CN110590876B - High-purity stevioside and preparation method thereof - Google Patents
High-purity stevioside and preparation method thereof Download PDFInfo
- Publication number
- CN110590876B CN110590876B CN201910965942.6A CN201910965942A CN110590876B CN 110590876 B CN110590876 B CN 110590876B CN 201910965942 A CN201910965942 A CN 201910965942A CN 110590876 B CN110590876 B CN 110590876B
- Authority
- CN
- China
- Prior art keywords
- resin
- stevioside
- adsorption
- solution
- column
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
- C07H1/00—Processes for the preparation of sugar derivatives
- C07H1/06—Separation; Purification
- C07H1/08—Separation; Purification from natural products
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
- C07H15/00—Compounds containing hydrocarbon or substituted hydrocarbon radicals directly attached to hetero atoms of saccharide radicals
- C07H15/20—Carbocyclic rings
- C07H15/24—Condensed ring systems having three or more rings
- C07H15/256—Polyterpene radicals
Abstract
The invention relates to a high-purity stevioside and a preparation method thereof, wherein stevia rebaudiana is used as a raw material, a water extraction method is adopted, an extracting solution is subjected to Ultra-filtration separation by an Ultra-flo membrane to remove impurities such as polysaccharide, protein, tannin, solid suspended matters and the like, then an ADS-7 adsorption resin column is used for removing a large amount of pigment impurities, a desorption solution is concentrated and recycled with ethanol, then an RS-2 adsorption resin column is used, an adsorption effluent liquid is concentrated and dried to obtain a stevioside product, the purity of the product can reach 97-99%, and the yield is 8-9% (based on dry stevia rebaudiana powder). The method has the characteristics of simple process, no use of toxic organic solvent, high product purity, accordance with food safety requirements and the like.
Description
Technical Field
The invention relates to the field of deep processing of natural organic chemistry and agricultural products, in particular to high-purity stevioside and a preparation method thereof.
Background
Stevioside is an important natural active substance in stevia rebaudiana and is an excellent sweetening agent, the sweetness is 200-300 times that of cane sugar, the heat is 1/300 of the cane sugar, the edible safety is high, the stevioside has the effects of reducing blood pressure, diminishing inflammation, improving immunity and the like, is an ideal novel sweetening agent with high sweetness, low calorie and good taste, and has a certain curative effect on diabetes and hyperlipidemia. In 1995, the FDA in the united states approved that stevioside can be sold and consumed as a "dietary supplement", in 2004, the united health organization in the world formally agreed upon a resolution that allows stevioside to be used worldwide, and in 2008, the FDA in the united states officially approved that high purity stevioside can be used as a sweetener in foods and beverages in the united states, which approval greatly expanded the range of application of stevioside in the field of food additives and also made high purity stevioside products a market hotspot. In recent years, with the intensive research on the chemical structure, the physicochemical property and the biological activity of the components, a large amount of high-purity stevioside is required to be provided as a pharmaceutical raw material or a standard substance, and the new field puts higher demands on the purity of the product, while the traditional extraction technology and the product cannot meet the development requirements.
In recent years, many researches on the separation and purification of stevioside at home and abroad utilize a plurality of novel separation and preparation methods, but resin adsorption separation is mainly used, and the principle is to utilize the high adsorption selectivity of macroporous adsorption resin to the stevioside to decolor and purify the stevioside. The preparation process of stevioside generally comprises the steps of extraction, flocculation precipitation, macroporous resin adsorption of stevioside, desorption liquid concentration, drying and the like.
The content of stevioside in the dry leaves of the stevia rebaudiana is 10-18%, and the stevioside is easily dissolved in water, methanol, ethanol and other solutions. Methanol is toxic and rarely used as an extractant, and a lot of lipid substances, especially chlorophyll, can be extracted when ethanol is used for extraction, so that the decolorization effect is seriously influenced. The water extraction method is low in cost, but can extract a large amount of water-soluble impurities, such as polysaccharide, pectin, tannin, organic acid, protein, pigment, organic salt and the like, and the water-soluble impurities cannot directly enter the macroporous adsorption resin column so as to avoid serious resin pollution and reduce the adsorption separation performance of the resin. The impurity removal and decoloration of the stevioside extracting solution mostly adopt flocculation precipitation and centrifugal separation methods, but the flocculation method has high cost and low efficiency, impurities introduced by adding a flocculating agent need to be removed in the subsequent process, and simultaneously, precipitates can adsorb a part of stevioside, so that the yield is reduced. The existing resin adsorption method is used for extracting and separating stevioside, and only products with the purity of below 90 percent can be obtained. In order to further improve the purity of the product, the product can be refined by adopting a recrystallization method and a high-efficiency counter-current chromatography. The recrystallization method has the advantages of large energy consumption, slow crystal growth, long time consumption, low yield, product purity only reaching about 95 percent, and complicated mother liquor recovery process. The high-efficiency reverse-phase chromatography has high requirements on equipment, and the optimization of a solvent system is time-consuming, labor-consuming and difficult in practical application. How to further improve the purity of the stevioside product is a serious problem which always troubles manufacturers.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a method for preparing high-purity stevioside, which is a method for preparing high-purity stevioside by a resin adsorption method, has simple process, does not use toxic organic solvents, has high product purity and meets the food safety requirements. The invention mainly combines membrane ultrafiltration and twice resin column chromatography separation technologies to separate and purify stevioside from the extract of stevia rebaudiana and prepare the stevioside product with the purity of more than 97 percent. The technological design principle is that Ultra-filtration is carried out by using an Ultra-flo membrane to primarily remove impurities from stevioside extracting solution, ADS-7 macroporous adsorption resin is used for decoloring, and then the screening, adsorbing and separating functions of RS-2 gel type ultrahigh cross-linked adsorption resin are used for further decoloring and purifying stevioside solution with the purity of about 90%, so that the purity of the product reaches more than 97%.
