Method for co-producing mulberry leaf protein, polysaccharide, flavone and 1-deoxynojirimycin from mulberry leaves

Abstract

The invention discloses a method for co-producing mulberry leaf protein, polysaccharide, flavone and 1-deoxynojirimycin, which is a co-production technical scheme that mulberry leaves are used as raw materials to prepare 60% mulberry leaf protein as a first product, 60% mulberry leaf polysaccharide as a second product, 80% mulberry leaf flavone as a third product and 90% 1-deoxynojirimycin as a fourth product. The method specifically comprises the following steps: (1) primary extraction of mulberry leaves; (2) secondary extraction of mulberry leaves and separation and purification of flavone components; (3) separation and purification of the 1-deoxynojirimycin; (4) extracting mulberry leaves for the third time and separating and purifying protein; and (5) separating and purifying the mulberry leaf polysaccharide. Four products are obtained from the raw material mulberry leaves through continuous extraction and separation, the cost of a single product is reduced, the production efficiency is improved, the solvent dosage is reduced, the energy consumption is reduced, and benefits are maximized; the process operation is convenient, rapid and effective, and the comprehensive utilization degree of mulberry leaf resources is improved. The method is suitable for mulberry leaf resource development and utilization.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of comprehensive utilization of natural resources, in particular, to the comprehensive utilization of mulberry leaves, and more particularly to a method for simultaneously extracting and purifying mulberry leaf protein, polysaccharide, flavone and 1-deoxynojirimycin from mulberry leaves. BACKGROUND

[0002] There have been many achievements in the comprehensive utilization of mulberry leaves, such as: producing low-sugar mulberry moon cakes (CN201210568232.8); preparing sodium copper chlorophyllin from mulberry leaves (CN201510756290.7); extracting mulberry leaf flavone (CN202510546158.7); producing tea substitutes (CN202510639108.3); producing meal replacement foods (CN202510937772.6); preparing prebiotic plant extract dietary powder (CN202510967376.8), and the like. However, so far, there has been no application for simultaneously taking mulberry leaf protein, mulberry leaf polysaccharide, mulberry leaf flavone and 1-deoxynojirimycin as target products. SUMMARY

[0003] The present application aims to provide a method for co-producing mulberry leaf protein, mulberry leaf polysaccharide, mulberry leaf flavone and 1-deoxynojirimycin, realizing the continuous extraction and purification of high-purity protein, polysaccharide, flavone and 1-deoxynojirimycin extract products from mulberry leaves, and providing a way for the high-value utilization of mulberry leaves.

[0004] The method provided by the present application is a co-production technical solution for preparing 60% content mulberry leaf protein as the first product, 60% content mulberry leaf polysaccharide as the second product, 80% content mulberry leaf flavone as the third product, and 90% content 1-deoxynojirimycin as the fourth product, using mulberry leaves as raw materials. The specific method comprises the following steps: (1) First extraction of mulberry leaves Take dry mulberry leaves as raw materials, crush them into coarse powder for standby use; add water for extraction, then filter to obtain residue 1 for standby use; combine the extraction liquid to obtain mulberry leaf extraction liquid, then stand for cooling, filter, and ultrafilter to obtain ultrafiltration concentrated liquid and permeate for standby use; (2) Second extraction of mulberry leaves and separation and purification of flavone components Extract dregs 1 with high-concentration alcohol, then filter to obtain dregs 2 for later use; combine the extracts to obtain mulberry leaf flavonoid extract, remove alcohol under reduced pressure, dilute with water, let stand, filter, and load the filtrate and ultrafiltration permeate onto a macroporous resin column of the same properties as D101, AB-8, or DM130. Wash away polar impurities with deionized water, collect the column eluent and washing liquid to obtain 1-deoxynojirimycin, and load the column feed solution 1; first elute the macroporous resin column with low-concentration ethanol to remove impurities, then elute with high-concentration ethanol solvent, collect the eluent to obtain mulberry leaf flavonoid eluent; concentrate the mulberry leaf flavonoid eluent into an extract, add ethanol, heat and stir to dissolve, let stand and cool, filter, concentrate and dry to obtain mulberry leaf flavonoids.

