Water bath extraction process optimization method for arbutin in pear leaves based on BBD response surface method

Abstract

The invention relates to the technical field of plant extraction, in particular to a BBD response surface method-based water bath extraction process optimization method for arbutin in pear leaves. The method comprises the following steps: S1, placing treated pear leaves in an electrothermal blowing drying box, drying to constant weight, crushing with a crusher, and sieving to obtain sample powder; s2, putting the sample powder prepared in the step S1 into a conical flask with a plug, adding a certain volume of an extracting agent, covering the conical flask with the plug, centrifuging after extraction is finished, taking a certain volume of supernate, determining the content of arbutin in the extracting agent by adopting ultraviolet-visible spectrophotometry, and calculating the yield. According to the method for optimizing the water bath extraction process of arbutin in pear leaves based on the BBD response surface method, the pear leaves are used as raw materials, the water bath method is adopted, on the basis of a single-factor test, the extraction time, the ethanol volume fraction, the water bath temperature and the liquid-material ratio are used as factors, and the four-factor three-level BBD response surface method is used for optimizing the extraction process conditions of arbutin.

Description

Technical Field

[0001] This invention relates to the field of plant extraction technology, and in particular to an optimized method for water bath extraction of arbutin from pear leaves based on BBD response surface methodology. Background Technology

[0002] Pear, a perennial deciduous fruit tree belonging to the genus *Pyrus* of the Rosaceae family, is abundant in North my country, Northeast China, Northwest China, and the Yangtze River basin. Pear leaves are rich in nutrients and medicinal components, such as catechins, arbutin, flavonols, hydroxycinnamic acid, and flavonoids. These components possess physiological activities including antioxidant, antiviral, immune-boosting, health-maintaining, and cardiovascular disease-preventing properties. Arbutin, in particular, exhibits significant skin-whitening and blemish-removing activity, along with various other pharmacological activities such as antitussive and antiasthmatic effects, antioxidant, antibacterial, astringent, and immune-enhancing properties. It is widely used in skin whitening, skin disease treatment, and health products, and is currently a major raw material commonly used in whitening cosmetics both domestically and internationally.

[0003] my country has abundant pear resources, but their comprehensive utilization is low, currently limited to fruit sales and deep processing. After the annual fruit harvest, the pear leaves that continue to grow are often left to wither and rot in the fields, resulting in resource waste. Therefore, this invention uses pear leaves as raw material and arbutin as the extraction target. It studies the absorption of arbutin in different solvents and compares two extraction methods: water bath extraction and ultrasound-assisted extraction. To improve the yield of arbutin from pear leaves, the water bath method was adopted. Based on single-factor experiments, extraction time, ethanol volume fraction, water bath temperature, and liquid-to-solid ratio were used as factors. A four-factor, three-level Box-Behnken Design (RBD) response surface methodology (RSM) was used to optimize the extraction process conditions of arbutin. A method for water bath extraction and UV-Vis spectrophotometric determination of arbutin content was established. This aims to provide a reference for the comprehensive development and utilization of pear leaves, while also helping to reduce ecological and environmental pressures and promote harmonious social development. Summary of the Invention

[0004] Therefore, it is necessary to provide an optimization method for the water bath extraction of arbutin from pear leaves based on the BBD response surface methodology to address the aforementioned technical problems.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The optimization method for water bath extraction of arbutin from pear leaves based on BBD response surface methodology is as follows: S1: After washing the freshly picked pear leaves, let them air dry in a cool place, place them in an electric heating drying oven, dry them to constant weight, pulverize them with a pulverizer and sieve them to obtain sample powder; S2: Take the sample powder prepared in step S1, place it in a stoppered conical flask, add a certain volume of extractant, stopper the flask, centrifuge after extraction, take a certain volume of supernatant, and determine the content of arbutin in the extractant by ultraviolet-visible spectrophotometry, and calculate the yield.

