Pterostilbene-based stability enhanced antioxidant as well as preparation method and application thereof

Abstract

The invention relates to the technical field of functional antioxidants, in particular to a stability-enhanced antioxidant based on pterostilbene and a preparation method and application thereof. The pterostilbene tablet comprises the following components in percentage by weight: 10-30% of pterostilbene, 8-20% of Arabic gum, 5-15% of tocopheryl succinate, 1-5% of disodium ethylene diamine tetraacetate, 30-60% of beta-cyclodextrin, 2-8% of rosmarinic acid, 1-6% of chitosan quaternary ammonium salt, 0.5-3% of nano silicon dioxide and 2-7% of polyglycerol fatty acid ester. In the preparation process, beta-cyclodextrin and pterostilbene form an inclusion compound, the dispersity of nano silicon dioxide and chitosan quaternary ammonium salt is improved through hydrogen bonds, and tea polyphenol or ascorbyl palmitate can be added to enhance the synergistic effect. The antioxidant is high in stability, high in pterostilbene retention rate, uniform in dispersion, free of agglomeration, excellent in antioxidant activity, suitable for the fields of foods, cosmetics and medicines, simple in preparation process, low in consumption and suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of functional antioxidant technology, in particular to a stability-enhanced antioxidant based on pterostilbene and a preparation method and application thereof. BACKGROUND

[0002] With the continuous improvement of product quality and safety requirements in the food, cosmetic and pharmaceutical industries, the application demand of antioxidants, as a key additive to delay the oxidation of active ingredients and prolong the shelf life of products, continues to grow. As a natural polyphenolic compound, pterostilbene has excellent free radical scavenging ability, anti-inflammatory activity and biological safety, and is more in line with the needs of consumers for "natural and green" than traditional synthetic antioxidants, showing broad application prospects in many fields. However, the stability defects of pterostilbene itself seriously limit its industrial application - on the one hand, pterostilbene molecules are rich in phenolic hydroxyl groups, which are prone to react with oxygen and light, and will be significantly degraded in 1-2 months under normal temperature storage conditions, resulting in a decrease of more than 50% in antioxidant activity; on the other hand, pterostilbene has poor solubility, with a solubility of only 0.1-0.5 mg / mL in aqueous systems and less than 5 mg / mL in oil systems, making it difficult to disperse uniformly in product matrices, which not only affects the uniformity of antioxidant effect, but also may cause product appearance defects due to local aggregation.

[0003] To solve the stability and solubility problems of pterostilbene, existing technologies mainly use inclusion, emulsification or compounding to modify it. In the inclusion technology, β-cyclodextrin is commonly used as an inclusion carrier, but the inclusion rate of single β-cyclodextrin for pterostilbene is only 60-70%, and the inclusion compound is easily dissociated under high temperature and high humidity conditions, which cannot achieve long-term stability; some studies try to introduce gum arabic as an auxiliary inclusion material, which can increase the inclusion rate to about 80%, but gum arabic has strong hydrophilicity and poor dispersibility in oil systems, limiting its application in oil-based foods and oily skin care products. In terms of emulsification technology, existing solutions mostly use single polysorbate emulsifier, which can improve the dispersibility of pterostilbene, but the stability of the emulsion system is poor, and it is easy to separate, break and cause pterostilbene to precipitate when the temperature is above 40°C or when it is stored for a long time, which not only loses the antioxidant effect, but also may cause product deterioration.

[0004] Compounding modification is another main direction of existing technologies, and traditional compounding schemes mostly compound pterostilbene with tocopherol and rosemary extract to improve antioxidant activity through synergistic effect, but ignore the compatibility problem between components - the lipophilicity of tocopherol and the weak polarity of pterostilbene are significantly different, and they are easy to separate in aqueous systems; rosemary acid in rosemary extract is easy to combine with metal ions, and trace amounts of Fe 3+ , Cu 2+It can catalyze the oxidation of rosmarinic acid, and accelerate the failure of the entire antioxidant system. In addition, the existing compound scheme lacks design for "metal ion chelation", and the oxidation chain reaction caused by metal ions is not effectively inhibited, so that the shelf life of the product is still difficult to break through 3 months in the substrate containing metal ions.

[0005] At the same time, the existing preparation process of pterostilbene antioxidant also has many shortcomings. In the inclusion reaction link, the parameters such as reaction temperature and stirring rate are controlled roughly, resulting in large fluctuation of inclusion rate and poor batch stability of the product; single stirring emulsification is often used in the emulsification link, the particle size distribution of the emulsion droplets is wide, and sedimentation is easy to occur; freeze-drying is often used in the drying link, although the active ingredients can be preserved, but the energy consumption is high, the production cycle is long, the production cost is 3-5 times of that of spray drying, and it is difficult to meet the needs of industrial production. In addition, the application of nanomaterials in the prior art is limited to simple addition, without considering the interaction between nanoparticles and other ingredients - such as directly adding nano-silicon dioxide can improve the dispersibility, but the nanoparticles are easy to agglomerate to form micron-sized particles, which in turn leads to rough texture or poor skin feel of the product.

[0006] With the increasing requirements of consumers for product shelf life and use experience, as well as the demand for low-energy production process, the existing technology has been unable to meet the development of the industry - it cannot solve the core problem of long-term stability of pterostilbene, and it is also difficult to balance solubility, dispersibility and production economy. Therefore, developing a stable enhanced antioxidant that can simultaneously realize high stability, high dispersibility and high activity of pterostilbene, and is suitable for multi-field application, has become a key technical problem that needs to be broken through in the current industry. SUMMARY

[0007] (I) Technical problems solved

[0008] In view of the shortcomings of the prior art, the present application provides a stable enhanced antioxidant based on pterostilbene and its preparation method and application.

[0009] (II) Technical solutions

[0010] A stable enhanced antioxidant based on pterostilbene, comprising the following components by weight percentage: pterostilbene 10-30%, gum arabic 8-20%, tocopherol succinate 5-15%, ethylenediaminetetraacetic acid disodium 1-5%, beta-cyclodextrin 30-60%, rosmarinic acid 2-8%, chitosan quaternary ammonium salt 1-6%, nano-silicon dioxide 0.5-3%, and polyglycerol fatty acid ester 2-7%.