[0005] Take the ultrafiltration permeate and the 1-deoxynojirimycin loading solution and pass them through a cation exchange resin column. Wash with deionized water and then elute with a certain concentration of ammonia solution. Concentrate the eluent and dissolve the extract in high concentration ethanol. Filter the solution. Add activated carbon to the filtrate for decolorization and heat to dissolve it under stirring using conventional methods. Filter to remove insoluble residue. Concentrate the filtrate and let it stand to crystallize. Recrystallize the crude crystals to obtain 1-deoxynojirimycin crystals. (4) Third extraction of mulberry leaves and separation and purification of proteins Extract the dregs 2 with a certain concentration of NaOH solution, filter, and obtain the filtrate. Adjust the pH of the extract to 3 with HCl solution to produce protein precipitation. Let it stand, filter, and then dissolve and precipitate it again with water to obtain mulberry leaf protein. (5) Isolation and purification of mulberry leaf polysaccharides Take the ultrafiltration concentrate, concentrate it under vacuum, add reagents to precipitate, let it stand, filter, wash, and obtain the precipitate. Dissolve it in water, precipitate it again with alcohol, filter, and dry to obtain mulberry leaf polysaccharide.

[0006] In step (1) of the above method, the water added is deionized water, and the mass of the added water is 10 to 15 times the mass of the mulberry leaves; the extraction temperature is 90℃ to 100℃, and the extraction is performed 2 to 3 times, with each extraction lasting 1 to 2 hours; the cooling time is 8 to 15 hours; and the ultrafiltration is performed using an ultrafiltration membrane with a molecular weight of 50,000 Daltons.

[0007] In step (2) of the above method, the high-concentration alcohol is 70% ethanol, and the added mass is 10 to 15 times the mass of mulberry leaves; the extraction temperature is 60℃ to 80℃, and the extraction is performed 2 to 3 times; the volume after de-ethanolification under reduced pressure is controlled at 1 / 3 to 1 / 5 of the original volume; the added water is deionized water, and the added mass is 3 to 5 times the volume after de-ethanolification under reduced pressure; the amount of deionized water used is 2 BV; the mass fraction of the low-concentration ethanol used for elution and impurity removal is 10% to 20%, and the amount used is 1 to 1.5 BV; the mass fraction of the high-concentration ethanol used for elution is 60% to 70%, and the amount used is 3 to 5 BV; the concentration of the mulberry leaf flavonoid eluent is controlled at 1 / 6 to 1 / 10 of the original volume; the alcohol added after concentration is 95% ethanol, and the amount used is 3 to 5 times the total amount of material; the heating temperature is 60℃; the stirring time is 30 min; and the standing cooling time is 2 to 3 h.

[0008] The amount of deionized water used in step (3) of the above method is 2 BV.

[0009] In step (4) of the above method, the concentration of the ultrafiltration concentrate is controlled at 1 / 6 to 1 / 10 of the original volume. After concentration, 95% ethanol is added, and the extraction is performed 2 to 3 times, with the amount added being 2 to 5 times the total volume of the material. The standing time is 8 to 15 hours. The alcohol washing solution is 80% to 90% ethanol, and the amount used is 1 / 20 to 1 / 10 of the total volume of the material. The concentration of the added NaOH solution is 0.125 mol / L, and the amount added is 10 to 15 times the total volume of the material. The extraction temperature is 40℃, and each extraction lasts 1 to 2 hours, with 2 extractions. The HCl solution is 35% to 37%. The standing time is 8 to 15 hours. The water is deionized water, and the amount used is 1 / 20 to 1 / 10 of the total volume of the material.

[0010] In step (5) of the above method, the polysaccharide raw material solution is concentrated to 1 / 6 to 1 / 10 of its original volume; the precipitating agent is ethanol, and the standing time is 8 to 15 hours; the cleaning solution is 80% to 90% ethanol, and the amount used is 1 / 20 to 1 / 10 of the total volume of the material.

[0011] The advantages of this invention are: four products are obtained from the raw mulberry leaves through continuous extraction and separation, which greatly reduces the cost of a single product, significantly improves production efficiency, reduces solvent consumption, reduces energy consumption, and maximizes benefits; the process is convenient, fast and effective, improves the comprehensive utilization of mulberry leaf resources, and is suitable for the development and utilization of mulberry leaf resources. Attached Figure Description

[0012] Figure 1 The HPLC chromatogram of DNJ product is shown. Figure 2 This is the chromatogram of the DNJ standard. Figure 3The HPLC chromatogram of the flavonoid product is shown. Figure 4 This is a standard curve for protein UV assay. Figure 5 This is the standard curve for the UV determination of polysaccharides. Figure 6 This is a flowchart of the process route of the present invention. Detailed Implementation