[0006] As a preferred embodiment of the optimized water bath extraction process of arbutin from pear leaves based on BBD response surface methodology provided by the present invention, in step S1, the freshly picked pear leaves are washed with tap water and deionized water, air-dried in a cool place, placed in an electric heating drying oven, and dried to constant weight at a temperature of 45°C. The leaves are then pulverized with a pulverizer, passed through a 60-mesh sieve, and sealed for storage.

[0007] In a preferred embodiment of the optimized water bath extraction process of arbutin from pear leaves based on BBD response surface methodology provided by the present invention, in step S2, the extractant is an aqueous ethanol solution.

[0008] As a preferred embodiment of the optimized water bath extraction process of arbutin from pear leaves based on BBD response surface methodology provided by the present invention, in step S2, the extraction is performed using a water bath method.

[0009] As a preferred embodiment of the optimized water bath extraction process of arbutin from pear leaves based on BBD response surface methodology provided by the present invention, the extraction conditions of the water bath method are as follows: extraction time 157 min, ethanol volume fraction 62%, water bath temperature 84℃, and liquid-to-solid ratio 73:1 mL / g.

[0010] As a preferred embodiment of the optimized water bath extraction process of arbutin from pear leaves based on BBD response surface methodology provided by the present invention, the extraction steps of the water bath method are as follows: Weigh 0.5g of pear leaf powder into three stoppered conical flasks, add 25mL of 60% ethanol, incubate in a water bath for 60min, cool naturally to room temperature, centrifuge, transfer the supernatant to a 100mL volumetric flask and dilute to volume, using deionized water as a reference for scanning in the wavelength range of 200nm-800nm.

[0011] As a preferred embodiment of the optimized water bath extraction process of arbutin from pear leaves based on the BBD response surface methodology provided by the present invention, the detection wavelength of the ultraviolet-visible spectrophotometer is 285 nm.

[0012] As a preferred embodiment of the optimized water bath extraction process of arbutin from pear leaves based on BBD response surface methodology provided by the present invention, the calculation expression for the arbutin yield is as follows: Arbutin yield / % = (arbutin mass / g) / (sample powder mass / g) × 100%.

[0013] An arbutin extracted according to the method described above.

[0014] It is clear without a doubt that the technical solution described above in this application can solve the technical problem that this application aims to address.

[0015] Meanwhile, through the above technical solutions, the present invention has at least the following beneficial effects: The present invention provides an optimization method for the water bath extraction of arbutin from pear leaves based on BBD response surface methodology. Based on single-factor experiments, the extraction process of arbutin from pear leaves was optimized using BBD response surface methodology.

[0016] This invention uses pear leaves as raw material and employs a water bath method. Based on single-factor experiments, the extraction process conditions of arbutin were optimized using a four-factor, three-level BBD response surface methodology, with extraction time, ethanol volume fraction, water bath temperature, and liquid-to-solid ratio as factors. The results showed that the maximum yield of arbutin in pear leaves was achieved at an extraction time of 157 min, an ethanol volume fraction of 62%, a water bath temperature of 84℃, and a liquid-to-solid ratio of 73:1 mL / g, which was 15.72 ± 0.12 mg / g. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the absorption curves of arbutin of the present invention in different extractants; Figure 2 This is a schematic diagram of the absorption curves of the ultrasonic method and the water bath method of the present invention; Figure 3 This is a schematic diagram of the arbutin standard curve of the present invention; Figure 4 This is a schematic diagram illustrating the effect of extraction time on arbutin yield according to the present invention; Figure 5 This is a schematic diagram illustrating the effect of ethanol volume fraction on arbutin yield according to the present invention. Figure 6This is a schematic diagram illustrating the effect of water bath temperature on arbutin yield according to the present invention. Figure 7 This is a schematic diagram illustrating the effect of the liquid-to-solid ratio on the yield of arbutin according to the present invention; Figure 8 This is a response surface plot showing the effect of the extraction conditions of this invention on the yield of arbutin. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0021] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] Reference Figures 1-8 An optimization method for water bath extraction of arbutin from pear leaves based on BBD response surface methodology.

