Compound star anise and oligofructose drink and preparation process thereof

Abstract

The application relates to the technical field of plant beverage processing, and discloses a compound star anise liquor and fructooligosaccharide beverage and a preparation process thereof, which is prepared from 11.8wt%-19.6wt% of star anise liquor extract, 8wt%-15wt% of fructooligosaccharide, 0.1wt%-0.3wt% of anhydrous citric acid, potassium sorbate, sodium ascorbate and purified water; the process comprises the following steps: preparing high-concentration fructooligosaccharide syrup by using part of the purified water, adding the extract and sodium ascorbate into the fructooligosaccharide syrup to obtain a high-viscosity complex mother liquor, sterilizing and rapidly cooling the mother liquor under near-neutral conditions, preparing a deep quenching liquid by mixing the remaining purified water, anhydrous citric acid and potassium sorbate, and synchronously colliding and mixing the cooled mother liquor and the deep quenching liquid to carry out sterile filling. The application improves the dispersion state of the hydrophobic components by using a local high-concentration polysaccharide environment, decouples the heating sterilization process and the acid adjusting process, effectively inhibits polysaccharide hydrolysis and essential oil coalescence, and improves the physical and chemical stability of the finished product.

Description

Technical Field

[0001] This invention relates to the field of plant-based beverage processing technology, specifically to a compound star anise syrup and fructooligosaccharide beverage and its preparation process. Background Technology

[0002] Star anise, a traditional food and medicine, possesses warming and dispersing properties, as well as regulating qi and stomach function. It is often used to improve symptoms such as stomach cold, abdominal distension, and indigestion. Fructooligosaccharides, a high-quality prebiotic, can promote the proliferation of bifidobacteria in the intestines, thus acting as a laxative and regulating gut microbiota. Combining star anise extract (such as star anise syrup) with fructooligosaccharides can create a dual regulatory effect: warming the stomach and regulating qi, and acting as a prebiotic for the intestines. In the industrial production of plant-based beverages and health drinks, the above-mentioned active ingredients are typically compounded in an aqueous phase and then heat-processed to meet commercial aseptic standards.

[0003] In existing conventional compounding processes, raw materials are typically mixed directly and then sterilized by heating in a single step. Fructooligosaccharides (FOS) are heat-sensitive polysaccharides, and the glycosidic bonds in their molecular structure are easily broken under the combined effects of acidic environments and high temperatures. Conventional beverage formulations often include acidity regulators to improve flavor and incorporate preservatives. This exposes the mixed liquid to both high temperatures and high proton concentrations during sterilization, leading to a significant degradation of FOS into monosaccharides. This degradation not only results in the loss of prebiotic components but also alters the sugar composition of the system, making it difficult to meet the health-conscious positioning of some products that do not cause additional blood sugar fluctuations.

[0004] Meanwhile, trans-anetinoside, the main pharmacologically active component in star anise syrup, is a hydrophobic volatile oil component. In conventional aqueous dispersion systems, the solubility parameters change after high-temperature heating and subsequent cooling. Hydrophobic droplets easily overcome energy barriers, diffusing and coalescing, leading to physical instability phenomena such as oil phase precipitation and liquid turbidity during storage. Furthermore, trans-anetinoside, containing a double bond structure, is susceptible to thermal oxidative degradation under conventional high-temperature processing environments due to dissolved oxygen, generating anisaldehyde, which has a pungent odor and affects the beverage's sensory aroma and effective pharmacological activity. To address dispersion and stability issues, existing technologies often rely on adding chemical emulsifiers or thickeners, but this often increases the complexity of the formulation and may negatively impact the product's natural and mild properties. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a compound star anise syrup and fructooligosaccharide beverage and its preparation process, which solves the problems in existing conventional beverage preparation processes where fructooligosaccharides are easily degraded and lost under acid-heat co-bath conditions, and where hydrophobic components in plant extracts easily aggregate and become turbid in the aqueous phase.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a compound star anise syrup and fructooligosaccharide beverage, which adopts the following technical solution:

[0008] A compound star anise syrup and fructooligosaccharide beverage, comprising the following components in weight percentage:

[0009] Star anise extract, 11.8 wt% to 19.6 wt%;

[0010] Fructooligosaccharides 8wt% to 15wt%;

[0011] Anhydrous citric acid 0.1wt% to 0.3wt%;

[0012] Potassium sorbate 0.05 wt%;

[0013] Sodium ascorbate 0.05 wt%;

[0014] Purified water 65wt% to 80wt%;

[0015] The compound star anise syrup and fructooligosaccharide beverage is a clarified liquid.

[0016] By employing the above technical solution, the compounding of oligofructose and star anise extract in a specific ratio results in a high hydroxyl content in the oligofructose molecule. These groups can establish intermolecular hydrogen bonds with the nonpolar trans-anetinoside molecules in the star anise extract. This intermolecular force exhibits a certain dispersing effect in the macroscopic aqueous phase, allowing the hydrophobic plant volatile oil components to achieve uniform dispersion in the aqueous phase without relying on exogenous emulsifiers. Simultaneously, sodium ascorbate acts as a reducing agent in the system, preferentially consuming dissolved oxygen, which helps to slow down the thermal oxidation reaction of the double bond structure in trans-anetinoside, reducing the risk of the formation of the oxidation byproduct anisaldehyde. Therefore, this method helps maintain a clear and homogeneous system and contributes to the stability of the active ingredient activity.

[0017] Preferably, the star anise extract is a pale yellow, homogeneous filtrate without visible sediment or oil rings; the total content of trans-anetinoside in the star anise extract is ≥0.5wt% based on the total mass of the extract.

[0018] By adopting the above technical solution, the appearance of the extract and the minimum content of the core pharmacological components are limited, which is conducive to the finished product having the basic effects of warming the stomach and regulating qi; high-purity fructooligosaccharides can reduce the interference of impurities on the hydrogen bond complex network, thereby helping to maintain the physical stability of the system's dispersion state.

[0019] Preferably, the preparation method of star anise extract includes: adding dried star anise fruit and purified water into an extraction tank at a mass ratio of 1:10; connecting a reflux condenser to the top of the extraction tank to reflux volatile components during the extraction process; performing two water extractions at a constant temperature of 80°C for 2 hours each time; combining the two extracts and performing preliminary filtration through a 100-mesh filter to remove plant residues, obtaining a filtrate; concentrating the filtrate under reduced pressure at 60°C until the solid content reaches 5.0 wt% to 8.0 wt%, obtaining a concentrate; and cooling the concentrate to room temperature and then performing fine filtration through a 400-mesh stainless steel filter.

[0020] By employing the above technical solution, the condensation reflux device is used to retain and reflux the volatile trans-anetinoside during the water extraction stage, which helps to improve the extraction rate of the target component. Combining reduced-pressure concentration solids parameters with multi-stage filtration, the basic concentration of the extract is maintained while removing coarse plant fibers and large suspended particles, providing relatively consistent material conditions for the subsequent complexation process.

[0021] Secondly, the present invention provides a preparation process for a compound star anise syrup and fructooligosaccharide beverage, which adopts the following technical solution:

[0022] A preparation process for a compound star anise syrup and fructooligosaccharide beverage, applied to the aforementioned compound star anise syrup and fructooligosaccharide beverage, includes the following steps:

[0023] Take a portion of purified water, heat it, and then add all the oligofructose to dissolve it, thus making a concentrated syrup;

[0024] After cooling the concentrated syrup by opening the jacket cooling system, star anise extract and sodium ascorbate were added dropwise under stirring to obtain a high-viscosity complexing mother liquor.