[0011] The β-cyclodextrin forms a thermodynamically stable inclusion compound with pterostilbene by means of the ring cavity structure, which isolates pterostilbene from light and oxygen, and reduces the rate of oxidative degradation; the nano-silicon dioxide is a hydrophilic nanoparticle, and the surface is rich in hydroxyl groups, which form intermolecular hydrogen bonds with the amino groups and hydroxyl groups in the chitosan quaternary ammonium salt molecules; through the interaction, the nano-silicon dioxide forms a uniform dispersion of "micro-carriers" in the system, avoids the agglomeration of chitosan quaternary ammonium salt, and adsorbs pterostilbene inclusion compound and rosmarinic acid; the polyglycerol fatty acid ester reduces the interfacial tension between the aqueous phase and the organic phase, promotes the dissolution and dispersion of oil-soluble ingredients such as pterostilbene and tocopherol succinate in the aqueous phase, and at the same time cooperates with the arabic gum to construct a stable colloidal system to prevent the occurrence of stratification and precipitation during storage; the ethylenediaminetetraacetic acid disodium chelate system may exist in trace amounts of metal ions, which avoids the catalysis of metal ions on the oxidation of active ingredients.

[0012] Preferably, 0.1-2% of tea polyphenols by mass percentage are further included; the tea polyphenols are a mixture of catechins extracted from green tea, wherein the content of epigallocatechin gallate (EGCG) is not less than 60%, and the remaining components include epigallocatechin, epigallocatechin gallate, epicatechin gallate, and epicatechin (EGCG:EGC:ECG:EC=6:2:1:1).

[0013] Preferably, 0.5-4% of ascorbyl palmitate by mass percentage are further included; the purity of ascorbyl palmitate is not less than 98%, the melting point range is 107-117℃, and the melting enthalpy is 120-130J / g as determined by differential scanning calorimetry, which ensures good thermal stability in the system.

[0014] Preferably, the purity of pterostilbene is not less than 98%, and the particle size is controlled to be 1-10μm; the particle size distribution span (D90-D10) / D50≤1.2 as determined by a laser particle size analyzer, which ensures uniform particle size; the pterostilbene is prepared by a supercritical CO2 extraction-molecular distillation combined process, and the specific process is as follows: taking pterocarpus wood or pterocarpus leaf as raw material, crushing to a particle size of 0.5-1mm, loading into a supercritical extraction kettle, introducing CO2, controlling the extraction pressure to be 30-40MPa, the extraction temperature to be 40-50℃, the CO2 flow rate to be 20-30L / h, and the extraction time to be 2-3 hours to obtain a pterostilbene crude extract; the crude extract is sent to a molecular distillation equipment, and the distillation temperature is controlled to be 80-90℃, the vacuum degree is controlled to be 0.001-0.005MPa, and the scraper membrane rotation speed is controlled to be 300-400rpm, so as to remove low-boiling-point impurities and high-boiling-point impurities in the crude extract by molecular distillation, and finally obtain high-purity pterostilbene.

[0015] Preferably, the nano-silicon dioxide is a hydrophilic fumed silicon dioxide with a particle size of 10-50nm and a specific surface area of 150-300m 2 / g, and its pore volume is 0.8-1.2 cm 3 / g, and the surface hydroxyl content is 2-3 / nm 2 The nano-silica needs to be modified by silane coupling agent KH560 before use. The modification process is as follows: the nano-silica is added into an ethanol-water mixed solution, the solid-liquid ratio is controlled to be 1:20-30, and stirring and dispersion are performed for 10-15 minutes; the silane coupling agent KH560 is added, the amount is 5-8% of the mass of the nano-silica, the temperature is raised to 60-80°C, and stirring is performed at a speed of 200-300 rpm for 1-2 hours; after the reaction is completed, the modified nano-silica is collected by centrifugal separation, washed with ethanol for 3-4 times to remove the unreacted silane coupling agent, and then dried at 100-110°C for 2-3 hours to obtain the modified nano-silica.

[0016] Preferably, the polyglycerol fatty acid ester is specifically polyglycerol-6-stearate, the HLB value is 8-12, the emulsifying capacity is 30-40 mL as determined by the emulsification method, the acid value is not more than 3 mgKOH / g, the saponification value is in the range of 140-160 mgKOH / g, and the iodine value is ≤2 gI2 / 100g.

[0017] Preferably, the degree of substitution of the β-cyclodextrin is 4.0-7.0, the moisture content is not more than 12%, and the ash content is ≤0.1%;

[0018] The inclusion reaction of β-cyclodextrin and pterostilbene is carried out at a temperature of 50-60°C, specifically: after the β-cyclodextrin is added into the emulsion, the temperature is raised to 50-60°C, the stirring speed is kept at 300-500 rpm, and the reaction time is 1-2 hours; during the reaction, the free concentration of pterostilbene is monitored in real time by high performance liquid chromatography (HPLC), and when the free pterostilbene concentration no longer decreases, it is determined that the inclusion reaction reaches equilibrium.

[0019] Preferably, the preparation method of the stability-enhanced antioxidant based on pterostilbene comprises the following detailed steps:

[0020] S1. Preparation of aqueous phase: add gum arabic, disodium ethylenediaminetetraacetate, and polyglycerol fatty acid ester into deionized water according to the formula proportion, control the solid-liquid ratio of the aqueous phase to be 1:5-10; add the mixed solution into a reaction kettle with stirring device and temperature control jacket, start stirring, set the stirring speed to 200-300 rpm, at the same time, pass hot water through the jacket to raise the temperature, so that the temperature in the reaction kettle rises to 60-80°C; keep the temperature and stirring speed for 30-50 minutes, take samples every 10 minutes during this period to observe, until the mixed solution appears uniform and transparent, and no solid particles are visible with the naked eye, it is determined that the preparation of the aqueous phase is completed; after the preparation is completed, the temperature of the aqueous phase is reduced to 45-55°C for standby;

[0021] S2. Preparation of organic phase: add the formula proportion of pterostilbene and tocopherol succinate into 70-95% ethanol; add the mixed solution into a beaker with stirring and temperature control function, place it in a constant temperature water bath, set the water bath temperature to 40-50°C, start stirring at a speed of 150-200 rpm, and continue stirring for 20-30 minutes; during this period, observe the mixed solution every 5 minutes with a glass rod, until the mixed solution is clear and transparent with no solid residue, and determine that the organic phase preparation is complete; after preparation, keep the organic phase temperature at 40-50°C for standby;

[0022] S3. Emulsification treatment: slowly add the organic phase prepared in step S2 to the aqueous phase prepared in step S1 at a rate of 1-3 mL / min through a peristaltic pump, while increasing the stirring speed of the reaction kettle from 200-300 rpm to 500-1000 rpm, and keeping the temperature in the reaction kettle at 45-55°C by jacket temperature control; during the addition process, take samples every 5 minutes and measure the particle size distribution of the emulsion by laser particle size analyzer to ensure that the droplet size is concentrated in the range of 0.1-1 μm; after the addition is completed, continue to maintain the stirring speed and temperature for 20-40 minutes for emulsification, until the emulsion appears uniform milky white without stratification, and determine that the emulsification is complete;