[0024] 1. Materials and Methods 1.1 Materials and Instruments The pear leaves were harvested from the pear orchard in Nanwu Village, Mazhuang Street, Qindu District, Xianyang City, Shaanxi Province; anhydrous ethanol (analytical grade) was from Tianjin Tianli Chemical Reagent Co., Ltd.; sulfuric acid was from Taicang Hu Reagent Co., Ltd.; hydrochloric acid was from Kunshan Jincheng Reagent Co., Ltd.; and arbutin standard was from Shanghai Yuanye Biotechnology Co., Ltd.

[0025] The UV-Vis spectrophotometer (UV-1800PC-DS2) is from Shanghai Meipuda Instrument Co., Ltd.; the analytical balance (FA2004) is from Shanghai Liangping Instrument Co., Ltd.; the electric heating drying oven (DHG-9030A) is from Shanghai Yiheng Scientific Instrument Co., Ltd.; the electric hot water bath (HH-S4) is from Beijing Kewei Yongxing Instrument Co., Ltd.; the centrifuge (TD4Z-WS) is from Zhangjiagang Xinhua Chemical Machinery Co., Ltd.; the ultrasonic cleaner (KH2200DB) is from Kunshan Hechuang Ultrasonic Instrument Co., Ltd.; the pulverizer (LDP-200) is from Hebi Hengke Instrument Co., Ltd.; and the 60-mesh standard sieve is from Shaoxing Shangyu Haoquan Sieve Factory.

[0026] 1.2 Experimental Methods 1.2.1 Sample Preparation Wash the freshly picked pear leaves with tap water and deionized water, let them air dry in a cool place, place them in an electric hot air drying oven, set the temperature to 45℃, dry them to constant weight, crush them with a pulverizer, pass them through a 60-mesh sieve, and store them in a sealed container for later use.

[0027] 1.2.2 Arbutin Extraction Method Take 0.5 g of the sample powder prepared in step 1.2.1, place it in a stoppered conical flask, add a certain volume of extraction reagent, stopper the flask, and extract under the optimized extraction conditions. After extraction, centrifuge, take a certain volume of supernatant, and determine the arbutin content in the extraction reagent using ultraviolet-visible spectrophotometry. Calculate the yield using the following expression: Arbutin yield / % = (arbutin mass / g) / (sample powder mass / g) × 100%; 1.2.3 Experimental Design for the Selection of Detection Wavelength for Arbutin 1.2.3.1 Solution Preparation Accurately weigh approximately 0.25 g of arbutin standard into a 100 mL beaker using an analytical balance. Dissolve the standard in deionized water, 60% ethanol, 60% ethanol + 0.1% H₂SO₄, and 60% ethanol + 0.1% HCl, respectively. Transfer the solutions to 250 mL amber volumetric flasks, dilute to volume, and mix well. Accurately transfer 3.00 mL of this solution into a 100 mL volumetric flask, and dilute to volume with deionized water, 60% ethanol, 60% ethanol + 0.1% H₂SO₄, and 60% ethanol + 0.1% HCl, respectively. Mix well and prepare three parallel aliquots.

[0028] 1.2.3.2 Absorption curve scanning The prepared solution from step 1.2.3.1 was subjected to spectral scanning with reference solutions of deionized water, 60% ethanol, 60% ethanol + 0.1% H2SO4, and 60% ethanol + 0.1% HCl, respectively, in the wavelength range of 200 nm - 800 nm.

[0029] 1.2.4 Selection of Extraction Method 1.2.4.1 Water bath method Weigh 0.5g of pear leaf powder into three stoppered conical flasks, add 25 mL of 60% ethanol, incubate in a water bath for 60 min, cool naturally to room temperature, centrifuge, transfer the supernatant to a 100 mL volumetric flask and dilute to volume. Use deionized water as a reference for scanning, with a wavelength range of 200 nm - 800 nm.

