A method for extracting folin from isodon japonicus

Abstract

The application discloses a method for extracting leaf pectin of Rhus copallinum Linn. The method comprises the following steps: pretreating raw materials, extracting pectin, separating the acid extraction liquid, concentrating the acid extraction liquid, precipitating pectin and drying the pectin. The pectin obtained by the method has a galacturonic acid content, a drying loss and an acid insoluble ash content all meeting the requirements of GB25533-2010, and the pectin is white and does not need to be subjected to a bleaching process. The method has the advantages of high extraction rate, safety and easy operation, and can effectively improve the utilization rate of Rhus copallinum Linn. and the extracted pectin has good commercial value.

Description

Technical Field

[0001] This invention belongs to the field of pectin extraction technology, and mainly relates to a method for extracting pectin from the leaves of *Bambusa textilis*. Background Technology

[0002] Pectin is a large-molecule polysaccharide containing anions that exists in the cell walls of plants. It has the effects of inhibiting the growth of colon cancer cells, lowering cholesterol levels, anti-oxidation, and regulating immunity. It also has good gelling and emulsifying properties and is used as a thickener and emulsifier in a variety of foods.

[0003] Premna puberula Pamp. is a plant used for both medicinal and edible purposes. It is rich in pectin, protein, vitamins, and minerals, and has effects such as clearing heat and detoxifying, reducing swelling, and stopping bleeding. my country is a major consumer of pectin, and its consumption is increasing year by year. Obtaining pectin solely from apple pomace and citrus peels is no longer sufficient to meet the demand. Premna puberula, with a pectin content of 20-30%, can be used as a raw material for pectin extraction.

[0004] There are various methods for extracting pectin, with efficiency, economy, safety, and environmental friendliness being the core considerations for edible pectin extraction. Enzymatic extraction of pectin can meet the requirements of high efficiency, safety, and environmental friendliness, but it is costly.

[0005] Based on this, the present invention provides a method for extracting pectin from the leaves of *Bambusa textilis* based on food-grade organic acids. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a method for extracting pectin from the leaves of *Bambusa textilis* based on food-grade organic acids, thereby solving the problem of high cost in existing pectin extraction processes.

[0007] The technical solution of this invention is: a method for extracting pectin from the leaves of *Bauhinia purpurea*, comprising the following steps:

[0008] Step 1: Preparation of dried powder from leaves of *Clerodendrum trichotomum*: Select mature and healthy leaves of *Clerodendrum trichotomum*, wash and drain them, blanch them at high temperature, dry them, pulverize them in a pulverizer and then sieve them to obtain dried powder;

[0009] Step 2, Pectin Extraction: Weigh the dried powder of *Bungarus odoratus* leaves, add edible acid solution, and extract the pectin in a constant temperature water bath to obtain an acid extract of pectin.

[0010] Step 3: Separation of acid extract: Cool the acid extract to room temperature, separate and filter the acid extract, and collect the clear filtrate;

[0011] Step 4: Filtrate Concentration: Concentrate the filtrate using a rotary evaporator;

[0012] Step 5, pectin separation: Add twice the volume of ethanol to the concentrate, stir thoroughly to precipitate the pectin, seal, let stand at room temperature, centrifuge to remove the filtrate, and collect the pectin.

[0013] Step 6: Pectin drying: Dry the pectin, grind it, sieve it, and collect the fine pectin powder.

[0014] The fixation temperature in step one is 100-110℃, the fixation time is 10-15 min, the drying temperature is 60-70℃, the drying time is 6-8 h, and the sieve mesh size is 60-80 mesh.

[0015] The edible acid mentioned in step two is a food-grade tartaric acid solution. The tartaric acid powder is dissolved in distilled water, and the pH is adjusted to 1.55-1.75. The solid-liquid ratio (g / mL) of the dried powder of *Clerodendrum trichotomum* leaves to the acid solution is 1:40-1:60. The water bath temperature is 80-100℃, and the extraction time is 60-80 min.

[0016] In step three, the centrifuge speed is 8000 rpm and the centrifugation time is 2-4 min.

[0017] In step four, the filtrate is concentrated to 1 / 2 to 1 / 3 of its volume using a rotary evaporator.

[0018] The ethanol mentioned in step five is 95% food-grade ethanol. Let it stand at room temperature for 1 to 1.5 hours, centrifuge at 8000 rpm for 1 to 2 minutes, remove the filtrate by centrifugation, wash the pectin with 95% ethanol, centrifuge again to collect the pectin, until the filtrate is clear and the pectin is colorless.

