stratification.

[0102] 1.5 Criteria for evaluating L-ascorbic acid content:

[0103] Color impact: 1.0 - 1.4: Color deteriorates significantly, such as discoloration or fading; 1.5 - 1.9: Color changes to some extent but does not affect the overall appearance; 2.0 - 2.5: Color remains basically unchanged, maintaining its bright and natural appearance.

[0104] Acidity variation: 1.0 - 1.4: Acidity variation is too large, affecting the taste; 1.5 - 1.9: Acidity varies to some extent but is still within an acceptable range; 2.0 - 2.5: Acidity variation is small and does not affect the overall taste.

[0105] Vitamin flavor: 1.0 - 1.4: The vitamin flavor is very weak or not harmonious with the overall flavor; 1.5 - 1.9: The vitamin flavor is relatively weak but basically harmonious; 2.0 - 2.5: The vitamin flavor is rich and perfectly integrated with the overall flavor.

[0106] 2. Physicochemical property testing

[0107] The pH value is determined according to national food safety standards and meets the product's positioning. This can be verified through orthogonal experiments, indicating that it is weakly acidic with a pH range of 3.0-4.0. The soluble solids content needs to balance taste and health requirements. Additives must be compliant, and the use of flavoring agents must comply with GB 2760 "Standards for the Use of Food Additives".

[0108] 3. Microbial testing

[0109] The relevant pathogenic bacteria should meet the requirements of GB 29921 (Salmonella, Staphylococcus aureus, etc.) and should not be detected. The total bacterial count and Escherichia coli count should meet the requirements of GB 7101-2022 National Food Safety Standard for Beverages.

[0110] 2.1 Determination of total colony count

[0111] Select 2-3 suitable dilutions of sample homogenate, and pipette 1 mL of homogenate from each dilution into a sterile petri dish. Immediately pour 15-20 mL of nutrient agar medium cooled to 46°C into the dish and rotate the dish to mix thoroughly. After the agar solidifies, invert the plate and incubate at 36°C for 48 hours, then count the samples.

[18] .

[0112] 2.2 Detection of Escherichia coli count

[0113] Three suitable dilutions of the sample were homogenized, and three 10 mL LST broth tubes were inoculated for each dilution and incubated at 36°C for 24 h. Gas production was observed, and the gas-producing tubes were transferred to BGLB broth tubes and incubated at 48°C for 24-48 h. Based on the number of gas-producing tubes, the MPN (Multiple Count of Coliforms) value per 100 mL of sample was reported using the MPN lookup table. Simultaneously, the VRBA plate count method was used for verification. The gas-producing LST broth culture was streaked onto VRBA plates and incubated at 36°C for 18-24 h. Colonies meeting the characteristic criteria were selected for confirmatory testing.

[19] .

[0114] 2.3 Detection of pathogenic bacteria

[0115] For Salmonella, add 25 mL of sample to 225 mL of buffered peptone water (BPW) and incubate at 36°C for 8-18 hours. Then, streak the sample onto Salmonella chromogenic medium and bismuth sulfite agar (BS) plates and incubate at 36°C for 24-48 hours. Pick suspected colonies for biochemical and serological identification.

[0116] For Shigella, add 25 mL of sample to 225 mL of GN enrichment broth and incubate at 36°C for 6-8 hours. Then, streak the sample onto Shigella chromogenic medium and HE agar plates and incubate at 36°C for 18-24 hours. Pick suspicious colonies for biochemical and serological identification.

[0117] For Staphylococcus aureus, add 25 mL of sample to 225 mL of 7.5% sodium chloride broth and incubate at 36°C for 18-24 hours. Then, streak the sample onto B-P agar plates and incubate at 36°C for 24-48 hours. Pick suspicious colonies for plasma coagulase testing.

[20] .

[0118] 3. Results

[0119] 3.1 Sensory evaluation results

[0120] The effect of different concentrations of willowherb extract on taste was determined, with three parallel sets of data. The relationships between the sets are shown in Figure 9. Figure 9 shows that as the amount of willowherb extract increased from 0.6 g to 1.8 g, the flavor of the beverage gradually improved, reaching its optimum at 0.9 g, and then gradually decreased. Single-factor experiments indicated that 0.9 g was the optimum flavor concentration.

[0121] 3.2 Results of Orthogonal Experiments

[0122] Based on the single-factor experimental method, the content of flavoring agents such as fructooligosaccharides is planned within a certain range. The optimal scheme and significance of pH value and sensory evaluation are determined by further optimizing the design of orthogonal experiments.

[0123] Table 4 Experimental Design and Results

[0124]

[0125] Table 5 Sensory Evaluation Results

[0126]

[0127] Table 6. Significance of ANOVA

[0128]

[0129] Table 4 can be used to draw Figure 10 and Figure 11 Based on the average values ​​of different levels of each factor, the level with the largest average value for each factor was selected as the optimal level. The optimal combination was: willowherb extract 0.9g / 30ml, fructooligosaccharides 2.4g / 30ml, citric acid 0.15g / 30ml, xanthan gum 0.048g / 30ml, and ascorbic acid 0.12g / 30ml.

[0130] The range reflects the magnitude of the influence of each factor on the experimental results. The largest range is for willowherb extract, indicating that willowherb extract has the most significant impact on the sensory quality of beverages; followed by fructooligosaccharides; and xanthan gum has a relatively smaller impact.

[0131] Figure 11 and Table 4-6 show that willowherb extract and fructooligosaccharides have a significant impact. The optimal formulation combination was found to be: willowherb extract 0.9 g / 30 ml, fructooligosaccharides 2.4 g / 30 ml, citric acid 0.15 g / 30 ml, xanthan gum 0.048 g / 30 ml, and ascorbic acid 0.12 g / 30 ml.