[0030] 1.2.4.2 Ultrasonic-assisted extraction method Weigh 0.5 g of pear leaf powder into three stoppered conical flasks, add 25 mL of 60% ethanol, sonicate at 70% power for 40 min, centrifuge, transfer the supernatant to a 100 mL volumetric flask and make up to volume, using deionized water as a reference for scanning, with a wavelength range of 200 nm - 800 nm.

[0031] 1.2.5 Plotting the Standard Curve Accurately weigh approximately 0.35 g of arbutin standard, dissolve it in 60% ethanol, and dilute to a 500 mL volumetric flask to obtain a 0.7 mg / mL arbutin standard solution. Transfer 0 mL, 1 mL, 2 mL, 4 mL, 6 mL, 8 mL, and 10 mL of the above standard solution to 100 mL volumetric flasks, respectively, and dilute to a final volume of 100 mL with 60% ethanol. Measure the absorbance of the arbutin series standard solutions at 285 nm. Plot a standard curve with mass concentration as the X-axis and absorbance as the Y-axis.

[0032] 1.2.6 Experimental Design for Water Bath Extraction 1.2.6.1 Single-factor experimental design Based on the arbutin extraction method in step 1.2.2, the effects of extraction time, ethanol volume fraction, water bath temperature, and liquid-to-solid ratio on the arbutin yield were investigated.

[0033] (1) Water bath temperature The water bath temperature was set at 60℃, the ethanol volume fraction was 70%, the liquid-to-solid ratio was 50:1 mL / g, and the extraction times were 30 min, 60 min, 90 min, 120 min, 150 min, and 180 min, respectively. Under these conditions, the effect of different extraction times on the yield of arbutin was investigated.

[0034] (2) Volume fraction of ethanol The water bath temperature was set at 60℃, the liquid-to-solid ratio at 50:1 mL / g, the extraction time at 150 min, and the ethanol volume fractions at 0%, 20%, 40%, 60%, 80%, and 100%, respectively. Under these conditions, the effect of ethanol volume fraction on the yield of arbutin was investigated.

[0035] (3) Liquid-to-material ratio The ethanol volume fraction was 60%, the liquid-to-solid ratio was 50:1 mL / g, the extraction time was 150 min, and the water bath temperatures were room temperature (22℃), 40℃, 60℃, 80℃, and boiling water temperature (96℃). Under these conditions, the effect of different water bath temperatures on the yield of arbutin was investigated.

[0036] (4) Extraction time The water bath temperature was set at 80℃, the ethanol volume fraction was 60%, the extraction time was 150 min, and the liquid-to-solid ratios were 10:1 mL / g, 25:1 mL / g, 50:1 mL / g, 75:1 mL / g, 100:1 mL / g, and 250:1 mL / g. Under these conditions, the effect of different liquid-to-solid ratios on the yield of arbutin was investigated.

[0037] 1.2.6.2 Response Surface Method Experimental Design Based on the results of the single-factor experiments, and in accordance with the Box-Behnken central composite design (BBD) experimental principle, four factors were selected: extraction time (A), ethanol volume fraction (B), water bath temperature (C), and liquid-to-solid ratio (D). For each factor, three levels (high, medium, and low) were selected. The four-factor, three-level response surface methodology was used to design the experiment. The experimental factors and levels are shown in Table 1.

[0038] Table 1: Response Surface Factor Level Table

[0039] 2. Results and Analysis 2.1 Selection of arbutin detection wavelength like Figure 1 As shown, arbutin aqueous solution exhibits maximum absorption at 221 nm and 282 nm. In 60% ethanol or 60% ethanol + 0.1% HCl solution, both maximum absorption peaks of arbutin exhibit a red shift to 223 nm and 285 nm, respectively. In 60% ethanol + 0.1% H2SO4, the maximum absorption peak at 285 nm further red-shifts to 286 nm. Since the area around 220 nm is close to the nearest absorption limit of the solvent and is significantly affected by noise, this study selected a certain volume fraction of ethanol as the extraction solvent and 285 nm as the detection wavelength.