[0019] The drying temperature in step six is ​​40-50℃, the drying time is 8-10 hours, and the sieve mesh size is 80-100 mesh.

[0020] The beneficial effects of the present invention are: (1) The present invention uses acid extraction and alcohol precipitation to extract plant pectin, which improves the extraction rate, ensures safety, and has a simple process, easy-to-control conditions, and strong practicality.

[0021] (2) The pectin extracted from the leaves of the bromhidrosis plant by the technology of this invention has good safety and high purity, and does not require pectin decolorization treatment, thus reducing the process cost. Attached Figure Description

[0022] Figure 1 The effect of different organic acids on the extraction rate of pectin from *Bambusa textilis* leaves;

[0023] Figure 2 The color differences of pectin extracted from *Clerodendrum trichotomum* leaves by different organic acids (A-D represent pectin obtained by extracting *Clerodendrum trichotomum* leaves with tartaric acid, citric acid, lactic acid, and acetic acid, respectively).

[0024] Figure 3 The effect of the material-to-liquid ratio on the extraction rate of pectin from the leaves of *Bambusa textilis*.

[0025] Figure 4The effect of temperature on the extraction rate of pectin from the leaves of *Bambusa textilis* (a type of shrub).

[0026] Figure 5 The effect of pH value on the extraction rate of pectin from the leaves of *Bambusa textilis*.

[0027] Figure 6 The effect of extraction time on the extraction rate of pectin from *Bambusa textilis* leaves;

[0028] Figure 7 The response surface to the effects of two different factors on the pectin yield of *Bambusa textilis* leaves. Detailed Implementation

[0029] The present invention will be described in detail below with reference to the embodiments, but it should not be construed as limiting the present invention.

[0030] Example:

[0031] A method for extracting pectin from the leaves of *Bauhinia purpurea* (a type of shrub), comprising the following steps:

[0032] (1) Preparation of dry powder from leaves of *Bombyx mori*: Select mature and healthy leaves of *Bombyx mori*, wash and drain them with tap water, place them in an electric heating drying oven at 105℃ for 10 min to fix the greening, and dry them at 60℃ for 8 h to dry them. After being pulverized by a pulverizer, the dry powder is obtained by passing it through a 60-mesh sieve.

[0033] (2) Pectin extraction: Weigh 5g of dried powder of *Bambusa textilis* leaves and put it into an Erlenmeyer flask. Add food-grade tartaric acid solution (dissolve tartaric acid powder in distilled water and adjust pH to 1.65). The ratio of dried powder of *Bambusa textilis* leaves to acid solution is 1:50 (g / mL). Place the flask in a 95℃ constant temperature water bath to extract the pectin for 70 minutes to obtain the acid extract of pectin.

[0034] (3) Separation of acid extract: Cool the pectin extract of the leaves of the bromhidrosis plant to room temperature, centrifuge the acid extract at 8000 rpm for 3 min in a centrifuge, filter it with a Buchner funnel, and collect the clear filtrate.

[0035] (4) Filtrate concentration: Concentrate the filtrate to 1 / 3 of its volume using a RE-2000A rotary evaporator;

[0036] (5) Pectin separation: Add twice the volume of 95% food-grade ethanol to the concentrate, stir thoroughly with a glass cup to precipitate the pectin, seal with plastic wrap, let stand at room temperature for 1 hour, centrifuge at 8000 rpm for 1 minute, remove the filtrate, and then wash the pectin with a small amount of 95% ethanol. When washing, use a glass rod to break up the pectin and mix it with the ethanol. Centrifuge again to collect the pectin. Repeat this process 3 times until the filtrate is clear and the pectin is colorless.

[0037] (6) Pectin drying: Place the pectin in an electric heating drying oven at 45°C for 8 hours to dry, grind it in a mortar and pestle, sieve it through a 100-mesh sieve, and collect the fine pectin powder.

[0038] Pectin extraction rate is calculated using the following formula:

[0039]

[0040] In the formula: ρ is the pectin extraction rate, m is the pectin mass (g), and m0 is the mass of dried leaf powder (g).

