AU2021100017A4

AU2021100017A4 - Method for adsorption, separation and purification of xylooligosaccharides in simulated moving bed

Info

Publication number: AU2021100017A4
Application number: AU2021100017A
Authority: AU
Inventors: Shuangjing LANG; Lidong Wang
Original assignee: Heilongjiang Bayi Agricultural University
Current assignee: Heilongjiang Bayi Agricultural University
Priority date: 2021-01-04
Filing date: 2021-01-04
Publication date: 2021-04-08
Anticipated expiration: 2029-01-04

Abstract

The present disclosure relates to a method for the adsorption, separation and purification of xylooligosaccharides in a simulated moving bed using a cation exchange resin as the adsorption 5 medium. The xylooligosaccharide solution is separated and purified in the simulated moving bed device, then concentrated and dried to obtain a xylooligosaccharide powder. The present disclosure allows for continuous production, improved production efficiency and reduced amount of resin and solvent used in each step with a recovery rate of above 75% and a purity of above 95% as well. 8 DRAWINGS Desorbent D 'IMonos charides (A) desorption II Extract A+D Cn C-I Feed A+B O Mon saccharides (A) adsorption Raffinate B+DL Partial desorption IV 'oflD R na. IP F~ill

Description

DRAWINGS

Desorbent D

'IMonos charides (A) desorption

II

Extract A+D

C-I Cn

Feed A+B

O Mon saccharides (A) adsorption

Raffinate B+DL Partial desorption R IV na. IP 'oflD

F~il

METHOD FOR ADSORPTION, SEPARATION AND PURIFICATION OF XYLOOLIGOSACCHARIDES IN SIMULATED MOVING BED TECHNICAL FIELD

[0001] The present disclosure relates to a method for the separation of xylooligosaccharides, and particularly relates to a method for the adsorption, separation and purification of xylooligosaccharides in a simulated moving bed using a cation exchange resin as the adsorption medium.

O BACKGROUD

[0002] Xylooligosaccharides are linear oligosaccharides consisting of 2 to 7 xyloses linked by P-1,4 glycosidic bonds, but predominantly consisting of disaccharides and trisaccharides. Xylooligosaccharides can promote the proliferation of Bifidobacterium, a beneficial bacterium inherent in the human intestine, thereby inhibiting the growth of spoilage bacteria in the intestine and reducing the formation of toxic fermentation products. When ingested together with calcium, xylooligosaccharides promote the absorption of calcium. The function of xylooligosaccharides to promote calcium absorption is not possessed by other functional oligosaccharides.

[0003] Xylans in wheat bran are complex polysaccharides, and mostly are O xylooligosaccharides. Good purification results can be achieved by techniques such as polyacrylamide gel column chromatography and membrane separation; however, due to the high cost and difficulty in regeneration of gel, a large one-time investment is required to realize industrial production; the membrane separation method is limited by the membrane technology, which significantly increases the production cost, and which has low production efficiency and high energy consumption; and activated carbon, as an adsorption medium, can also achieve a certain separation effect, but the degree of continuous production is not high.

SUMMARY

[0004] The present disclosure aims to overcome the shortcomings of the prior art and provides a method for the adsorption, separation and purification of xylooligosaccharides in a simulated moving bed using a cation exchange resin as the adsorption medium.

[0005] The method for the adsorption, separation and purification of xylooligosaccharides in a simulated moving bed resin comprises:

[0006] a. Concentrating a xylooligosaccharide solution comprising 75.63% of xylooligosaccharides, 23.56% of monosaccharides and 0.81% of other ingredients to a solution with a sugar concentration of 50% by mass for use;

[0007] b. Soaking a cation exchange resin with an aqueous solution of 6% hydrochloric acid for 24 h, washing with water until it is neutral, and then soaking it with 4% sodium hydroxide for 24 h, washing with water until it is neutral for use;

[0008] c. Preparing the xylooligosaccharide solution into a sample solution, passing it into the simulated moving bed for separation and purification, the concentration of the feed solution is 25% by mass, and with the cation exchange resin as the adsorbent, and ultrapure water as the eluent, continuously feeding the solution and water and discharging at a temperature of 70°C to obtain a xylooligosaccharide solution with a purity of 95% and a yield of 75%;