Specifically, the preparation method comprises the following steps: 1) extraction: crushing dried stevia rebaudiana leaves, and stirring and extracting with deionized water at 80 ℃ to obtain an extracting solution which is dark brown; 2) ultra-flo membrane ultrafiltration: removing a large amount of impurities such as polysaccharide, protein, tannin, solid suspended matters and the like in the extract through ultrafiltration separation of a plate-type Ultra-flo membrane, wherein the concentration of stevioside in the ultrafiltration dialysate is 7-12 g/L, the purity is about 40%, and the yield is about 13% (calculated on dry stevia rebaudiana powder); 3) ADS-7 resin adsorption decoloration: ADS-7 adsorption resin on the ultrafiltration dialysate has high adsorption capacity and adsorption selectivity to stevioside, and a large amount of pigment impurities flow out in the adsorption process, so that the stevioside is adsorbed on the resin. Then, desorbing by using ethanol water solution, wherein the concentration of stevioside in desorption solution is 10-20 g/L, the purity is 85% -90%, and the yield reaches about 10% (based on dry stevia powder); 4) and (3) screening and adsorbing by RS-2 resin: and (3) concentrating the desorption solution under reduced pressure to recover ethanol, feeding the concentrated solution onto an RS-2 resin column, adsorbing the pigment by resin, enabling the stevioside not to be adsorbed and to flow out along with the effluent, collecting the effluent, concentrating under reduced pressure, and drying to obtain a stevioside solid product, wherein the purity of the product can reach 97-99%, and the yield is 8-9% (based on the dry stevia rebaudiana powder).
Furthermore, the preparation method comprises the following steps:
1) extraction: and (3) crushing the dried stevia leaves, adding 15-20 times of deionized water by weight, stirring and extracting at 80 ℃ for two times, extracting for 2 hours each time, carrying out coarse filtration by using gauze, and combining filtrates to obtain a dark brown extracting solution.
2) Ultra-flo membrane ultrafiltration: pumping the stevioside extracting solution into an Ultra-flo membrane device at normal temperature and normal pressure for ultrafiltration purification, wherein the process conditions are as follows: inlet pressure 4bar and outlet pressure 2 bar. After being concentrated to a certain degree, water is added for washing, and the water addition amount is about 1/4 of the initial feed liquid. The ultrafiltration membrane is a polyvinylidene fluoride (PVDF) membrane with the molecular weight cutoff of 4 ten thousand, the average membrane flux is large, and the concentration multiple can reach 4-5 times. The ultrafiltration can remove a large amount of water-soluble protein, polysaccharide, pectin, tannin, pigment, solid suspended matters and other impurities in the extracting solution, improve the quality of the water extracting solution and facilitate the subsequent process.
3) ADS-7 resin adsorption decoloration: the ADS-7 resin is macroporous styrene-divinylbenzene copolymer, the resin skeleton is loaded with quaternary ammonium groups, the average pore diameter is 25-35 nm, and the specific surface area is 100-120 m2(iv) a particle size of 0.30 to 0.60mm per gram. Adsorbing the 9-12 BV ultrafiltration dialysate by an ADS-7 resin column (the adsorption flow rate is 2-3 BV/h), adsorbing the stevioside on the resin, and allowing a large amount of impurities such as pigments to flow out. After adsorption, 2BV of pure water is firstly used for washing the column (the washing flow rate is 4BV/h), then 4-6 BV of 60% ethanol water solution is used for desorption (the desorption flow rate is 1.5-2 BV/h), and desorption liquid is collected.
4) And (3) screening and adsorbing by RS-2 resin: the RS-2 resin is gel type ultrahigh cross-linked adsorption resin, the skeleton structure is styrene-divinylbenzene copolymer, and the resin has a nano-microporous structure, the pore volume is 0.50-0.60 mL/g, the average pore diameter is 1.40-1.70 nm, and the specific surface area is 1300-1500 m2(iv) g, average particle diameter of 0.18 to 0.42 mm. And concentrating the ADS-7 resin desorption solution under reduced pressure to recover ethanol, and feeding 10-20 BV of concentrated solution to an RS-2 resin column (the adsorption flow rate is 2-3 BV/h). In the process of column adsorption, a small amount of impurities such as micromolecular pigments and the like in the solution can enter the RS-2 resin pore canal and are adsorbed by the resin; stevioside with a large molecular weight cannot enter the resin pores and flows out along with the effluent. The column liquid is light yellow, and the stevioside effluent is colorless after being adsorbed by RS-2 resin.
5) And (3) concentrating under reduced pressure and drying: concentrating the stevioside effluent under reduced pressure, and drying to obtain white stevioside powder product.