[0041] Determination of pectin physicochemical properties:

[0042] Loss on drying: determined according to the direct drying method in GB 5009.3-2016;

[0043] Determination of acid-insoluble ash: Performed according to Appendix A.3 of GB 25533-2010;

[0044] Determination of total galacturonic acid content: determined according to Appendix A.4 of GB 25533-2010;

[0045] The physicochemical properties of the pectin prepared according to the above method in the embodiments of the present invention are shown in the table below.

[0046]

[0047] Single-factor experiment on pectin extraction from *Bletilla striata* leaves: Screening of pectin extractants from *Bletilla striata* leaves: 5g of dried *Bletilla striata* leaf powder was weighed and extracted using citric acid, tartaric acid, lactic acid, and acetic acid as extractants at a material-to-liquid ratio of 1:40 (g / mL), pH 1.60, temperature 90℃, and time 80 min. The extract was filtered, and the filtrate was concentrated to 1 / 3 volume. The pectin was precipitated with 2 times the volume of 95% ethanol and placed in a 4℃ refrigerator for 1 hour. Then, it was centrifuged for 1 minute (8000 r / min), washed with a small amount of 95% ethanol until the filtrate was colorless, and dried at 45℃ to constant weight. Comparative experimental results showed that the pectin extraction rate using tartaric acid as the extractant was higher. Figure 1 The resulting pectin is white. Figure 2 Since no further decolorization is required and the appearance is more in line with commercial requirements, tartaric acid is a suitable extractant for the pectin of *Bambusa textilis* leaves.

[0048] I. Single-factor experiment on tartaric acid extraction of pectin

[0049] ① Effect of solid-liquid ratio on pectin extraction rate: Following the screening process for pectin extractants from *Clerodendrum trichotomum*, tartaric acid was used as the extractant. The extraction temperature was fixed at 95℃, the extraction time at 70 min, and the pH of the extractant was 1.65. Experiments were conducted with solid-liquid ratios of 1:20 (g / mL), 1:30 (g / mL), 1:40 (g / mL), 1:50 (g / mL), and 1:60 (g / mL), with each group repeated three times. The results showed that within the solid-liquid ratio range of 1:20 to 1:60 (g / mL), pectin extraction rate initially increased and then decreased, reaching its maximum at 1:50 (g / mL). Figure 3 When the material-to-liquid ratio is too high (insufficient extractant), the raw materials are not fully dissolved, resulting in a low pectin extraction rate. When the material-to-liquid ratio is too low (excessive extractant), the diffusion distance of pectin molecules is lengthened, the diffusion force decreases, the amount of precipitated pectin decreases, and the pectin yield is low.

[0050] ② Effect of extraction temperature on pectin extraction rate: Following the screening process for pectin extractant from *Clerodendrum trichotomum*, with a fixed material-to-liquid ratio of 1:40 (g / mL), an extraction time of 70 min, and an extractant pH of 1.65, experiments were conducted at temperatures of 80℃, 85℃, 90℃, 95℃, and 100℃, with each group repeated three times. The results showed that within the extraction temperature range of 80–100℃, pectin extraction rate first increased and then decreased, reaching its maximum at 95℃. Figure 4 As temperature increases, molecular motion intensifies, promoting the dissociation of tartaric acid, making pectin easier to dissolve and increasing the pectin extraction rate. When the temperature reaches 100℃, pectin undergoes thermal depolymerization, and the products of thermal depolymerization cannot be precipitated by ethanol, thus reducing the extraction rate.

[0051] ③ Effect of pH on pectin extraction rate: Following the screening process for pectin extractants from *Clerodendrum trichotomum*, tartaric acid was used as the extractant. The solid-liquid ratio was fixed at 1:40 (g / mL), the extraction temperature was 95℃, and the extraction time was 70 min. The pH values ​​of the extractant were selected as 1.55, 1.65, 1.75, 1.85, and 1.95 for the experiment, with each group repeated three times. The results showed that within the pH range of 1.55–1.95, pectin extraction rate first increased and then decreased, reaching its maximum at pH 1.65. Figure 5 Increased acidity promotes the hydrolysis of protopectin into water-soluble pectin, thus increasing the pectin extraction rate. However, when the acidity is too high, the hydrolysis reaction of pectin in the solution is intense, causing pectin molecules to depolymerize and resulting in a decrease in the extraction rate.