[0009] The adsorbent is any one of the cation exchange resin Amberlite IR-120, DIAION-UBK530, PUROLITE-PCR642Ca, D001, or 001x7; wherein the flow rate of the feed pump is 1.5 to 5 mL/min, and the pressure is 0.2 to 0.4 MPa; the flow rate of the elution pump is 3 to 8 mLmin, and the pressure is 0.5 to 0.9 MPa; the flow rate of the circulation pump is 7 to 15 mL/min, and the pressure is 0.3 to 0.6 MPa; the switching time is 250 to 420 s;

[0010] d. Concentrating the xylooligosaccharide solution prepared in step c, followed by spray drying to obtain a xylooligosaccharide powder.

[0011] Beneficial effects

[0012] The xylooligosaccharide solution is prepared from wheat bran under the condition of a specific feed solution ratio through processes such as ultrasonic, high temperature and high pressure cooking, enzymatic hydrolysis, impurity removal via flocculation, ion exchange, and the like. The compositional ingredients, as determined by the HPLC analysis, include 75.63% of xylooligosaccharides, 23 .56% of monosaccharides and 0. 8 1% of other ingredients. The system to be separated is basically a mixture of oligosaccharides and monosaccharides.

[0013] In the present disclosure, the xylooligosaccharide solution is separated and purified in the simulated moving bed device using the cation exchange resin as the adsorption medium, which allows for continuous production, improved production efficiency and reduced amount of resin and solvent used in each step with a recovery rate of above 75% and a purity of above 95%. The present disclosure can realize continuous production, be easily popularized in industry, and is favorable for saving energy and reducing emission.

BRIEF DESCRIPTION OF THE DRAWING

[0014] FIG. 1 is a flowchart of the adsorption and separation in the simulated moving bed.

DESCRIPTION OF THE EMBODIMENTS

[0015] The simulated moving bed chromatography separation system used in the present disclosure consists of a distributor valve system (including a rotary valve), a separation system (including 12 resin columns) and a control system. Among these, the rotary valve is the core, with 12 channels, each of which is connected to the separation column to realize the entry and exit of the mobile phase. When the continuous adsorption and elution system is running, the separation column and the supporting chassis are fixed, and the rotary valve rotates intermittently at a prescribed rate, so that the 12 resin columns can achieve continuous adsorption and elution of the feed solution. The 12 channels of the rotary valve are matched with the fixed ends of the 12 columns. When the system is running, the stream of solution flowing into or out of these fixed channels is constant and unintermittent. When the rotary valve rotates for a single complete circle, each resin column undergoes a complete adsorption-elution process. When a certain channel is removed from the upper part of the separation column, the stream of solution temporarily stops until another channel is moved to be in communication with the next resin column, thus ensuring that the resin column can only receive the stream of solution from one channel at any time.

[0016] The cation exchange resin is selected as the adsorption and separation medium. The resin is first soaked in an aqueous solution of 6% hydrochloric acid for 24 h, washed with water until it is neutral, and then soaked with 4% sodium hydroxide for 24 h, washed with water until it is neutral for use. When the xylooligosaccharide solution flows through the separation column, due to the size exclusion effect of the resin, the xylooligosaccharides do not enter the inside of the resin pores, while the monosaccharides enter the inside of the resin pores. When eluted with distilled water, the xylooligosaccharide components are washed out first, and the monosaccharide components are washed out later.

[0017] The treated cation exchange resin is soaked in distilled water for wet packing. The volume of the separation column is 100.48 cm 3 . 100 mL of wet resin are weighed and filled into the separation column, making sure that the resin density in the separation column is uniform.

[0018] The maximum adsorption capacity of the cation exchange resin, the minimum amount of the solvent and the maximum separation performance are used as the indicators to determine the optimal distribution and connection mode of each zone. The flowchart is as shown in Table l and FIG. 1.