[0023] S4. Complex reaction: add the formula amount of β-cyclodextrin to the emulsified emulsion, start the heating device of the reaction kettle, increase the temperature from 45-55°C to 50-60°C, adjust the stirring speed to 300-500 rpm, and keep the conditions for 1-2 hours for inclusion reaction; during the reaction, measure the concentration of free pterostilbene in the emulsion every 30 minutes by high performance liquid chromatography (HPLC), and stop the inclusion reaction when the free concentration stabilizes at 0.1-0.2 mg / mL; then add the formula amount of rosmarinic acid, chitosan quaternary ammonium salt and pretreated nano-silicon dioxide to the reaction kettle, start the cooling device, reduce the temperature in the reaction kettle to 30-50°C, adjust the stirring speed to 200-300 rpm, and continue stirring for 30-60 minutes; during the stirring process, monitor the dissolution state of rosmarinic acid by ultraviolet-visible spectrophotometer to ensure that it is completely dissolved without precipitation, and determine that the complex reaction is complete;

[0024] S5. Spray drying: the mixed solution prepared in step S4 is sent into the feed inlet of a spray drying device through a peristaltic pump, and the spray drying parameters are set as follows: air inlet temperature 160-180 DEG C, air outlet temperature 70-90 DEG C, feed rate 10-20 mL / min, atomization pressure 0.2-0.3 MPa; during the drying process, the air outlet humidity is monitored in real time through an online humidity monitor to ensure that the air outlet humidity is less than or equal to 5%; the dried powder product falls into a collector, and is immediately transferred into a sealed bag after collection to prevent moisture absorption; the collected powder is sieved through a 100-200 mesh sieve to remove possible caked particles, and the final stability-enhanced antioxidant based on pterostilbene is obtained; the content of pterostilbene in the product is determined through high performance liquid chromatography (HPLC) to ensure that the content meets the formula requirements, and the moisture content of the product is determined through a moisture meter to be less than or equal to 3% to ensure the storage stability of the product.

[0025] Preferably, the nanosilica added in step S4 needs to be subjected to ultrasonic dispersion treatment before use, and the specific ultrasonic dispersion process is as follows: a formula amount of nanosilica is added into deionized water, and the solid-liquid ratio is controlled to be 1:20-30 to obtain a nanosilica dispersion liquid; the dispersion liquid is added into an ultrasonic cleaning instrument, and the ultrasonic power is set to 300-500 W and the ultrasonic frequency is set to 20-40 kHz, and the ultrasonic treatment is started; during the ultrasonic treatment, the temperature of the dispersion liquid is controlled to be not higher than 40 DEG C through a constant temperature water bath, and the particle size distribution of the nanosilica in the dispersion liquid is measured every 5 minutes through a laser particle size analyzer; after 10-20 minutes of ultrasonic treatment, when the particle size distribution of the nanosilica is concentrated in 10-50 nm and D90 is less than or equal to 50 nm, the ultrasonic treatment is stopped; after the ultrasonic dispersion is completed, the nanosilica dispersion liquid is immediately added into the reaction kettle to avoid agglomeration caused by long storage time.

[0026] Preferably, the stability-enhanced antioxidant based on pterostilbene is applied in the fields of food, cosmetics and medicine.

[0027] (Three) beneficial technical effects

[0028] Compared with the prior art, the beneficial effects of the present application are:

[0029] 1. By β-cyclodextrin inclusion and multi-component synergistic protection, a "double stabilization system" is constructed - the ring cavity of β-cyclodextrin can wrap up the molecule of pterostilbene, isolate the contact of light, oxygen and pterostilbene, and greatly reduce the oxidation degradation rate; at the same time, disodium ethylenediaminetetraacetate can chelate trace metal ions in the system to avoid the catalysis of metal ions on the oxidation of pterostilbene and other active ingredients, and the "microcarrier" formed by hydrogen bond combination of chitosan quaternary ammonium salt and nano silicon dioxide can further fix the inclusion complex of pterostilbene to prevent the dissociation of the inclusion complex. Compared with the existing single inclusion technology, the antioxidant of the present application has significantly higher retention rate of pterostilbene under normal temperature and humidity conditions, can realize long-term stability for more than 6 months, and fully meets the shelf life requirements of food, cosmetics and drugs.

[0030] 2. By synergistic emulsification of polyglycerol fatty acid ester and gum arabic, and modified dispersion of nano silicon dioxide, the uniform dispersion of the antioxidant in the multiphase system is realized - polyglycerol fatty acid ester can reduce the water-oil interfacial tension, promote the dissolution of oil-soluble ingredients such as pterostilbene in the aqueous phase; gum arabic cooperates with polyglycerol fatty acid ester to construct a double-layer protection film to prevent the cream from separating; the modified nano silicon dioxide is not only uniformly dispersed itself, but also can adsorb various active ingredients to avoid local aggregation. Whether in water-phase food, oil-phase food, or in oil-in-water and water-in-oil cosmetics, the antioxidant of the present application can be uniformly dispersed without precipitation and stratification, which not only ensures the consistency of antioxidant effect, but also avoids the defects of product appearance and use experience.

[0031] 3. By multi-component synergistic effect, the overall antioxidant performance is significantly improved - the synergistic system formed by pterostilbene, tea polyphenols and rosemary acid can scavenge free radicals through different mechanisms, covering a wider oxidation path; the compounding of tocopherol succinate and ascorbic acid palmitate can realize the regeneration and circulation of antioxidants, prolonging the antioxidant period. At the same time, the antioxidant has high biological safety, which is suitable for application in multiple fields such as food, cosmetics and drugs: in the field of food, it can effectively delay the rancidity of oil and fat, avoiding the safety hazards of synthetic antioxidants; in the field of cosmetics, it can improve the anti-free radical ability of products and protect the skin from oxidative damage; in the field of drugs, it can protect easily oxidized active ingredients and ensure the stability of drug efficacy.