[0013] Example 1: Take 400 kg of dried mulberry leaves, add 6000 L of deionized water, boil and keep warm at about 95°C for 2 hours to extract, and release the extract; add 4000 L of deionized water to extract again for 1 hour, and release the extract to obtain residue 1; combine the extracts to obtain extract 1; extract 1 is placed in a cold settling tank for 12 hours, filtered, and then passed through a 50,000 molecular weight ultrafiltration membrane to obtain ultrafiltration concentrate and permeate. Add 4000 L of 70% ethanol to residue 1 and extract at 60°C for 2 hours, and release the extract; add 4000 L of 70% ethanol to extract again for 1 hour, and release the extract to obtain residue 2; combine the extracts to obtain extract 2; remove alcohol from extract 2 under reduced pressure, dilute with 5000 L of deionized water, let stand, filter, and obtain mulberry leaf flavonoid extract. Add 4000 L of 0.125 mol / L NaOH solution to residue 2 and extract at 40℃ for 2 h, then release the extract. Repeat the extraction with 4000 L of 0.125 mol / L NaOH solution for 1 h, then release the extract. Combine the extracts to obtain extract 3. Then perform the following operations: (1) Take the mulberry leaf flavonoid extract and ultrafiltration permeate and pass them through a 400L DM130 column (diameter-to-height ratio of about 1:7). Wash with 2 BV of water, collect the eluent and water wash liquid and pass them through a 400L D201 anion exchange resin. Wash with 800L of water and then elute with 1200L of 3% ammonia solution. Concentrate the eluent to a relative density of 1.23 (50℃). Add 2 times the weight of the extract to dissolve it in 95% ethanol, filter, add 1.5kg of activated carbon to the filtrate and heat and stir to dissolve. Filter the solution and let it crystallize to obtain 2.1kg of crude 1-deoxynojirimycin crystals. Add 50kg of 95% ethanol to the crude crystals and dissolve them. After filtration, recrystallize the filtrate, filter and dry the crystals to obtain 1.05kg of 1-deoxynojirimycin crystals with a purity greater than 90%. After washing with water, wash the DM130 column with 600L of 15% ethanol to remove impurities and then pass it through a 1200L column. Elute with 65% ethanol, concentrate the eluent under vacuum to remove alcohol, add 400L of water and perform a second column pass, wash with 600L of water to remove impurities, elute with 1200L of 60% ethanol, concentrate the eluent under vacuum to form an extract, add 3-5 times the weight of the extract of 95% ethanol, heat and stir at 60℃ to dissolve, let stand and cool for 2-3 hours, filter, concentrate the filtrate and dry it in a vacuum drying oven to obtain 3.9kg of yellow mulberry leaf flavonoid extract; (2) The ultrafiltration concentrate was concentrated under vacuum to a volume of about 100L, 400L of 95% ethanol was added and stirred evenly. The mixture was allowed to stand for 8-15 hours, then filtered. The filter residue was washed with 20L of 85% ethanol and dried to obtain 22kg of precipitate. The precipitate was dissolved in water and ethanol was added to 95% for a second alcohol precipitation. The mixture was allowed to stand for 8-15 hours, then filtered. The filter residue was washed with 20L of 90% ethanol to obtain 12kg of mulberry leaf polysaccharide. The pH of extract 3 was adjusted to 3 with HCl solution, and the mixture was allowed to stand for 8-15 hours. The mixture was then filtered. The filter residue was dissolved in 20L of deionized water, and after filtration, 20L of 90% ethanol was added to the filter residue to dissolve it. The mixture was allowed to stand, filtered, and dried to obtain 10kg of mulberry leaf protein extract.