[0019] Table1 Distribution mode of each zone Zone number Zone name Distribution mode Zone I Adsorption zone 3 preparation columns (in series) Zone II Rectification zone 3 preparation columns (in series) Zone III Desorption zone 3 preparation columns (in series) Zone IV Buffer zone 3 preparation columns (in series)

[0020] The components of the feed to the simulated moving bed are monosaccharides (component A) and xylooligosaccharides (component B); the eluent is ultrapure water (component D); and the order of adsorption strength is D>A>B. The adsorption bed is divided into four zones, as shown in FIG 1:

[0021] Zone I (adsorption zone): This zone is mainly used to adsorb A from the feed, a mixed solution of xylooligosaccharides and monosaccharides (A+B). The adsorbent and water that move upward preferentially adsorb A and a small amount of B in the feed; at the same time, the adsorbed D is partially replaced, and the raffinate B+D is partially discharged and recycled at the bottom of the zone.

[0022] Zone II (rectification zone): This zone is mainly used to desorb B from the adsorbent and refine A. The adsorbent containing the stream (A+B+D) rising at the bottom of the zone is in countercurrent contact with the stream of the monosaccharide solution (A+D) flowing downwardly from the top. The adsorption strength is A>B, and B is desorbed; the adsorbent that flows upwardly contains A+D only, and B can be completely desorbed by adjusting the flow valve.

[0023] Zone III (desorption zone): The Ultrapure water (D) enters from the top of this zone, and is in countercurrent contact with the adsorbent containing the monosaccharide solution (A+D) rising at the bottom; A is replaced by D, and at the same time, a part of the stream is drawn from the bottom as an extract, and the remaining flows into zone II to act as a reflux stream.

[0024] Zone IV (buffer zone): The ultrapure water (D) rising from the bottom of this zone is in countercurrent contact with the xylooligosaccharide solution (B+D) circulating from the top of the column back to the bottom of the column. According to the adsorption balance, the part of xylooligosaccharides is adsorbed, and D is partially replaced and recycled into zone III together with fresh D, which reduces the need of fresh desorbent.

[0025] The raffinate discharged at the bottom of zone I mainly contains a mixed solution of xylooligosaccharides and water, and the extract drawn at the bottom of zone III mainly contains a mixed solution of monosaccharides and water. Through the stepping of the rotary valve, the inlet and outlet valves of the adsorption columns are regularly switched, so that the positions of the inlet and outlet of each stream are constantly changed, realizing the purpose of continuously separating xylooligosaccharides and monosaccharides.

[0026] Example 1

[0027] A method for the adsorption, separation and purification of xylooligosaccharides in the simulated moving bed resin comprises:

[0028] a. Concentrating a xylooligosaccharide solution containing 75.63% of xylooligosaccharides, 23.56% of monosaccharides and 0.81% of other ingredients to a solution with a sugar concentration of 50% by mass for use;

[0029] b. Soaking a cation exchange resin with an aqueous solution of 6% hydrochloric acid for 24 h, washing with water until it is neutral, and then soaking it with 4% sodium hydroxide for 24 h, washing with water until it is neutral for use;

[0030] c. Preparing the xylooligosaccharide solution into a sample solution, passing it into the simulated moving bed for separation and purification, the concentration of the feed solution is 25% by mass, and with the cation exchange resin as the adsorbent, and ultrapure water as the eluent, continuously feeding the solution and water and discharging at a temperature of 70°C to obtain a xylooligosaccharide solution with a purity of 95% and a yield of 75%;

[0031] In the continuous adsorption and separation using the simulated moving bed according to the present disclosure, the adsorbent is any one of the cation exchange resin Amberlite IR-120, DIAION-UBK530, PUROLITE-PCR642Ca, D001, or 001x7; wherein the flow rate of the feed pump is 1.5 to 5 mL/min, and the pressure is 0.2 to 0.4 MPa; the flow rate of the elution pump is 3 to 8 mL/min, and the pressure is 0.5 to 0.9 MPa; the flow rate of the circulation pump is 7 to 15 mL/min, and the pressure is 0.3 to 0.6 MPa; the switching time is 250 to 420 s;

[0032] d. Concentrating the xylooligosaccharide solution prepared in step c, followed by spray drying to obtain a xylooligosaccharide powder.