[0032] 4. The preparation method of the present application has optimized process flow, low energy consumption and good batch stability - the inclusion reaction is carried out by precisely controlling the temperature and stirring rate to ensure stable and efficient inclusion rate; the emulsification step uses peristaltic pump dripping combined with high-speed stirring to control the uniformity of emulsion droplet size; spray drying is selected in the drying step, which greatly shortens the production cycle compared with freeze drying, reduces energy consumption and production cost. At the same time, the parameters of each step in the process are clear, easy to realize industrialized production, and the performance difference between product batches is small, which can meet the quality control requirements of large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0033] Fig. 1 is a preparation method flow chart of a stability-enhanced antioxidant based on pterostilbene according to the present application;

[0034] Fig. 2 is a comparison graph of pterostilbene retention rate of examples and comparative examples;

[0035] Fig. 3 is a comparison graph of inclusion compound dissociation rate of examples and comparative examples;

[0036] Fig. 4 is a comparison graph of soybean oil preservation days and storage stability of examples and comparative examples. DETAILED DESCRIPTION

[0037] According to the present application, the detailed description is as follows: Figs. 1 to 4

[0038] I. Raw material preparation

[0039] The raw materials and specifications used in each example and comparative example are as follows:

[0040] Pterostilbene: purity 98.5%, particle size 3-8 μm, prepared by supercritical CO2 extraction process, no organic solvent residue;

[0041] Gum arabic: viscosity 350 mPa . s, moisture content 8%, ash content 0.05%;

[0042] Tocopherol succinate: purity 96%, acid value 1.5 mgKOH / g, peroxide value 0.3 meq / kg;

[0043] Disodium ethylenediaminetetraacetate: purity 99.2%, pH 5.0, drying loss 0.5%;

[0044] β-Cyclodextrin: degree of substitution 5.5, moisture content 10%, solubility 20 g / 100 mL (25°C);

[0045] Rosmarinic acid: purity 95%, melting point 171-175°C, moisture content 0.8%;

[0046] Chitosan quaternary ammonium salt: degree of deacetylation 92%, molecular weight 30000 Da, viscosity 150 mPa . s;

[0047] Nano-silicon dioxide: hydrophilic, particle size 20-40 nm, specific surface area 200 m 2 / g, modified by silane coupling agent KH560;

[0048] ​Polyglyceryl-6-stearate: HLB value 10, acid value 2 mg KOH / g, saponification value 150 mg KOH / g, iodine value 1.2 g I2 / 100 g;

[0049] Tea polyphenols: epigallocatechin gallate content 65%, catechin component ratio epigallocatechin gallate: epigallocatechin: epicatechin gallate: epicatechin = 6:2:1:1;

[0050] Ascorbyl palmitate: purity 98.5%, melting point 110°C, loss on drying 0.3%;

[0051] Ethanol: analytical pure, concentration 95%, moisture content 5%;

[0052] Deionized water: conductivity 8 μS / cm, total dissolved solids content 5 mg / L.

[0053] II. Example 1

[0054] Formulation by weight percentage: pterostilbene 20%, gum arabic 15%, tocopheryl succinate 10%, disodium ethylenediaminetetraacetate 3%, β-cyclodextrin 40%, rosemary acid 5%, chitosan quaternary ammonium salt 3%, nano-silicon dioxide 1%, polyglyceryl-6-stearate 3%.

[0055] Preparation steps:

[0056] S1. Preparation of aqueous phase: 15 grams of gum arabic, 3 grams of disodium ethylenediaminetetraacetate, and 3 grams of polyglyceryl-6-stearate were added to 190 grams of deionized water, with a solid-liquid ratio of 1:6.3. The mixture was added to a 500-milliliter reaction kettle with a stirring device and a temperature control jacket, stirring was started and the stirring rate was set to 250 rpm, and hot water was passed through the jacket to raise the temperature at the same time. The temperature in the reaction kettle was raised to 70°C, and the temperature and stirring rate were kept constant for 40 minutes of continuous stirring, during which samples were taken every 10 minutes for observation, until the mixture was uniformly transparent and no solid particles were visible to the naked eye. After completion, the temperature of the aqueous phase was reduced to 50°C for standby.

[0057] S2. Preparation of organic phase: 20 grams of pterostilbene and 10 grams of tocopheryl succinate were added to 80 grams of 95% ethanol. The mixture was added to a beaker with stirring and temperature control function, placed in a constant temperature water bath, and the water bath temperature was set to 50°C, stirring was started and the stirring rate was set to 180 rpm, and stirring was continued for 25 minutes. During this period, a small amount of the mixture was observed every 5 minutes with a glass rod, until the mixture was clear and transparent with no solid residue. After completion, the temperature of the organic phase was kept at 50°C for standby.

[0058] S3. Emulsification: The organic phase prepared in step S2 was slowly added into the aqueous phase prepared in step S1 at a rate of 2 mL / min by using a peristaltic pump, while the stirring rate of the reactor was increased from 250 rpm to 800 rpm and the temperature was kept at 50 °C by controlling the jacket temperature. During the addition process, samples were taken every 5 minutes and the particle size distribution of the emulsion was measured by a laser particle size analyzer to ensure that the droplet size was concentrated in the range of 0.3-0.8 pm. After the addition was completed, the stirring rate and the temperature were kept constant for 30 minutes to ensure that the emulsion was homogeneous and no phase separation occurred.

[0059] S4. Complexation: 40 g of β-cyclodextrin was added into the emulsion, and the temperature was increased from 50 °C to 55 °C by turning on the heating device of the reactor. The stirring rate was adjusted to 400 rpm, and the complexation reaction was carried out for 1.5 hours. During the reaction, the concentration of free dasatinib in the emulsion was measured by high performance liquid chromatography every 30 minutes. When the concentration of free dasatinib was stable at 0.15 mg / mL, the complexation reaction was stopped, and the complexation rate was 88%. Then, 5 g of rosmarinic acid, 3 g of chitosan quaternary ammonium salt, and 1 g of pre-treated nano-silica were added into the reactor. The ultrasonic dispersion parameters of the nano-silica were power 400 W, time 20 minutes, and solid-liquid ratio 1:25. The temperature was decreased to 40 °C by turning on the cooling device of the reactor, and the stirring rate was adjusted to 250 rpm. The stirring was continued for 45 minutes. During the stirring, the dissolution state of the rosmarinic acid was monitored by a UV-visible spectrophotometer to ensure that it was completely dissolved and no precipitation was generated.

[0060] S5. Spray drying: The mixture prepared in step S4 was fed into the inlet of a spray drying device by using a peristaltic pump. The spray drying parameters were set as follows: inlet air temperature 170 °C, outlet air temperature 80 °C, feed rate 15 mL / min, and atomization pressure 0.25 MPa. During the drying process, the outlet air humidity was monitored in real time by an online humidity monitor to ensure that the outlet air humidity was ≤5%. The powder product after drying fell into a collector, and was immediately transferred into a sealed bag to prevent moisture absorption. The collected powder was sieved through a 150-mesh sieve to remove possible agglomerated particles, and the proportion of the sieve residue was ≤1%. The final stability-enhanced antioxidant based on dasatinib was obtained. The content of dasatinib in the product was determined by high performance liquid chromatography, which met the requirements of the formula. The water content of the product was 2.5% as determined by a moisture meter.