The invention adopts a membrane ultrafiltration method to treat the stevioside extracting solution, removes a large amount of impurities such as polysaccharide, protein, pigment, solid suspended matters and the like in the extracting solution, can effectively reduce the burden of subsequent resin treatment, and is beneficial to the improvement of the product quality. The resin separation technology has the advantages of low energy consumption, environment-friendly process, convenient operation and the like, and is used for extracting and separating stevioside.
One of the key points of the invention is that through two-stage resin adsorption coordination, namely 3) ADS-7 resin adsorption decoloration, the stevioside adsorption capacity and adsorption selectivity are high, a large amount of pigment impurities flow out in the adsorption process, and the stevioside is adsorbed on the resin. And then desorbing by using an ethanol water solution, taking the desorbed solution, concentrating the desorbed solution under reduced pressure, recovering the concentrated solution after ethanol recovery, taking the concentrated solution as the upper column solution in the step 4), and separating the concentrated solution by sieving and adsorbing through RS-2 resin, wherein the pigment is adsorbed by the resin, and the stevioside is not adsorbed and flows out along with the effluent, so that the purity of the product is improved from 85-90% to 97-99%.
The specific scheme is as follows:
a preparation method of high-purity stevioside comprises the following steps:
step 1): crushing dry stevia rebaudiana leaves, adding deionized water, heating and stirring for extraction to obtain an extracting solution;
step 2): ultrafiltering the obtained extractive solution with plate-type Ultra-flo ultrafiltration membrane, and collecting ultrafiltered dialysate;
step 3): adsorbing the collected ultrafiltration dialysate on ADS-7 adsorption resin to adsorb stevioside on the resin, desorbing the pigment with ethanol water solution, and collecting desorption solution;
step 4): concentrating the desorption solution collected in the previous step under reduced pressure to recover ethanol, feeding the concentrated solution on RS-2 resin, adsorbing pigment by the resin, not adsorbing stevioside, collecting effluent, concentrating under reduced pressure, and drying to obtain stevioside solid product.
Further, the extraction in the step 1) is performed by stirring and extracting deionized water with the weight 15-20 times of the total weight of the dry leaves of the stevia rebaudiana at 70-85 ℃.
Further, the ultrafiltration membrane in the step 2) is a polyvinylidene fluoride membrane, and the molecular weight cutoff is 3.5-4.5 ten thousand.
Further, the inlet pressure of the ultrafiltration separation in the step 2) is 4 +/-1 bar, the outlet pressure is 2 +/-1 bar, and after the concentration is 4 +/-1 times, water is added for washing.
Further, the ADS-7 adsorption resin in the step 3) is quaternary ammonium type styrene-bis (styrene-bis) amineThe styrene polymer has an average pore diameter of 25-35 nm and a specific surface area of 100-120 m2(iv) a particle size of 0.30 to 0.60mm per gram.
Further, the column loading amount of the ADS-7 adsorption resin in the step 3) is 9-12 BV, and the adsorption flow rate is 2-3 BV/h.
Further, the desorption agent desorbed in the step 3) is a 60% ethanol water solution with the concentration of 4-6 BV, and the desorption flow rate is 1.5-2 BV/h.
Further, the RS-2 resin in the step 4) is gel type ultrahigh cross-linked adsorption resin which is a styrene-divinylbenzene polymer with a nano-microporous structure, the pore volume is 0.50-0.60 mL/g, the average pore diameter is 1.40-1.70 nm, and the specific surface area is 1300-1500 m2(iv) a particle size of 0.15 to 0.30mm per gram.
Further, the column loading amount of the RS-2 resin in the step 4) is 10-20 BV, and the adsorption flow rate is 2-3 BV/h.
The invention also protects the high-purity stevioside prepared by the preparation method of the high-purity stevioside, and the purity of the prepared high-purity stevioside is 97.0-99.9%.
Has the advantages that: compared with the prior resin adsorption method, the method has the following remarkable advantages:
1) the membrane separation technology is adopted to replace the traditional flocculation process, and no ion is doped, so that the ion exchange process in the traditional production process can be cancelled, the production process is simplified, the membrane separation technology has high efficiency, and a large amount of extracting solution can be continuously treated.
2) Chromatographic separation by adopting a two-stage resin adsorption method: according to the first stage, the ADS-7 adsorption resin has high adsorption selectivity and adsorption capacity for stevioside, a large amount of impurities such as pigments flow out in the adsorption process, 60% ethanol water solution is adopted for desorption after adsorption is finished, the purposes of enrichment and concentration can be achieved, the purity of stevioside is improved to 85-90% from about 40%, and the concentration is improved to 10-20 g/L from 7-12 g/L. The second-stage RS-2 adsorption resin has molecular sieving adsorption performance, namely, selective adsorption can be carried out according to the size of molecules. The RS-2 resin has moderate aperture (aperture is 1.40-1.70 nm), small molecular impurities can freely enter and exit from resin pore passages in the adsorption process and are adsorbed by the resin, and the molecular weight of stevioside is higher than that of steviosideLarge enough not to enter the resin pores and flow out with the effluent. Therefore, the RS-2 resin only adsorbs impurities with small molecular size in the stevioside solution, does not adsorb stevioside with high content (85-90 percent of the stevioside), and has large specific surface area (1300-1500 m)2/g) has a high adsorption capacity for impurities, so that a large amount of steviol glycoside solution can be treated with a small amount of resin. The purity of the product can reach 97-99% after RS-2 resin purification.