[0033] Example 2

[0034] A method for the adsorption, separation and purification of xylooligosaccharides in the simulated moving bed resin comprises:

[0035] a. Concentrating a xylooligosaccharide solution containing 75.63% of xylooligosaccharides, 23.56% of monosaccharides and 0. 8 1% of other ingredients to a solution with a sugar concentration of 50% by mass for use;

[0036] b. Soaking a cation exchange resin with an aqueous solution of 6% hydrochloric acid for 24 h, washing with water until it is neutral, and then soaking it with 4% sodium hydroxide for 24 h, washing with water until it is neutral for use;

[0037] c. Preparing the xylooligosaccharide solution into a sample solution, passing it into the simulated moving bed for separation and purification, the concentration of the feed solution is 25% by mass, and with the cation exchange resin as the adsorbent, and ultrapure water as the eluent, continuously feeding the solution and water and discharging at a temperature of 70°C to obtain a xylooligosaccharide solution with a purity of 95% and a yield of 75%;

[0038] The adsorbent is the cation exchange resin Amberlite IR-120; the flow rate of the feed pump is 1.5 mL/min, and the pressure is 0.2 MPa; the flow rate of the elution pump is 3 mL/min, and the pressure is 0.5 MPa; the flow rate of the circulation pump is 7 mL/min, and the pressure is 0.3 MPa; the switching time is 250 s;

[0039] d. Concentrating the xylooligosaccharide solution prepared in step c, followed by spray drying to obtain a xylooligosaccharide powder.

[0040] Example 3

[0041] The adsorbent in this example is the cation exchange resin D001, wherein the flow rate of the feed pump is 5 mL/min, and the pressure is 0.4 MPa; the flow rate of the elution pump is 8 mLmin, and the pressure is 0.9 MPa; the flow rate of the circulation pump is 15 mL/min, and the pressure is 0.6 MPa; the switching time is 420 s; and the remaining is the same as that of Example 2.

[0042] Example 4

[0043] The adsorbent in this example is the cation exchange resin PUROLITE-PCR642Ca, wherein the flow rate of the feed pump is 3 mL/min, and the pressure is 0.43 MPa; the flow rate of the elution pump is 5 mL/min, and the pressure is 0.7 MPa; the flow rate of the circulation pump is 11 mL/min, and the pressure is 0.4 MPa; the switching time is 285 s; and the remaining is the same as that of Example 2.

Claims

Claims WHAT IS CLAIMED IS:

1. A method for the adsorption, separation and purification of xylooligosaccharides in a simulated moving bed resin using a xylooligosaccharide solution as the raw material and a cation exchange resin as the adsorption medium, comprising:

a. concentrating a xylooligosaccharide solution containing 75.63% of xylooligosaccharides, 23.56% of monosaccharides and 0.81% of other ingredients to a solution with a sugar concentration of 50% by mass for use;

b. soaking the cation exchange resin with an aqueous solution of 6% hydrochloric acid for 24 h, washing with water until it is neutral, and then soaking it with 4% sodium hydroxide for 24 h, washing with water until it is neutral for use;

c. preparing the xylooligosaccharide solution into a sample solution, passing it into the simulated moving bed for separation and purification, the concentration of the feed solution is 25% by mass, and with the cation exchange resin as the adsorbent, and ultrapure water as the eluent, continuously feeding the solution for adsorption and elution at a temperature of 70°C to obtain a xylooligosaccharide solution with a purity of 95% and a yield of 75%;

the adsorbent is any one of the cation exchange resin Amberlite IR-120, DIAION-UBK530, PUROLITE-PCR642Ca, D001, or 001x7; wherein the flow rate of the feed pump is 1.5 to 5 mL/min, and the pressure is 0.2 to 0.4 MPa; the flow rate of the elution pump is 3 to 8 mL/min, and the pressure is 0.5 to 0.9 MPa; the flow rate of the circulation pump is 7 to 15 mL/min, and the pressure is 0.3 to 0.6 MPa; the switching time is 250 to 420 s;

d. concentrating the xylooligosaccharide solution prepared in step c, followed by spray drying to obtain a xylooligosaccharide powder.