A method for extracting total flavonoids from rose hips by ultrasonic-assisted deep eutectic solvent

Abstract

The application discloses a method for extracting total flavones from rose hips by means of ultrasonic-assisted deep eutectic solvent, and belongs to the technical field of plant effective component extraction. First, the rose hips after freeze-drying are selected, deseeded, crushed and sieved to obtain rose hip powder; then, a hydrogen bond acceptor and a hydrogen bond donor are heated and mixed, water is added to reduce viscosity, and a deep eutectic solvent is obtained; finally, the rose hip powder and the deep eutectic solvent are mixed, ultrasonic extraction is carried out, subsequent centrifugal separation is carried out, the supernatant is collected, and rose hip total flavone extraction liquid is obtained. Under the optimal conditions that choline chloride and 1,4-butanediol are used as the deep eutectic solvent, the molar ratio is 1:2, the water content is 33.78 wt%, and the solid-liquid ratio is 1 g:54.162 mL, the extraction rate of the rose hip total flavones can reach 101.614 mg / g. The deep eutectic solvent used in the application has the green environmental protection characteristics of low toxicity, biodegradability and low volatility, and effectively avoids the environmental pollution and safety risks caused by organic solvents.

Description

Technical Field

[0001] This invention belongs to the field of plant active ingredient extraction technology, specifically relating to a method for extracting total flavonoids from Rosa rugosa fruit using ultrasound-assisted eutectic solvent extraction. Background Technology

[0002] Rosa davurica Pall., the mature fruit of a deciduous shrub belonging to the genus Rosa in the family Rosaceae, is mainly distributed in Northeast and North my country, as well as Siberia and the Far East of Russia. It is also known as wild rosehip or mountain rose. Its fruit has long been used as a food and medicine source, possessing high health and medicinal value. Modern pharmacological research has found that the active ingredients in Rosa davurica exhibit diverse biological functions, including antioxidant, antibacterial, anti-inflammatory, and immune-enhancing effects. These effects are closely related to its abundant secondary metabolites. Among these, total flavonoids are one of the main active components, exerting multiple protective effects through free radical scavenging, lipid peroxidation inhibition, and regulation of inflammatory factors, showing great application potential in the development of functional foods, pharmaceuticals, and cosmetics.

[0003] To date, several extraction techniques for total flavonoids from Rosa rugosa fruit have been reported. Traditional extraction strategies mostly rely on polar solvents such as water or alcohols, using the "like dissolves like" principle to promote the dissolution of total flavonoids. Common methods include maceration, reflux heating, and ultrasonic treatment; however, these methods still have many shortcomings. For example, using an ethanol-water mixed solvent for reflux heating, although the equipment is simple and inexpensive, often requires high extraction temperatures and long operating times, resulting in high energy consumption, and high temperatures can easily lead to the decomposition of thermally unstable components. In addition, ethanol is a volatile organic compound, which poses certain environmental burdens and safety concerns during use. Compared with traditional organic solvents, deep eutectic solvents (DES) have excellent thermal stability and low melting points, making them easy to operate under ambient temperature conditions. At the same time, the synthesis process of DES is simple, the raw materials used are inexpensive, non-toxic, and biodegradable, which can effectively reduce environmental pollution.

[0004] In recent years, ultrasound-assisted extraction (UAE) has been widely used in the field of natural product extraction due to its cavitation effect, which induces cell wall disruption and enhances mass transfer. However, the extraction performance of this technology remains highly dependent on the solvent system used. Specifically, although some studies have attempted to combine ultrasound with organic solvents such as ethanol for the extraction of total flavonoids, and have improved the extraction effect to some extent, the final extraction rate is still low and does not meet the standards for large-scale production. Furthermore, the problems of organic solvent residue and volatilization have not been fundamentally solved. Therefore, developing a novel ultrasound-assisted extraction method that simultaneously possesses high extraction efficiency and good environmental adaptability has become an important direction for the development of current natural product extraction technologies.

[0005] In summary, existing extraction technologies for total flavonoids from Rosa rugosa generally suffer from drawbacks such as poor solvent compatibility, low extraction efficiency, high energy consumption, and residual organic solvents. Therefore, there is an urgent need to develop a novel, efficient, environmentally friendly, and easily controllable extraction method to overcome the shortcomings of traditional processes, further improve the extraction efficiency and environmental safety of total flavonoids from Rosa rugosa, and thus provide technical support for its large-scale utilization. Summary of the Invention

[0006] This invention aims to address the problems existing in the background technology by providing an ultrasound-assisted eutectic solvent extraction method for total flavonoids from Rosa rugosa fruit. This method is carried out under mild conditions, which helps to protect the bioactivity of total flavonoids while achieving a high extraction rate. Compared with existing technologies, this invention has significant advantages in extraction efficiency, environmental friendliness, and process controllability, providing a feasible technical approach for the green and efficient extraction of total flavonoids from Rosa rugosa fruit, with broad application prospects.

[0007] The present invention discloses a method for ultrasonic-assisted extraction of total flavonoids from Rosa rugosa fruit using an eutectic solvent, the steps of which are as follows:

[0008] (1) Take freeze-dried rose hips, select, remove seeds, crush and sieve to obtain rose hip powder;

[0009] (2) Heat and mix the hydrogen bond acceptor and hydrogen bond donor, stir until transparent, add water to reduce viscosity and obtain a eutectic solvent;

[0010] (3) Mix the rosehip powder with a eutectic solvent and perform ultrasonic extraction. Then centrifuge and collect the supernatant to obtain the total flavonoid extract of rosehip, thus completing the extraction of total flavonoids from rosehip.

[0011] As a preferred option, in step (1), the fruit powder is obtained by passing it through a 30-50 mesh sieve;

[0012] Preferably, in step (2), the hydrogen bond acceptor is one or more of choline chloride, betaine and choline bitartrate; the hydrogen bond donor is one or more of proline, citric acid, malic acid, propionic acid, acetic acid, urea, 1,4-butanediol, glycerol, ethylene glycol, glucose, sucrose, fructose and xylitol.

[0013] Preferably, in step (2), the molar ratio of hydrogen bond acceptor to hydrogen bond donor is 1:1~3.

[0014] Preferably, in step (2), the water content of the eutectic solvent after adding water to reduce viscosity is 10~60 wt%.

[0015] Preferably, in step (3), the solid-liquid ratio of rosehip powder to eutectic solvent is 1 g: 10~100 mL.

[0016] Preferably, in step (3), the ultrasonic extraction time is 10~200 minutes and the ultrasonic extraction temperature is 10~80℃.

[0017] Preferably, in step (3), the centrifugation speed is 5000~10000 r / min and the centrifugation time is 10~30 min.

[0018] More preferably, in step (2), the molar ratio of hydrogen bond acceptor to hydrogen bond donor is 1:2.

[0019] More preferably, in step (2), the water content of the eutectic solvent after adding water to reduce viscosity is 15~35 wt%.

[0020] More preferably, in step (3), the ultrasonic extraction time is 30~150 minutes and the ultrasonic extraction temperature is 20~60℃.

[0021] More preferably, in step (3), the solid-liquid ratio of rosehip powder to eutectic solvent is 1 g: 30~80 mL.

[0022] More preferably, in step (3), the centrifugation speed is 6000~8000 r / min and the centrifugation time is 15~25 min.

[0023] The beneficial technical effects of this invention are as follows: This invention systematically optimizes the extraction process of total flavonoids from Rosa rugosa by constructing an ultrasound-assisted eutectic solvent extraction system. Experimental results show that the optimal solvent is a eutectic solvent prepared by mixing choline chloride and 1,4-butanediol at a molar ratio of 1:2. Under optimized conditions of 33.78 wt% water content, a solid-liquid ratio of 1 g:54.162 mL, an extraction temperature of 49 ℃, and an extraction time of 108 min, the extraction rate of total flavonoids from Rosa rugosa can reach 101.614 mg / g. Compared with the traditional ultrasound-assisted 70 wt% ethanol extraction method (total flavonoid extraction rate of 72.877 mg / g, Comparative Example 1), the extraction efficiency of this method is improved by 39.43%. In addition, the eutectic solvent used in this method has green and environmentally friendly characteristics such as low toxicity, biodegradability, and low volatility, effectively avoiding the environmental pollution and safety risks caused by organic solvents.

[0024] The extraction process proposed in this invention, carried out under mild conditions and within a short time, effectively protects the natural activity of total flavonoids from Rosa rugosa fruit and achieves a high yield of Rosa rugosa fruit total flavonoid extract. This process demonstrates excellent performance in extraction efficiency, environmental friendliness, and operational controllability, providing a reliable technical route for the green and efficient extraction of total flavonoids from Rosa rugosa fruit, and has broad application prospects. Attached Figure Description

[0025] To make the technical solutions of the embodiments of the present invention or the prior art clearer and easier to understand, the accompanying drawings required in the embodiments will be briefly described below. It should be noted that the following drawings only correspond to some embodiments of the present invention, and those skilled in the art can derive other drawings from these drawings without creative effort.

[0026] Figure 1 This is a graph showing the effect of different types of DES solvents on the extraction rate of total flavonoids from Rosa rugosa fruit in this invention; the vertical axis represents the extraction rate of total flavonoids from Rosa rugosa fruit in different types of DES solvents, and the horizontal axis represents different solvent types (the hydrogen bond acceptor is choline chloride, and the hydrogen bond donors are malic acid (DES-1), proline (DES-2), citric acid (DES-3), propionic acid (DES-4), urea (DES-5), 1,4-butanediol (DES-6), glycerol (DES-7), ethylene glycol (DES-8), acetic acid (DES-9), glucose (DES-10), sucrose (DES-11), fructose (DES-12), and xylitol (DES-13)); the specific extraction rate values ​​are shown in Table 1.

[0027] Figure 2The graph shows the effect of different DES moisture contents on the total flavonoid extraction rate of Rosa rugosa fruit in this invention. The vertical axis represents the total flavonoid extraction rate of Rosa rugosa fruit under different DES moisture contents, and the horizontal axis represents different DES moisture contents (15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%). The specific extraction rate values ​​are shown in Table 2.

[0028] Figure 3 This is a graph showing the effect of different solid-liquid ratios on the total flavonoid extraction rate of Rosa rugosa fruit in this invention. The vertical axis represents the total flavonoid extraction rate of Rosa rugosa fruit under different solid-liquid ratios, and the horizontal axis represents different DES solid-liquid ratios (1 g:40 mL, 1 g:50 mL, 1 g:60 mL, 1 g:70 mL, 1 g:80 mL). The specific extraction rate values ​​are shown in Table 3.

[0029] Figure 4 The graph shows the effect of different extraction times on the total flavonoid extraction rate of Rosa rugosa fruit in this invention. The vertical axis represents the total flavonoid extraction rate of Rosa rugosa fruit at different extraction times, and the horizontal axis represents different extraction times (30, 60, 90, 120, 150 min). The specific extraction rate values ​​are shown in Table 4.

[0030] Figure 5 The graph shows the effect of different extraction temperatures on the total flavonoid extraction rate of Rosa rugosa fruit in this invention. The vertical axis represents the total flavonoid extraction rate of Rosa rugosa fruit at different temperatures, and the horizontal axis represents different extraction temperatures (20, 30, 40, 50, 60℃). The specific extraction rate values ​​are shown in Table 5.

[0031] Figure 6 This is a 3D response surface plot showing the effect of liquid-to-solid ratio and DES water content on the total flavonoid extraction rate from Rosa rugosa fruit in this invention.

[0032] Figure 7 This is a 3D response surface plot showing the effect of liquid-solid ratio and extraction time on the total flavonoid extraction rate from Rosa rugosa fruit in this invention.

[0033] Figure 8 This is a 3D response surface plot showing the effect of liquid-solid ratio and extraction temperature on the total flavonoid extraction rate from Rosa rugosa fruit in this invention.

[0034] Figure 9 This is a 3D response surface plot showing the effect of extraction time and DES moisture content on the total flavonoid extraction rate from Rosa rugosa fruit in this invention.

[0035] Figure 10 This is a 3D response surface plot showing the effect of DES moisture content and extraction temperature on the total flavonoid extraction rate from Rosa rugosa fruit in this invention.

[0036] Figure 11 This is a 3D response surface plot showing the effect of extraction time and extraction temperature on the total flavonoid extraction rate from Rosa rugosa fruit in this invention. Detailed Implementation

[0037] The present invention will be specifically described below with reference to embodiments. However, it should be understood that these embodiments are descriptive and not limiting, and should not be construed as limiting the scope of protection of the present invention. All experimental operations used in the embodiments are conventional techniques in the art. For parts not specifically annotated in the text, those skilled in the art can refer to commonly used reference books, scientific and technological literature, or relevant operation manuals prior to the filing date of this invention. The following embodiments are only used to illustrate the present invention and are not intended to limit its scope. Unless otherwise specified, the technical means used in the embodiments are all conventional operations well known in the art, and the raw materials used are all commercially available products.

[0038] Example 1

[0039] This embodiment provides a method for extracting total flavonoids from Rosa rugosa fruit using an ultrasound-assisted eutectic solvent (choline chloride / 1,4-butanediol). Specifically:

[0040] (1) Take freeze-dried rose hips, select, remove seeds, crush and pass through a 40-mesh sieve to obtain rose hip powder;

[0041] (2) Preparation of eutectic solvent: Choline chloride and proline (citric acid, malic acid, propionic acid, acetic acid, urea, 1,4-butanediol, glycerol, ethylene glycol, glucose, sucrose, fructose, xylitol) were mixed in a molar ratio of 1:2, and then water was added to the specified water content (15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%). The mixture was stirred at 80 °C until the solution was homogeneous and transparent to prepare the eutectic solvent. The total flavonoids in 0.5 g of Rosa rugosa fruit powder were extracted using 15 mL of different eutectic solvents (solid-liquid ratio of 1 g:30 mL) to obtain a total volume of 15 mL of Rosa rugosa fruit total flavonoid extract. The extraction rates were compared to select the optimal eutectic solvent for extraction.

[0042] The total flavonoid extraction rate of the obtained Rosa rugosa fruit extract was determined by the sodium nitrite-aluminum nitrate colorimetric method. Specifically, rutin was used as the standard. 15 mL of different concentrations of rutin standard solution (prepared with 70% ethanol as solvent to concentrations of 0, 0.02, 0.04, 0.06, 0.08, and 0.10 mg / mL) were placed in a 50 mL volumetric flask. 2 mL of NaNO₂ solution (5%, w / v) was added, mixed, and allowed to stand at room temperature for 6 min. Then, 2 mL of Al(NO₃)₃ solution (10%, w / v) was added, mixed, and allowed to stand at room temperature for 6 min. Finally, 20.0 mL of NaOH solution (4%, w / v) was added, mixed, and the volume was adjusted to 50 mL with 70% ethanol. The solution was allowed to stand for 15 min. The absorbance was measured at 514 nm. A standard curve was plotted with rutin concentration (mg / mL) on the x-axis and absorbance values ​​on the y-axis, yielding the regression equation: y = 5.0414x - 0.0039 (R²). 2 =0.9996).

[0043] Dilute 0.3 mL of the total flavonoid extract from Rosa rugosa prepared in the above steps to 15 mL to obtain a diluted solution (dilution factor of 50). Measure its absorbance y and substitute it into the above regression equation to obtain the rutin mass concentration of the diluted solution (i.e., the total flavonoid mass concentration of the diluted solution, mg / mL). Multiply this by the dilution factor to obtain the total flavonoid mass concentration of the Rosa rugosa total flavonoid extract (mg / mL). Multiply this by the total volume of the flavonoid extract prepared earlier (15 mL) to obtain the total flavonoid mass in 15 mL of the total flavonoid extract. Divide this by the mass of Rosa rugosa powder used in preparing the Rosa rugosa total flavonoid extract (0.5 g) to obtain the total flavonoid extraction rate.

[0044] Y =

[0045] Y: Total flavonoid extraction rate (mg / g);

[0046] Dilution factor (in this embodiment, =50);

[0047] : The mass concentration of rutin in the diluted solution obtained after substituting into the regression equation (i.e., the total flavonoid mass concentration of the diluted solution, mg / mL).

[0048] The total volume of the flavonoid extract obtained (in this example, =15 mL, corresponding to a solid-liquid ratio of 1 g:30 mL; when the solid-liquid ratio is 1 g:40 mL, 1 g:50 mL, 1 g:60 mL, 1 g:70 mL, and 1 g:80 mL, V is 20, 25, 30, 35, and 40 mL respectively.

[0049] The mass of rosehip powder used in preparing the total flavonoid extract of rosehip (in this example, ...) =0.5g).

[0050] (3) Extraction of total flavonoids from Rosa rugosa fruit: 0.5 g of Rosa rugosa fruit powder was mixed with 20-40 mL of eutectic solvent (solid-liquid ratios of 1 g:40 mL, 1 g:50 mL, 1 g:60 mL, 1 g:70 mL, and 1 g:80 mL, respectively), and extracted at the specified extraction temperatures (20 ℃, 30 ℃, 40 ℃, 50 ℃, and 60 ℃) for extraction times of 30, 60, 90, 120, and 150 min, respectively, to obtain a mixture; the mixture was centrifuged at 7000 r / min for 20 minutes, and the supernatant was collected to obtain the total flavonoid extract of Rosa rugosa fruit, and the total flavonoid extraction rate was determined.

[0051] Comparative Example 1

[0052] The only difference between Comparative Example 1 and Example 1 is that the eutectic solvent was replaced with a 70% ethanol solution by volume. All other operating steps and process parameters were kept the same as in Example 1. Thus, the total flavonoid extract of Rosa rugosa fruit was obtained, and its total flavonoid extraction rate was determined.

[0053] Effect verification

[0054] 1. Experimental Methods

[0055] 1.1 Single-factor experiment

[0056] Based on Example 1 of this invention, the effects of eutectic solvent formulation, eutectic solvent solid-liquid ratio, water content, extraction temperature, and extraction time on the extraction effect of total flavonoids from Rosa rugosa fruit were investigated through single-factor experiments.

[0057] 1.1.1 Eutectic Solvent Formulation

[0058] Under the conditions of a fixed water content of 30 wt%, a solid-liquid ratio of 1 g:30 mL for Rosa rugosa fruit powder and a eutectic solvent, an extraction temperature of 50 ℃, and an extraction time of 60 min, the effects of different compositions of the eutectic solvent on the extraction efficiency of total flavonoids from Rosa rugosa fruit were investigated, and the optimal eutectic solvent formulation was screened. Specific results are shown in Table 1.

[0059] Table 1: Selection of Eutectic Solvent Formulation

[0060]

[0061] 1.1.2 Optimization of water content in eutectic solvent

[0062] Under fixed conditions of a eutectic solvent composition (choline chloride to 1,4-butanediol molar ratio of 1:2), a solid-liquid ratio of 1 g:30 mL, an extraction temperature of 50 ℃, and an extraction time of 60 min, the effects of different water contents (set as 15 wt%, 20 wt%, 25 wt%, 30 wt%, and 35 wt%) in the eutectic solvent on the extraction efficiency of total flavonoids from Rosa rugosa fruit were investigated. The relevant results are shown in Table 2.

[0063] Table 2: Effect of moisture content on the extraction efficiency of total flavonoids from Rosa rugosa fruit

[0064]

[0065] 1.1.3 Optimization of the solid-liquid ratio of eutectic solvent and rosehip powder

[0066] Under the conditions of a fixed eutectic solvent composition (choline chloride to 1,4-butanediol molar ratio of 1:2), a water content of 30 wt%, an extraction temperature of 50 ℃, and an extraction time of 60 min, the effects of different solid-liquid ratios (1 g:40 mL, 1 g:50 mL, 1 g:60 mL, 1 g:70 mL, and 1 g:80 mL, respectively) of Rosa rugosa fruit powder to the eutectic solvent on the extraction efficiency of total flavonoids from Rosa rugosa fruit were investigated. The relevant results are shown in Table 3.

[0067]

[0068] Table 3: Effect of solid-liquid ratio on the extraction efficiency of total flavonoids from Rosa rugosa fruit

[0069] 1.1.4 Extraction Time Optimization

[0070] Under the conditions of a fixed eutectic solvent composition (choline chloride to 1,4-butanediol molar ratio of 1:2), a water content of 30 wt%, an extraction temperature of 50 ℃, and a solid-liquid ratio of 1 g:60 mL, the effects of extraction time (set to 30, 60, 90, 120, and 150 min, respectively) on the extraction efficiency of total flavonoids from Rosa rugosa fruit were investigated. The relevant results are shown in Table 4.

[0071] Table 4: Effect of extraction time on the extraction efficiency of total flavonoids from Rosa rugosa fruit

[0072]

[0073] 1.1.5 Extraction Temperature Optimization

[0074] Under fixed eutectic solvent composition (choline chloride to 1,4-butanediol molar ratio of 1:2), water content of 30 wt%, extraction time of 120 min, and solid-liquid ratio of 1 g:60 mL, the effect of extraction temperature (set at 20 ℃, 30 ℃, 40 ℃, 50 ℃, and 60 ℃) on the extraction efficiency of total flavonoids from Rosa rugosa fruit was investigated. The relevant results are shown in Table 5.

[0075] Table 5: Effect of extraction temperature on the extraction efficiency of total flavonoids from Rosa rugosa fruit

[0076]

[0077] Experiments revealed that the eutectic solvent with a water content of 30% exhibited the highest extraction efficiency. This was primarily attributed to its suitable fluidity and extensive hydrogen bond network, which facilitates mass transfer. Single-factor experiments determined the optimal extraction temperature (50℃), extraction time (120 min), water content (30 wt%), composition of the eutectic solvent (choline chloride / 1,4-butanediol), and solid-liquid ratio (1:60 g / mL).

[0078] 1.2 Optimization of Box / Behnken Response Surface Extraction Conditions

[0079] To further optimize the extraction conditions of total flavonoids from Rosa rugosa fruit, a four-factor, three-level Box / Behnken response surface design (BBD) was adopted based on the results of previous single-factor experiments. The solid-liquid ratio (1:50, 1:60, 1:70 g / mL), water content (25 wt%, 30 wt%, 35 wt%), extraction time (90, 120, 150 min), and extraction temperature (40℃, 50℃, 60℃) were used as the four independent variables, with the total flavonoid extraction rate as the response value. A total of 29 experiments (including 5 central point replicates) were conducted. A quadratic regression model was established to optimize the extraction process. The relevant results are shown in Tables 6 and 7, which correspond to the 3D response surface effects of different factors on the total flavonoid extraction rate of Rosa rugosa fruit. Figures 6-11 .

[0080] Table 6: Conditions of each experimental group

[0081]

[0082] Table 7: Test Results of Each Experimental Group

[0083]

[0084] The experimental data were analyzed using Design / Expert13 software for fit testing and multiple regression analysis to explore the relationship between the four variables and the extraction rate (Y) of total flavonoids from Rosa rugosa fruit, thereby determining the optimal extraction conditions. The final second-order polynomial equation for the extraction rate of total flavonoids from Rosa rugosa fruit is as follows:

[0085] Y=96.88 / 0.0334A+6.22B / 2.44C / 7.68D / 11.97AB+7.44AC / 0.2312AD / 1.39BC+3.57BD / 5.95CD / 10.39A 2 / 8.85B 2 / 8.80C 2

[0086] In this model, A, B, C, and D correspond to the four independent variables in the table above. The p-value of this model is highly significant (<0.001), the F-value is 23.74, and the lack-of-fit term is not significant, indicating that the model can effectively describe the extraction process. The coefficient of determination R in this experiment is... 2 =0.9596, Corrected coefficient of determination R 2 adj =0.9192, indicating a good model fit and that the predicted value is close to the actual value. Predicted R... 2 =0.8304, and R 2 and R 2 adj The small difference indicates a high correlation between the predicted and actual values, demonstrating that the model is representative and accurately reflects the relationship between various factors and the response values. Therefore, this model can be used for the effective prediction and analysis of the total flavonoid extraction rate from Rosa rugosa fruit.

[0087] Furthermore, the reliability of the optimized model parameters was verified. The optimal extraction conditions for total flavonoids from Rosa rugosa fruit were: extraction time 108 min, DES water content 33.78%, solid-liquid ratio 1 g:54.162 mL, and extraction temperature 49℃. Under these conditions, the predicted extraction rate was 100.4326 mg / g. A verification experiment was conducted under these optimized conditions, and the actual extraction rate of total flavonoids from Rosa rugosa fruit was measured to be 101.61 ± 1.24 mg / g, which was basically consistent with the predicted value. The relative deviation was 1.18%, which was within a reasonable range, thus successfully determining the optimal extraction parameters.

[0088] While keeping other extraction conditions the same, a comparative extraction experiment was conducted by replacing the extraction solvent with 70% ethanol (Comparative Example 1). The extraction rate using ultrasound-assisted eutectic solvent extraction was 39.43% higher than that using ultrasound-assisted ethanol extraction, fully demonstrating the superiority of the optimized extraction scheme of this invention. The Box / Behnken response surface methodology was used to optimize the process parameters for ultrasound-assisted eutectic solvent extraction of total flavonoids from Rosa rugosa, which is accurate and reliable, and has good practical application value.

Claims

1. A method for ultrasound-assisted extraction of total flavonoids from Rosa rugosa fruit using an eutectic solvent, comprising the following steps: (1) Take freeze-dried rose hips, select, remove seeds, crush and sieve to obtain rose hip powder; (2) Heat and mix the hydrogen bond acceptor and hydrogen bond donor, stir until transparent, add water to reduce viscosity and obtain a eutectic solvent; (3) Mix the rosehip powder with a eutectic solvent and perform ultrasonic extraction. Then centrifuge and collect the supernatant to obtain the total flavonoid extract of rosehip, thus completing the extraction of total flavonoids from rosehip.

2. The method for ultrasonic-assisted extraction of total flavonoids from Rosa rugosa fruit using an eutectic solvent as described in claim 1, characterized in that: In step (1), the rosehip powder is obtained after passing through a 30-50 mesh sieve.

3. The method for ultrasonic-assisted extraction of total flavonoids from Rosa rugosa fruit using an eutectic solvent as described in claim 1, characterized in that: In step (2), the hydrogen bond acceptor is one or more of choline chloride, betaine and choline bitartrate; the hydrogen bond donor is one or more of proline, citric acid, malic acid, propionic acid, acetic acid, urea, 1,4-butanediol, glycerol, ethylene glycol, glucose, sucrose, fructose and xylitol.

4. The method for ultrasonic-assisted extraction of total flavonoids from Rosa rugosa fruit using an eutectic solvent as described in claim 1, characterized in that: In step (2), the molar ratio of hydrogen bond acceptor to hydrogen bond donor is 1:1~3.

5. The method for ultrasonic-assisted extraction of total flavonoids from Rosa rugosa fruit using an eutectic solvent as described in claim 1, characterized in that: In step (2), the water content of the eutectic solvent after adding water to reduce viscosity is 10~60 wt%.

6. The method for ultrasonic-assisted extraction of total flavonoids from Rosa rugosa fruit using an eutectic solvent as described in claim 1, characterized in that: In step (3), the solid-liquid ratio of rosehip powder to eutectic solvent is 1 g: 10~100 mL.

7. The method for ultrasonic-assisted extraction of total flavonoids from Rosa rugosa fruit using an eutectic solvent as described in claim 1, characterized in that: In step (3), the ultrasonic extraction time is 10~200 minutes and the ultrasonic extraction temperature is 10~80 ℃.

8. The method for ultrasonic-assisted extraction of total flavonoids from Rosa rugosa fruit using an eutectic solvent as described in claim 1, characterized in that: In step (3), the centrifugation speed is 5000~10000 r / min and the centrifugation time is 10~30 min.

Images