[0052] ④ Effect of extraction time on pectin extraction rate: With a fixed material-to-liquid ratio of 1:40 (g / mL), extraction temperature of 95℃, and extraction solvent pH of 1.65, experiments were conducted at extraction times of 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, and 110 min, with each group repeated three times. The results showed that within the extraction time range of 30–110 min, pectin extraction rate first increased and then decreased, reaching its maximum at 70 min. Figure 6 Due to the accumulation of heat, the hydrolysis of protopectin is accelerated, so the pectin extraction rate increases with the extension of extraction time. However, when the time is too long, the extraction rate decreases due to the destruction of molecular structure.

[0053] II. Response Surface Optimization Experiment

[0054] Based on the single-factor experiment, with the material-to-liquid ratio, extraction temperature, extraction time, and pH as independent variables and the pectin extraction rate as the response value, the Box-Behnken design was used (see the table below).

[0055]

[0056] The optimal extraction conditions for pectin from *Clerodendrum trichotomum* leaves were obtained using a response surface methodology: a solid-liquid ratio of 1:54.16 (g / mL), an extraction temperature of 96.29℃, an extraction time of 67.41 min, and an extraction solvent pH of 1.63 (g / mL). Figure 7 The theoretical pectin extraction rate was 27.14%. To facilitate operation, the process parameters were modified as follows: material-to-liquid ratio 1:50 (g / mL), extraction temperature 95℃, extraction time 70 min, and extractant pH 1.65. Under these conditions, three parallel experiments were conducted, and the actual average pectin extraction rate was 27.10%. The actual value is close to the theoretical value, indicating that the optimized process is feasible.

[0057] It should be noted that those skilled in the art can make various modifications and improvements without departing from the principles of this invention, and all such modifications and improvements fall within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the appended claims.

Claims

1. A method for extracting pectin from the leaves of *Bambusa textilis*, characterized in that: Includes the following steps: Step 1: Preparation of dried powder from leaves of *Clerodendrum trichotomum*: Select mature and healthy leaves of *Clerodendrum trichotomum*, wash and drain them, blanch them at high temperature, dry them, pulverize them in a pulverizer and then sieve them to obtain dried powder; Step 2, Pectin Extraction: Weigh the dried powder of *Bungarus odoratus* leaves, add edible acid solution, and extract the pectin in a constant temperature water bath to obtain an acid extract of pectin. Step 3: Separation of acid extract: Cool the acid extract to room temperature, separate and filter the acid extract, and collect the clear filtrate; Step 4: Filtrate Concentration: Concentrate the filtrate using a rotary evaporator; Step 5, pectin separation: Add twice the volume of ethanol to the concentrate, stir thoroughly to precipitate the pectin, seal, let stand at room temperature, centrifuge to remove the filtrate, and collect the pectin. Step Six: Pectin Drying: Dry the pectin, grind it, sieve it, and collect the fine pectin powder; the edible acid mentioned in Step Two is a food-grade tartaric acid solution. Dissolve the tartaric acid powder in distilled water, adjust the pH to 1.55~1.75, and the solid-liquid ratio (g / mL) of the dried *Clerodendrum trichotomum* leaf powder to the acid solution is 1:40~1:

60. The water bath temperature is 80~100℃, and the extraction time is 60~80min; the ethanol mentioned in Step Five is 95% food-grade ethanol. Let it stand at room temperature for 1~1.5 h, centrifuge at 8000 rpm for 1~2 min, remove the filtrate by centrifugation, wash the pectin with 95% ethanol, and collect the pectin by centrifugation again until the filtrate is clear and the pectin is colorless.

2. The method for extracting pectin from the leaves of *Clerodendrum trichotomum* according to claim 1, characterized in that: The fixation temperature in step one is 100~110℃, the fixation time is 10~15 min, the drying temperature is 60~70℃, the drying time is 6~8 h, and the sieve mesh is 60~80 mesh.

3. The method for extracting pectin from *Clerodendrum trichotomum* leaves according to claim 1, characterized in that: In step three, the centrifuge speed is 8000 rpm and the centrifugation time is 2-4 min.

4. The method for extracting pectin from *Clerodendrum trichotomum* leaves according to claim 1, characterized in that: In step four, the filtrate is concentrated to 1 / 2 to 1 / 3 of its volume using a rotary evaporator.

5. The method for extracting pectin from the leaves of *Clerodendrum trichotomum* according to claim 1, characterized in that: The drying temperature in step six is ​​40-50℃, the drying time is 8-10 h, and the sieve mesh size is 80-100 mesh.

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