[0040] Figure 1 In the formula, 1 represents H2O; 2 represents 60% ethanol; 3 represents 60% ethanol + 0.1% H2SO4; and 4 represents 60% ethanol + 0.1% HCl.

[0041] 2.2 Selection of Extraction Method like Figure 2 As shown, the absorption curve of the water bath method has maximum absorption at 285 nm and 323 nm. Although the ultrasonic method utilizes the cavitation and mechanical effects generated by ultrasound to cause the tissue cells to rupture instantly and release many intracellular components rapidly, its maximum absorption wavelengths are 323 nm, 417 nm, and 672 nm, and it does not have maximum absorption near 285 nm. Therefore, this study chose the water bath method to extract arbutin from pear leaves.

[0042] Figure 2In the above, 1 is the water bath method; 2 is the ultrasound-assisted method.

[0043] 2.3 Plotting the Standard Curve A linear regression was performed on absorbance (A) against arbutin concentration (c, μg / mL), yielding the regression equation for arbutin: Y = 0.0105X - 0.0018, r = 0.9999. The standard curve is shown below. Figure 3 As shown, the mass concentration of arbutin exhibits a good linear relationship in the range of 5 μg / mL to 65 μg / mL.

[0044] 2.4 Single-factor experiment 2.4.1 Effect of extraction time on arbutin yield The effect of extraction time on arbutin yield is as follows: Figure 4 As shown in the figure, the yield of arbutin did not change significantly when the extraction time was between 30 and 90 minutes, indicating incomplete extraction and a low yield. With prolonged extraction time, cell swelling increased, and the arbutin yield gradually increased, reaching its maximum at 150 minutes, after which it decreased. The results indicate that the optimal extraction time is 150 minutes.

[0045] 2.4.2 Effect of ethanol volume fraction on arbutin yield The water content in the extractant has a significant impact on the extraction of arbutin from pear leaves, and the effect of ethanol volume fraction on the arbutin yield is as follows: Figure 5 As shown, with increasing ethanol volume fraction, the swelling degree of plant cells increases, which facilitates the extraction of arbutin from cell vacuoles by the extractant penetrating the cell wall, resulting in an increasing arbutin yield. The yield reaches its maximum when the ethanol volume fraction reaches 60%. Afterward, the yield decreases with further increases in ethanol volume fraction. This is mainly because, firstly, excessively high ethanol volume fraction leads to protein denaturation, forming a protective film that hinders arbutin mass transfer; secondly, high ethanol concentrations promote the dissolution of other alcohol-soluble and lipid-soluble substances, which compete with arbutin for distribution in the extractant. The results indicate that a suitable ethanol volume fraction is 60%.

[0046] 2.4.3 Effect of water bath temperature on arbutin yield The effect of water bath temperature on arbutin yield is as follows: Figure 6 As shown, initially, the yield of arbutin increased with increasing water bath temperature, reaching its maximum at 80℃. Afterward, the yield began to decrease with further increases in water bath temperature. The results indicate that the optimal water bath temperature is 80℃.

[0047] 2.4.4 Effect of liquid-to-solid ratio on arbutin yield The effect of different liquid-to-solid ratios on arbutin yield is as follows: Figure 7 As shown in the figure, with the increase of the liquid-to-solid ratio, more arbutin bonds with proteins or polysaccharides break, leading to dissolution and a gradual increase in arbutin yield. The yield reaches its maximum when the liquid-to-solid ratio is 75:1 mL / g. Afterward, with further increases in the liquid-to-solid ratio, the arbutin yield no longer increases and shows a slight decreasing trend. The results indicate that the optimal liquid-to-solid ratio is 75:1 mL / g.