[0025] The high-viscosity complex mother liquor was pasteurized and then rapidly cooled in a closed sterile pipeline through a heat exchange section.

[0026] Anhydrous citric acid and potassium sorbate were added to the remaining purified water and stirred to dissolve. After sterilization and filtration and forced cooling to maintain a constant temperature, a cryogenic quenching solution was obtained.

[0027] The high-viscosity complexing mother liquor after rapid cooling and the deep cryogenic quenching liquid are simultaneously injected into an online static mixer for collision mixing to obtain the finished product, which is then aseptically filled.

[0028] The sum of the weight of the purified water and the remaining purified water equals the total weight of the purified water.

[0029] By adopting the above technical solution, the present invention adjusts the order of mixing and heat treatment in the preparation process, and its main mechanism is as follows:

[0030] On the one hand, during the material mixing stage, purified water is used to dissolve all polysaccharide components. Because the locally high-concentration polysaccharide system binds a large number of free water molecules, this can reduce the system's water activity and relative permittivity to some extent, promoting a transition of the solvent environment towards weak polarity. When star anise extract is added dropwise to this environment, the difficulty for hydrophobic essential oil molecules to overcome the interfacial energy barrier decreases, making it easier for them to form hydrogen-bonded complexes with polysaccharide molecules, thus promoting the initial dispersion of the active ingredients.

[0031] On the other hand, considering the characteristic that the hydrolysis rate of fructooligosaccharide glycosidic bonds depends on proton concentration and temperature, the addition of citric acid was postponed by adjusting the order of pH adjustment and high-temperature sterilization. The high-viscosity complex mother liquor containing fructooligosaccharides was sterilized under near-neutral conditions. At this point, the solution lacked a large number of catalytic protons, and the activation energy required for glycosidic bond breakage was relatively high, thus slowing down the degradation process of the polysaccharide components under high-temperature heat load.

[0032] Furthermore, during the mixing process, the cryogenic quenching fluid carrying acid and preservatives mixes with the hot mother liquor inside the static mixer. This fluid convergence causes a rapid temperature drop, and this heat dissipation physically slows down the thermal motion of molecules within the system. This restricts the long-distance diffusion and collision fusion of trans-anisole droplets in the aqueous phase, reducing the probability of droplet ripening and phase separation, thus contributing to the preservation of the dispersed structure. Simultaneously, the system's pH is adjusted to a weakly acidic standard at low temperature. This not only further controls the acid hydrolysis of fructooligosaccharides but also promotes the conversion of potassium sorbate into non-dissociated sorbic acid molecules, which then disperse near the oil-water interface, thus balancing the system's antibacterial requirements with its physical stability.

[0033] Preferably, the purified water accounts for 10.0 wt% to 20.0 wt% of the total weight; the heating temperature is 60°C to 65°C; and the dissolution time is 15 min to 20 min.

[0034] By adopting the above technical solution and controlling the initial solvent input, it is helpful to maintain a high mass fraction of oligofructose within the system. This concentration range can reduce the relative permittivity of the system, providing a physical environment with water-soluble growth-promoting effects for the subsequent introduction of hydrophobic components. At the same time, the set temperature and time parameters are conducive to the dissolution of polysaccharide powder and, to a certain extent, prevent the material from burning due to excessive heating.

[0035] Preferably, the concentrated syrup is cooled to 35°C to 40°C; star anise extract is added dropwise at a stirring speed of 1500 rpm to 3000 rpm, and high-shear stirring is maintained for 10 min to 15 min after the addition is completed.

[0036] The above-mentioned technical solution was adopted, and the cooling range was set to account for the high viscosity of high-concentration syrup at room temperature. Controlling the temperature within this range allows the system to maintain good fluidity. The mechanical stress provided by stirring helps to break the initial interfacial tension between the essential oil and the aqueous phase, causing the star anise extract to be sheared into tiny droplets, increasing the effective contact surface area, and thus promoting the formation of hydrogen-bonded complex structures.

[0037] Preferably, the pasteurization temperature is 85°C and the holding time is 15 min; the natural pH value of the high-viscosity complexing mother liquor during pasteurization is within the range of 6.1 to 6.5; after pasteurization, the temperature is rapidly reduced to 49°C to 74°C in a closed sterile pipeline through a heat exchange section.

[0038] By adopting the above technical solution, the near-neutral natural pH value controls the acidic catalytic protons in the solution, which is beneficial to maintaining the retention rate of fructooligosaccharides under sterilization conditions of 85℃. The initial rapid cooling operation in the pipeline after sterilization reduces some of the sensible heat carried by the system, narrows the temperature difference span during subsequent mixing, and reduces the energy consumption of the refrigeration equipment while reducing the risk of instantaneous local boiling of the subsequent acid mixture due to excessive heat.

[0039] Preferably, the forced cooling constant temperature is controlled between 2°C and 4°C; the sterilization filtration uses a 0.22μm microporous filter membrane.

[0040] By adopting the above technical solution, on the one hand, the microfiltration membrane is used to physically sterilize the acid and preservative added later, which helps to control the microbial indicators of the production process; on the other hand, the fluid is forced to cool to a lower temperature range, giving the fluid a larger heat capacity, and providing a cold source medium for rapid cooling in the subsequent online mixing step.

[0041] Preferably, after collision mixing in an online static mixer, the temperature of the finished product drops instantly to 22°C to 28°C, and the pH value of the finished product is fixed within the range of 3.5 to 4.2.

[0042] By adopting the above technical solution, the fluid rapidly crosses the temperature range where phase separation is likely to occur and reaches room temperature after collisional mixing, which helps to suppress the thermodynamically driven droplet aggregation effect. At the same time, the system establishes a target weakly acidic environment, and the polysaccharide component structure tends to be stable under relatively low temperature conditions, which is conducive to the final product meeting the design requirements in terms of physicochemical properties and sensory characteristics, and improves the stability of the product under storage conditions.

[0043] This invention provides a compound star anise syrup and fructooligosaccharide beverage and its preparation process. It has the following beneficial effects:

[0044] 1. This invention utilizes a process sequence of first preparing a high-concentration fructooligosaccharide solution with purified water, followed by the addition of star anise extract. This process leverages the relatively low dielectric constant of the high-concentration polysaccharide system to improve the polarity of the aqueous environment. The hydroxyl groups in the fructooligosaccharide molecule can generate intermolecular forces with the hydrophobic components in the star anise extract, allowing the non-polar plant volatile oil components to be uniformly distributed in the aqueous phase without the addition of exogenous emulsifiers. This material mixing method inhibits the precipitation of essential oil droplets, improving the physical stability and macroscopic clarity of the compound beverage during storage.

[0045] 2. This invention adjusts the sequence of heating sterilization and acidity adjustment processes, placing pasteurization before adding citric acid to maintain a near-neutral natural pH during the heating phase. This process design avoids the hydrolysis of fructooligosaccharides under high temperature and high proton concentration conditions, slowing down the glycosidic bond breaking process. The decoupling of heat load and acidic conditions effectively ensures the retention rate of fructooligosaccharides in the finished product, reduces the risk of polysaccharide degradation into monosaccharides, and facilitates the achievement of the physicochemical and health function requirements of the product formulation design.

[0046] 3. This invention utilizes an online mixing device to rapidly mix the sterilized high-temperature mother liquor with a low-temperature solution containing acidity regulators and preservatives. This operation allows the system temperature and pH to decrease simultaneously within a short time. The rapid temperature decay shortens the time window during cooling when hydrophobic droplets are prone to diffusion and coalescence, helping to maintain the microscopic dispersion structure. Simultaneously, the low temperature combined with the weakly acidic environment promotes the transformation of preservative molecules into a non-dissociated state and their tendency to distribute at the phase interface. This rapid fixation of the physicochemical state protects the heat-sensitive components while further enhancing the phase stability of the system. Attached Figure Description

[0047] Figure 1 This is a graph showing the variation of the relative permittivity of fructooligosaccharide solutions with different mass fractions according to the present invention;

[0048] Figure 2 The diagram shows the dispersion effect test of star anise extract according to the present invention; wherein, (a) is a diagram showing the change in transmittance of the mixture after adding star anise extract under different initial mass fractions of oligofructose, and (b) is a diagram showing the comparison of transmittance of the mixture obtained by the direct dilution group and the high concentration pre-complexed group under the ratio conditions of Example 2.

[0049] Figure 3 Transient response diagrams of physicochemical parameters of the fluid mixing process in Test Example 2 of the present invention are shown; wherein, (a) is a diagram showing the dynamic change of fluid temperature over time after mixing mother liquor and acid solution; and (b) is a diagram showing the dynamic change of pH value of the system over time within the same time scale.

[0050] Figure 4This is a graph showing the trend of optical turbidity of each group of samples in this invention as the constant temperature storage time increases;

[0051] Figure 5 This is a superimposed comparison image of high performance liquid chromatography (HPLC) of some samples from this invention.

[0052] Figure 6 This is a superimposed comparison of gas chromatograms of the various extracts of the present invention. Detailed Implementation

[0053] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] Preparation Examples 1-3:

[0055] Preparation Example 1:

[0056] This preparation example provides an extract of star anise dew, including the following steps:

[0057] Weigh 1000g of dried star anise fruit, wash with purified water to remove surface impurities, and then drain.

[0058] Place the star anise fruit into an extraction tank and add 10,000g of purified water at a mass ratio of 1:10;

[0059] The top of the extraction tank is connected to a condensation reflux device, which condenses and refluxes volatile components during the extraction process to reduce the loss of volatile components such as trans-anetinoside.

[0060] Water extraction was carried out at a constant temperature of 80℃ for 2 hours each time, for a total of 2 extractions. The extracts from the two extractions were combined and then filtered through a 100-mesh filter to remove plant residues.

[0061] The obtained filtrate was placed in a vacuum concentration apparatus and concentrated at 60°C under reduced pressure, with continuous monitoring of the moisture content, until the solid content of the concentrate reached 5.0 wt%. The concentrate was then cooled to room temperature and subsequently filtered through a 400-mesh stainless steel filter. A pale yellow, homogeneous filtrate without visible sediment or oil rings was collected for later use. For gas chromatography analysis, a quantitative amount of star anise extract was extracted with hexane and then analyzed. The total trans-anetinoside content in the star anise extract was ≥0.5 wt%.

[0062] Preparation Example 2:

[0063] This preparation example provides an extract of star anise dew, including the following steps:

[0064] Weigh 1000g of dried star anise fruit, wash with purified water to remove surface impurities, and then drain.

[0065] Place the star anise fruit into an extraction tank and add 10,000g of purified water at a mass ratio of 1:10;

[0066] The top of the extraction tank is connected to a condensation reflux device, which condenses and refluxes volatile components during the extraction process to reduce the loss of volatile components such as trans-anetinoside.

[0067] Water extraction was performed at a constant temperature of 80℃ for 2 hours each time, for a total of 2 extractions.

[0068] The extracts from the two extractions were combined and initially filtered through a 100-mesh filter to remove plant residues. The resulting filtrate was then placed in a vacuum concentration apparatus and concentrated under reduced pressure at 60°C, with continuous monitoring of the moisture content of the system, until the solid content of the concentrate reached 6.5 wt%.

[0069] The concentrated solution was cooled to room temperature and then filtered through a 400-mesh stainless steel filter. The resulting pale yellow, homogeneous filtrate, free of visible precipitate and oil rings, was collected for later use. For gas chromatography analysis, a quantitative amount of the star anise extract was extracted with hexane and then injected for analysis. The total trans-anetinoside content in the star anise extract was ≥0.5 wt%.

[0070] Preparation Example 3:

[0071] This preparation example provides an extract of star anise dew, including the following steps:

[0072] Weigh 1000g of dried star anise fruit, wash with purified water to remove surface impurities, and then drain.

[0073] Place the star anise fruit into an extraction tank and add 10,000g of purified water at a mass ratio of 1:10;

[0074] The top of the extraction tank is connected to a condensation reflux device, which condenses and refluxes volatile components during the extraction process to reduce the loss of volatile components such as trans-anetinoside.

[0075] Water extraction was performed at a constant temperature of 80℃ for 2 hours each time, for a total of 2 extractions.

[0076] The extracts from the two extractions were combined and then filtered through a 100-mesh filter to remove plant residues.

[0077] The obtained filtrate was placed in a vacuum concentration apparatus and concentrated at 60°C, with continuous monitoring of the moisture content, until the solid content of the concentrate reached 8.0 wt%. The concentrate was then cooled to room temperature and subsequently filtered through a 400-mesh stainless steel filter. A pale yellow, homogeneous filtrate without visible sediment or oil rings was collected for later use. For gas chromatography analysis, a quantitative amount of the star anise extract was extracted with hexane and then analyzed. The total trans-anetinoside content in the star anise extract was ≥0.5 wt%.

[0078] Examples 1-3:

[0079] Example 1:

[0080] This embodiment provides a preparation process for a compound star anise syrup and fructooligosaccharide beverage, including the following steps:

[0081] (1) Preparation of ingredients: Based on a total weight of 10,000g, weigh 800g (8.0%) of fructooligosaccharide, 1180g (11.8%) of star anise extract, 8,000g (80.0%) of purified water, 10g (0.1%) of anhydrous citric acid, 5g (0.05%) of potassium sorbate, and 5g (0.05%) of sodium ascorbate.

[0082] (2) Preparation of high-concentration FOS mother liquor: 1000g of the above purified water was injected into the reactor and heated to 60℃. 800g of fructooligosaccharides were added to the reactor and dissolved at a stirring speed of 500rpm for 15min to make concentrated syrup. At this time, the local FOS concentration was about 44.4%. The jacket cooling was turned on to cool the system to 40℃.

[0083] (3) Dielectric control and homogeneous complexation: Maintain the reactor temperature at 40°C and increase the stirring speed to 1500 rpm. Slowly add 1180 g of star anise extract, and after the addition is complete, add 5 g of sodium ascorbate. Maintain high shear stirring for 10 min to obtain a high-viscosity complexing mother liquor.

[0084] (4) Concentrated near-neutral sterilization: The high-viscosity complex mother liquor is pumped to a tubular sterilizer by a rotary pump and pasteurized at 85°C for 15 minutes under the condition that the natural pH of the liquid is about 6.5. After sterilization, the high-viscosity complex mother liquor is rapidly cooled to 74°C in a closed sterile pipeline through a heat exchange section before entering the subsequent online mixing step.

[0085] (5) Preparation of cryogenic quenching solution: Pour the remaining 7000g of purified water into a sterile mixing tank, add 10g of anhydrous citric acid and 5g of potassium sorbate and stir to dissolve. Filter the mixture through a 0.22μm microporous membrane for sterilization and then force-cool it to a constant temperature of 4℃ to obtain the cryogenic quenching solution.

[0086] (6) Online phase inversion acidification and filling: Sterilized high-viscosity complexing mother liquor at 74°C is introduced into the online static mixer of the main pipeline, while cryogenic quenching liquid at 4°C is injected simultaneously through a branch high-pressure pump. After the two fluids collide and mix, the temperature drops instantly to about 25°C, the pH value stabilizes at about 4.2, and the fluid transforms into a clear liquid. It is then sent to the aseptic filling line for closed filling to obtain the finished product.

[0087] Example 2:

[0088] This embodiment provides a preparation process for a compound star anise syrup and fructooligosaccharide beverage, including the following steps:

[0089] (1) Preparation of ingredients: Based on a total weight of 10,000g, weigh 1,150g (11.5%) of fructooligosaccharide, 1,500g (15.0%, obtained from Preparation Example 2) of star anise extract, 7,320g (73.2%) of purified water, 20g (0.2%) of anhydrous citric acid, 5g (0.05%) of potassium sorbate, and 5g (0.05%) of sodium ascorbate.

[0090] (2) Preparation of high-concentration FOS mother liquor: 1500g of the above purified water was injected into the reactor and heated to 62℃. 1150g of fructooligosaccharide was added to the reactor and dissolved at a stirring rate of 650rpm for 18min to make concentrated syrup. At this time, the local FOS concentration was about 43.4%. The jacket cooling was turned on to cool the system to 38℃.

[0091] (3) Dielectric regulation and homogeneous complexation: Maintain the reactor temperature at 38°C and increase the stirring speed to 2200 rpm. Slowly add 1500 g of star anise extract, and after the addition is complete, add 5 g of sodium ascorbate. Maintain high shear stirring for 12 min to obtain a high-viscosity complexing mother liquor.

[0092] (4) Concentrated near-neutral sterilization: The high-viscosity complex mother liquor is pumped to a tubular sterilizer by a rotary pump and pasteurized at 85°C for 15 minutes under the condition that the natural pH of the liquid is about 6.3. After sterilization, the high-viscosity complex mother liquor is rapidly cooled to 49°C in a closed sterile pipeline through a heat exchange section before entering the subsequent online mixing step.

[0093] (5) Preparation of cryogenic quenching solution: Pour the remaining 5820g of purified water into a sterile mixing tank, add 20g of anhydrous citric acid and 5g of potassium sorbate and stir to dissolve. Filter the mixture through a 0.22μm microporous membrane for sterilization and then force-cool it to a constant temperature of 3℃ to obtain the cryogenic quenching solution.

[0094] (6) Online phase inversion acidification and filling: Sterilized high-viscosity complexing mother liquor at 49°C is introduced into the online static mixer of the main pipeline, while cryogenic quenching liquid at 3°C ​​is injected simultaneously through a branch high-pressure pump. After the two fluids collide and mix, the temperature drops instantly to about 22°C, the pH value settles at about 3.8, and the fluid transforms into a clear liquid. It is then sent to the aseptic filling line for closed filling to obtain the finished product.

[0095] Example 3:

[0096] This embodiment provides a preparation process for a compound star anise syrup and fructooligosaccharide beverage, including the following steps:

[0097] (1) Preparation of ingredients: Based on a total weight of 10,000g, weigh 1,500g (15.0%) of fructooligosaccharide, 1,960g (19.6%) of star anise extract (obtained from Preparation Example 3), 6,500g (65.0%) of purified water, 30g (0.3%) of anhydrous citric acid, 5g (0.05%) of potassium sorbate, and 5g (0.05%) of sodium ascorbate.

[0098] (2) Preparation of high-concentration FOS mother liquor: 2000g of the above purified water was injected into the reactor and heated to 65℃. 1500g of fructooligosaccharide was added to the reactor and dissolved at a stirring rate of 800rpm for 20min to make concentrated syrup. At this time, the local FOS concentration was about 42.9%. The jacket cooling was turned on to cool the system to 35℃.

[0099] (3) Dielectric control and homogeneous complexation: Maintain the reactor temperature at 35°C and increase the stirring speed to 3000 rpm. Slowly add 1960 g of star anise extract, and after the addition is complete, add 5 g of sodium ascorbate. Maintain high shear stirring for 15 min to obtain a high-viscosity complexing mother liquor.

[0100] (4) Concentrated near-neutral sterilization: The high-viscosity complex mother liquor is pumped to a tubular sterilizer by a rotary pump and pasteurized at 85°C for 15 minutes under the condition that the natural pH of the liquid is about 6.1. After sterilization, the high-viscosity complex mother liquor is rapidly cooled to 50°C in a closed sterile pipeline through a heat exchange section before entering the subsequent online mixing step.

[0101] (5) Preparation of cryogenic quenching solution: Pour the remaining 4500g of purified water into a sterile mixing tank, add 30g of anhydrous citric acid and 5g of potassium sorbate and stir to dissolve. Filter the mixture through a 0.22μm microporous membrane for sterilization and then force-cool it to a constant temperature of 2℃ to obtain the cryogenic quenching solution.

[0102] (6) Online phase inversion acidification and filling: Sterilized high-viscosity complexing mother liquor at 50°C is introduced into the online static mixer of the main pipeline, while cryogenic quenching liquid at 2°C is injected simultaneously through a branch high-pressure pump. After the two fluids collide and mix, the temperature drops instantly to about 28°C, the pH value settles at about 3.5, and the fluid transforms into a clear liquid. It is then sent to the aseptic filling line for closed filling to obtain the finished product.

[0103] Comparative Examples 1-4:

[0104] Comparative Example 1:

[0105] The difference compared to Example 2 is that a conventional mixed sterilization process is used.

[0106] Specifically, heat all 7320g of purified water in the formula to 62℃, then add oligofructose, anhydrous citric acid, potassium sorbate, and sodium ascorbate at once to dissolve them; cool to 38℃ and then add star anise extract dropwise and mix thoroughly; finally, pasteurize the acidic mixture directly at 85℃ for 15min at a pH of approximately 3.8, cool, and then fill into containers. The rest is the same.

[0107] Comparative Example 2:

[0108] The difference compared to Example 2 is that: no separation of purified water was performed, and no high-concentration mother liquor was formed.

[0109] Specifically, 7320g of purified water from the entire formulation was heated to 62°C to dissolve the fructooligosaccharides. At this point, the FOS concentration was only about 13.6%, far below the dielectric regulation concentration of over 40%. Then, star anise extract was added dropwise at 38°C, followed by the addition of sodium ascorbate for mixing. The mixture was then pasteurized at 85°C for 15 minutes to near neutral pH, cooled to approximately 22°C, and then acidified and preserved with a sterile filtered solution of citric acid and potassium sorbate. The final pH was approximately 3.8. The remaining formulation amounts were the same as in Example 2.

[0110] Comparative Example 3:

[0111] The difference compared to Example 2 is that the timing of acid addition has been changed.

[0112] Specifically, after preparing the high-concentration FOS mother liquor and complexing it with star anise extract, anhydrous citric acid of the prescribed amount is added to the high-viscosity mother liquor before pasteurization at 85°C to lower the pH of the system to approximately 3.8. After sterilization, it is then mixed with cryogenic dilution water containing only potassium sorbate. Everything else is the same.

[0113] Comparative Example 4:

[0114] The difference compared to Example 2 is that the deep cryogenic quenching collision step was omitted.

[0115] Specifically, after near-neutral sterilization at 85℃, online collision mixing is not performed using a 3℃ cryogenic solution; instead, the sterilized concentrated mother liquor is slowly cooled to approximately 22℃ using a conventional heat exchanger, and then diluted with room-temperature residual purified water using conventional stirring. This residual purified water contains pre-dissolved anhydrous citric acid and potassium sorbate, resulting in a final pH of approximately 3.8. All other steps remain the same.

[0116] Test Examples 1-5:

[0117] Test Example 1: Feasibility Verification of Dielectric Modulation of High-Concentration Fructooligosaccharides

[0118] This test example verifies the changes in the polar characteristics of fructooligosaccharide aqueous solutions in the high concentration range through quantitative detection of physicochemical properties, and evaluates the impact of this polarity change on the dispersion state of hydrophobic components. The experimental subjects include fructooligosaccharide solutions of different mass fractions prepared with purified water, and samples from different mixing paths set according to the formulation ratio of Example 2.

[0119] Oligofructose with a purity meeting food-grade requirements and purified water were mixed and stirred in a constant temperature water bath at 40°C to prepare oligofructose solutions with mass fractions of 12.5 wt%, 21.2 wt%, 33.6 wt%, 41.8 wt%, and 48.5 wt%, respectively.

[0120] The relative permittivity of the oligofructose solutions with different mass fractions was determined using a high-frequency dielectric constant measuring instrument at a test frequency of 1 MHz and a temperature of 40 ℃. The average value of each sample after stabilization was taken.

[0121] Add 15g of star anise extract to every 100g of the above-mentioned fructooligosaccharide solution. Slowly add the star anise extract to the fructooligosaccharide solution and process it with a disperser at 2000rpm for 15min to obtain a mixture.

[0122] The mixture was transferred to a quartz cuvette and allowed to stand to defoam. The transmittance was then measured using a UV-Vis spectrophotometer at a detection wavelength of 600 nm.

[0123] To further verify the necessity of the process in the example where a high-concentration local environment is first formed before adding the star anise extract, a supplementary simulation was conducted according to the formulation ratio of Example 2. A direct dilution group and a high-concentration pre-complexation group were set up. In the direct dilution group, fructooligosaccharides were directly dissolved in all purified water before adding the star anise extract; in the high-concentration pre-complexation group, a concentrated syrup with a local FOS concentration of approximately 43.4% was first prepared using 1500g of purified water and 1150g of fructooligosaccharides, and then 1500g of star anise extract was added dropwise. Both groups were treated at 38℃ and 2200rpm for 12min, and the transmittance at 600nm was measured. The formulation path test in Example 2 was mainly used to verify the effect of different mixing paths on the dispersion effect of star anise; the relative permittivity of the mixed system was not measured separately.

[0124] Table 1. Test results of dielectric modulation and dispersibility of star anise extract in different fructooligosaccharide systems.

[0125] Test type Sample group Initial mass fraction of oligofructose / wt% Local mass fraction of FOS when exposed to star anise / wt% FOS mass fraction (wt%) after adding star anise extract Relative permittivity transmittance / % Appearance Matrix testing at different FOS concentrations Experimental matrix A 12.5 12.5 Approximately 10.9 73.82 12.4 turbid Matrix testing at different FOS concentrations Experimental matrix B 21.2 21.2 Approximately 18.4 67.15 18.7 turbid Matrix testing at different FOS concentrations Experimental matrix C 33.6 33.6 Approximately 29.2 54.91 35.2 Slight turbidity Matrix testing at different FOS concentrations Experimental matrix D 41.8 41.8 Approximately 36.3 41.34 87.6 Uniform and transparent Matrix testing at different FOS concentrations Experimental matrix E 48.5 48.5 Approximately 42.2 37.86 92.1 Uniform and transparent Example 2: Proportioning Path Test direct dilution group 13.6 13.6 Approximately 11.6 — 24.7 Noticeably turbid Example 2: Proportioning Path Test High concentration pre-complexed group 43.4 43.4 Approximately 27.7 — 85.8 Uniform and transparent

[0126] Figure 1 This is a graph showing the variation of the relative permittivity of oligofructose solutions with different mass fractions in Test Example 1 of this invention.

[0127] Figure 2 This is a test diagram of the dispersion effect of star anise extract in Test Example 1 of the present invention. (a) is a diagram showing the change in transmittance of the mixture after adding star anise extract under different initial mass fractions of oligofructose. (b) is a comparison diagram of the transmittance of the mixture obtained by the direct dilution group and the high concentration pre-complexed group under the ratio conditions of Example 2.

[0128] Experimental conclusion:

[0129] According to the data in Table 1, in the matrix tests with different FOS concentrations, as the mass fraction of fructooligosaccharides increased from 12.5 wt% to 48.5 wt%, the relative permittivity of the system decreased from 73.82 to 37.86, while the transmittance increased from 12.4% to 92.1% after adding star anise extract. When the mass fraction of fructooligosaccharides was below 33.6 wt%, although the relative permittivity of the system decreased with increasing concentration, it remained above 50. The measurement results indicate that a large number of free water molecules still exist in the solvent environment at this point, and the system exhibits strong aqueous polarity. The star anise extract contains hydrophobic trans-anestin, which is difficult to disperse stably in a strongly polar aqueous environment. After adding star anise extract, the transmittance of the mixture was below 40%, and the appearance was turbid, indicating that the effective components were not uniformly distributed.

[0130] When the mass fraction of fructooligosaccharides reaches 41.8 wt% or higher, the relative permittivity of the solution decreases to below 41.34, and the system transforms into a relatively low-polarity environment. This indicates that the polyhydroxyl structure in high-concentration fructooligosaccharide molecules binds with water molecules, reducing the number of free water molecules and altering the overall polarity of the solvent. Under the condition of decreased relative permittivity, the transmittance of the mixture increases to over 87.6%. Fructooligosaccharides exhibit a dispersing effect at locally high concentrations; their polyhydroxyl structure can reconstruct the hydrogen bond network in the aqueous phase and promote the stable dispersion of hydrophobic components such as trans-anetinoside in the aqueous phase through van der Waals forces, dipole interactions, and steric confinement. The significant increase in transmittance verifies that high-concentration fructooligosaccharides can improve the dispersibility of star anise extract in aqueous systems.

[0131] In the formulation path test of Example 2, the local FOS mass fraction when star anise extract came into contact with fructooligosaccharides in the direct dilution group was only 13.6%. After adding star anise extract, the FOS mass fraction of the system was approximately 11.6%, with a transmittance of only 24.7% and a noticeably cloudy appearance. In contrast, the local FOS mass fraction when star anise extract came into contact with fructooligosaccharides in the high-concentration pre-complexed group was 43.4%. Even after the addition of star anise extract, the overall FOS mass fraction of the system decreased to approximately 27.7%, yet it still maintained a transmittance of 85.8% and a uniform, transparent appearance. These results indicate that the key to the process in this example lies in the formation of a locally high-concentration dielectric-controlled environment during the initial contact between star anise extract and fructooligosaccharides, rather than requiring the FOS mass fraction in the final mother liquor to remain above 40%.

[0132] Test Example 2: Transient Temperature and pH Response Test of Mixing Process

[0133] This test example evaluates the impact of the mixing process on phase separation and reaction kinetics by measuring the transient changes in system temperature and pH during fluid mixing. The experimental subjects were the high-viscosity complex mother liquor produced in the preparation process of Example 2 and an acidic solution cooled to 3°C.

[0134] A high-viscosity complexing mother liquor was obtained after being heated to 85°C and then rapidly cooled to 49°C in a closed sterile pipeline. Simultaneously, an acidic purified aqueous solution containing citric acid and potassium sorbate was prepared and kept at a constant temperature of 3°C using a refrigeration system for later use.

[0135] High-frequency data acquisition devices are deployed within the fluid pipelines and static mixer. Thermocouple temperature sensors and pH electrodes are installed at the confluence of the two fluid streams, and multiple probes are installed at fixed intervals downstream of the static mixer. The spatial distance is converted into fluid mixing time using the linear velocity of the fluid within the pipeline.

[0136] The operating parameters of the dual-channel infusion pump were set to simultaneously inject the high-viscosity complex mother liquor at 49°C and the acid solution at 3°C ​​into the static mixer at a constant mass flow rate for mixing.

[0137] Start the data acquisition system and set the sampling frequency to 10Hz. Continuously record the real-time temperature and pH values ​​from the instant the two fluids come into contact until 2.5 seconds after mixing. Repeat the experiment three times and extract the data at the corresponding time points to calculate the average value.

[0138] Table 2 Transient response data during the mixing process of high-viscosity complexing mother liquor and acid solution.

[0139] Mixing time / s Real-time fluid temperature / °C Real-time pH value 0 48.7 6.26 0.2 31.8 4.65 0.4 24.5 3.98 0.6 22.7 3.84 0.8 22.3 3.82 1 22.2 3.82 1.5 22.1 3.81 2 22.1 3.82 2.5 22 3.81

[0140] Figure 3 This is a transient response diagram of the physicochemical parameters of the fluid mixing process in Test Example 2 of this invention. Sub-figure (a) shows the dynamic change of fluid temperature over time after mixing the mother liquor and acid solution; sub-figure (b) shows the dynamic change of pH value of the system over time within the same time scale.

[0141] Experimental conclusion:

[0142] According to the data in Table 2, the temperature decrease and pH adjustment within the system exhibited a high degree of synchronization during the fluid mixing process. Within 0.6 seconds after the two fluids converged, the real-time temperature of the mixture rapidly decreased from 48.7℃ to 22.7℃. This rapid temperature drop directly reduced the thermal kinetic energy of the molecules in the system. In conventional plant extract compounding processes, systems containing hydrophobic substances such as trans-anetinoside typically experience a long mass transfer time during the slow cooling phase, making it easy for hydrophobic components to coalesce and lead to solution turbidity. The static mixing operation used in this experiment allowed the system to quickly pass through the temperature range where phase rearrangement is likely to occur. The microscopic dispersion structure established in the aqueous phase was fixed during this process, thus helping to reduce the possibility of subsequent flocculation or precipitation of plant essential oil components.

[0143] Within this temperature decrease timeframe, the pH of the system also changed significantly. The mixture transitioned from near-neutral (6.26) to weakly acidic (3.84) within 0.6 seconds, a pH shift occurring after a substantial drop in fluid temperature. Considering that the hydrolysis of glycosidic bonds in fructooligosaccharide molecules requires overcoming corresponding activation energies, the existing thermal energy of the fluid is insufficient to rapidly initiate the aforementioned hydrolysis reaction when the system is simultaneously under low temperature and acidic conditions. Under the established weakly acidic conditions, the preservative component potassium sorbate gradually transforms into non-dissociated sorbic acid molecules, which readily distribute at the microscopic interface between the aqueous phase and the plant essential oil components. Simultaneous adjustment of temperature and pH was achieved within a short time through fluid collision mixing. This process parameter control not only helps suppress the thermal acid degradation of fructooligosaccharides but also ensures the physical stability of the hydrophobic droplets dispersed in the aqueous phase.

[0144] Test Example 3: Physical Stability and Sensory State Test

[0145] This test example assesses the impact of the preparation process on the physical stability of the hydrophobic components in the extract by measuring the changes in optical turbidity of the liquid under different storage times and centrifugation. The experimental subjects were the beverages prepared in Examples 1 to 3, and the reference solutions prepared in Comparative Examples 2 and 4.

[0146] Finished product samples were randomly selected from the aseptic filling lines of Examples 1 to 3, and Comparative Examples 2 and 4. Each group of samples was divided into multiple portions and placed in a constant temperature and light-proof storage cabinet at 25°C to simulate the normal storage environment of the product.

[0147] A turbidity meter was used as the detection device. Before testing, the instrument was calibrated using a formalin standard solution with known turbidity to ensure that the measurement range covered 0 to 100 NTU and that the measurement error met the specifications.

[0148] Samples from the corresponding batches were removed from the incubator on days 1, 30, and 90 of storage. Without shaking the samples, a suitable amount of liquid was injected into a cuvette for measurement. Three readings were taken for each group, and the average value was recorded.

[0149] After 90 days of static storage, a portion of the sample was transferred to centrifuge tubes and centrifuged continuously at 10,000 rpm for 10 minutes at room temperature. After centrifugation, the presence of oil rings, flocculation layers, or sediments in the centrifuge tubes was checked, avoiding the upper oil rings and bottom sediments. The middle aqueous phase was then sampled for turbidity measurement to simultaneously assess the system's ability to maintain its phase under centrifugation.

[0150] Table 3. Turbidity changes of each group of samples under different treatment conditions.

[0151] Sample group Day 1 Turbidity / NTU Turbidity on day 30 / NTU Turbidity on day 90 / NTU Turbidity of the middle layer water phase after centrifugation / NTU Appearance after centrifugation Example 1 2.1 2.5 3.2 3.4 No layering, no oil ring Example 2 1.8 2.1 2.6 2.7 No layering, no oil ring Example 3 1.6 1.9 2.3 2.4 No layering, no oil ring Comparative Example 2 42.6 58.3 74.5 29.6 There was obvious floating oil ring and flocculation at the bottom. Comparative Example 4 14.8 33.5 56.1 24.7 Slight oil rings and flocculent layer

[0152] Figure 4 This is a graph showing the change in optical turbidity of each group of samples in Test Example 3 of this invention as a function of constant temperature storage time. The data points and lines in the graph record the average turbidity of Examples 1 to 3 and Comparative Examples 2 and 4 on day 1, day 30, and day 90.

[0153] Experimental conclusion:

[0154] According to the data in Table 3, the turbidity of the samples in Examples 1 to 3 remained below 4.0 NTU during the 90-day static storage period, and the turbidity of the middle aqueous phase did not change significantly after centrifugation. No oil rings, flocculent layers, or precipitates were observed in the centrifuge tubes. The high-viscosity fructooligosaccharide network formed during the preparation process exerted a certain spatial confinement effect on the hydrophobic trans-anesanthin. The measurement data to some extent reflect that this compound system can maintain a uniform distribution of the non-polar extract without the addition of exogenous emulsifiers, which meets the goal of clear and precipitate-free formulation design.

[0155] In the comparative tests, it was found that changes in process nodes caused differences in the physical state of the samples. In Comparative Example 2, because the purified water was not separated, the fructooligosaccharides dissolved directly in the total formulation water volume, resulting in a turbidity of 42.6 NTU on day 1. The lower concentration of the oligosaccharide solution had a limited effect on the relative permittivity of the system, and the aqueous phase retained strong polarity. Due to the lack of a local environment with a low proportion of free water, the hydrophobic components in the extract were unable to form stable intermolecular forces with the oligosaccharide system, leading to phase separation in the early stages of preparation. As storage time increased, the accumulation of hydrophobic droplets caused the turbidity to rise to 74.5 NTU. Although the turbidity of the middle aqueous phase decreased to 29.6 NTU after centrifugation, obvious floating oil rings and bottom flocculation appeared in the centrifuge tubes, indicating that the system did not remain stable and clear, but rather experienced oil phase enrichment and solid-liquid separation.

[0156] Comparative Example 4 reflects the impact of cooling rate on the phase state of the system. After a slow cooling process, the turbidity of this group of samples showed an increasing trend over time, reaching 56.1 NTU on day 90. During slow cooling, the system components maintained a state of thermal motion for a relatively long period. Due to the gradual change in ambient temperature, hydrophobic droplets had certain conditions for diffusion and recombination, making them prone to maturation. The fusion of small droplets into larger particles led to enhanced light scattering, thus altering the clarity of the liquid. After centrifugation, this group of samples exhibited a slight oil ring and flocculation layer, further indicating that slow cooling could not effectively fix the dispersion state of the hydrophobic components. This comparative result demonstrates that using low-temperature solutions for rapid mixing and cooling in the process can shorten the time window for molecular diffusion, limit the migration and aggregation of hydrophobic droplets, and is engineering feasible for maintaining the long-term clarity of compound beverages.

[0157] Test Example 4: Fructooligosaccharide Retention Rate Test

[0158] This test example determined the actual content of fructooligosaccharides in products after different processing steps to evaluate the effect of heating and pH adjustment sequence on the degradation reaction of fructooligosaccharides. The finished products of Examples 1 to 3, as well as Comparative Examples 1 and 3, were selected as the test subjects, and sugar molecules with different degrees of polymerization were separated and quantified using liquid chromatography.

[0159] Transfer 5.0 mL of the sample from the finished product to a volumetric flask, add deionized water to bring the volume to 50 mL and mix well. Place the diluted solution in an ultrasonic cleaner and sonicate at room temperature for 20 min. Extract the sample solution, filter it through a 0.45 μm aqueous microporous membrane, and collect the filtrate in a sample vial for later use.

[0160] Analysis was performed using a high-performance liquid chromatograph equipped with a differential refractive index detector (HPLC) and an amino analytical column. The mobile phase was a mixture of acetonitrile and deionized water (70:30 v / v), degassed, and eluted isocratically at a flow rate of 1.0 mL / min. The column oven temperature and detector optical unit temperature were both set to 35 °C, and the injection volume was 10 μL.

[0161] Weigh out the standards for fructooligosaccharides (FOS), fructooligosaccharides (FOS), and fructooligosaccharides (FOS), and prepare mixed standard solutions of different concentrations with deionized water. Perform the determination under the chromatographic conditions described above, plot a standard curve using the peak area of ​​each component against the concentration, and calculate the linear regression equation.

[0162] Each group of filtrates was analyzed using an instrument, and the chromatograms and target peak areas were recorded. The mass fractions of fructotriose, fructotetraose, and fructopentose in the sample were calculated using the standard curve equation, and the sum of these three was taken as the actual total amount of fructooligosaccharides detected. The retention rate of fructooligosaccharides was calculated using the following formula: Retention rate / % = Actual total amount detected ÷ Theoretical amount added × 100%.

[0163] Table 4. Results of determination of the content and retention rate of each component of fructooligosaccharide in the examples and comparative examples.

[0164] Sample group Theoretical addition amount (g / 100g) Detection level of fructooligosaccharides (g / 100g) Detection level of fructotetrasaccharide (g / 100g) Detection of pentose sucrose (g / 100g) Actual total detected amount (g / 100g) Retention rate / % Example 1 8 2.94 3.82 1.09 7.85 98.1 Example 2 11.5 4.18 5.57 1.54 11.29 98.2 Example 3 15 5.41 7.26 2.05 14.72 98.1 Comparative Example 1 11.5 2.87 3.25 0.81 6.93 60.3 Comparative Example 3 11.5 3.12 3.74 0.95 7.81 67.9

[0165] Figure 5 This is a superimposed comparison of high-performance liquid chromatography (HPLC) images of some samples from Test Example 4 of this invention. The figures show the chromatographic signal responses of Examples 1 to 3 and Comparative Examples 1 and 3 under the same detection conditions, reflecting the influence of different preparation processes on the content of carbohydrate components in the samples.

[0166] Experimental conclusion:

[0167] According to the data in Table 4, different preparation processes have varying effects on the retention rate of fructooligosaccharides (FOS). After sterilization at 85°C, the FOS retention rates of the samples in Examples 1 to 3 were all above 98.0%. The function of FOS depends on the glycosidic bond structure, and the stability of the glycosidic bond in the thermal processing system is affected by the pH of the solution. In these examples, the sterilization process was carried out under near-neutral pH conditions, where the concentration of free protons in the system was low. Under the 85°C heating condition, the near-neutral environment maintained the activation energy barrier of the hydrolysis reaction, delaying the conversion of FOS to monosaccharides. Figure 5 As can be seen from the chromatogram overlay, the curves of the examples show high response values ​​during the peak elution time of fructooligosaccharides to pentasaccharides, and very low response values ​​in the hydrolysis product region around the retention time of 5 min.

[0168] Comparative Example 1 involved uniform heating and sterilization after mixing, while Comparative Example 3 involved adding citric acid to lower the pH value of the system before heating and sterilization. The results showed that the retention rates of fructooligosaccharides in the two groups decreased to 60.3% and 67.9%, respectively. Figure 5 In the comparative curves, the response value decreases in the peak region of the oligosaccharide component, while the response value increases significantly at the peak positions of hydrolyzed products such as monosaccharides. When heating is performed under acidic conditions, the combined effect of protons and heat energy promotes the hydrolysis and breakage of glycosidic bonds. Comparative experiments show that delaying acidity adjustment until after heat sterilization can reduce the degradation of oligosaccharide components while achieving sterilization. This process control method helps maintain the required content of fructooligosaccharides in the finished product and reduces the risk of fructooligosaccharides hydrolyzing into monosaccharides under hot and acidic conditions.

[0169] Test Example 5: Trans-Anethole Retention and Oxidation Test

[0170] This test example determined the content of trans-anesanthin and the formation of its oxidation product, anisaldehyde, in the finished product after heat sterilization and other processes, in order to evaluate the protective effect of the timing of antioxidant addition and the physical state of the matrix on volatile components. The finished products of Examples 1 to 3 and Comparative Example 1 were selected as the extraction and determination subjects.

[0171] Transfer 10.0 mL of liquid from each component into a separatory funnel and add 10.0 mL of n-hexane. Shake for 10 min to ensure full contact between the aqueous and organic phases, then allow to separate into layers. Collect the upper organic phase, and repeat the extraction once more by adding 10.0 mL of n-hexane to the aqueous phase. Combine the two organic phases, dehydrate and dry with anhydrous sodium sulfate, filter, and transfer the filtrate to a vial for analysis.

[0172] The determination was performed using a gas chromatograph equipped with a flame ionization detector (FIDD), and a weakly polar capillary column was selected for separation. High-purity nitrogen was used as the carrier gas, and the column flow rate was controlled at 1.0 mL / min. The injection port temperature was set to 250 °C, and a split injection mode with a split ratio of 10:1 was used. The temperature program was set to an initial temperature of 80 °C held for 2 min, followed by an increase to 200 °C at a rate of 8 °C / min and a hold for 5 min. The detector temperature was set to 260 °C.

[0173] Weigh out trans-anetinoside and anisaldehyde standards, and prepare mixed standard solutions of different concentrations using n-hexane. Inject the solutions sequentially, plot a standard curve with component concentration on the x-axis and peak area on the y-axis, and calculate the linear regression equation.

[0174] The extract of the sample was analyzed using an instrument, and the area of ​​the target chromatographic peak was recorded. The mass fractions of trans-anetinoside and anisaldehyde in the sample were calculated by substituting the values ​​into the standard curve. The mass percentage of oxidation products was calculated using the following formula: Mass percentage of oxidation products / % = Anisaldehyde detection amount ÷ (Trans-anetinoside detection amount + Anisaldehyde detection amount) × 100%.

[0175] Table 5. Results of determination of trans-anisole and anisaldehyde content in the examples and comparative examples.

[0176] Sample group Trans-anetine content detected (g / 100g) Anisaldehyde detection amount (g / 100g) Oxidation product mass percentage / % Example 1 0.052 0.0012 2.25 Example 2 0.071 0.0015 2.07 Example 3 0.094 0.0021 2.18 Comparative Example 1 0.043 0.0163 27.48

[0177] Figure 6 This is a superimposed comparison of gas chromatograms of the extracts from each group in Test Example 5 of this invention. The figure shows the chromatographic response trajectories of Examples 1 to 3 and Comparative Example 1 under the same detection conditions, reflecting the influence of different preparation processes on the degree of trans-anescenol oxidative degradation.

[0178] Experimental conclusion:

[0179] According to the data in Table 5, the trans-anetinoside content in Examples 1 to 3 was all above 0.05 g / 100 g, meeting the physicochemical standards. Volatile oil components containing double bonds are easily oxidized by dissolved oxygen and heat load, resulting in anisaldehyde. Experimental measurements showed that the anisaldehyde production in the examples was low, with the oxidation product mass percentage below 3%. The increased trans-anetinoside retention rate may be related to the timing of sodium ascorbate addition. Early addition of sodium ascorbate helps consume dissolved oxygen in the system; furthermore, the high concentration of fructooligosaccharides creates steric hindrance for gas molecule diffusion, limiting the rate of dissolved oxygen migration to the hydrophobic phase. These factors synergistically slow down the thermal oxidation process of trans-anetinoside during the heating stage.

[0180] The data from Comparative Example 1 reflect the effect of different mixing and heating sequences on volatile components. In Comparative Example 1, where a high concentration of oligosaccharides was not formed and the mixture was directly mixed and heated under acidic conditions, the detection amount of trans-anestin decreased to 0.043 g / 100 g, below the lower limit of the quality standard. Figure 6 The chromatograms showed that Comparative Example 1 had a high anisaldehyde response peak near the retention time of 8 min, with oxidation products accounting for 27.48% of the total mass. Hydrophobic droplets have a large specific surface area in a conventional aqueous phase, and under heating conditions of 85℃, dissolved oxygen readily reacts with unsaturated bonds. A decrease in the content of characteristic components affects the stability of star anise's characteristic components in the product, and an increase in oxidation byproducts also impacts the sensory quality of the star anise aroma in the beverage. The results indicate that preparing a high-concentration mixture beforehand and adding antioxidants in advance can reduce the loss of effective components during heat sterilization, helping to meet the product's physicochemical and sensory requirements.

Claims

1. A compound star anise syrup and fructooligosaccharide beverage, characterized in that, It is made from the following components by weight percentage: Star anise extract, 11.8 wt% to 19.6 wt%; Fructooligosaccharides 8wt% to 15wt%; Anhydrous citric acid 0.1wt% to 0.3wt%; Potassium sorbate 0.05 wt%; Sodium ascorbate 0.05 wt%; Purified water 65wt% to 80wt%; The compound star anise syrup and fructooligosaccharide beverage is a clarified liquid.

2. The compound star anise syrup and fructooligosaccharide beverage according to claim 1, characterized in that, The star anise extract is a pale yellow, homogeneous filtrate without any visible sediment or oil rings.

3. The compound star anise syrup and fructooligosaccharide beverage according to claim 1, characterized in that, Based on the total mass of the extract, the total content of trans-anetinoside in the star anise extract is ≥0.5wt%.

4. The compound star anise syrup and fructooligosaccharide beverage according to claim 1, characterized in that, The preparation method of the star anise extract includes: Add dried star anise fruit and purified water to the extraction tank at a mass ratio of 1:10; The top of the extraction tank is connected to a condensation reflux device, which condenses and refluxes the volatile components during the extraction process; Two water extraction treatments were carried out under constant temperature of 80℃, each lasting 2 hours. The two extracts were combined and then filtered through a 100-mesh filter to remove plant residues, yielding the filtrate. The filtrate was concentrated under reduced pressure at 60°C until the solid content reached 5.0 wt% to 8.0 wt% to obtain a concentrated solution. The concentrate is cooled to room temperature and then finely filtered through a 400-mesh stainless steel filter.

5. A preparation process for a compound star anise syrup and fructooligosaccharide beverage according to any one of claims 1-4, characterized in that, Includes the following steps: A portion of the purified water is heated and then added to all of the oligofructose to dissolve it, thus preparing a concentrated syrup. After cooling the concentrated syrup by opening the jacket cooling system, the star anise extract and sodium ascorbate are added dropwise under stirring to obtain a high-viscosity complexing mother liquor. The high-viscosity complex mother liquor was pasteurized and then rapidly cooled in a closed sterile pipeline through a heat exchange section. Add the anhydrous citric acid and potassium sorbate to the remaining purified water and stir to dissolve. After sterilization filtration and forced cooling to maintain a constant temperature, a cryogenic quenching solution is obtained. The rapidly cooled sterilized high-viscosity complexing mother liquor and the cryogenic quenching liquid are simultaneously injected into an online static mixer for collision mixing to obtain the finished product, which is then aseptically filled. The sum of the weights of the purified water in the portion and the remaining purified water equals the total weight of the purified water.

6. The preparation process according to claim 5, characterized in that, The purified water in this portion accounts for 10.0 wt% to 20.0 wt% of the total weight; The temperature for the heating is 60°C to 65°C; The dissolution time is 15 to 20 minutes.

7. The preparation process according to claim 5, characterized in that, The concentrated syrup is cooled to 35°C to 40°C; The star anise extract was added dropwise at a stirring speed of 1500 rpm to 3000 rpm, and high-shear stirring was maintained for 10 min to 15 min after the addition was completed.

8. The preparation process according to claim 5, characterized in that, The pasteurization process was carried out at a temperature of 85°C for 15 minutes. During the pasteurization process, the natural pH value of the high-viscosity complexing mother liquor is within the range of 6.1 to 6.5; After pasteurization, the temperature is rapidly reduced to 49°C to 74°C in the heat exchange section of the closed sterile pipeline.

9. The preparation process according to claim 5, characterized in that, The forced cooling constant temperature is controlled between 2°C and 4°C; The sterilization filtration uses a 0.22μm microporous filter membrane.

10. The preparation process according to claim 5, characterized in that, After the collision mixing in the online static mixer, the temperature of the finished product drops instantly to 22°C to 28°C, and the pH value of the finished product is fixed within the range of 3.5 to 4.2.

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