[0014] Example 2: Take 600 kg of dried mulberry leaves, add 9000 L of deionized water, boil at approximately 94°C and keep warm for 2 hours to extract, then release the extract; add 6000 L of deionized water and repeat extraction for 1 hour, then release the extract to obtain residue 1. Combine the extracts to obtain extract 1, and place extract 1 in a cold settling tank for 12 hours. Filter, then pass through a 50,000 molecular weight ultrafiltration membrane to obtain ultrafiltration concentrate and permeate. Add 6000 L of 70% ethanol to residue 1 and reflux extract at 75°C for 2 hours, then release the extract; add 6000 L of 70% ethanol and repeat extraction for 1 hour, then release the extract to obtain residue 2, and combine the extracts to obtain extract 2; remove alcohol from extract 2 under reduced pressure, dilute with 7500 L of deionized water, let stand, and filter to obtain mulberry leaf flavonoid extract. Add 6000 L of 0.125 mol / L NaOH solution to residue 2 and extract at 40℃ for 2 h. Collect the extract. Repeat the extraction with 6000 L of 0.125 mol / L NaOH solution for 1 h, collect the extract, and combine the extracts to obtain extract 3. Then perform the following operations: (1) Take the mulberry leaf flavonoid extract and ultrafiltration permeate and pass them through a 600L DM130 column chromatography (diameter-to-height ratio of about 1:7). Wash with 2 BV of water, collect the eluent and water wash liquid and pass them through a 600L D201 anion exchange resin. Wash with 800L of water and then elute with 1800L of 3% ammonia solution. Concentrate the eluent to a relative density of 1.23 (50℃). Add 2 times the weight of the extract to dissolve it in 95% ethanol, filter, add 2.25kg of activated carbon to the filtrate and heat and stir to dissolve it. Filter the solution and let it crystallize to obtain 2.98kg of crude 1-deoxynojirimycin crystals. Add 75kg of 95% ethanol to the crude crystals and dissolve them. After filtration, recrystallize the filtrate, filter and dry the crystals to obtain 1.48kg of 1-deoxynojirimycin crystals with a purity greater than 90%. After washing with water, use a 900L DM130 column chromatography. The extract was washed with 15% ethanol and water to remove impurities, then eluted with 1800L of 65% ethanol and water. The eluent was concentrated under vacuum to remove alcohol, and after adding 600L of water, it was subjected to a second column chromatography. The extract was then washed with 900L of water to remove impurities, and eluted with 1800L of 60% ethanol. The eluent was concentrated to form an extract, and 3-5 times the weight of the extract in 95% ethanol was added. The extract was heated and stirred at 60°C to dissolve, and allowed to stand and cool for 2-3 hours. The extract was then filtered, concentrated, and dried in a vacuum drying oven to obtain 5.8kg of yellow mulberry leaf flavonoid extract.

[0015] (2) The ultrafiltration concentrate was concentrated under vacuum to a volume of approximately 150 L, then 600 L of 95% ethanol was added and stirred until homogeneous. The mixture was allowed to stand for 8–15 h, then filtered. The residue was washed with 30 L of 95% ethanol and dried to obtain 31 kg of precipitate. After water-soluble precipitation, ethanol was added to bring the concentration to 95% for a second alcohol precipitation. The mixture was allowed to stand for 8–15 h, then filtered. The residue was washed with 15 L of 90% ethanol to obtain 17 kg of mulberry leaf polysaccharide. Extract 3 was adjusted to pH 3 with HCl solution, allowed to stand for 8–15 h, filtered, and the residue was washed multiple times with 30 L of deionized water, then washed with 30 L of 90% ethanol and dried to obtain 13 kg of mulberry leaf protein extract.

[0016] Example 3: Take 800 kg of dried mulberry leaves, add 12000 L of deionized water, boil at approximately 95°C and keep warm for 2 hours to extract, then release the extract; add 8000 L of deionized water and repeat extraction for 1 hour, then release the extract to obtain residue 1. Combine the extracts to obtain extract 1; cold settle extract 1 in a cold settling tank for 12 hours, filter with defatted cotton, and then pass through a 50000 molecular weight ultrafiltration membrane to obtain ultrafiltration concentrate and permeate. Add 8000 L of 70% ethanol to residue 1 and reflux extract at 70°C for 2 hours, then release the extract; add 8000 L of 70% ethanol and repeat extraction for 1 hour, then release the extract to obtain residue 2. Combine the extracts to obtain extract 2; remove alcohol from extract 2 under reduced pressure, dilute with 10000 L of deionized water, let stand, filter, and obtain mulberry leaf flavonoid extract. Add 8000 L of 0.125 mol / L NaOH solution to residue 2 and extract at 40℃ for 2 h. Collect the extract. Repeat the extraction with 8000 L of 0.125 mol / L NaOH solution for 1 h, collect the extract, and combine the extracts to obtain extract 3. Then perform the following operations: (1) Take the mulberry leaf flavonoid extract and ultrafiltration permeate and pass them through an 800L DM130 column (diameter-to-height ratio of about 1:7), wash with 2 BV of water, collect the eluent and water wash liquid and load it onto an 800L D201 anion exchange resin, wash with 1600L of water; then elute with 2400L 3% ammonia solution, concentrate the eluent to a relative density of 1.23 (50℃), add 2 times the weight of the extract of 95% ethanol and 4kg of activated carbon, heat and stir to dissolve; after filtration, the filtrate is placed to crystallize to obtain 3.80kg of crude 1-deoxynojirimycin crystals, add 100L of 95% ethanol to dissolve the crude crystals and filter, collect the filtrate for recrystallization, filter the recrystallized crystals and dry them to obtain 1.85kg of 1-deoxynojirimycin crystals with a purity greater than 90%; after washing with water, wash the DM130 column with 1200L of 15% ethanol to remove impurities, and then use 2000L of ethanol to remove impurities. The eluent was eluted with 65% ethanol and water. The eluent was concentrated under vacuum to remove the ethanol. After adding 600L of water, the eluent was passed through the column twice. Then, it was washed with 1200L of water to remove impurities. The eluent was eluted with 2400L of 60% ethanol. The eluent was concentrated into an extract. 3-5 times the weight of the extract in 95% ethanol was added. The extract was heated and stirred at 60℃ to dissolve. After standing and cooling for 2-3 hours, the extract was filtered. The filtrate was concentrated and then dried in a vacuum drying oven to obtain 8.1kg of yellow mulberry leaf flavonoid extract.