Drawings
In order to illustrate the technical solution of the present invention more clearly, the drawings will be briefly described below, and it is apparent that the drawings in the following description relate only to some embodiments of the present invention and are not intended to limit the present invention.
Fig. 1 is a process flow diagram for preparing high purity steviol glycosides as provided in example 1 of the present invention.
Detailed Description
Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein. The examples do not specify particular techniques or conditions, and are performed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available. In the following examples, "%" means weight percent, unless otherwise specified.
Example 1:
1) extraction: adding 15L deionized water into 1000g sweet stevia dry powder, extracting at 80 deg.C for 2 hr, coarse filtering with gauze, and mixing filtrates to obtain 13.5L dark brown extractive solution.
2) Ultra-flo membrane ultrafiltration: 13.5L of the sweet polyglycoside extract is pumped into an Ultra-flo membrane device for ultrafiltration and purification at normal temperature and pressure, and the process conditions are as follows: inlet pressure 4bar and outlet pressure 2 bar. After concentrating to 3.4L, adding 3.4L water jacket to wash, and collecting 13.4L dialysate. The ultrafiltration membrane is polyvinylidene fluoride (PVDF) membrane with molecular weight cutoff of 4 ten thousand, and the average membrane flux is 37.8L.m2.h-1. The concentration of stevioside in the dialysate was 10.24g/L, the purity was 42.53%, and the yield was 13.82% (based on dry stevia powder).
3) ADS-7 resin adsorption decoloration: adsorbing with ADS-7 resin column (column volume of 1.5L, column inner diameter of 6.2cm, column height of 50cm, diameter-height ratio of 1:8) on 13.4L of ultrafiltration dialysate at adsorption flow rate of 2BV/h, adsorbing stevioside on the resin, and allowing a large amount of pigment and other impurities to flow out. After adsorption, the column is washed by 2BV of pure water at the flow rate of 4BV/h, then desorbed by 4BV of 60% ethanol aqueous solution at the flow rate of 1.5BV/h, and 6L of desorption solution is collected. The concentration of stevioside in the desorption solution is 17.11g/L, the purity is 87.32%, and the yield is 10.27% (based on the dry powder of stevia rebaudiana Bertoni).
4) And (3) screening and adsorbing by RS-2 resin: the ADS-7 resin desorption solution is decompressed and concentrated to 2.6L (the concentration is 41.79g/L), the 2.6L concentrated solution is put on an RS-2 resin column (the column volume is 0.2L, the inner diameter of the column is 3.1cm, the column height is 27cm, the diameter-height ratio is 1:8.7), and the adsorption flow rate is 2 BV/h. In the adsorption process, impurities such as pigments with small molecular weight are adsorbed by the resin, while stevioside with large molecular weight is not adsorbed and flows out along with the effluent. After adsorption, the column was washed with 2BV of pure water, and 2.8L of effluent was collected (0.2L of effluent collected at the beginning was not sweet and discarded), with the stevioside concentration of 33.15 g/L.
5) And (3) concentrating under reduced pressure and drying: concentrating under reduced pressure, and drying to obtain white stevioside product 95.35g with purity of 97.35% and yield of 9.28% (based on dry powder of stevia rebaudiana Bertoni).
Example 2:
1) extraction: adding 17L deionized water into 1000g sweet stevia dry powder, extracting at 80 deg.C for 2 hr, coarse filtering with gauze, and mixing filtrates to obtain 15.2L dark brown extractive solution.
2) Ultra-flo membrane ultrafiltration: 15.2L of the sweet polyglycoside extract is pumped into an Ultra-flo membrane device for ultrafiltration and purification at normal temperature and pressure, and the process conditions are as follows: inlet pressure 4bar and outlet pressure 2 bar. After concentrating to 4.1L, adding 4.1L water jacket to wash, and collecting 15.0L dialysate. The ultrafiltration membrane is polyvinylidene fluoride (PVDF) membrane with molecular weight cutoff of 4 ten thousand, and the average membrane flux is 40.5L.m2.h-1. The dialysate contains steviol glycosides at a concentration of8.52g/L, the purity is 41.56%, and the yield is 12.95% (based on the dry powder of stevia rebaudiana Bertoni).
3) ADS-7 resin adsorption decoloration: adsorbing with ADS-7 resin column (column volume of 1.5L, column inner diameter of 6.2cm, column height of 50cm, diameter-height ratio of 1:8) on 15.0L of ultrafiltration dialysate at adsorption flow rate of 2.5BV/h, adsorbing stevioside on the resin, and allowing a large amount of pigment and other impurities to flow out. After adsorption, the column was washed with 2BV of pure water at a flow rate of 4BV/h, then desorbed with 5BV of 60% ethanol in water at a flow rate of 2BV/h, and 7.5L of desorption solution was collected. The concentration of stevioside in the desorption solution is 13.12g/L, the purity is 90.15%, and the yield is 9.84% (based on the dry powder of stevia rebaudiana Bertoni).
4) And (3) screening and adsorbing by RS-2 resin: the ADS-7 resin desorption solution is concentrated to 3.1L (the concentration is 31.59g/L) under reduced pressure, the 3.1L concentrated solution is put on an RS resin column (the column volume is 0.2L, the inner diameter of the column is 3.1cm, the column height is 27cm, the diameter-height ratio is 1:8.7), and the adsorption flow rate is 2.5 BV/h. In the adsorption process, impurities such as pigments with small molecular weight are adsorbed by resin, stevioside with large molecular weight is not adsorbed and flows out along with the effluent, 2BV pure water is used for washing the column after adsorption is finished, 3.3L of effluent is collected together (0.2L of effluent collected at the beginning is not sweet and is discarded), and the concentration of the stevioside is 27.23 g/L.