[0132] 3.3 Quality Evaluation

[0133] 3.3.1 Detection of total bacterial colonies and Escherichia coli count

[0134] The total number of microbial colonies and the number of Escherichia coli in Liulan Sleep Aid Beverage were determined by taking the prepared product that had been stored for one month and testing it. Three sets of data were measured in parallel, and the average value was taken. The results are shown in Table 7.

[0135] Table 7. Results of total bacterial colony count and Escherichia coli detection

[0136]

[0137] Table 6 shows that the total bacterial count is ≤ 10000 CFU / mL and the coliform count is ≤ 10 CFU / mL, which meets the requirements of the National Food Safety Standard for Beverages (GB 7101-2022).

[0138] 3.3.2 Detection of pathogenic bacteria

[0139] Table 8 Detection results of pathogenic bacteria

[0140]

[0141] To determine whether Willowherb Sleep Aid Beverage contained pathogenic bacteria, parallel testing was conducted on three batches, and the results are shown in Table 8. Table 8 shows that Willowherb Sleep Aid Beverage did not contain any pathogenic bacteria. Overall, the total bacterial count and coliform count were below the national standard limits, and no pathogenic bacteria such as Salmonella, Shigella, or Staphylococcus aureus were detected. This indicates that the beverage meets the requirements of the National Food Safety Standard for Beverages (GB 7101-2022) in terms of microbiological safety.

[0142] This invention, through systematic optimization of the ratio of willowherb extract, fructooligosaccharides, xanthan gum, citric acid, and L-ascorbic acid, has resulted in a formula (willowherb extract, fructooligosaccharides, citric acid, xanthan gum, L-ascorbic acid) that, while ensuring excellent color, flavor, and taste, achieves low sugar content (due to the prebiotic effect of fructooligosaccharides), suitable acidity (pH 3.5-3.7), and good stability, making it suitable for a wide range of consumers, including those with diabetes. Furthermore, by exploring the effects of pH value and the amount of flavoring agents, the optimal conditions for preparing the willowherb sleep-aid beverage were determined. Quality and functional evaluation tests on samples demonstrated that the optimized ultrasonic-assisted extraction process (55℃, material-to-liquid ratio 1:20, soaking for 150 min) is highly efficient and easy to operate. The beverage preparation process is simple, reproducible, and facilitates standardized production and large-scale promotion, providing a feasible path for the high-value development of willowherb resources. In addition, fructooligosaccharides (FOS) are internationally recognized as "bifidus factors" that can significantly increase beneficial bacteria such as Bifidobacteria in the gut. Furthermore, FOS can promote the absorption of minerals such as calcium, iron, and zinc, complementing the nutrients in willowherb and enhancing the overall health value of the beverage. FOS hardly participates in sugar metabolism and does not raise blood sugar. The sleep-aiding properties of willowherb combined with its low-sugar characteristics make it suitable as a nighttime beverage for diabetic patients.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A functional beverage containing willowherb water extract, characterized in that, It contains the following components in the following mass-volume ratios: 0.6-1.8 g / 30 mL of willowherb water extract, 1.2-3.6 g / 30 mL of fructooligosaccharides, 0.06-0.18 g / 30 mL of citric acid, 0.036-0.084 g / 30 mL of xanthan gum, and 0.03-0.15 g / 30 mL of L-ascorbic acid.

2. The functional beverage according to claim 1, characterized in that, The beverage has a pH value of 3.5-3.

7.

3. The functional beverage according to claim 1 or 2, characterized in that, The dry extract of willowherb water is prepared by the following method: dried and pulverized willowherb raw material is mixed with deionized water at a material-to-liquid ratio of 1:18-1:22 g / mL, soaked at 50-60℃ for 75-225 minutes, ultrasonically extracted for 35 minutes, filtered, the filtrate is collected and concentrated and dried to obtain the product.

4. The functional beverage according to claim 3, characterized in that, The extraction process of the willowherb water extract is as follows: ultrasonic temperature 55℃, soaking time 150 minutes, and material-to-liquid ratio 1:20 g / mL.

5. A method for preparing a functional beverage as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Preparation of water extract of willowherb: The dried and pulverized willowherb raw material was mixed with water at a material-liquid ratio of 1:18-1:22 g / mL, soaked at 50-60℃ for 75-225 minutes, and then ultrasonically extracted at the same temperature for 35 minutes. After filtration, the filtrate was concentrated and dried to obtain dry extract of willowherb water extract. (2) Preparation: Based on 30 mL, weigh 0.6-1.2 g of dry extract of willowherb water, 1.8-3.0 g of fructooligosaccharides, 0.12-0.18 g of citric acid, 0.036-0.060 g of xanthan gum and 0.06-0.12 g of L-ascorbic acid, add water to 30 mL, and mix thoroughly until the solution is homogeneous and clear; (3) Post-processing: The prepared beverage is bottled, sealed and sterilized to obtain the final product.

6. The method according to claim 5, characterized in that, The preferred formulation described in step (2) is: 0.9 g / 30 ml of willowherb water extract, 2.4 g / 30 ml of fructooligosaccharides, 0.15 g / 30 ml of citric acid, 0.048 g / 30 ml of xanthan gum and 0.12 g / 30 ml of L-ascorbic acid.

7. The method according to claim 5, characterized in that, The sterilization described in step (3) is pasteurization or high-temperature instantaneous sterilization.

8. The method according to claim 5, characterized in that, The power of the ultrasonic extraction in step (1) is 200-400W.

9. The use of the functional beverage according to any one of claims 1-4 in the preparation of health food products for improving sleep or relieving anxiety.

Images