[0017] (2) The ultrafiltration concentrate was concentrated under vacuum to a volume of approximately 200 L, then 800 L of 95% ethanol was added and stirred until homogeneous. The mixture was allowed to stand for 8–15 h, then filtered. The filter residue was washed with 20 L of 85% ethanol and dried to obtain 40 kg of precipitate. After water-soluble precipitation, ethanol was added to bring the concentration to 95% for a second alcohol precipitation. The mixture was allowed to stand for 8–15 h, then filtered. The filter residue was washed with 20 L of 90% ethanol to obtain 22 kg of mulberry leaf polysaccharide. Extract 3 was adjusted to pH 3 with HCl solution, allowed to stand for 8–15 h, filtered, and the filter residue was washed multiple times with 40 L of deionized water and dried to obtain 18.5 kg of mulberry leaf protein extract.

[0018] Table 1. Product content and yield of three batches of the example.

[0019] From Table 1, we can draw the following conclusions: ① The products obtained from the three examples all meet the requirements of the co-production scheme of this invention, namely, using mulberry leaves as raw materials to prepare mulberry leaf protein with a content of 60%, mulberry leaf polysaccharide with a content of 60%, mulberry leaf flavonoids with a content of 80%, and 1-deoxynojirimycin with a content of 90%. ② By changing the amount of mulberry leaves used, the co-production scheme can consistently produce qualified products that meet the requirements, proving that the production process in the co-production scheme has high repeatability and stability and can meet different production capacity needs.

Claims

1. A method for co-producing mulberry leaf protein, polysaccharides, flavonoids and 1-deoxynojirimycin, characterized in that... This method is a co-production technology scheme using mulberry leaves as raw material to prepare a first product containing 60% mulberry leaf protein, a second product containing 60% mulberry leaf polysaccharide, a third product containing 80% mulberry leaf flavonoids, and a fourth product containing 90% 1-deoxynojirimycin; the specific method includes the following steps: (1) Primary extraction of mulberry leaves Take dried mulberry leaves as raw material, crush them into coarse powder and set aside; add water to extract, then filter to obtain dregs 1 for use; combine the extracts to obtain mulberry leaf extract, then let stand and cool, filter, and then ultrafilter to obtain ultrafiltration concentrate and permeate for use. (2) Secondary extraction of mulberry leaves and separation and purification of flavonoid components Extract dregs 1 with high-concentration alcohol, then filter to obtain dregs 2 for later use; combine the extracts to obtain mulberry leaf flavonoid extract, remove alcohol under reduced pressure, dilute with water, let stand, filter, and load the filtrate and ultrafiltration permeate onto a macroporous resin column of the same properties as D101, AB-8, or DM130. Wash away impurities with deionized water, collect the column eluent and washing liquid to obtain 1-deoxynojirimycin, and load the column feed solution 1; first elute the macroporous resin column with low-concentration ethanol to remove impurities, then elute with high-concentration ethanol solvent, collect the eluent to obtain mulberry leaf flavonoid eluent; concentrate the mulberry leaf flavonoid eluent into an extract, add alcohol, heat and stir to dissolve, let stand and cool, filter, concentrate and dry to obtain mulberry leaf flavonoids; (3) Isolation and purification of 1-deoxynojirimycin Take the ultrafiltration permeate and the 1-deoxynojirimycin loading solution and pass them through a cation exchange resin column. Wash with deionized water and then elute with a certain concentration of ammonia solution. Concentrate the eluent and dissolve the extract in high concentration ethanol. Filter the solution. Add activated carbon to the filtrate for decolorization and heat to dissolve it under stirring using conventional methods. Filter to remove insoluble residue. Concentrate the filtrate and let it stand to crystallize. Recrystallize the crude crystals to obtain 1-deoxynojirimycin crystals. (4) Third extraction of mulberry leaves and separation and purification of proteins Extract the dregs 2 with a certain concentration of NaOH solution, filter, and obtain the filtrate. Adjust the pH of the extract to 3 with HCl solution to produce protein precipitation. Let it stand, filter, and then dissolve and precipitate it again with water to obtain mulberry leaf protein. (5) Isolation and purification of mulberry leaf polysaccharides Take the ultrafiltration concentrate, concentrate it under vacuum, add ethanol to precipitate, let it stand, filter it, wash it, and obtain the precipitate; after water dissolution, precipitate it again with alcohol, filter it, and dry it to obtain mulberry leaf polysaccharide.

2. The method for co-producing mulberry leaf protein, polysaccharides, flavonoids and 1-deoxynojirimycin according to claim 1, characterized in that... The water added in step (1) is deionized water, and the mass of the added water is 10 to 15 times the mass of the mulberry leaves; the extraction temperature is 60°C, and the extraction is performed 2 to 3 times, with each extraction lasting 1 to 2 hours; the cooling time is 8 to 15 hours; and the ultrafiltration is performed using an ultrafiltration membrane with a molecular weight of 50,000 Daltons.

3. The method for co-producing mulberry leaf protein, polysaccharides, flavonoids and 1-deoxynojirimycin according to claim 1, characterized in that... In step (2), the high-concentration alcohol is 70% ethanol, and the added mass is 10 to 15 times the mass of mulberry leaves; the extraction temperature is 60°C, and the extraction is performed 2 to 3 times; the volume after de-ethanolification under reduced pressure is controlled at 1 / 3 to 1 / 5 of the original volume; the added water is deionized water, and the added mass is 3 to 5 times the volume after de-ethanolification under reduced pressure; the amount of deionized water used is 2 BV; the mass fraction of the low-concentration ethanol used for elution and impurity removal is 10% to 20%, and the amount used is 1 to 1.5 BV; the mass fraction of the high-concentration ethanol used for elution is 60% to 70%, and the amount used is 3 to 5 BV; the concentration of the mulberry leaf flavonoid eluent is controlled at 1 / 6 to 1 / 10 of the original volume; the alcohol added after concentration is 95% ethanol, and the amount used is 3 to 5 times the total amount of material; the heating temperature is 60°C; the stirring time is 30 min; and the standing and cooling time is 2 to 3 h.

4. The method for co-producing mulberry leaf protein, polysaccharides, flavonoids and 1-deoxynojirimycin according to claim 1, characterized in that... In step (3), the amount of deionized water used is 2 BV.

5. The method for co-producing mulberry leaf protein, polysaccharides, flavonoids and 1-deoxynojirimycin according to claim 1, characterized in that... In step (4), the ultrafiltration concentrate is concentrated to 1 / 6 to 1 / 10 of its original volume. After concentration, 95% ethanol is added, and the extraction is performed 2 to 3 times, with the amount added being 2 to 5 times the total volume of the material. The settling time is 8 to 15 hours. The alcohol washing solution is 80% to 90% ethanol, and the amount used is 1 / 20 to 1 / 10 of the total volume of the material. The concentration of the added NaOH solution is 0.125 mol / L, and the amount added is 10 to 15 times the total volume of the material. The extraction temperature is 40°C, and each extraction lasts 1 to 2 hours, with 2 extractions. The HCl solution is 35% to 37%. The settling time is 8 to 15 hours. The water is deionized water, and the amount used is 1 / 20 to 1 / 10 of the total volume of the material.

6. The method for co-producing mulberry leaf protein, polysaccharides, flavonoids and 1-deoxynojirimycin according to claim 1, characterized in that... In step (5), the polysaccharide raw material solution is concentrated to 1 / 6 to 1 / 10 of its original volume; the precipitating agent is ethanol; the standing time is 8 to 15 hours; the cleaning solution is 80% to 90% ethanol, and the amount used is 1 / 20 to 1 / 10 of the total volume of the material.

Images