5) And (3) concentrating under reduced pressure and drying: concentrating the stevioside effluent under reduced pressure, and drying to obtain 91.22g of powdery stevioside product with purity of 98.51% and yield of 8.99% (based on dry stevia powder).
Example 3:
1) extraction: extracting 1000g sweet stevia dry powder with 20L deionized water at 80 deg.C under stirring twice, each time for 2 hr, coarse filtering with gauze, and mixing filtrates to obtain dark brown extractive solution 18.4L.
2) Ultra-flo membrane ultrafiltration: 18.4L of the sweet polyglycoside extract is pumped into an Ultra-flo membrane device for ultrafiltration and purification at normal temperature and pressure, and the process conditions are as follows: the pressure was 4bar and 2 bar. After concentrating to 4.5L, adding 4.5L water jacket to wash, and collecting 18.2L dialysate. The ultrafiltration membrane is polyvinylidene fluoride (PVDF) membrane with molecular weight cutoff of 4 ten thousand, and the average membrane flux is 47.8L.m2.h-1. The concentration of stevioside in the dialysate was 7.23g/L, the purity was 39.82%, and the yield was 13.16% (based on dry stevia powder).
3) ADS-7 resin adsorption decoloration: adsorbing with ADS-7 resin column (column volume of 1.5L, column inner diameter of 6.2cm, column height of 50cm, diameter-height ratio of 1:8) on 18.2L of ultrafiltration dialysate at adsorption flow rate of 3BV/h, adsorbing stevioside on the resin, and allowing a large amount of pigment and other impurities to flow out. After adsorption, the column is washed by 2BV of pure water at the flow rate of 4BV/h, then desorbed by 6BV of 60% ethanol water at the flow rate of 2BV/h, and 8.6L of desorption solution is collected. The concentration of stevioside in the desorption solution is 11.61g/L, the purity is 85.29%, and the yield is 9.98% (based on the dry powder of stevia rebaudiana Bertoni).
4) And (3) RS resin screening and adsorption: and concentrating the ADS-7 resin desorption solution to 3.9L (the concentration is 23.65g/L) under reduced pressure, feeding the 3.9L concentrated solution into an RS resin column (the column volume is 0.2L, the column inner diameter is 3.1cm, the column height is 27cm, the diameter-height ratio is 1:8.7), and the adsorption flow rate is 3 BV/h. In the adsorption process, impurities such as pigments with small molecular weight are adsorbed by resin, stevioside with large molecular weight is not adsorbed and flows out along with the effluent, 2BV pure water is used for washing the column after adsorption is finished, 4.2L of effluent is collected together (0.4L of effluent collected at the beginning is not sweet and is discarded), and the concentration of the stevioside is 21.79 g/L.
5) And (3) concentrating under reduced pressure and drying: concentrating the stevioside effluent under reduced pressure, and drying to obtain 92.33g of powdery stevioside product with purity of 99.12% and yield of 9.15% (based on dry stevia powder).
Example 4
1) Extraction: adding 15L deionized water into 1000g sweet stevia dry powder, extracting at 70 deg.C for 2 hr, coarse filtering with gauze, and mixing filtrates to obtain dark brown extractive solution.
2) Ultra-flo membrane ultrafiltration: pumping the sweet polyglycoside extract into an Ultra-flo membrane device at normal temperature and pressure for ultrafiltration and purification, wherein the process conditions are as follows: the pressure was 5bar and 3 bar. Concentrating to 5 times, adding water, washing, and collecting dialysate. The ultrafiltration membrane is a polyvinylidene fluoride (PVDF) membrane with a molecular weight cut-off of 4.5 ten thousand.
3) ADS-7 resin adsorption decoloration: adsorbing with ADS-7 resin column (column volume of 1.5L, column inner diameter of 6.2cm, column height of 50cm, diameter-height ratio of 1:8) at adsorption flow rate of 3BV/h, adsorbing stevioside on the resin, and allowing a large amount of pigment and other impurities to flow out. After adsorption, the column is washed by 2BV of pure water at the flow rate of 4BV/h, then desorbed by 5BV of 60% ethanol water at the flow rate of 1.5BV/h, and the desorption solution is collected.
4) And (3) RS resin screening and adsorption: and concentrating the ADS-7 resin desorption solution under reduced pressure, and allowing the concentrated solution to pass through an RS resin column (the column volume is 0.2L, the column inner diameter is 3.1cm, the column height is 27cm, and the diameter-height ratio is 1:8.7), and the adsorption flow rate is 3 BV/h. In the adsorption process, impurities such as pigment with small molecular weight are adsorbed by resin, stevioside with large molecular weight is not adsorbed and flows out along with the effluent, 2BV of pure water is used for washing the column after adsorption is finished, and the effluent is collected (0.4L of the effluent collected at the beginning has no sweet taste and is discarded).
5) And (3) concentrating under reduced pressure and drying: concentrating the stevioside effluent under reduced pressure, and drying to obtain powdery stevioside product with purity of more than 99%.