[0061] III. Example 2

[0062] The formula is in weight percentage: dasatinib 15%, gum arabic 12%, tocopherol succinate 8%, disodium ethylenediaminetetraacetate 2%, β-cyclodextrin 45%, rosmarinic acid 4%, chitosan quaternary ammonium salt 2%, nano-silica 0.8%, polyglycerol-6-stearate 4%, tea polyphenol 1%, ascorbic acid palmitate 2.2%.

[0063] Preparation steps:

[0064] S1. Preparation of aqueous phase: 12 grams of gum arabic, 2 grams of disodium ethylenediaminetetraacetate, 4 grams of polyglyceryl-6-palmitate, 1 gram of tea polyphenols were added to 170 grams of deionized water, and the solid-liquid ratio was controlled at 1:7.1. The mixture was added to a 500-milliliter reaction kettle with a stirring device and a temperature control jacket, the stirring was turned on and the stirring rate was set to 220 rpm, and at the same time, hot water was passed through the jacket to raise the temperature. The temperature in the reaction kettle was raised to 75°C, and the temperature and stirring rate were maintained for 35 minutes of continuous stirring, during which the mixture was observed every 10 minutes, until the mixture was uniform and transparent and no solid particles were visible to the naked eye. After completion, the temperature of the aqueous phase was reduced to 48°C for standby.

[0065] S2. Preparation of organic phase: 15 grams of pterostilbene, 8 grams of tocopherol succinate, and 2.2 grams of ascorbic acid palmitate were added to 60 grams of 90% ethanol. The mixture was added to a beaker with stirring and temperature control function, placed in a constant temperature water bath, and the water bath temperature was set to 45°C, the stirring was turned on and the stirring rate was set to 160 rpm, and the stirring was continued for 22 minutes. During this period, the mixture was observed every 5 minutes with a glass rod, until the mixture was clear and transparent and no solid residue was left. After completion, the temperature of the organic phase was maintained at 45°C for standby.

[0066] S3. Emulsification treatment: the organic phase prepared in step S2 was slowly added to the aqueous phase prepared in step S1 at a rate of 1.5 mL / min by peristaltic pump, while the stirring rate of the reaction kettle was increased from 220 rpm to 700 rpm, and the temperature in the reaction kettle was maintained at 48°C by temperature control through the jacket. During the addition process, samples were taken every 5 minutes, and the particle size distribution of the emulsion was determined by a laser particle size analyzer to ensure that the droplet size was concentrated in the range of 0.2-0.7 μm. After the addition was completed, the stirring rate and temperature were maintained for 35 minutes of emulsification, until the emulsion was uniform and milky white and no stratification was observed.

[0067] S4. Complexation reaction: 45 g of β-cyclodextrin was added into the emulsified emulsion, and the temperature of the reactor was raised from 48 °C to 52 °C. The stirring speed was adjusted to 350 rpm, and the inclusion reaction was carried out for 1.2 hours. During the reaction, the concentration of free pterostilbene in the emulsion was determined by high performance liquid chromatography every 30 minutes. When the free concentration was stable, the inclusion reaction was stopped, and the inclusion rate was 86%. Then, 4 g of rosmarinic acid, 2 g of chitosan quaternary ammonium salt, and 0.8 g of pre-treated nano-silicon dioxide were added into the reactor. The ultrasonic dispersion parameters of the nano-silicon dioxide were power 350 W, time 15 minutes, and solid-liquid ratio 1:25. The temperature of the reactor was lowered to 35 °C, and the stirring speed was adjusted to 220 rpm. The stirring was continued for 50 minutes. During the stirring, the dissolution state of the rosmarinic acid was monitored by ultraviolet-visible spectrophotometer to ensure that it was completely dissolved and no precipitation was generated.

[0068] S5. Spray drying: The mixed solution prepared in step S4 was sent into the feed inlet of the spray drying equipment by peristaltic pump. The spray drying parameters were set as follows: inlet air temperature 165 °C, outlet air temperature 75 °C, feed rate 12 mL / min, and atomization pressure 0.25 MPa. During the drying process, the outlet air humidity was monitored in real time by an online humidity monitor to ensure that the outlet air humidity was ≤5%. The dried powder product fell into the collector, which was immediately transferred into a sealed bag to prevent moisture absorption. The collected powder was sieved through a 150-mesh sieve to remove possible caked particles, and the proportion of the sieve residue was ≤1%. The final pterostilbene-based stability-enhanced antioxidant was obtained. The content of pterostilbene in the product was determined by high performance liquid chromatography, which met the formula requirements. The water content of the product was 2.3% as determined by a moisture meter.

[0069] IV. Example 3

[0070] The formula is in percentage by weight: pterostilbene 25%, gum arabic 18%, tocopherol succinate 12%, disodium ethylenediaminetetraacetate 4%, β-cyclodextrin 30%, rosmarinic acid 6%, chitosan quaternary ammonium salt 4%, nano-silicon dioxide 2%, polyglycerol-6-stearate 5%, tea polyphenols 1.5%, ascorbic acid palmitate 3.5%.

[0071] Preparation steps:

[0072] S1. Preparation of aqueous phase: 18 grams of gum arabic, 4 grams of disodium ethylenediaminetetraacetate, 5 grams of polyglyceryl-6-palmitate, 1.5 grams of tea polyphenols were added to 220 grams of deionized water, and the solid-liquid ratio was controlled at 1:5.5. The mixture was added to a 500-milliliter reaction kettle with a stirring device and a temperature control jacket, and the stirring was started with a stirring rate of 280 rpm, and hot water was introduced through the jacket to raise the temperature. The temperature in the reaction kettle was raised to 80°C, and the stirring rate and temperature were maintained for 45 minutes, during which the mixture was observed every 10 minutes, until the mixture was uniform and transparent and no solid particles were visible to the naked eye. After completion, the temperature of the aqueous phase was reduced to 52°C for standby.

[0073] S2. Preparation of organic phase: 25 grams of pterostilbene, 12 grams of tocopherol succinate, and 3.5 grams of ascorbic acid palmitate were added to 100 grams of 95% ethanol. The mixture was added to a beaker with stirring and temperature control function, placed in a constant temperature water bath, and the water bath temperature was set to 50°C, the stirring was started with a stirring rate of 200 rpm, and the stirring was continued for 28 minutes. During this period, the mixture was observed every 5 minutes with a glass rod, until the mixture was clear and transparent and no solid residue was left. After completion, the temperature of the organic phase was maintained at 50°C for standby.

[0074] S3. Emulsification treatment: The organic phase prepared in step S2 was slowly added to the aqueous phase prepared in step S1 at a rate of 2.5 mL / min through a peristaltic pump, while the stirring rate of the reaction kettle was increased from 280 rpm to 900 rpm, and the temperature in the reaction kettle was maintained at 52°C through the jacket temperature control. During the dripping process, samples were taken every 5 minutes, and the particle size distribution of the emulsion was determined by a laser particle size analyzer to ensure that the droplet size was concentrated in the range of 0.4-0.9 μm. After the dripping was completed, the stirring rate and temperature were maintained for 25 minutes to emulsify, until the emulsion was uniform and milky white and no stratification was observed.

[0075] S4. Complexation reaction: 30 grams of β-cyclodextrin was added to the emulsified emulsion, the temperature in the reaction kettle was raised from 52°C to 58°C by starting the heating device, the stirring rate was adjusted to 450 rpm, and the inclusion reaction was carried out for 1.8 hours under the above conditions. During the reaction, the concentration of free pterostilbene in the emulsion was determined by high performance liquid chromatography every 30 minutes, and when the free concentration was stable, the inclusion reaction was stopped, and the inclusion rate was 89% at this time. Then 6 grams of rosmarinic acid, 4 grams of chitosan quaternary ammonium salt, and 2 grams of pre-treated nano-silicon dioxide were added to the reaction kettle, wherein the ultrasonic dispersion parameters of the nano-silicon dioxide were power 450 W, time 18 minutes, and solid-liquid ratio 1:25. The temperature in the reaction kettle was lowered to 45°C by starting the cooling device, and the stirring rate was adjusted to 280 rpm, and the stirring was continued for 35 minutes. During the stirring process, the dissolution state of rosmarinic acid was monitored by a UV-visible spectrophotometer to ensure that it was completely dissolved and no precipitation was generated.

[0076] S5. Spray drying: The mixed solution prepared in step S4 was sent into the feeding port of the spray drying equipment by peristaltic pump, and the spray drying parameters were set as an air inlet temperature of 175℃, an air outlet temperature of 85℃, a feeding rate of 18 mL / min, and an atomization pressure of 0.25 MPa. The air outlet humidity was monitored in real time during the drying process by an online humidity monitor to ensure that the air outlet humidity was ≤5%. The dried powder product fell into a collector, and was immediately transferred into a sealed bag after collection to prevent moisture absorption. The collected powder was sieved through a 150-mesh sieve to remove possible caked particles, and the proportion of the sieve residue was ≤1%, to obtain the final stability-enhanced antioxidant based on pterostilbene. The content of pterostilbene in the product was determined by high-performance liquid chromatography to meet the requirements of the formula, and the water content of the product was determined by a moisture meter to be 2.7%.

[0077] Test method

[0078] Pterostilbene retention rate determination: High-performance liquid chromatography (HPLC) was used, and the chromatographic conditions were as follows: a C18 column (Sumx 250 mm x 4.6 mm, 5 μm), a mobile phase of methanol / 0.05% trifluoroacetic acid aqueous solution = 80:20 (v / v), a flow rate of 1.0 mL / min, a column temperature of 30℃, a detection wavelength of 300 nm, and a sample injection volume of 2 μL. The peak areas of pterostilbene before storage (0 days) and after accelerated storage (45℃, RH 75%, light shielding) for 30 days were determined, and the retention rate = (peak area after storage / initial peak area) x 100%.

[0079] Free metal ion content determination: Inductively coupled plasma mass spectrometry (ICP-MS) (instrument model: ThermoiCAP RQ, according to the “Inductively Coupled Plasma Emission Spectrometer Operation Specification”) was used. The sample was subjected to microwave digestion with nitric acid (digestion instrument: CEM MARS6) and then loaded onto the machine. The detection limit was 0.001 mg / kg, and the types of metal ions tested included Fe, Cu, Pb, Cd, and Hg.

[0080] Inclusion complex dissociation rate determination: The inclusion complex refers to a supramolecular inclusion complex formed by pterostilbene and β-cyclodextrin in a molar ratio of 1:2 in the present application (refer to “raw material ratio” in Example 1: pterostilbene 25 g, β-cyclodextrin 82 g), which is used to improve the stability of pterostilbene.

[0081] Test method: centrifugal separation method (centrifuge model: TG16-WS, according to the “Centrifuge Operation Specification”), 1 g of sample was dissolved in 10 mL of deionized water, centrifuged at 3000 rpm for 15 min, the supernatant was collected, and the free pterostilbene content in the supernatant was determined by the HPLC method described in 1.1 above; another 1 g of sample was ultrasonically extracted with methanol for 30 min (ultrasonic instrument: KQ-300DE), and the total pterostilbene content was determined, and the dissociation rate = (free pterostilbene content / total pterostilbene content) x 100%.

[0082] Soybean oil preservation test: GB / T5538-2021 "Determination of Peroxide Value of Animal and Vegetable Oils", 0.1% (w / w) antioxidant was added to soybean oil (marketed first-grade soybean oil, batch number: 20250601), placed in a 60°C accelerated oxidation box (model: DHG-9140A, refer to "blower drying oven operation specification"), peroxide value (POV) was measured every day, POV≥10 meq / kg was the deterioration standard, and the preservation days were recorded.

[0083] Cream additive test: an oil-in-water cream base formula (glycerol 10%, stearic acid 5%, Tween-80 3%, deionized water 82%) was prepared, 0.5% (w / w) antioxidant was added, and stored at 45°C for 3 months (incubator: SPX-100B-Z, refer to "biochemical incubator operation specification"), the appearance (whether delamination, precipitation) was observed every week, and the rating was as follows: ① excellent: no delamination, no precipitation; ② poor: solid precipitation appeared.

[0084] Oral liquid auxiliary rating standard: the rating is based on "free radical scavenging rate", the test method is DPPH method: take 0.1% antioxidant oral liquid sample (oral liquid base formula: sucrose 5%, citric acid 0.2%, deionized water 94.8%), add 0.1 mmol / L DPPH ethanol solution, avoid light reaction for 30 min, measure absorbance at 517 nm, scavenging rate = (1-sample absorbance / blank absorbance) x 100%. Rating standard: scavenging rate≥90% is "very high", 80%-89% is "high", 60%-79% is "moderate", and <60% is "low".

[0085] Storage stability, i.e. the percentage of antioxidant activity retained after 6 months of storage at room temperature and humidity, was tested by the DPPH free radical scavenging rate method, and the calculation method was = (scavenging rate after storage / initial scavenging rate) x 100%.

[0086] V. Comparative Example

[0087] The formula is in weight percentage: pterostilbene 20%, beta-cyclodextrin 50%, tocopherol 10%, polysorbate-80 10%, rosemary extract 10%, and does not contain nano-silicon dioxide, chitosan quaternary ammonium salt, disodium ethylenediaminetetraacetate, polyglyceryl-6-palmitate, tea polyphenol, ascorbic acid palmitate, etc.

[0088] Preparation steps:

[0089] S1. 20 grams of pterostilbene and 10 grams of tocopherol were added to 100 grams of 95% ethanol, and stirred to dissolve in a 45°C water bath, the stirring rate was 180 rpm, and the stirring time was 25 minutes.

[0090] S2. Add 50 grams of β-cyclodextrin and 10 grams of polysorbate-80 into 200 grams of deionized water, and dissolve in a 60°C water bath with stirring at a stirring rate of 200 rpm for 30 minutes.

[0091] S3. Add the organic phase prepared in step S1 into the aqueous phase prepared in step S2, and emulsify at a stirring rate of 500 rpm for 20 minutes at an emulsification temperature of 45°C.

[0092] S4. Add 10 grams of rosemary extract to the emulsified mixture, and cool to 30°C, and stir at a stirring rate of 200 rpm for 30 minutes.

[0093] S5. Freeze-dry the mixture, set the drying temperature to -50°C, and dry for 24 hours to obtain the dried product.

[0094] The antioxidant stability test results of the examples and comparative examples are shown in the following table:

[0095] Table 1

[0096]

[0097] The antioxidant application performance test results of the examples and comparative examples are shown in the following table:

[0098] Table 2

[0099]

[0100] As can be seen from the above results, the examples 1-3 have significantly better stability than the comparative examples due to the use of β-cyclodextrin inclusion, nanosilica dispersion, and multi-component synergy design. After 6 months of storage, the pterostilbene retention rate of the examples is all above 90% and maintains a uniform powder state, while the pterostilbene retention rate of the comparative examples is only 58% and appears to be caked and discolored. This is because the ethylenediaminetetraacetic acid disodium salt in the examples chelates metal ions, avoiding the catalysis of metal ions on oxidation reactions, and the microcarrier structure formed by the chitosan quaternary ammonium salt and nanosilica effectively prevents the dissociation of the inclusion.

[0101] In terms of application performance, the examples have excellent performance in various fields due to good dispersibility and strong antioxidant synergy. In the soybean oil preservation test, the oxidation induction period of the examples is 4-5 times that of the comparative examples; when added to face cream, the examples can be uniformly dispersed while the comparative examples are precipitated; and when used as an auxiliary material in oral liquids, the free radical scavenging effect of the examples is significantly better than that of the comparative examples. Examples 2 and 3 further improve the antioxidant effect through synergy by adding tea polyphenols and ascorbic acid palmitate. The comparative examples have obvious defects in stability and application effect due to the lack of key components and optimized processes.

[0102] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A stability-enhancing antioxidant based on pterostilbene, characterized in that, The product comprises the following components by weight percentage: pterostilbene 10-30%, gum arabic 8-20%, tocopheryl succinate 5-15%, disodium EDTA 1-5%, β-cyclodextrin 30-60%, rosmarinic acid 2-8%, chitosan quaternary ammonium salt 1-6%, nano-silica 0.5-3%, and polyglycerol fatty acid ester 2-7%; β-Cyclodextrin, through its cyclic cavity structure, undergoes an inclusion reaction with pterostilbene to form a thermodynamically stable inclusion complex. This inclusion structure isolates pterostilbene from light and oxygen, thus reducing its oxidative degradation rate. Nano-silica, being hydrophilic nanoparticles, has a surface rich in hydroxyl groups. These hydroxyl groups form intermolecular hydrogen bonds with the amino and hydroxyl groups in chitosan quaternary ammonium salt molecules. Through this interaction, nano-silica forms a uniformly dispersed "micro-carrier" in the system, preventing the aggregation of chitosan quaternary ammonium salt and adsorbing pterostilbene inclusion complex and rosmarinic acid. Polyglycerol fatty acid esters reduce the interfacial tension between the aqueous and organic phases, promoting the dissolution and dispersion of oil-soluble components such as pterostilbene and tocopheryl succinate in the aqueous phase. Simultaneously, it synergistically constructs a stable colloidal system with gum arabic, preventing stratification and precipitation during storage. Disodium EDTA chelates any trace metal ions that may be present in the system, preventing metal ions from catalyzing the oxidation of active components.

2. The stability-enhancing antioxidant based on pterostilbene according to claim 1, characterized in that, It also includes 0.1-2% by mass of tea polyphenols; these tea polyphenols are a mixture of catechins extracted from green tea, of which the content of epigallocatechin gallate (EGCG) is not less than 60%, and the remaining components include epigallocatechin, epicatechin gallate, epicatechin, etc., with the ratio of each catechin component controlled at EGCG:EGC:ECG:EC=6:2:1:

1.

3. The stability-enhancing antioxidant based on pterostilbene according to claim 1, characterized in that, It also includes 0.5-4% by mass of ascorbate palmitate; the purity of ascorbate palmitate is not less than 98%, the melting point range is 107-117℃, and its enthalpy of fusion is 120-130J / g as determined by differential scanning calorimetry, ensuring its good thermal stability in the system.

4. The stability-enhancing antioxidant based on pterostilbene according to claim 1, characterized in that, The purity of pterostilbene is not less than 98%, and the particle size is controlled within 1-10 μm. The particle size distribution span (D90-D10) / D50 is measured by a laser particle size analyzer and is ≤1.2 to ensure uniform particle size. This pterostilbene is prepared using a supercritical CO2 extraction-molecular distillation combined process. The specific process is as follows: using sandalwood or sandalwood leaves as raw materials, crushing them to a particle size of 0.5-1 mm, loading them into a supercritical extraction vessel, introducing CO2, controlling the extraction pressure at 30-40 MPa, the extraction temperature at 40-50℃, the CO2 flow rate at 20-30 L / h, and the extraction time at 2-3 hours to obtain a crude extract of pterostilbene. The crude extract is then sent to a molecular distillation device, controlling the distillation temperature at 80-90℃, the vacuum degree at 0.001-0.005 MPa, and the scraper rotation speed at 300-400 rpm. Molecular distillation removes low-boiling-point impurities and high-boiling-point impurities from the crude extract, finally obtaining high-purity pterostilbene.

5. The stability-enhancing antioxidant based on pterostilbene according to claim 1, characterized in that, Nano-silica is a hydrophilic fumed silica with a particle size of 10-50 nm, a specific surface area of ​​150-300 m² / g, and a pore volume of 0.8-1.2 cm³ / g determined by the BET method. The surface hydroxyl content is 2-3 hydroxyl groups / nm². Before use, nano-silica needs to be modified with silane coupling agent KH560. The modification process is as follows: nano-silica is added to an ethanol-water mixture, with a solid-liquid ratio of 1:20-30, and stirred for 10-15 minutes. Then, silane coupling agent KH560 is added at 5-8% of the nano-silica mass. The temperature is raised to 60-80℃, and the mixture is stirred at 200-300 rpm for 1-2 hours. After the reaction, the modified nano-silica is collected by centrifugation, washed 3-4 times with ethanol to remove unreacted silane coupling agent, and then dried at 100-110℃ for 2-3 hours to obtain modified nano-silica.

6. The stability-enhancing antioxidant based on pterostilbene according to claim 1, characterized in that, The polyglycerol fatty acid ester is specifically polyglycerol-6-stearate, with an HLB value of 8-12. Its emulsifying ability, determined by the emulsification method, is 30-40 mL. Its acid value does not exceed 3 mg KOH / g, its saponification value ranges from 140-160 mg KOH / g, and its iodine value is ≤2 g I2 / 100g.

7. The stability-enhancing antioxidant based on pterostilbene according to claim 1, characterized in that, The degree of substitution of β-cyclodextrin is 4.0-7.0, the moisture content is not more than 12%, and the ash content is ≤0.1%. The inclusion reaction of β-cyclodextrin with pterostilbene was carried out at a temperature of 50-60℃. Specifically, after adding β-cyclodextrin to the emulsion, the temperature was raised to 50-60℃, and the stirring rate was maintained at 300-500 rpm for 1-2 hours. During the reaction, the free concentration of pterostilbene was monitored in real time by high performance liquid chromatography (HPLC). When the concentration of free pterostilbene no longer decreased, the inclusion reaction was determined to have reached equilibrium.

8. A method for preparing a stability-enhancing antioxidant based on pterostilbene as described in claim 1, characterized in that, The following detailed steps are included: S1. Preparation of the aqueous phase: Add gum arabic, disodium EDTA, and polyglycerol fatty acid esters to deionized water according to the formula ratio, controlling the solid-liquid ratio of the aqueous phase to be 1:5-10; add the mixture to a reactor equipped with a stirring device and a temperature control jacket, turn on the stirring, set the stirring speed to 200-300 rpm, and simultaneously circulate hot water through the jacket to raise the temperature inside the reactor to 60-80℃; maintain this temperature and stirring speed and continue stirring for 30-50 minutes, taking samples every 10 minutes during this period, until the mixture becomes uniform and transparent, with no visible solid particles, indicating that the preparation of the aqueous phase is complete; after preparation, lower the temperature of the aqueous phase to 45-55℃ for later use; S2. Preparation of the organic phase: Add pterostilbene and tocopherol succinate to 70-95% ethanol according to the formula ratio; add the mixture to a beaker equipped with stirring and temperature control functions, place it in a constant temperature water bath, set the water bath temperature to 40-50℃, turn on the stirrer, stir at a speed of 150-200 rpm, and stir continuously for 20-30 minutes; during this period, use a glass rod to dip a small amount of the mixture every 5 minutes to observe, until the mixture is clear and transparent with no solid residue, indicating that the preparation of the organic phase is complete; after preparation, maintain the temperature of the organic phase at 40-50℃ for later use; S3. Emulsification: The organic phase prepared in step S2 is slowly added dropwise to the aqueous phase prepared in step S1 at a rate of 1-3 mL / min using a peristaltic pump. At the same time, the stirring speed of the reactor is increased from 200-300 rpm to 500-1000 rpm, and the temperature inside the reactor is maintained at 45-55℃ by jacket temperature control. During the dropwise addition, samples are taken every 5 minutes, and the particle size distribution of the emulsion is measured by a laser particle size analyzer to ensure that the droplet size is concentrated in 0.1-1 μm. After the dropwise addition is completed, the stirring speed and temperature are maintained for another 20-40 minutes until the emulsion is uniformly milky white and there is no stratification. The emulsification is then considered complete. S4. Composite Reaction: Add the prescribed amount of β-cyclodextrin to the emulsion after emulsification. Turn on the heating device of the reaction vessel and raise the temperature from 45-55℃ to 50-60℃. Adjust the stirring speed to 300-500 rpm and maintain this condition for the inclusion reaction for 1-2 hours. During the reaction, determine the concentration of free pterostilbene in the emulsion by high performance liquid chromatography (HPLC) every 30 minutes. When the free concentration stabilizes at 0.1-0.2 mg / mL, stop the inclusion reaction. Then add the prescribed amount of rosmarinic acid, chitosan quaternary ammonium salt, and pretreated nano-silica to the reaction vessel. Turn on the cooling device and lower the temperature inside the reaction vessel to 30-50℃. Adjust the stirring speed to 200-300 rpm and continue stirring for 30-60 minutes. During stirring, monitor the dissolution state of rosmarinic acid with a UV-Vis spectrophotometer to ensure that it is completely dissolved and no precipitate is formed. The composite reaction is then considered complete. S5. Spray Drying: The mixture prepared in step S4 is fed into the inlet of the spray drying equipment via a peristaltic pump. The spray drying parameters are set as follows: inlet air temperature 160-180℃, outlet air temperature 70-90℃, feed rate 10-20mL / min, and atomization pressure 0.2-0.3MPa. During the drying process, the outlet air humidity is monitored in real time using an online humidity monitor to ensure that the outlet air humidity is ≤5%. The dried powdered product falls into a collector and is immediately transferred to a sealed bag to prevent moisture absorption. The collected powder is sieved through a 100-200 mesh sieve to remove any possible agglomerated particles, resulting in the final pterostilbene-based stability-enhancing antioxidant. The pterostilbene content in the product is determined by high performance liquid chromatography (HPLC) to ensure that the content meets the formulation requirements. At the same time, the moisture content of the product is determined by a moisture analyzer to be ≤3% to ensure the product's storage stability.

9. The method for preparing a stability-enhancing antioxidant based on pterostilbene according to claim 8, characterized in that, The nano-silica added in step S4 needs to be ultrasonically dispersed before use. The specific ultrasonic dispersion process is as follows: add the prescribed amount of nano-silica to deionized water, control the solid-liquid ratio to 1:20-30, and obtain a nano-silica dispersion; add the dispersion to an ultrasonic cleaner, set the ultrasonic power to 300-500W and the ultrasonic frequency to 20-40kHz, and start the ultrasonic treatment; during the ultrasonic treatment, control the temperature of the dispersion to not exceed 40℃ by a constant temperature water bath, and measure the particle size distribution of nano-silica in the dispersion every 5 minutes using a laser particle size analyzer; after ultrasonic treatment for 10-20 minutes, when the particle size distribution of nano-silica is concentrated in 10-50nm and D90≤50nm, stop the ultrasonic treatment; after ultrasonic dispersion is completed, immediately add the nano-silica dispersion to the reaction vessel to avoid agglomeration due to prolonged standing.

10. The application of the pterostilbene-based stability-enhancing antioxidant according to claim 1 in the fields of food, cosmetics, and pharmaceuticals.

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