[0048] 2.5 Response Surface Optimization Experiment 2.5.1 BBD Test Results Based on the single-factor experiments, the Box-Behnken (BBD) response surface methodology was used to conduct experiments at a total of 29 experimental points. The yield of arbutin is shown in Table 2.

[0049] Table 2: BBD Experimental Design and Results

[0050] 2.5.2 Establishment of the regression model equation and significance test Using Design-expert 7.0.0 statistical software, regression fitting was performed on the experimental data in Table 2 to obtain a multiple quadratic regression equation model: Y=15.54+0.53A+0.38B+0.37C–0.34D+0.15AB+1.49AC–0.17AD +0.71BC +0.13BD–0.19CD–1.73A 2 –1.61B 2 -1.25C 2 –2.08D 2 R 2 =0.9602; The model was subjected to a significance test analysis, and the results are shown in Table 3.

[0051] Table 3: Results of ANOVA for the Quadratic Regression Model

[0052] Note: A p-value less than 0.05 indicates that the factor has a significant impact on the response value.

[0053] As shown in Table 3, the p-value of the model is less than 0.0001, and the F-value of the lack-of-fit term is 4.53 (p = 0.0794), indicating that the quadratic polynomial model equation used in the experiment is highly significant; the lack-of-fit term is not significant relative to the absolute error; the correlation coefficient R0 2The value was 0.9602. Therefore, the model fits the experiment well and can reflect the true relationship between each factor and the response value. This model can be used to analyze and predict the yield changes of arbutin under different extraction conditions. The first-order terms of the model have a significant effect on the yield of arbutin (p < 0.05); the interaction between extraction time and water bath temperature, and between ethanol volume fraction and water bath temperature are significant (p < 0.05), while the interaction between extraction time and ethanol volume fraction, extraction time and liquid-to-solid ratio, ethanol volume fraction and liquid-to-solid ratio, and water bath temperature and liquid-to-solid ratio are not significant (p > 0.05); the second-order terms are all significant (p < 0.05), indicating that the effects of each factor on the yield of arbutin are not simple linear relationships.

[0054] 2.5.3 Response Surface Analysis and Optimization Response surface graphs can be plotted based on the regression equation model to examine the shape of the fitted response surface and analyze the effects of extraction time, ethanol volume fraction, water bath temperature, and liquid-to-solid ratio on arbutin yield. The response surface graphs visually reflect the influence of each factor and its interactions on the response value.

[0055] Figure 8 (a) is a response surface plot of the effects of extraction time and ethanol volume fraction on arbutin yield. It can be seen that the surface plot increases with increasing extraction time and ethanol volume fraction. When the extraction time is 150 min and the ethanol volume fraction is 60%, the yield begins to decrease. The optimal range can be determined from the figure: extraction time 140 min–160 min, ethanol volume fraction 55%–65%.

[0056] Figure 8 (b)–(f) show the response surface plots of the effects of the interaction between extraction time and water bath temperature, extraction time and liquid-to-solid ratio, ethanol volume fraction and water bath temperature, ethanol volume fraction and liquid-to-solid ratio, and water bath temperature and liquid-to-solid ratio on the yield of arbutin, respectively. As the corresponding two factors increase, the yield of arbutin shows a trend of first increasing and then decreasing. The response surface opens downwards, and there is an extreme value within the selected range, which is the highest point of the response surface and also the center point of the minimum ellipse of the contour lines. From the figures, the optimal range can be determined as follows: extraction time 140 min–160 min, ethanol volume fraction 55%–65%, water bath temperature ℃–85℃, and liquid-to-solid ratio 67.5∶1 mL / g–82.5∶1 mL / g.