Example 5
1) Extraction: extracting 1000g sweet stevia dry powder with 18L deionized water at 85 deg.C under stirring twice, each for 2 hr, coarse filtering with gauze, and mixing filtrates to obtain dark brown extractive solution 18.4L.
2) Ultra-flo membrane ultrafiltration: 18.4L of the sweet polyglycoside extract is pumped into an Ultra-flo membrane device for ultrafiltration and purification at normal temperature and pressure, and the process conditions are as follows: the pressure is 3bar and the pressure is 1 bar. After concentrating 3 times, adding water for washing, and collecting dialysate. The ultrafiltration membrane is a polyvinylidene fluoride (PVDF) membrane with a molecular weight cut-off of 3.5 ten thousand.
3) ADS-7 resin adsorption decoloration: adsorbing with ADS-7 resin column (column volume of 1.5L, column inner diameter of 6.2cm, column height of 50cm, diameter-height ratio of 1:8) at adsorption flow rate of 2BV/h, adsorbing stevioside on the resin, and allowing a large amount of pigment and other impurities to flow out. After adsorption, the column is washed by 2BV pure water at the flow rate of 4BV/h, then desorbed by 4BV 60% ethanol water solution at the flow rate of 2BV/h, and the desorption solution is collected.
4) And (3) RS resin screening and adsorption: and concentrating the ADS-7 resin desorption solution under reduced pressure, and allowing the concentrated solution to pass through an RS resin column (the column volume is 0.2L, the column inner diameter is 3.1cm, the column height is 27cm, and the diameter-height ratio is 1:8.7), and the adsorption flow rate is 2 BV/h. In the adsorption process, impurities such as pigment with small molecular weight are adsorbed by resin, stevioside with large molecular weight is not adsorbed and flows out along with the effluent, 2BV of pure water is used for washing the column after adsorption is finished, and the effluent is collected (0.4L of the effluent collected at the beginning has no sweet taste and is discarded).
5) And (3) concentrating under reduced pressure and drying: concentrating the stevioside effluent under reduced pressure, and drying to obtain powdery stevioside product with purity of more than 99%.
Comparative example 1
1) Extraction: extracting 1000g dry powder of sweet stevia with 15L deionized water at 80 deg.C under stirring twice, leaching for 2 hr each time, coarse filtering with gauze, mixing filtrates, and filtering with Buchner funnel to obtain dark brown clarified solution 12.8L. The concentration of stevioside in the dialyzate was 11.21g/L, the purity was 34.16%, and the yield was 14.35% (based on dry stevia powder).
2) ADS-7 resin adsorption decoloration: adsorbing 12.8L of clarified solution with ADS-7 resin column (column volume of 1.5L, column inner diameter of 6.2cm, column height of 50cm, and diameter-height ratio of 1:8), adsorbing stevioside at flow rate of 2BV/h, and allowing a large amount of pigment and other impurities to flow out. After adsorption, the column is washed by 2BV of pure water at the flow rate of 4BV/h, then desorbed by 4BV of 60% ethanol aqueous solution at the flow rate of 1.5BV/h, and 6L of desorption solution is collected. The concentration of stevioside in the desorption solution is 15.34g/L, the purity is 72.18%, and the yield is 9.20% (based on the dry powder of stevia rebaudiana Bertoni).
4) And (3) screening and adsorbing by RS-2 resin: the ADS-7 resin desorption solution is concentrated under reduced pressure to 2.61L (the concentration is 34.62g/L), the 2.61L concentrated solution is loaded on an RS-2 resin column (the column volume is 0.2L, the inner diameter of the column is 3.1cm, the column height is 27cm, the diameter-height ratio is 1:8.7), and the adsorption flow rate is 2 BV/h. In the adsorption process, impurities such as pigments with small molecular weight are adsorbed by the resin, while stevioside with large molecular weight is not adsorbed and flows out along with the effluent. After adsorption, the column was washed with 2BV of pure water, and 2.9L of effluent was collected (0.1L of effluent collected at the beginning was not sweet and discarded), with the stevioside concentration of 29.87 g/L.
5) And (3) concentrating under reduced pressure and drying: concentrating under reduced pressure, and drying to obtain white stevioside product 90.98g with purity of 95.21% and yield of 8.66% (based on dry powder of stevia rebaudiana Bertoni).
Compared with the example 1, in the experimental process, the extract is directly loaded on the ADS-7 resin column after being filtered and clarified, the adsorption capacity and the adsorption selectivity of the resin to stevioside are reduced due to the fact that the extract contains a large amount of water-soluble protein, polysaccharide, tannin and other impurities, the purity of the obtained product is only 72.18% (87.32% in the example 1), the product purity is low, the adsorption burden of the RS-2 resin impurities is directly heavy, and the product purity is only 95.21%. Because the extracting solution is directly fed into the resin column without ultrafiltration impurity removal, the adsorption performance and the adsorption selectivity of the resin are influenced, the pollution of the resin is serious, the regeneration difficulty of the resin is increased, and the service life of the resin is shortened.
Comparative example 2
1) Extraction: adding 15L deionized water into 1000g sweet stevia dry powder, extracting at 80 deg.C for 2 hr, coarse filtering with gauze, and mixing filtrates to obtain 13.6L dark brown extractive solution.
2) Ultra-flo membrane ultrafiltration: 13.6L of the sweet polyglycoside extract is pumped into an Ultra-flo membrane device for ultrafiltration and purification at normal temperature and pressure, and the process conditions are as follows: inlet pressure 4bar and outlet pressure 2 bar. After concentrating to 3.5L, adding 3.5L water jacket to wash, and collecting 13.6L dialysate. The ultrafiltration membrane is polyvinylidene fluoride (PVDF) membrane with molecular weight cutoff of 4 ten thousand, and the average membrane flux is 36.9L.m2.h-1. The concentration of stevioside in the dialysate was 10.83g/L, the purity was 40.69%, and the yield was 14.73% (based on dry stevia powder).
3) AB-8 resin adsorption decoloration: adsorbing 13.6L of the ultrafiltration dialysate with AB-8 resin column (column volume of 1.5L, column inner diameter of 6.2cm, column height of 50cm, and diameter-height ratio of 1:8), adsorbing at flow rate of 2BV/h, adsorbing stevioside on the resin, and allowing a large amount of pigment and other impurities to flow out. After adsorption, the column was washed with 2BV of pure water at a flow rate of 4BV/h, then desorbed with 5BV of 60% ethanol in water at a flow rate of 1.5BV/h, and 7.5L of desorption solution was collected. The concentration of stevioside in the desorption solution is 12.76g/L, the purity is 67.52 percent, and the yield is 9.57 percent (calculated by the dry powder of stevia rebaudiana Bertoni).
4) Further adsorbing and decoloring HZ-801 resin: the AB-8 resin desorption solution is decompressed and concentrated to 3.0L (the concentration is 31.62g/L), the 3.0L concentrated solution is put on an HZ-801 resin column (the column volume is 0.8L, the inner diameter of the column is 4.8cm, the column height is 44cm, the diameter-height ratio is 1:9.2), and the adsorption flow rate is 2 BV/h. In the adsorption process, stevioside is adsorbed on the resin, and impurities such as pigment flow out. After adsorption, the column was washed with 2BV of pure water at a flow rate of 4BV/h, then desorbed with 3BV of 70% ethanol aqueous solution at a flow rate of 1.5BV/h, and 2.4L of desorption solution was collected. The concentration of stevioside in the desorption solution is 31.57 g/L.
5) And (3) concentrating under reduced pressure and drying: concentrating under reduced pressure, and drying to obtain the final product 82.04g with purity of 92.35% and yield of 7.58% (based on dry powder of stevia rebaudiana Bertoni).
Compared with the example 1, in the experimental process, the extractive solution is ultrafiltered and purified and then is adsorbed and decolorized by two resin methods, wherein the AB-8 resin is weak polar adsorption resin (the average pore diameter is 130-140 nm, the specific surface area is 480-520 m)2(g) average particle diameter of 0.30 to 1.25mm), and the HZ-801 resin is a nonpolar adsorption resin (average pore diameter of 70 to 80nm, specific surface area of 880- & ltSUB & gt 920 m)2(ii)/g, average particle diameter of 0.30 to 1.25 mm). The ultrafiltration dialysate is firstly adsorbed and decolored by AB-8 resin, and the purity of the product is only improved to 67.52 percent (the purity of the product can reach 87.32 percent after ADS-7 resin is decolored in the embodiment 1); the AB-8 resin desorption solution is concentrated and then is subjected to further decoloration and purification by an HZ-801 resin column, and the purity of the final product is only 92.35% (the purity of the product can reach 97.35% after the RS-2 resin is sieved and adsorbed in the embodiment 1). The results of two resin purifications are lower than that of the example 1, and the column loading of the RS-2 resin in the example 1 is 13BV, while the column loading of the HZ-801 resin is only 3.75BV, and the treatment capacity is far lower than that of the RS-2 resin. When the stevioside solution is put on a HZ-801 resin column, the stevioside is adsorbed by the resin, and impurities such as pigment and the like flow out along with the effluent; when the stevioside solution is applied to the RS-2 resin column, small molecular impurities can freely enter and exit the resin pore passages in the adsorption process and are adsorbed by the resin because the RS-2 resin has a moderate pore diameter (the pore diameter is 1.40-1.70 nm), and the stevioside has a large molecular weight, cannot enter the resin pore passages and flows out along with an effluent liquid. Therefore, the RS-2 resin only adsorbs impurities with small molecular size in the stevioside solution, does not adsorb stevioside with high content (85-90 percent of the stevioside), and has large specific surface area (1300-1500 m)2/g) has a high adsorption capacity for impurities, so that a large amount of steviol glycoside solution can be treated with a small amount of resin.
The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.