[0057] Software analysis revealed the optimal extraction conditions for arbutin from pear leaves using the water bath method as follows: extraction time 157.09 min, ethanol volume fraction 62.24%, water bath temperature 84.31℃, and liquid-to-solid ratio 73.35:1 mL / g. Under these optimal conditions, the predicted arbutin yield was 15.77 mg / g. Considering practical operating conditions, the extraction parameters were modified to: extraction time 157 min, ethanol volume fraction 62%, water bath temperature 84℃, and liquid-to-solid ratio 73:1 mL / g. Three parallel experiments yielded an arbutin yield of 15.72 ± 0.12 mg / g, representing increases of 3.97% and 25.76% compared to previously reported yields (15.12 mg / g and 12.5 mg / g), respectively.

[0058] 3. Conclusion Based on single-factor experiments, this invention optimized the extraction process of arbutin from pear leaves using BBD response surface methodology. The main focus was on the effects of extraction time, ethanol volume fraction, water bath temperature, and liquid-to-solid ratio on the arbutin yield. Under the determined process conditions, the single-pass yield of arbutin was 15.72 ± 0.12 mg / g. This method provides a thorough and high-yield extraction of arbutin from pear leaves, and is simple and environmentally friendly, offering valuable reference for the comprehensive development and utilization of pear leaves.

[0059] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An optimization method for water bath extraction of arbutin from pear leaves based on BBD response surface methodology, characterized in that, The steps are as follows: S1: After washing the freshly picked pear leaves, let them air dry in a cool place, place them in an electric heating drying oven, dry them to constant weight, pulverize them with a pulverizer and sieve them to obtain sample powder; S2: Take the sample powder prepared in step S1, place it in a stoppered conical flask, add a certain volume of extractant, stopper the flask, centrifuge after extraction, take a certain volume of supernatant, and determine the content of arbutin in the extractant by ultraviolet-visible spectrophotometry, and calculate the yield.

2. The method for optimizing the water bath extraction process of arbutin from pear leaves based on BBD response surface methodology according to claim 1, characterized in that, In step S1, the freshly picked pear leaves are washed with tap water and deionized water, air-dried in a cool place, placed in an electric heating drying oven, set at 45℃, dried to constant weight, pulverized with a pulverizer, passed through a 60-mesh sieve, and sealed for storage.

3. The method for optimizing the water bath extraction process of arbutin from pear leaves based on BBD response surface methodology according to claim 1, characterized in that, In step S2, the extractant is an aqueous ethanol solution.

4. The method for optimizing the water bath extraction process of arbutin from pear leaves based on BBD response surface methodology according to claim 1, characterized in that, In step S2, extraction is performed using a water bath method.

5. The method for optimizing the water bath extraction process of arbutin from pear leaves based on BBD response surface methodology according to claim 4, characterized in that, The extraction conditions for the water bath method are as follows: extraction time 157 min, ethanol volume fraction 62%, water bath temperature 84℃, and liquid-to-solid ratio 73:1 mL / g.

6. The method for optimizing the water bath extraction process of arbutin from pear leaves based on BBD response surface methodology according to claim 4, characterized in that, The extraction steps of the water bath method are as follows: Weigh 0.5g of pear leaf powder into three stoppered conical flasks, add 25mL of 60% ethanol, incubate in a water bath for 60min, cool naturally to room temperature, centrifuge, transfer the supernatant to a 100mL volumetric flask and dilute to volume, using deionized water as a reference for scanning in the wavelength range of 200nm-800nm.

7. The method for optimizing the water bath extraction process of arbutin from pear leaves based on BBD response surface methodology according to claim 1, characterized in that, The detection wavelength of the ultraviolet-visible spectrophotometer is 285 nm.

8. The method for optimizing the water bath extraction process of arbutin from pear leaves based on BBD response surface methodology according to claim 1, characterized in that, The formula for calculating the yield of arbutin is as follows: Arbutin yield / % = (arbutin mass / g) / (sample powder mass / g) × 100%.

9. Arbutin extracted by any one of claims 1-8.

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