Claims (1)
1. A preparation method of high-purity stevioside is characterized by comprising the following steps: the method comprises the following steps:
step 1): crushing dried stevia rebaudiana leaves, adding deionized water, heating and stirring for extraction, wherein the deionized water accounts for 15-20 times of the total weight of the dried stevia rebaudiana leaves, and stirring and extracting at 70-85 ℃ to obtain an extracting solution;
step 2): ultrafiltering the obtained extractive solution with plate-type Ultra-flo ultrafiltration membrane at inlet pressure of 4 + -1 bar and outlet pressure of 2 + -1 bar, concentrating by 4 + -1 times, adding water, washing, and collecting ultrafiltered dialysate; the ultrafiltration membrane is a polyvinylidene fluoride membrane with the molecular weight cutoff of 3.5-4.5 ten thousand;
step 3): adsorbing the collected ultrafiltration dialysate on ADS-7 adsorption resin to adsorb stevioside on the resin, desorbing the pigment with ethanol water solution, and collecting desorption solution; the ADS-7 adsorption resin is a quaternary amine type styrene-divinylbenzene polymer, the average pore diameter is 25-35 nm, and the specific surface area is 100-120 m2Per gram, the average particle diameter is 0.30-0.60 mm; the column loading amount of the ADS-7 adsorption resin is 9-12 BV, and the adsorption flow rate is 2-3 BV/h; the desorption agent for desorption is a 60% ethanol water solution with the desorption flow rate of 4-6 BV, and the desorption flow rate is 1.5-2 BV/h;
step 4): concentrating the desorption solution collected in the previous step under reduced pressure to recover ethanol, and adding the ethanol into the concentrated solutionThe column loading amount of the RS-2 resin is 10-20 BV, the adsorption flow rate is 2-3 BV/h, pigments are adsorbed by the resin, stevioside is not adsorbed, an effluent liquid is collected, and a stevioside solid product is obtained through reduced pressure concentration and drying; the RS-2 resin is gel type ultrahigh cross-linked adsorption resin, is a styrene-divinylbenzene polymer with a nano-microporous structure, has a pore volume of 0.50-0.60 mL/g, an average pore diameter of 1.40-1.70 nm and a specific surface area of 1300-1500 m2(iv) a particle size of 0.15 to 0.30mm per gram.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910965942.6A CN110590876B (en) | 2019-10-12 | 2019-10-12 | High-purity stevioside and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910965942.6A CN110590876B (en) | 2019-10-12 | 2019-10-12 | High-purity stevioside and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110590876A CN110590876A (en) | 2019-12-20 |
| CN110590876B true CN110590876B (en) | 2020-09-11 |
Family
ID=68866720
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910965942.6A Active CN110590876B (en) | 2019-10-12 | 2019-10-12 | High-purity stevioside and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110590876B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113429444B (en) * | 2021-04-25 | 2022-08-09 | 杭州天草科技有限公司 | Method for separating and purifying rubusoside from stevia rebaudiana mother liquor sugar |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106831906A (en) * | 2017-01-13 | 2017-06-13 | 西安天丰生物科技有限公司 | A kind of ultrasonic wave added method extraction of steviosides from STEVIA REBAUDIANA |
| CN207102357U (en) * | 2017-03-21 | 2018-03-16 | 上海万唐工程技术有限公司 | A kind of rolling ultrafiltration membrane |
-
2019
- 2019-10-12 CN CN201910965942.6A patent/CN110590876B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106831906A (en) * | 2017-01-13 | 2017-06-13 | 西安天丰生物科技有限公司 | A kind of ultrasonic wave added method extraction of steviosides from STEVIA REBAUDIANA |
| CN207102357U (en) * | 2017-03-21 | 2018-03-16 | 上海万唐工程技术有限公司 | A kind of rolling ultrafiltration membrane |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110590876A (en) | 2019-12-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106008645B (en) | A kind of method that momordica grosvenori glycoside V is extracted from Momordica grosvenori | |
| CN108516997B (en) | Method for extracting rubusoside from sweet tea leaves | |
| CN105061526B (en) | A kind of extracting method of high-purity Rubusoside | |
| CN108752231B (en) | Method for extracting theanine from sweet tea and simultaneously extracting rubusoside and tea polyphenol | |
| CN101671294B (en) | Method for continuously extracting and separating 1-deoxynojirimycin (DNJ) and flavone from folium mori | |
| CN105294790A (en) | Method for extracting high-purity steviol glycosides from stevia rebaudiana | |
| CN109180755A (en) | A method of extracting Rubusoside from sweet tea | |
| CN109535209B (en) | Process method for extracting and purifying stevioside from stevia rebaudiana | |
| CN107629105A (en) | A kind of method of purification of flavor momordica glycoside V | |
| CN111574372B (en) | Method for extracting chlorogenic acid from Chinese herbal medicine by electrodialysis method | |
| CN107936079A (en) | A kind of method for preparing high-purity momordica glycoside V | |
| CN103788152A (en) | Method for preparing geniposide in eucommia leaf | |
| CN110590876B (en) | High-purity stevioside and preparation method thereof | |
| CN109369733B (en) | Method for simultaneously extracting multiple flavonoid compounds from tartary buckwheat leaves | |
| CN102443619A (en) | Method for extracting chlorogenic acid and hederagenin from honeysuckle flower | |
| CN109717445B (en) | Sweet taste composition and preparation method and application thereof | |
| JP6768970B2 (en) | How to prepare rubusoside | |
| CN103980335A (en) | Mogroside V preparation method | |
| CN110437290A (en) | A kind of steviol glycoside extracting and developing and purification process | |
| CN111635402B (en) | Separation and purification method of pyrroloquinoline quinone | |
| CN110917240B (en) | Continuous method for separating multiple effective components from cyclocarya paliurus | |
| CN108997359B (en) | Method for extracting chlorophyll from stevioside production waste residues | |
| CN105238841B (en) | Cephalosporin adsorbs the recycling of DCPC and method for transformation in waste liquid | |
| CN103408614A (en) | Novel preparation technique of steviosin and Rebaudioside-A | |
| CN110776537A (en) | A method for preparing stevioside or RA from stevia rebaudiana Bertoni |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |